Search

Purpose: Unsupervised item-response theory (IRT) models such as polytomous IRT based on recursive partitioning (IRTrees) and mixture IRT (MixIRT) models can be used to assess differential item functioning (DIF) in patient-reported outcome measures (PROMs) when the covariates associated with DIF are unknown a priori. This study examines the consistency of results for IRTrees and MixIRT models. Methods: Data were from 4478 individuals in the Alberta Provincial Project on Outcome Assessment in Coronary Heart Disease registry who received cardiac angiography in Alberta, Canada, and completed the Hospital Anxiety and Depression Scale (HADS) depression subscale items. The partial credit model (PCM) based on recursive partitioning (PCTree) and mixture PCM (MixPCM) were used to identify covariates associated with differential response patterns to HADS depression subscale items. Model covariates included demographic and clinical characteristics. Results: The median (interquartile range) age was 64.5(15.7) years, and 3522(78.5%) patients were male. The PCTree identified 4 terminal nodes (subgroups) defined by smoking status, age, and body mass index. A 3-class PCM fits the data well. The MixPCM latent classes were defined by age, disease indication, smoking status, comorbid diabetes, congestive heart failure, and chronic obstructive pulmonary disease. Conclusion: PCTree and MixPCM were not consistent in detecting covariates associated with differential interpretations of PROM items. Future research will use computer simulations to assess these models' Type I error and statistical power for identifying covariates associated with DIF. [ABSTRACT FROM AUTHOR]

Background: People with kidney failure often require surgery and experience worse postoperative outcomes compared to the general population, but existing risk prediction tools have excluded those with kidney failure during development or exhibit poor performance. Our objective was to derive, internally validate, and estimate the clinical utility of risk prediction models for people with kidney failure undergoing non-cardiac surgery. Design, setting, participants, and measures: This study involved derivation and internal validation of prognostic risk prediction models using a retrospective, population-based cohort. We identified adults from Alberta, Canada with pre-existing kidney failure (estimated glomerular filtration rate [eGFR] < 15 mL/min/1.73m2 or receipt of maintenance dialysis) undergoing non-cardiac surgery between 2005–2019. Three nested prognostic risk prediction models were assembled using clinical and logistical rationale. Model 1 included age, sex, dialysis modality, surgery type and setting. Model 2 added comorbidities, and Model 3 added preoperative hemoglobin and albumin. Death or major cardiac events (acute myocardial infarction or nonfatal ventricular arrhythmia) within 30 days after surgery were modelled using logistic regression models. Results: The development cohort included 38,541 surgeries, with 1,204 outcomes (after 3.1% of surgeries); 61% were performed in males, the median age was 64 years (interquartile range [IQR]: 53, 73), and 61% were receiving hemodialysis at the time of surgery. All three internally validated models performed well, with c-statistics ranging from 0.783 (95% Confidence Interval [CI]: 0.770, 0.797) for Model 1 to 0.818 (95%CI: 0.803, 0.826) for Model 3. Calibration slopes and intercepts were excellent for all models, though Models 2 and 3 demonstrated improvement in net reclassification. Decision curve analysis estimated that use of any model to guide perioperative interventions such as cardiac monitoring would result in potential net benefit over default strategies. Conclusions: We developed and internally validated three novel models to predict major clinical events for people with kidney failure having surgery. Models including comorbidities and laboratory variables showed improved accuracy of risk stratification and provided the greatest potential net benefit for guiding perioperative decisions. Once externally validated, these models may inform perioperative shared decision making and risk-guided strategies for this population. [ABSTRACT FROM AUTHOR]

Introduction: Information on early, guideline discordant referrals in nephrology is limited. Our objective was to investigate trends in referral patterns to nephrology for patients with chronic kidney disease (CKD). Methods: Retrospective cohort study of adults with ≥1 visits to a nephrologist from primary care with ≥1 serum creatinine and/or urine protein measurement <180 days before index nephrology visit, from 2006 and 2019 in Alberta, Canada. Guideline discordant referrals were those that did not meet ≥1 of: Estimated glomerular filtration rate (eGFR) ˂ 30 mL/min/1.73m2, persistent albuminuria (ACR ≥ 300 mg/g, PCR ≥ 500 mg/g, or Udip ≥ 2+), or progressive and persistent decline in eGFR until index nephrology visit (≥ 5 mL/min/1.73m2). Results: Of 69,372 patients with CKD, 28,518 (41%) were referred in a guideline concordant manner. The overall rate of first outpatient visits to nephrology increased from 2006 to 2019, although guideline discordant referrals showed a greater increase (trend 21.9 per million population/year, 95% confidence interval 4.3, 39.4) versus guideline concordant referrals (trend 12.4 per million population/year, 95% confidence interval 5.7, 19.0). The guideline concordant cohort were more likely to be on renin-angiotensin system blockers or beta blockers (hazard ratio 1.14, 95% confidence interval 1.12, 1.16), and had a higher risk of CKD progression (hazard ratio 1.09, 95% confidence interval 1.06, 1.13), kidney failure (hazard ratio 7.65, 95% confidence interval 6.83, 8.56), cardiovascular event (hazard ratio 1.40, 95% confidence interval 1.35,1.45) and mortality (hazard ratio 1.58, 95% confidence interval 1.52, 1.63). Conclusions: A significant proportion nephrology referrals from primary care were not consistent with current guideline-recommended criteria for referral. Further work is needed to identify quality improvement initiatives aimed at enhancing referral patterns of patients with CKD. [ABSTRACT FROM AUTHOR]

Background: The growing burden associated with population aging, dementia and multimorbidity poses potential challenges for the sustainability of health systems worldwide. We sought to examine how the intersection among age, dementia and greater multimorbidity is associated with health care costs. Methods: We did a retrospective population-based cohort study in Alberta, Canada, with adults aged 65 years and older between April 2003 and March 2017. We identified 31 morbidities using algorithms (30 algorithms were validated), which were applied to administrative health data, and assessed costs associated with hospital admission, provider billing, ambulatory care, medications and long-term care (LTC). Actual costs were used for provider billing and medications; estimated costs for inpatient and ambulatory patients were based on the Canadian Institute for Health Information's resource intensive weights and Alberta's cost of a standard hospital stay. Costs for LTC were based on an estimated average daily cost. Results: There were 827 947 people in the cohort. Dementia was associated with higher mean annual total costs and individual mean component costs for almost all age categories and number of comorbidities categories (differences in total costs ranged from $27 598 to $54 171). Similarly, increasing number of morbidities was associated with higher mean total costs and component costs (differences in total costs ranged from $4597 to $10 655 per morbidity). Increasing age was associated with higher total costs for people with and without dementia, driven by increasing LTC costs (differences in LTC costs ranged from $115 to $9304 per age category). However, there were no consistent trends between age and non-LTC costs among people with dementia. When costs attributable to LTC were excluded, older age tended to be associated with lower costs among people with dementia (differences in non-LTC costs ranged from -$857 to -$7365 per age category). Interpretation: Multimorbidity, older age and dementia were all associated with increased use of LTC and thus health care costs, but some costs among people with dementia decreased at older ages. These findings illustrate the complexity of projecting the economic consequences of the aging population, which must account for the interplay between multimorbidity and dementia. [ABSTRACT FROM AUTHOR]

Background: People with kidney failure have a high incidence of major surgery, though the risk of perioperative outcomes at a population-level is unknown. Our objective was to estimate the proportion of people with kidney failure that experience acute myocardial infarction (AMI) or death within 30 days of major non-cardiac surgery, based on surgery type.Methods: In this retrospective population-based cohort study, we used administrative health data to identify adults from Alberta, Canada with major surgery between April 12,005 and February 282,017 that had preoperative estimated glomerular filtration rates (eGFRs) < 15 mL/min/1.73m2 or received chronic dialysis. The index surgical procedure for each participant was categorized within one of fourteen surgical groupings based on Canadian Classification of Health Interventions (CCI) codes applied to hospitalization administrative datasets. We estimated the proportion of people that had AMI or died within 30 days of the index surgical procedure (with 95% confidence intervals [CIs]) following logistic regression, stratified by surgery type.Results: Overall, 3398 people had a major surgery (1905 hemodialysis; 590 peritoneal dialysis; 903 non-dialysis). Participants were more likely male (61.0%) with a median age of 61.5 years (IQR 50.0-72.7). Within 30 days of surgery, 272 people (8.0%) had an AMI or died. The probability was lowest following ophthalmologic surgery at 1.9% (95%CI: 0.5, 7.3) and kidney transplantation at 2.1% (95%CI: 1.3, 3.2). Several types of surgery were associated with greater than one in ten risk of AMI or death, including retroperitoneal (10.0% [95%CI: 2.5, 32.4]), intra-abdominal (11.7% [8.7, 15.5]), skin and soft tissue (12.1% [7.4, 19.1]), musculoskeletal (MSK) (12.3% [9.9, 15.5]), vascular (12.6% [10.2, 15.4]), anorectal (14.7% [6.3, 30.8]), and neurosurgical procedures (38.1% [20.3, 59.8]). Urgent or emergent procedures had the highest risk, with 12.1% experiencing AMI or death (95%CI: 10.7, 13.6) compared with 2.6% (1.9, 3.5) following elective surgery.Conclusions: After major non-cardiac surgery, the risk of death or AMI for people with kidney failure varies significantly based on surgery type. This study informs our understanding of surgery type and risk for people with kidney failure. Future research should focus on identifying high risk patients and strategies to reduce these risks. [ABSTRACT FROM AUTHOR]

Background Improving recognition of patients at increased risk of acute kidney injury (AKI) in the community may facilitate earlier detection and implementation of proactive prevention measures that mitigate the impact of AKI. The aim of this study was to develop and externally validate a practical risk score to predict the risk of AKI in either hospital or community settings using routinely collected data. Methods Routinely collected linked datasets from Tayside, Scotland, were used to develop the risk score and datasets from Kent in the UK and Alberta in Canada were used to externally validate it. AKI was defined using the Kidney Disease: Improving Global Outcomes serum creatinine–based criteria. Multivariable logistic regression analysis was performed with occurrence of AKI within 1 year as the dependent variable. Model performance was determined by assessing discrimination (C-statistic) and calibration. Results The risk score was developed in 273 450 patients from the Tayside region of Scotland and externally validated into two populations: 218 091 individuals from Kent, UK and 1 173 607 individuals from Alberta, Canada. Four variables were independent predictors for AKI by logistic regression: older age, lower baseline estimated glomerular filtration rate, diabetes and heart failure. A risk score including these four variables had good predictive performance, with a C-statistic of 0.80 [95% confidence interval (CI) 0.80–0.81] in the development cohort and 0.71 (95% CI 0.70–0.72) in the Kent, UK external validation cohort and 0.76 (95% CI 0.75–0.76) in the Canadian validation cohort. Conclusion We have devised and externally validated a simple risk score from routinely collected data that can aid both primary and secondary care physicians in identifying patients at high risk of AKI. [ABSTRACT FROM AUTHOR]

Importance Higher levels of red cell distribution width (RDW) are associated with adverse outcomes, especially in selected cohorts with or at risk for chronic disease. Whether higher RDW or the related parameter standard deviation of the red blood cell distribution (SD-RBC) can predict a broader range of outcomes in the general population is unknown. Objective To evaluate the association of RDW and SD-RBC with the risk of adverse outcomes in people from the general population. Design Population-based retrospective cohort study. Setting Health care system in a Canadian province (Alberta). Participants All 3,156,863 adults living in Alberta, Canada with at least one measure of RDW and SDRBC between 2003 and 2016. Data were analyzed in September 2018. Exposure RDW and SD-RBC, classified into percentiles (<1, 1–5, 5–25, 25–75, 75–95, 95–99, >99). Main outcomes All-cause death, first myocardial infarction, first stroke or transient ischemic attack, placement into long-term care (LTC), progression to renal replacement therapy (initiation of chronic dialysis or pre-emptive kidney transplantation), incident solid malignancy, and first hospitalization during follow-up. Results Over median follow-up of 6.8 years, 209,991 of 3,156,863 participants (6.7%) died. The risk of death increased with increasing RDW percentile. After adjustment, and compared to RDW in the 25th to 75th percentiles, the risk of death was lower for participants in the <25th percentiles but higher for participants in the 75th-95th percentiles (HR 1.42, 95% CI 1.40,1.43), the 95th-99th percentiles (HR 1.86, 95% CI 1.83,1.89) and the >99th percentile (HR 2.18, 95% CI 2.12,2.23). Similar results were observed for MI, stroke/TIA, incident cancer, hospitalization and LTC placement, but no association was found between RDW and ESRD. Findings were generally similar for SD-RBC, except that all associations tended to be stronger than for RDW, and both lower and higher values of SD-RBC were independently associated with ESRD. Conclusion and relevance RDW and SD-RBC may be useful as prognostic markers for people in the general population, especially for outcomes related to chronic illness. SD-RBC may be superior to RDW. [ABSTRACT FROM AUTHOR]

The article focuses on a study to determine the association of age with the likelihood of treatment of kidney failure. A community-based cohort study of adults in Alberta, Canada, who had outpatient estimated glomerular filtration rate measured between May 1, 2002 and March 31, 2008 and who did not require renal replacement therapy at baseline, was conducted. Main outcomes included adjusted rates of treated kidney failure, untreated kidney failure and death. The study concluded that in Alberta, Canada, rates of untreated kidney failure are significantly higher in older compared with younger individuals.

The article focuses on a study which investigated the association of estimated glomerular filtration rate (EGFR) and proteinuria with the risks of acute kidney injury and subsequent adverse clinical outcomes. Adults aged 18 years and more with a history of at least one outpatient measurement of serum creatinine and one of proteinuria within Alberta were considered in the study from May 1, 2002 to December 31, 2006. Results indicate that the risk of admission with acute kidney injury rose with the presence and severity of proteinuria and reduced eGFR.

Background: The Seattle Angina Questionnaire (SAQ) is a widely-used patient-reported outcomes measure in patients with heart disease. This study assesses the validity and reliability of the SAQ in a Canadian cohort of individuals with stable angina.Methods and Results: Data are from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) registry, a population-based registry of patients who received cardiac catheterization in Alberta, Canada. The cohort consists of 4052 patients undergoing cardiac catheterization for stable angina and completed the SAQ within 2 weeks. Exploratory factor analysis and confirmatory factor analysis (CFA) were used to assess the factorial structure of the SAQ. Internal and test-retest reliabilities of a new measure (i.e., SAQ-CAN) was measured using Cronbach α and intraclass correlation coefficient, respectively. CFA model fit was assessed using the root mean square error of approximation (RMSEA) and comparative fit index (CFI). Construct validity of the SAQ-CAN was assessed in relation to Hospital Anxiety and Depression Scales (HADS), Euro Quality of life 5 dimension (EQ5D), and original SAQ. Of the 4052 patients included in this analysis, 3281 (80.97%) were younger than 75 years old, while 3239 (79.94%) were male. Both exploratory and confirmatory factor analyses revealed a four-factorial structure consisting of 16 items that provided a better fit to the data (RMSEA = 0.049 [90% CI = (0.047, 0.052)]; CFI = 0.975). The 16-item SAQ demonstrated good to excellent internal reliability (Cronbach's α range from 0.77 to 0.90), moderate to strong correlation with the Original SAQ and EQ5D but negligible correlations with HADS.Conclusion: The SAQ-CAN has acceptable psychometric properties that are comparable to the original SAQ. We recommend its use for assessing coronary health outcomes in Canadian patients with Coronary Artery Disease. [ABSTRACT FROM AUTHOR]

Background: Despite the interrelationships between obesity, eGFR and albuminuria, few large studies examine how obesity modifies the association between these markers of kidney function and adverse clinical outcomes.Methods: We examined the joint associations between obesity, eGFR and albuminuria on four clinical outcomes (death, end-stage renal disease [ESRD], myocardial infarction [MI], and placement in a long-term care facility) using a population-based cohort with procedures from Alberta. Obesity was defined by body mass index ≥35 kg/m2 as defined by a fee modifier applied to an eligible procedure.Results: We studied 1,293,362 participants, of whom 171,650 (13.3%) had documented obesity (BMI ≥ 35 kg/m2 based on claims data) and 1,121,712 (86.7%) did not. The association between eGFR and death was J-shaped for participants with and without documented obesity. After full adjustment, obesity tended to be associated with slightly lower odds of mortality (OR range 0.71-1.02; p for interaction between obesity and eGFR 0.008). For participants with and without obesity, the adjusted odds of ESRD were lowest for participants with eGFR > 90 mL/min*1.73m2 and increased with lower eGFR, with no evidence of an interaction with obesity (p = 0.37). Although albuminuria and obesity were both associated with higher odds of ESRD, the excess risk associated with obesity was substantially attenuated at higher levels of albuminuria (p for interaction 0.0006). The excess risk of MI associated with obesity was observed at eGFR > 60 mL/min*1.73m2 but not at lower eGFR (p for interaction < 0.0001). Participants with obesity had a higher adjusted likelihood of placement in long-term care than those without, and the likelihood of such placement was higher at lower eGFR for those with and without obesity (p for interaction = 0.57).Conclusions: We found significant interactions between obesity and eGFR and/or albuminuria on the likelihood of adverse outcomes including death and ESRD. Since obesity is common, risk prediction tools for people with CKD might be improved by adding information on BMI or other proxies for body size in addition to eGFR and albuminuria. [ABSTRACT FROM AUTHOR]

The article discusses a study on the association between kidney function and major bleeding in older patients with atrial fibrillation starting warfarin treatment in Alberta. It presents the factors measured in the study including the outcome measure such as admission to hospital or visit to an emergency department for major bleeding. It also notes that the study focused on the safety and not efficacy of warfarin treatment by kidney function in these patients.

The article presents information on a cohort study conducted at Alberta, Canada to evaluate renal outcomes in invasive versus conservative management of acute coronary syndrome. It informs that people who received early invasive management for the syndrome were prone to develop acute kidney injury. The results manifest that no acute kidney injury required dialysis or progressed to end stage renal disease.

Chronic kidney disease (CKD) is associated with poor outcomes, perhaps due to a high burden of comorbidity. Most studies of CKD populations focus on concordant comorbidities, which cause CKD (such as hypertension and diabetes) or often accompany CKD (such as heart failure or coronary disease). Less is known about the burden of mental health conditions and discordant conditions (those not concordant but still clinically relevant, like dementia or cancer). Here we did a retrospective population-based cohort study of 530,771 adults with CKD residing in Alberta, Canada between 2003 and 2011. Validated algorithms were applied to data from the provincial health ministry to assess the presence/absence of 29 chronic comorbidities. Linkage between comorbidity burden and adverse clinical outcomes (mortality, hospitalization or myocardial infarction) was examined over median follow-up of 48 months. Comorbidities were classified into three categories: concordant, mental health/chronic pain, and discordant. The median number of comorbidities was 1 (range 0-15) but a substantial proportion of participants had 3 and more, or 5 and more comorbidities (25 and 7%, respectively). Concordant comorbidities were associated with excess risk of hospitalization, but so were discordant comorbidities and mental health conditions. Thus, discordant comorbidities and mental health conditions as well as concordant comorbidities are important independent drivers of the adverse outcomes associated with CKD. [ABSTRACT FROM AUTHOR]

Many patients with non-dialysis dependent chronic kidney disease (CKD) live far from the closest nephrologist; although reversible, this might constitute a barrier to optimal care. In order to evaluate outcomes, we selected 31,452 outpatients older than 18 years with an estimated glomerular filtration rate (eGFR) less than 45 ml/min per 1.73 m2 who had serum creatinine measured at least once during 2005 in Alberta, Canada. We then used logistic regression to examine the association between outcomes of 6545 patients who lived more than 50 km from the nearest nephrologist. Over a median follow-up of 27 months, 7684 participants died and 15,075 were hospitalized at least once. Compared with those living within 50 km, those further away were significantly less likely to visit a nephrologist or a multidisciplinary CKD clinic within 18 months of the index measurement of the eGFR. Similarly, remote dwellers with diabetes were significantly less likely to have hemoglobin A1c evaluated within 1 year of the index eGFR measurement, to have urinary albumin assessed biannually, or to receive an angiotensin converting enzyme inhibitor or receptor blocker in the setting of diabetes or proteinuria. Remote-dwelling participants were also significantly more likely to die or be hospitalized during follow-up than those living closer. Thus, among people with CKD, remote dwellers were less likely to receive specialist care, recommended laboratory testing, and appropriate medications, and were more likely to die or be hospitalized compared with those living closer to a nephrologist. [ABSTRACT FROM AUTHOR]

Background: Hospital- and physician-level variation for selection of percutaneous coronary intervention versus coronary artery bypass grafting (CABG) for patients with coronary artery disease has been associated with outcome differences. However, most studies excluded patients treated medically., Methods and Results: From 2010 to 2019, adults with 3-vessel or left main coronary artery disease at 3 hospitals (A, B, C) in Alberta, Canada, were categorized by treatment with medical therapy, percutaneous coronary intervention, or CABG. Multilevel regression models determined the proportion of variation in treatment attributable to patient, physician, and hospital factors, and survival models assessed outcomes including death and major adverse cardiovascular events over 5 years. Of 22 580 patients (mean age, 67 years; 80% men): 6677 (29%) received medical management, 9171 (41%) percutaneous coronary intervention, and 6732 (30%) CABG. Hospital factors accounted for 10.8% of treatment variation. In adjusted models (site A as reference), patients at sites B and C had 49% (95% CI, 44%-53%) and 43% (95% CI, 37%-49%) lower rates of medical therapy, respectively, and 31% (95% CI, 24%-38%) and 32% (95% CI, 24%-40%) lower rates of CABG. During 5.0 years median follow-up, 3287 (14.6%) patients died, with no intersite mortality differences. There were no between-site differences in acute coronary syndromes or stroke; patients at sites B and C had 24% lower risk (95% CI, 13%-34% and 11%-35%, respectively) of heart failure hospitalization., Conclusions: Hospital-level variation in selection of percutaneous coronary intervention, CABG, or medical therapy for patients with complex coronary artery disease was not associated with differences in 5-year mortality rates. Research and quality improvement initiatives comparing revascularization practices should include medically managed patients.

Background: Coronary artery disease (CAD) confers increased risks of premature mortality, non-fatal morbidity, and significant impairment in functional status and health-related quality of life. Routine administration of electronic patient-reported outcome measures (PROMs) and its real time delivery to care providers is known to have the potential to inform routine cardiac care and to improve quality of care and patient outcomes. This study describes a user-centered development and evaluation of the Alberta Provincial Project for Outcomes Assessment (APPROACH) electronic Patient Reported Outcomes Measurement (e-PROM) system. This e-PROM system is an electronic system for the administration of PROMs to patients with CAD and the delivery of the summarized information to their care providers to facilitate patient-physician communication and shared decision-making. This electronic platform was designed to be accessible via web-based and hand-held devices. Heuristic and user acceptance evaluation were conducted with patients and attending care providers., Results: The APPROACH e-PROM system was co-developed with patients and care providers, research investigators, informaticians and information technology experts. Five PROMs were selected for inclusion in the online platform after consultations with patient partners, care providers, and PROMs experts: the Seattle Angina Questionnaire, Patient Health Questionnaire, EuroQOL, and Medical Outcomes Study Social Support Survey, and Self-Care of Coronary Heart Disease Inventory. The heuristic evaluation was completed by four design experts who examined the usability of the prototype interfaces. User acceptance testing was completed with 13 patients and 10 cardiologists who evaluated prototype user interfaces of the e-PROM system., Conclusion: Both patients and physicians found the APPROACH e-PROM system to be easy to use, understandable, and acceptable. The APPROACH e-PROM system provides a user-informed electronic platform designed to incorporate PROMs into the delivery of individualized cardiac care for persons with CAD., (© 2024. The Author(s).)

Rationale & Objective: Clinical guidelines define chronic kidney disease (CKD) as abnormalities of kidney structure or function for>3 months. Assessment of the duration criterion may be implemented in different ways, potentially impacting estimates of disease incidence or prevalence in the population, individual diagnosis, and treatment decisions, especially for more severe cases. We investigated differences in incidence and prognosis of CKD stage G4 identified by 1 of 4 algorithms., Study Design: Population-based cohort study in Alberta, Canada., Setting & Participants: Residents>18 years old with incident CKD stage G4 (eGFR 15-29mL/min/1.73m 2 ) diagnosed between April 1, 2015, and March 31, 2018, based on administrative and laboratory data., Exposure: Four outpatient eGFR-based algorithms, increasing in stringency, for defining cohorts with CKD G4 were evaluated: (1) a single test, (2) first eGFR<30mL/min/1.73m 2 and a second eGFR 15-29mL/min/1.73m 2 measured>90 days apart (2 tests), (3) ≥2 eGFR measurements of<30mL/min/1.73m 2 sustained for>90 days (qualifying period) and the last eGFR in the qualifying period of 15-29mL/min/1.73m 2 (relaxed sustained), and (4) ≥2 consecutive measurements of 15-29mL/min/1.73m 2 for>90 days (rigorous sustained)., Outcome: Time to the earliest of death, eGFR improvement (a sustained increase in eGFR to≥30mL/min/1.73m 2 for>90 days and>25% increase from the index eGFR), or kidney failure., Analytical Approach: For each of the 4 cohorts, incidence rates and event-specific cumulative incidence functions at 1 year from cohort entry were estimated., Results: The incidence rates of CKD G4 decreased as algorithms became more stringent, from 190.7 (single test) to 79.9 (rigorous sustained) per 100,000 person-years. The 2 cohorts based on sustained reductions in eGFR were of comparable size and 1-year event-specific probabilities. The 2 cohorts based on a single test and a 2-test sequence were larger and experienced higher probabilities of eGFR improvement., Limitations: A short follow-up period of 1 year and a predominantly White population., Conclusions: The use of more stringent algorithms for defining CKD G4 results in substantially lower estimates of disease incidence, the identification of a group with a lower probability of eGFR improvement, and a higher risk of kidney failure. These findings can inform implementation decisions of disease definitions in clinical reporting systems and research studies., Plain-Language Summary: Although guidelines recommend>3 months to define chronic kidney disease (CKD), the methods for defining specific stages, particularly G4 (eGFR 15-29mL/min/1.73m 2 ) when referral to nephrology services is recommended, have been implemented differently across studies and surveillance programs. We studied differences in incidence and prognosis of CKD G4 cohorts identified by 4 algorithms using administrative and outpatient laboratory databases in Alberta, Canada. We found that, compared with a single-test definition, more stringent definitions resulted in a lower disease incidence and identified a group with worse short-term kidney outcomes. These findings highlight the impact of the choice of algorithm used to define CKD G4 on disease burden estimates at the population level, on individual prognosis, and on treatment/referral decisions., (Copyright © 2023 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Patients with coronary artery disease (CAD) experience significant angina symptoms and lifestyle changes. Revascularization procedures can result in better patient-reported outcomes (PROs) than optimal medical therapy (OMT) alone. This study evaluates the impact of response shift (RS) on changes in PROs of patients with CAD across treatment strategies., Methods: Data were from patients with CAD in the Alberta Provincial Project on Outcome Assessment in Coronary Heart Disease (APPROACH) registry who completed the 16-item Canadian version of the Seattle Angina Questionnaire at 2 weeks and 1 year following a coronary angiogram. Multi-group confirmatory factor analysis (MG-CFA) was used to assess measurement invariance across treatment groups at week 2. Longitudinal MG-CFA was used to test for RS according to receipt of coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or optimal medical therapy (OMT) alone., Results: Of the 3116 patients included in the analysis, 443 (14.2%) received CABG, 2049(65.8%) PCI, and the remainder OMT alone. The MG-CFA revealed a partial-strong invariance across the treatment groups at 2 weeks (CFI = 0.98, RMSEA [90% CI] = 0.05 [0.03, 0.06]). Recalibration RS was detected on the Angina Symptoms and Burden subscale and its magnitude in the OMT, PCI, and CABG groups were 0.32, 0.28, and 0.53, respectively. After adjusting for RS effects, the estimated target changes were largest in the CABG group and negligible in the OMT group., Conclusion: Adjusting for RS is recommended in studies that use SAQ-CAN to assess changes in patients with CAD who have received revascularization versus OMT alone., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Rationale & Objective: Survivors of acute kidney injury (AKI) are at high risk of adverse outcomes. Monitoring of kidney function, screening for proteinuria, use of statins and renin-angiotensin-aldosterone system (RAAS) inhibitors, and nephrology follow-up among survivors have not been fully characterized. We examined these processes of care after discharge in survivors of hospitalized AKI., Study Design: Population-based retrospective cohort study., Setting & Participants: Adults in Alberta, Canada, admitted to the hospital between 2009 and 2017, then followed from their discharge date until 2019 for a median follow-up of 2.7 years., Exposure: Hospital-acquired AKI diagnostically conforming to Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria for stage 2 or stage 3 disease, or the need for acute dialysis., Outcome: Outcomes after hospital discharge included the proportion of participants who had evaluation of kidney function, were seen by a specialist or general practitioner, and received postdischarge prescriptions for recommended medications for chronic kidney disease (CKD)., Analytical Approach: Cumulative incidence curves to characterize the proportion of participants who received each process of care outcome within the first 90 days and subsequent 1-year follow-up period after hospital discharge. To avoid risks associated with multiple hypothesis testing, differences were not statistically compared across groups., Results: The cohort (n=23,921) included 50.2% men (n=12,015) with a median age of 68.1 [IQR, 56.9-78.8] years. Within 90 days after discharge, 21.2% and 8.6% of patients with and without pre-existing CKD, respectively, were seen by a nephrologist; 60.1% of AKI survivors had at least 1 serum creatinine measured, but only 25.5% had an assessment for albuminuria within 90 days after discharge; 52.7% of AKI survivors with pre-existing CKD, and 51.6% with de novo CKD were prescribed a RAAS inhibitor within 4-15 months after discharge., Limitations: Retrospective data were collected as part of routine clinical care., Conclusions: The proportion of patients receiving optimal care after an episode of AKI in Alberta was low and may represent a target for improving long-term outcomes for this population., Plain-Language Summary: A study in Alberta, Canada, examined the care received by patients with acute kidney disease (AKI) during hospitalization and after discharge between 2007 and 2019. The results showed that a low proportion of patients with moderate to severe AKI were seen by a kidney specialist during hospitalization or within 90 days after discharge. Fewer than 25% of AKI patients had their kidney function monitored with both blood and urine tests within 90 days of discharge. Additionally, about half of AKI survivors with chronic kidney disease (CKD) were prescribed guideline recommended medications for CKD within 15 months after discharge. There is potential to improve health care delivery to these patients both in hospital and after hospital discharge., (Copyright © 2023 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The influence of fee-for-service reimbursement on cardiac imaging has not been compared with other payment models. Furthermore, variation in ordering practices is not well understood., Methods and Results: This retrospective, population-based cohort study using linked administrative data from Alberta, Canada included adults with chronic heart disease (atrial fibrillation, coronary artery disease, and heart failure) seen by cardiac specialists for a new outpatient consultation April 2012 to December 2018. Generalized linear mixed-effects models estimated the association of payment model (including the ability to bill to interpret imaging tests) and the use of cardiac imaging and quantified variation in cardiac imaging. Among 31 685 adults seen by 308 physicians at 136 sites, patients received an observed mean of 0.67 (95% CI, 0.67-0.68) imaging tests per consultation. After adjustment, patients seeing fee-for-service physicians had 2.07 (95% CI, 1.68-2.54) and fee-for-service physicians with ability to interpret had 2.87 (95% CI, 2.16-3.81) times the rate of receiving a test than those seeing salaried physicians. Measured patient, physician, and site effects accounted for 31% of imaging variation and, following adjustment, reduced unexplained site-level variation 40% and physician-level variation 29%., Conclusions: We identified substantial variation in the use of outpatient cardiac imaging related to physician and site factors. Physician payment models have a significant association with imaging use. Our results raise concern that payment models may influence cardiac imaging practice. Similar methods could be applied to identify the source and magnitude of variation in other health care processes and outcomes.

Background: For patients who initiate dialysis during a hospital admission and continue to require dialysis after discharge, outpatient dialysis management could be improved by better understanding the future likelihood of recovery to dialysis independence and the competing risk of death., Methods: We derived and validated linked models to predict the subsequent recovery to dialysis independence and death within 1 year of hospital discharge using a population-based cohort of 7657 patients in Ontario, Canada. Predictive variables included age, comorbidities, length of hospital admission, intensive care status, discharge disposition, and prehospital admission eGFR and random urine albumin-to-creatinine ratio. Models were externally validated in 1503 contemporaneous patients from Alberta, Canada. Both models were created using proportional hazards survival analysis, with the "Recovery Model" using Fine-Gray methods. Probabilities generated from both models were used to develop 16 distinct "Recovery and Death in Outpatients" (ReDO) risk groups., Results: ReDO risk groups in the derivation group had significantly distinct 1-year probabilities for recovery to dialysis independence (first quartile: 10% [95% confidence interval (CI), 9% to 11%]; fourth quartile: 73% [70% to 77%]) and for death (first quartile: 12% [11% to 13%]; fourth quartile: 46% [43% to 50%]). In the validation group, model discrimination was modest (c-statistics [95% CI] for recovery and for death quartiles were 0.70 [0.67 to 0.73] and 0.66 [0.62 to 0.69], respectively), but calibration was excellent (integrated calibration index [95% CI] was 7% [5% to 9%] and 4% [2% to 6%] for recovery and death, respectively)., Conclusions: The ReDO models generated accurate expected probabilities of recovery to dialysis independence and death in patients who continued outpatient dialysis after initiating dialysis in hospital. An online tool on the basis of the models is available at https://qxmd.com/calculate/calculator&#95;874 ., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of American Society of Nephrology.)

Objective: The aim of this study was to estimate the association between estimated glomerular filtration rate (eGFR) and acute myocardial infarction (AMI) or death after ambulatory noncardiac surgery., Summary Background Data: People with chronic kidney disease (CKD) commonly undergo surgical procedures. Although most are performed in an ambulatory setting, the risk of major perioperative outcomes after ambulatory surgery for people with CKD is unknown., Methods: In this retrospective population-based cohort study using administrative health data from Alberta, Canada, we included adults with measured preoperative kidney function undergoing ambulatory noncardiac surgery between April 1, 2005 and February 28, 2017. Participants were categorized into 6 eGFR categories (in mL/min/1.73m 2 )of ≥60 (G1-2), 45 to 59 (G3a), 30 to 44 (G3b), 15 to 29 (G4), <15 not receiving dialysis (G5ND), and those receiving chronic dialysis (G5D). The odds of AMI or death within 30 days of surgery were estimated using multivariable generalized estimating equation models., Results: We identified 543,160 procedures in 323,521 people with a median age of 66 years (IQR 56-76); 52% were female. Overall, 2338 people (0.7%) died or had an AMI within 30 days of surgery. Compared with the G1-2 category, the adjusted odds ratio of death or AMI increased from 1.1 (95% confidence interval: 1.0-1.3) for G3a to 3.1 (2.6-3.6) for G5D. Emergency Department and Urgent Care Center visits within 30 days were frequent (17%), though similar across eGFR categories., Conclusions: Ambulatory surgery was associated with a low risk of major postoperative events. This risk was higher for people with CKD, which may inform their perioperative shared decision-making and management., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Rationale & Objective: Collaborative approaches to vascular access selection are being increasingly encouraged to elicit patients' preferences and priorities where no unequivocally superior choice exists. We explored how patients, their caregivers, and clinicians integrate principles of shared decision making when engaging in vascular access discussions., Study Design: Qualitative description., Setting & Participants: Semistructured interviews with a purposive sample of patients, their caregivers, and clinicians from outpatient hemodialysis programs in Alberta, Canada., Analytical Approach: We used a thematic analysis approach to inductively code transcripts and generate themes to capture key concepts related to vascular access shared decision making across participant roles., Results: 42 individuals (19 patients, 2 caregivers, 21 clinicians) participated in this study. Participants identified how access-related decisions follow a series of major decisions about kidney replacement therapy and care goals that influence vascular access preferences and choice. Vascular access shared decision making was strengthened through integration of vascular access selection with dialysis-related decisions and timely, tailored, and balanced exchange of information between patients and their care team. Participants described how opportunities to revisit the vascular access decision before and after dialysis initiation helped prepare patients for their access and encouraged ongoing alignment between patients' care priorities and treatment plans. Where shared decision making was undermined, hemodialysis via a catheter ensued as the most readily available vascular access option., Limitations: Our study was limited to patients and clinicians from hemodialysis care settings and included few caregiver participants., Conclusions: Findings suggest that earlier, or upstream, decisions about kidney replacement therapies influence how and when vascular access decisions are made. Repeated vascular access discussions that are integrated with other higher-level decisions are needed to promote vascular access shared decision making and preparedness., (Copyright © 2022 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Providing support is important to maintain a patient on peritoneal dialysis (PD), though its impact on outcomes has not been investigated thoroughly. We examined the association between having support and risk of a transfer to hemodialysis., Methods: In this retrospective observational cohort study, we used data captured in the Dialysis Measurement Analysis and Reporting system about patients who started PD in Alberta, Canada, between 1 January 2013 and 30 September 2018. Support was defined as the availability of a support person in the home who was able, willing and available to provide support for PD in the patient's residence. The outcome of interest was a transfer to hemodialysis for at least 90 days. We estimated the cumulative incidence of a transfer over time accounting for competing risks and hazard ratios to summarise the association between support and a transfer. We split follow-up time as hazard ratios varied over time., Results: Six hundred and eighty-three incident PD patients, median age 58 years ( IQR : 47-68) and 35% female, were followed for a median of 15 months. The cumulative incidence of a transfer to hemodialysis at 24 months was 26%. Having support was associated with a reduced risk of a transfer between 3 and 12 months after the start of dialysis (HR 3-12mo : 0.44; 95% CI: 0.25-0.78), but not earlier (hazard ratio (HR) <3mo : 0.96; 95% confidence interval (CI): 0.55-1.69) or later (HR >12mo : 1.19; 95% CI: 0.65-2.17)., Conclusions: A transfer to hemodialysis is common. Having a support person at home is associated with a short-term protective effect after the initiation of PD.

Purpose: The Seattle Angina Questionnaire (SAQ) is a widely used patient-reported measure of health status in patients with coronary artery disease. Comparisons of SAQ scores amongst population groups and over time rely on the assumption that its factorial structure is invariant. This study evaluates the measurement invariance of the SAQ across different demographic and clinical groups and over time., Methods: Data were obtained from the Alberta Provincial Project on Outcome Assessment in Coronary Heart Disease registry, a registry of patients who received coronary angiogram in Alberta, Canada. The study cohort consists of adult patients who completed the paper-based version of the 16-item Canadian version of the SAQ (SAQ-CAN) 2 weeks and 1-year post-coronary angiogram between 2009 and 2016. Multi-group confirmatory factor analysis was used to assess configural, weak, strong, and strict measurement invariance across age groups, sex, angina type, treatment, and over time. Model fit was assessed using the comparative fit index and root mean square error of approximation., Results: Of the 8101 patients included in these analysis, 1300 (16.1%) were at least 75 years old, while 1755 (21.7%) were female, 5154 (63.6%) were diagnosed with acute coronary syndrome, 1177 (14.5%) received coronary artery bypass graft treatment, and 3279 had complete data on the SAQ-CAN at both occasions. There was evidence of strict invariance across age, sex, and angina type, and treatment groups, but partial strict invariance was established over time., Conclusion: SAQ-CAN can be used to compare the health status of coronary artery disease patients across population groups and over time., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Importance: Although the public is aware that cancer is associated with excess mortality and adverse outcomes, the clinical consequences of chronic kidney disease (CKD) are not well understood., Objective: To compare the clinical consequences of incident severe CKD and the first diagnosis with a malignant tumor, focusing on the 10 leading causes of cancer in men and women residing in Canada., Design, Setting, and Participants: This population-based cohort study enrolled individuals aged 19 years and older with severe CKD or certain types of cancer between 2004 and 2015 in Alberta, Canada. Data were analyzed in November 2021., Exposures: Individuals were categorized as having severe CKD (based on estimated glomerular filtration rate <30 mL/min/1.73 m2 or nephrotic albuminuria without dialysis or kidney transplantation) or nonmetastatic or metastatic cancer (defined by a diagnosis of lung, breast, colorectal, prostate, bladder, thyroid, kidney or renal pelvis, uterus, pancreas, or oral cancer)., Main Outcomes and Measures: All-cause mortality, number of hospitalizations, total number of hospital days, and placement into long-term care were calculated after diagnosis., Results: Of 200 494 individuals in the cohort (104 559 women [52.2%]; median [IQR] age, 66.8 [55.9-77.7] years), 51 159 (25.5%) had incident severe CKD, 115 504 (57.6%) had nonmetastatic cancer, and 33 831 (16.9%) had metastatic cancer. Kaplan-Meier 1-year survival was 83.3% (95% CI, 83.0%-83.6%) for patients with CKD, 91.2% (95% CI, 91.0%-91.4%) for patients with nonmetastatic cancer, and 52.8% (95% CI, 52.2%-53.3%) for patients with metastatic cancer. Kaplan-Meier 5-year survival was 54.6% (95% CI, 54.2%-55.1%) for patients with CKD, 76.6% (95% CI, 76.3%-76.8%) for patients with nonmetastatic cancer, and 33.9% (95% CI, 33.3%-34.4%) for patients with metastatic cancer. Compared with nonmetastatic cancer, the age-, sex-, and comorbidity-adjusted relative rate of death was similar for CKD (adjusted relative rate, 1.00; 95% CI, 0.97-1.03; P = .92) during the first year of follow-up and was higher for CKD at years 1 to 5 (adjusted relative rate 1.23; 95% CI, 1.19-1.26). During the first year of follow-up, for patients with CKD, adjusted rates of placement in long-term care (adjusted relative rate, 0.88; 95% CI, 0.82-0.94) and hospitalization (adjusted relative rate, 0.65; 95% CI, 0.64-0.66) were lower than rates for patients with nonmetastatic cancer; however, those rates were higher for the CKD group than for the nonmetastatic cancer group during years 1 to 5 (long-term care placement, adjusted relative rate, 1.36; 95% CI, 1.29-1.43; hospitalization, adjusted relative rate, 1.55; 95% CI, 1.52-1.58). As expected, adjusted rates of long-term care placement and hospitalization were higher for patients with metastatic cancer than for the other 2 groups., Conclusions and Relevance: In this study, mortality, hospitalization, and likelihood of placement into long-term care were similar for CKD and nonmetastatic cancer. These data highlight the importance of CKD as a public health problem.

Importance: Using the same level of estimated glomerular filtration rate (eGFR) to define chronic kidney disease (CKD) regardless of patient age may classify many elderly people with a normal physiological age-related eGFR decline as having a disease., Objective: To compare the outcomes associated with CKD as defined by a fixed vs an age-adapted eGFR threshold., Design, Setting, and Participants: This population-based cohort study was conducted in Alberta, Canada and used linked administrative and laboratory data from adults with incident CKD from April 1, 2009, to March 31, 2017, defined by a sustained reduction in eGFR for longer than 3 months below a fixed or an age-adapted eGFR threshold. Non-CKD controls were defined as being 65 years or older with a sustained eGFR of 60 to 89 mL/min/1.73 m2 for longer than 3 months and normal/mild albuminuria. The follow-up ended on March 31, 2019. The data were analyzed from February to April 2020., Exposures: A fixed eGFR threshold of 60 vs thresholds of 75, 60, and 45 mL/min/1.73 m2 for age younger than 40, 40 to 64, and 65 years or older, respectively., Main Outcomes and Measures: Competing risks of kidney failure (kidney replacement initiation or sustained eGFR <15 mL/min/1.73 m2 for >3 months) and death without kidney failure., Results: The fixed and age-adapted CKD cohorts included 127 132 (69 546 women [54.7%], 57 586 men [45.3%]) and 81 209 adults (44 582 women [54.9%], 36 627 men [45.1%]), respectively (537 vs 343 new cases per 100 000 person-years). The fixed-threshold cohort had lower risks of kidney failure (1.7% vs 3.0% at 5 years) and death (21.9% vs 25.4%) than the age-adapted cohort. A total of 53 906 adults were included in both cohorts. Of the individuals included in the fixed-threshold cohort only (n = 72 703), 54 342 (75%) were 65 years or older and had baseline eGFR of 45 to 59 mL/min/1.73 m2 with normal/mild albuminuria. The 5-year risks of kidney failure and death among these elderly people were similar to those of non-CKD controls, with a risk of kidney failure of 0.12% or less in both groups across all age categories and a risk of death at 69, 122, 279, and 935 times higher than the risk of kidney failure for 65 to 69, 70 to 74, 75 to 79, and 80 years or older, respectively., Conclusions and Relevance: This cohort study of adults with CKD suggests that the current criteria for CKD that use the same eGFR threshold for all ages may result in overestimation of the CKD burden in an aging population, overdiagnosis, and unnecessary interventions in many elderly people who have age-related loss of eGFR.

Objectives: Acute kidney injury (AKI) is common after cardiac surgery. We quantified the mortality and costs of varying degrees of AKI using a population-based cohort in Alberta, Canada., Methods: A cohort of patients undergoing cardiac surgery from 2004 to 2009 was assembled from linked Alberta administrative databases. AKI was classified by Kidney Disease Improving Global Outcomes stages of severity. Our outcomes were in-hospital mortality, length of stay, and costs; among survivors, we also examined mortality and costs at 365 days. Estimates were adjusted for demographic characteristics, comorbidities, and other covariates., Results: Ten thousand one hundred seventy participants were included, of whom 9771 patients were discharged to community. Overall in-hospital mortality, costs, and length of stay were 4%, 7 days, and Can $34,000, respectively. Postcardiac surgery, AKI occurred in 25%. Compared with those without AKI, AKI was independently associated with increased in-hospital mortality across severity categories, with the highest risk (adjusted odds ratio, 37.1; 95% confidence interval, 26.3-52.1; P < .001) in patients who required acute dialysis. AKI severity was associated with increased hospital days and costs, with costs ranging from 1.21 for stage 1 AKI (95% confidence interval, 1.17-1.23) to 2.74 for acute dialysis (95% confidence interval, 2.49-3.00) (P < .001) times higher than in patients without AKI, after covariate adjustment. Postdischarge to 365 days, patients with AKI continued to experience increased costs up to 1.35-fold, and patients who required dialysis acutely continued to experience a 2.86-fold increased mortality., Conclusions: AKI remains an important indicator of mortality and health care costs postcardiac surgery., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Importance: Severe acute kidney injury (AKI) is a serious postoperative complication. A tool for predicting the risk of AKI requiring kidney replacement therapy (KRT) after major noncardiac surgery might assist with patient counseling and targeted use of measures to reduce this risk., Objective: To derive and validate a predictive model for AKI requiring KRT after major noncardiac surgery., Design, Setting, and Participants: In this prognostic study, 5 risk prediction models were derived and internally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Alberta, Canada, between January 1, 2004, and December 31, 2013. The best performing model and corresponding risk index were externally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Ontario, Canada, between January 1, 2007, and December 31, 2017. Data analysis was conducted from September 1, 2019, to May 31, 2021., Exposures: Demographic characteristics, surgery type, laboratory measures, and comorbidities before surgery., Main Outcomes and Measures: Acute kidney injury requiring KRT within 14 days after surgery. Discrimination was assessed using the C statistic; calibration was assessed using calibration intercept and slope. Logistic recalibration was used to optimize model calibration in the external validation cohort., Results: The derivation cohort included 92 114 patients (52.2% female; mean [SD] age, 62.3 [18.0] years), and the external validation cohort included 709 086 patients (50.8% female; mean [SD] age, 61.0 [16.0] years). A total of 529 patients (0.6%) developed postoperative AKI requiring KRT in the derivation cohort, and 2956 (0.4%) developed postoperative AKI requiring KRT in the external validation cohort. The following factors were consistently associated with the risk of AKI requiring KRT: younger age (40-69 years: odds ratio [OR], 2.07 [95% CI, 1.69-2.53]; <40 years: OR, 3.73 [95% CI, 2.61-5.33]), male sex (OR, 1.55; 95% CI, 1.28-1.87), surgery type (colorectal: OR, 4.86 [95% CI, 3.28-7.18]; liver or pancreatic: OR, 6.46 [95% CI, 3.85-10.83]; other abdominal: OR, 2.19 [95% CI, 1.66-2.89]; abdominal aortic aneurysm repair: OR, 19.34 [95% CI, 14.31-26.14]; other vascular: OR, 7.30 [95% CI, 5.48-9.73]; thoracic: OR, 3.41 [95% CI, 2.07-5.59]), lower estimated glomerular filtration rate (OR, 0.97; 95% CI, 0.97-0.97 per 1 mL/min/1.73 m2 increase), lower hemoglobin concentration (OR, 0.99; 95% CI, 0.98-0.99 per 0.1 g/dL increase), albuminuria (mild: OR, 1.88 [95% CI, 1.52-2.33]; heavy: OR, 3.74 [95% CI, 2.98-4.69]), history of myocardial infarction (OR, 1.63; 95% CI, 1.32-2.03), and liver disease (mild: OR, 2.32 [95% CI, 1.66-3.24]; moderate or severe: OR, 4.96 [95% CI, 3.58-6.85]). In external validation, a final model including these variables showed excellent discrimination (C statistic, 0.95; 95% CI, 0.95-0.96), with sensitivity of 21.2%, specificity of 99.9%, positive predictive value of 38.1%, and negative predictive value of 99.7% at a predicted risk threshold of 10% or greater., Conclusions and Relevance: The findings suggest that this risk model can predict AKI requiring KRT after noncardiac surgery using routine preoperative data. The model may be feasible for implementation in clinical perioperative risk stratification for severe AKI.

Background: Guidelines recommend referral for nephrology consultation for people with severe chronic kidney disease (CKD) to improve care and renal outcomes, yet the advocated benefits of nephrology referral on CKD progression in this patient population are unclear., Methods: We linked laboratory and administrative data in Alberta, Canada to identify adults with stage 4 CKD between 2002 and 2014 (follow-up end on March 31, 2017). We studied the association between time-varying receipt of outpatient nephrology consultation and kidney failure (the earlier of renal replacement initiation or eGFR < 10 mL/min/1.73 m 2 for more than 3 months), accounting for the competing risk of death., Results: Of the 14,382 participants, 41% were ≥ 85 years old, 33% saw a nephrologist as an outpatient, 9% developed kidney failure, and 53% died over a median of 2.6 years. Compared with people who did not see a nephrologist before or at 7 months (median time to consultation), those who did were more likely to develop kidney failure [5-year risk (95% CI) 0.23 (0.21-0.24) vs 0.07 (0.065-0.075)]. With increasing age or higher eGFR, the 5-year risk of kidney failure became progressively smaller, from 0.24 (0.18-0.29) at age < 65 to 0.01 (0.006-0.015) at age ≥ 85 years and from 0.21 (0.18-0.23) at eGFR 15-19 to 0.066 (0.060-0.072) at eGFR 25-29 mL/min/1.73 m 2 ; yet, the hazard ratio of kidney failure (1.6-4.3) increased following nephrology consultation in people who were older or had higher eGFR., Conclusions: Adults with stage 4 CKD who see a nephrologist are more likely to develop kidney failure than those who don't, especially within lower absolute risk categories. Although selective referral may explain these findings, there is no evidence of an association between nephrology care and reduced risk of kidney failure in people with severe CKD. Studies are needed to assess the benefits of nephrology consultation in people with moderate CKD., (© 2020. Italian Society of Nephrology.)

Background: Acute kidney injury (AKI) is common after surgery and associated with increased mortality, costs, and lengths of hospitalization. We examined associations between angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB), diuretic, or nonsteroidal anti-inflammatory drug (NSAID) use after major surgery and AKI., Materials and Methods: We conducted a nested case-control study of patients who underwent major cardiac, thoracic, general, or vascular surgery in Calgary, Alberta, Canada. Cases with AKI were matched on age, gender, and surgery type with up to five controls without AKI within 30-d after surgery. Adjusted odds ratios (ORs) for AKI were determined based on postoperative administration of ACEIs/ARBs, diuretics, or NSAIDs., Results: Among 33,648 patients in the cohort, 2911 cases with AKI were matched to 9309 controls without AKI. Postoperative diuretic [OR = 1.96; 95% confidence interval (CI) = 1.68-2.29], but not ACEI/ARB (OR = 0.83; 95% CI = 0.72-0.95) or NSAID (OR = 1.12; 95% CI = 0.96-1.31), use was independently associated with higher odds of AKI (including stages 1 and 2/3 AKI) after all types of major surgery. There were increased adjusted odds of AKI 1 to 5 d after first exposure to diuretics and 1 d after first exposure to NSAIDs (but not after later exposures). Relationships between ACEI/ARB use and AKI varied by surgery type (p-interaction = 0.004), with lower odds of AKI observed among ACEI/ARB use after cardiac surgery (OR = 0.70; 95% CI = 0.57-0.81), but no difference after other major surgeries., Conclusions: Postoperative administration of diuretics and NSAIDs was associated with increased odds of AKI after major surgery. These findings characterize potentially modifiable medication exposures associated with AKI after surgery., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Rationale & Objective: Kidney disease is associated with an increased risk for postoperative morbidity and mortality. However, the incidence of major surgery on a population level is unknown. We aimed to determine the incidence of major surgery by level of kidney function., Study Design: Retrospective cohort study with entry from January 1, 2008, through December 31, 2009, and outcome surveillance from January 1, 2010, through December 31, 2016., Setting & Participants: Population-based study using administrative health data from Alberta, Canada; adults with an outpatient serum creatinine measurement or receiving maintenance dialysis formed the study cohort., Exposure: Participants were categorized into 6 estimated glomerular filtration rate (eGFR) categories: ≥60 (G1-G2), 45 to 59 (G3a), 30 to 44 (G3b), 15 to 29 (G4), and<15mL/min/1.73m 2 with (G5D) and without (G5) dialysis. eGFR was examined as a time-varying exposure based on means of measurements within 3-month ascertainment periods throughout the study period., Outcome: Major surgery defined as surgery requiring admission to the hospital for at least 24 hours., Analytical Approach: Incidence rates (IRs) for overall major surgery were estimated using quasi-Poisson regression and adjusted for age, sex, income, location of residence, albuminuria, and Charlson comorbid conditions. Age- and sex-stratified IRs of 13 surgery subtypes were also estimated., Results: 1,455,512 cohort participants were followed up for a median of 7.0 (IQR, 5.3) years, during which time 241,989 (16.6%) underwent a major surgery. Age and sex modified the relationship between eGFR and incidence of surgery. Men younger than 65 years receiving maintenance dialysis experienced the highest rates of major surgery, with an adjusted IR of 243.8 (95% CI, 179.8-330.6) per 1,000 person-years. There was a consistent trend of increasing surgery rates at lower eGFRs for most subtypes of surgery., Limitations: Outpatient preoperative serum creatinine measurement was necessary for inclusion and outpatient surgical procedures were not included., Conclusions: People with reduced eGFR have a significantly higher incidence of major surgery compared with those with normal eGFR, and age and sex modify this increased risk. This study informs our understanding of how surgical burden changes with differing levels of kidney function., (Copyright © 2020 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Objectives: Despite advances in medical therapy, reperfusion, and mechanical support, cardiogenic shock remains associated with excess morbidity and mortality. Accurate risk stratification may improve patient management. We compared the accuracy of established risk scores for cardiogenic shock., Methods: Patients admitted to tertiary care center cardiac care units in the province of Alberta in 2015 were assessed for cardiogenic shock. The Acute Physiology and Chronic Health Evaluation-II (APACHE-II), CardShock, intra-aortic balloon pump (IABP) Shock II, and sepsis-related organ failure assessment (SOFA) risk scores were compared. Receiver operating characteristic curves were used to assess discrimination of in-hospital mortality and compared using DeLong's method. Calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test., Results: The study included 3021 patients, among whom 510 (16.9%) had cardiogenic shock. Patients with cardiogenic shock had longer median hospital stays (median 11.0 vs 4.1 days, P < .001) and were more likely to die (29.0% vs 2.5%, P < .001). All risk scores were adequately calibrated for predicting hospital morality except for the APACHE-II score (Hosmer-Lemeshow P < .001). Discrimination of in-hospital mortality with the APACHE-II (area under the curve [AUC]: 0.72, 95% confidence interval [CI]: 0.66-0.76) and IABP-Shock II (AUC: 0.73, 95% CI: 0.68-0.77) scores were similar, while the CardShock (AUC: 0.76, 95% CI: 0.72-0.81) and SOFA (AUC: 0.76, 95%CI: 0.72-0.81) scores had better discrimination for predicting in-hospital mortality., Conclusions: In a real-world population of patients with cardiogenic shock, existing risk scores had modest prognostic accuracy, with no clear superior score. Further investigation is required to improve the discriminative abilities of existing models or establish novel methods.

Background: Acute kidney injury (AKI) is common in hospitalized patients and is associated with poor patient outcomes and high costs of care. The implementation of clinical decision support tools within electronic medical record (EMR) could improve AKI care and outcomes. While clinical decision support tools have the potential to enhance recognition and management of AKI, there is limited description in the literature of how these tools were developed and whether they meet end-user expectations., Methods: We developed and evaluated the content, acceptability, and usability of electronic clinical decision support tools for AKI care. Multi-component tools were developed within a hospital EMR (Sunrise Clinical Manager™, Allscripts Healthcare Solutions Inc.) currently deployed in Calgary, Alberta, and included: AKI stage alerts, AKI adverse medication warnings, AKI clinical summary dashboard, and an AKI order set. The clinical decision support was developed for use by multiple healthcare providers at the time and point of care on general medical and surgical units. Functional and usability testing for the alerts and clinical summary dashboard was conducted via in-person evaluation sessions, interviews, and surveys of care providers. Formal user acceptance testing with clinical end-users, including physicians and nursing staff, was conducted to evaluate the AKI order set., Results: Considerations for appropriate deployment of both non-disruptive and interruptive functions was important to gain acceptability by clinicians. Functional testing and usability surveys for the alerts and clinical summary dashboard indicated that the tools were operating as desired and 74% (17/23) of surveyed healthcare providers reported that these tools were easy to use and could be learned quickly. Over three-quarters of providers (18/23) reported that they would utilize the tools in their practice. Three-quarters of the participants (13/17) in user acceptance testing agreed that recommendations within the order set were useful. Overall, 88% (15/17) believed that the order set would improve the care and management of AKI patients., Conclusions: Development and testing of EMR-based decision support tools for AKI with clinicians led to high acceptance by clinical end-users. Subsequent implementation within clinical environments will require end-user education and engagement in system-level initiatives to use the tools to improve care.

Background: In studies showing associations between ambient air pollution and myocardial infarction (MI), data have been lacking on the inherent spatial variability of air pollution. The aim of this study was to determine whether the long-term spatial distribution of air pollution influences short-term temporal associations between air pollution and admission to hospital for MI., Methods: We identified adults living in Calgary who were admitted to hospital for an MI between 2004 and 2012. We evaluated associations between short-term exposure to air pollution (ozone [O 3 ], nitrogen dioxide [NO 2 ], sulfur dioxide [SO 2 ], carbon monoxide [CO], particulate matter < 10 μm in diameter [PM 10 ] and particulate matter < 2.5 μm in diameter [PM 2.5 ]), and hospital admissions for MI using a time-stratified, case-crossover study design. Air Quality Health Index (AQHI) scores were calculated from a composition of O 3 , NO 2 and PM 2.5 . Conditional logistic regression models were stratified by low, medium and high levels of neighbourhood NO 2 concentrations derived from land use regression models; results of these analyses are presented as odds ratios (ORs) with 95% confidence intervals (CIs)., Results: From 2004 to 2012, 6142 MIs were recorded in Calgary. Individuals living in neighbourhoods with higher long-term air pollution concentrations were more likely to be admitted to hospital for MI after short-term elevations in air pollution (e.g., 5-day average NO 2 : OR 1.20, 95% CI 1.03-1.40, per interquartile range [IQR]) as compared with regions with lower air pollution (e.g., 5-day average NO 2 : OR 0.90, 95% CI 0.78-1.04, per IQR). In high NO 2 tertiles, the AQHI score was associated with MI (e.g., 5-day average OR 1.13, 95% CI 1.02-1.24, per IQR; 3-day average OR 1.13, 95% CI 1.04-1.23, per IQR)., Interpretation: Our results show that the effect of air pollution on hospital admissions for MI was stronger in areas with higher NO 2 concentrations than that in areas with lower NO 2 concentrations. Individuals living in neighbourhoods with higher traffic-related pollution should be advised of the health risks and be attentive to special air quality warnings., Competing Interests: Competing interests: Michael Hill reports personal fees from Sun Pharma; nonfinancial support from Hoffmann–La Roche Canada; grants from Covidien (Medtronic), Boehringer–Ingelheim, Stryker, Medtronic and NoNO; and the patent “Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients.” Michael Hill owns stock in Calgary Scientific, a company that focuses on medical imaging software, is a director of the Canadian Neurological Sciences Federation, a not-for-profit group, is a director of Circle NeuroVascular, and has received grant support from Alberta Innovates Health Solutions, Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, and the National Institute of Neurological Disorders and Stroke. Gilaad Kaplan has received honoraria for speaking or consultancy from AbbVie, Janssen, Pfizer and Takeda. He has received research support from Ferring, Janssen, AbbVie, GlaxoSmithKline, Merck and Shire. He has been a consultant for Gilead. He shares ownership of a patent: Treatment of Inflammatory Disorders, Autoimmune Disease, and PBC. UTI Limited Partnership, assignee. Patent WO2019046959A1. PCT/CA2018/051098. 7 Sept. 2018. No other competing interests were declared., (Copyright 2020, Joule Inc. or its licensors.)

Importance: With population aging, the burden of many age-related chronic conditions, including kidney failure, is increasing globally., Objective: To investigate the risks of kidney failure and death in adults with incident stage IV chronic kidney disease (CKD)., Design, Setting, and Participants: This population-based cohort study obtained data recorded between July 30, 2002, and March 31, 2014, from the linked laboratory and administrative data set of Alberta Health in Alberta, Canada. All adults of the province of Alberta with stage IV CKD (estimated glomerular filtration rate [eGFR] of 15-30 mL/min/1.73 m2) were eligible for inclusion. Included individuals were followed up from study entry until the date of kidney failure, death, or censoring, whichever occurred first. Observations were censored at the date of emigration from the province, the study end date (March 31, 2017), or at 10 years after study entry. Data analyses were performed from January 2020 to June 2020., Main Outcomes and Measures: The primary outcome was kidney failure, defined as the earlier of either renal replacement (dialysis or kidney transplant) initiation or severe kidney impairment (eGFR <10 mL/min/1.73 m2). Incidence of stage IV CKD in Alberta was examined over time, along with the association between age at study entry and the competing risks of kidney failure and death. Cumulative incidence functions (95% CIs) were estimated to summarize absolute risks over time across categories of age, accounting for sex, diabetes, cardiovascular disease, eGFR, and albuminuria., Results: The study included 30 801 adults (mean [SD] age, 76.8 [13.3] years; 17 294 women [56.1%]) with stage IV CKD. Of these, 5511 developed kidney failure (17.9%) and 16 285 died (52.9%). The incidence rate of stage IV CKD increased sharply with advancing age; the absolute risk of kidney failure decreased with advancing age, and the risk of death increased, especially in those aged 85 years or older. Compared with the 5-year risk of death, the 5-year risk of kidney failure was higher in people younger than 65 years, similar in people aged 65 to 74 years, and lower for older age groups. For those aged 75 years or older, the risk of death was much higher than the risk of kidney failure: 6-fold higher among those aged 75 to 84 years (0.51 [95% CI, 0.5-0.52] vs 0.09 [95% CI, 0.08-0.09]) and 25-fold higher among those aged 85 years or older (0.75 [95% CI, 0.74-0.76] vs 0.03 [95% CI, 0.02-0.03]). The risk of death was higher than the risk of kidney failure by 24-fold among those aged 85 to 94 years (0.73 [95% CI, 0.72-0.74] vs 0.03 [95% CI, 0.02-0.03]) and by 149-fold among those aged 95 years or older (0.89 [95% CI, 0.87-0.92] vs <0.01 [95% CI, <0.01 to 0.01])., Conclusions and Relevance: This study found that, although the incidence rate of stage IV CKD increased with advancing age, the absolute risk of kidney failure decreased. Unlike other age-related conditions, the expected increase in the burden of kidney failure in the older adults may be less dramatic than expected.

Importance: Comparative outcome data examining the association of dialysis initiation with hospital length of stay and intensity of care in older adults with kidney failure are scarce, and prior studies are limited to patients treated by nephrology teams., Objective: To compare in-hospital days and intensity of care among older adults with kidney failure who were treated vs not treated with maintenance dialysis., Design, Setting, and Participants: This population-based, retrospective cohort study included adults in Alberta, Canada, 65 years or older with kidney failure, defined by at least 2 consecutive outpatient estimated glomerular filtration rate values of less than 10 mL/min/1.73 m2 spanning a period of at least 90 days from May 15, 2002, to March 31, 2014. Data were analyzed from August 1, 2017, to August 29, 2019., Exposures: Time-varying exposure to maintenance dialysis for treatment of kidney failure., Main Outcomes and Measures: The primary outcome was rate of in-hospital days. Secondary outcomes included rates of hospital admissions, intensive care unit admissions, cardiopulmonary resuscitations, inpatient palliative care, and emergency department visits; risk of in-hospital death; and time to admission to long-term care., Results: A total of 968 patients (median age, 78.5 [interquartile range, 72.4-84.7] years; 489 men [50.5%]; median follow-up, 2.0 [interquartile range, 0.8-3.9] years) were included in the analysis. Patients who underwent dialysis spent more adjusted in-hospital days per person-year (36.25 [95% CI, 30.72-41.77] vs 14.65 [95% CI, 12.28-17.02]; incidence rate ratio [IRR], 2.47 [95% CI, 1.99-3.08]). However, the dialysis group did not have a higher rate of hospital admissions (1.18 [95% CI 1.07-1.29] vs 1.32 [95% CI 1.17-1.48] per year; IRR, 0.89 [95% CI, 0.77-1.03]). Patients in the dialysis group had a higher rate of intensive care unit admissions per 1000 hospitalizations (98.37 [95% CI, 81.09-115.65] vs 54.51 [95% CI, 37.76-71.26]; IRR, 1.80 [95% CI, 1.28-2.54]) and lower rates of inpatient palliative care per 1000 in-hospital days (3.92 [95% CI, 3.13-4.72] vs 8.60 [95% CI, 6.3-11.0]; IRR, 0.45 [95% CI, 0.32-0.64])., Conclusions and Relevance: In this cohort study, compared with nondialysis care, patients who received maintenance dialysis spent more time in the hospital and were more likely to be admitted to intensive care units. This finding suggests trade-offs between longer survival and higher intensity of use of health care services as a function of dialysis initiation. Maintenance dialysis may be a proxy for the type of philosophy of care driving increased in-hospital time and intensive care and less use of palliative care.

Background: Cardiac rehabilitation (CR) is a guideline-indicated modality for reducing residual cardiovascular risk among patients undergoing coronary artery bypass grafting (CABG) surgery. However, many referred patients do not initiate or complete a CR program; even more patients are never even referred., Methods: All post-CABG patients in Calgary, Alberta, Canada, from January 1, 1996, to March 31, 2016, were included. Data were obtained from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology Rehabilitation databases. Automated referral to CR at discharge after CABG was instituted on July 1, 2007. We used interrupted time series analysis to evaluate the impact of automated referral on CR referral and completion rates and studied the association of these CR process markers with mortality., Results: A total of 8,118 patients underwent CABG surgery during the study period: 5,103 before automation and 3,015 after automation. Automation increased referral rates from 39.5% to 75.0% (P < 0.001). Automated referral was associated with a 7.2% increase in CR completion in the overall population (33.3% vs 26.1%; P < 0.001). In adjusted models, CR referral alone was not associated with reduced mortality (hazard ratio [HR] 0.84, 95% CI 0.64-1.11), but CR completion was (HR 0.43, 95% CI 0.31-0.61)., Conclusion: Automated referral in post-CABG patients resulted in modest improvement in CR program completion. Therefore, even when CR referral is automated to include all eligible patients, additional strategies to support CR program enrollment and completion remain necessary to achieve the desired health benefits., (Copyright © 2019 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: Contrast-induced acute kidney injury (CI-AKI) is a common and serious complication of invasive cardiac procedures. Quality improvement programs have been associated with a lower incidence of CI-AKI over time, but there is a lack of high-quality evidence on clinical decision support for prevention of CI-AKI and its impact on processes of care and clinical outcomes., Methods: The Contrast-Reducing Injury Sustained by Kidneys (Contrast RISK) study will implement an evidence-based multifaceted intervention designed to reduce the incidence of CI-AKI, encompassing automated identification of patients at increased risk for CI-AKI, point-of-care information on safe contrast volume targets, personalized recommendations for hemodynamic optimization of intravenous fluids, and follow-up information for patients at risk. Implementation will use cardiologist academic detailing, computerized clinical decision support, and audit and feedback. All 31 physicians practicing in all 3 of Alberta's cardiac catheterization laboratories will participate using a cluster-randomized stepped-wedge design. The order in which they are introduced to this intervention will be randomized within 8 clusters. The primary outcome is CI-AKI incidence, with secondary outcomes of CI-AKI avoidance strategies and downstream adverse major kidney and cardiovascular events. An economic evaluation will accompany the main trial., Conclusions: The Contrast RISK study leverages information technology systems to identify patient risk combined with evidence-based protocols, audit, and feedback to reduce CI-AKI in cardiac catheterization laboratories across Alberta. If effective, this intervention can be broadly scaled and sustained to improve the safety of cardiac catheterization., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Perceived social support is known to be an important predictor of health outcomes in patients with acute coronary syndrome (ACS). This study investigates patterns of longitudinal trajectories of patient-reported perceived social support in individuals with ACS., Methods: Data are from 3013 patients from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry who had their first cardiac catheterization between 2004 and 2011. Perceived social support was assessed using the 19-item Medical Outcomes Study Social Support Survey (MOS) 2 weeks, 1 year, and 3 years post catheterization. Group-based trajectory analysis based on longitudinal multiple imputation model was used to identify distinct subgroups of trajectories of perceived social support over a 3-year follow-up period., Results: Three distinct social support trajectory subgroups were identified, namely: "High" social support group (60%), "Intermediate" social support group (30%), and "Low" social support subgroup (10%). Being female (OR = 1.67; 95% CI = [1.18-2.36]), depression (OR = 8.10; 95% CI = [4.27-15.36]) and smoking (OR = 1.70; 95% CI = [1.23-2.35]) were predictors of the differences among these trajectory subgroups., Conclusion: Although the majority of ACS patients showed increased or fairly stable trajectories of social support, about 10% of the cohort reported declining social support. These findings can inform targeted psycho-social interventions to improve their perceived social support and health outcomes.

Importance: Abnormal measurements of kidney function or structure may be identified that do not meet criteria for acute kidney injury (AKI) or chronic kidney disease (CKD) but nonetheless may require medical attention. The Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for AKI proposed criteria for the definition of acute kidney diseases and disorders (AKD), which include AKI; however, the incidence and prognosis of AKD without AKI remain unknown., Objective: To characterize the incidence and outcomes of AKD without AKI, with or without CKD., Design, Setting, and Participants: Retrospective cohort study including all adult residents in a universal health care system in Alberta, Canada, without end-stage kidney disease (ESKD) and with at least 1 serum creatinine measurement between January 1 and December 31, 2008, in a community or hospital setting. Data analysis took place in 2018., Main Outcomes and Measures: The Kidney Disease: Improving Global Outcomes guideline definitions for CKD, AKI, and AKD based on serum creatinine, estimated glomerular filtration rate, and albuminuria criteria were applied to estimate the proportion of patients with CKD, AKI, and AKD without AKI, and combinations of the conditions. Patients were followed up for up to 8 years (study end date, June 31, 2016) to characterize their risks of mortality, development of new CKD, progression of preexisting CKD, and ESKD., Results: Among 1 109 099 Alberta residents included in the cohort, the mean (SD) age was 52.3 (17.6) years, and 43.0% were male. Findings showed that AKD without AKI was common (3.8 individuals without preexisting CKD and 0.6 with preexisting CKD per 100 population tested). In Cox proportional hazards and competing risks models over a median (interquartile range) of 6.0 (5.7-6.3) years of follow-up, AKD without AKI (compared with no kidney disease) was associated with higher risks of developing new CKD (37.4% vs 7.4%%; adjusted sub-hazard ratio [sHR], 3.17; 95% CI, 3.10-3.23), progression of preexisting CKD (49.5% vs 34.6%; adjusted sHR, 1.38; 95% CI, 1.33-1.44), ESKD (0.6% vs 0.1%; adjusted sHR, 8.56; 95% CI, 7.32-10.01), and death (25.8% vs 7.3%; adjusted hazard ratio, 1.42; 95% CI, 1.39-1.45)., Conclusions and Relevance: Criteria for AKD identified many patients who did not meet the criteria for CKD or AKI but had overall modestly increased risks of incident and progressive CKD, ESKD, and death. The clinical importance of AKD remains to be determined.

Background: As more patients at lower cardiovascular (CV) risk are treated with statins, the balance between cardiovascular benefits and the risk of adverse events becomes increasingly important., Methods: We did a population-based cohort study (May 1, 2002 to March 30, 2013) using province-wide laboratory and administrative data in Alberta. We studied new statin users aged 66 years of age and older who were not receiving renal replacement therapy at baseline. We assessed statin use at 30-day intervals to allow time-varying assessment of statin exposure in Cox proportional hazards models that examined the relation between statin use and hospitalization with acute kidney injury (AKI)., Results: Of the 128,140 new statin users, 47 and 46% were prescribed high- and medium-intensity regimens at the index date. During median follow-up of 4.6 years (interquartile range 2.2, 7.4), 9118 individuals were hospitalized for AKI. Compared to non-use, the use of high- and medium-intensity statin regimens was associated with significant increases in the adjusted risks of hospitalization with AKI: hazard ratios 1.16 [95% confidence interval (CI) 1.10, 1.23] and 1.07 (95% CI 1.01, 1.13), respectively. Risks of AKI were higher among women than men, and among users of angiotensin converting enzyme inhibitors/angiotensin receptor blockers than non-users, and among diuretic users (p for interaction 0.002, 0.01, and 0.04 respectively)., Conclusions: We found a graded, independent association between the intensity of statin use and the risk of hospitalization with AKI, although the absolute magnitude of the excess risk was small.

Importance: Clinical experience suggests that there are substantial differences in patient complexity across medical specialties, but empirical data are lacking., Objective: To compare the complexity of patients seen by different types of physician in a universal health care system., Design, Setting, and Participants: Population-based retrospective cohort study of 2 597 127 residents of the Canadian province of Alberta aged 18 years and older with at least 1 physician visit between April 1, 2014 and March 31, 2015. Data were analyzed in September 2018., Exposures: Type of physician seeing each patient (family physician, general internist, or 11 types of medical subspecialist) assessed as non-mutually exclusive categories., Main Outcomes and Measures: Nine markers of patient complexity (number of comorbidities, presence of mental illness, number of types of physicians involved in each patient's care, number of physicians involved in each patient's care, number of prescribed medications, number of emergency department visits, rate of death, rate of hospitalization, rate of placement in a long-term care facility)., Results: Among the 2 597 127 participants, the median (interquartile range) age was 46 (32-59) years and 54.1% were female. Over 1 year of follow-up, 21 792 patients (0.8%) died, the median (range) number of days spent in the hospital was 0 (0-365), 8.1% of patients had at least 1 hospitalization, and the median (interquartile range) number of prescribed medications was 3 (1-7). When the complexity markers were considered individually, patients seen by nephrologists had the highest mean number of comorbidities (4.2; 95% CI, 4.2-4.3 vs [lowest] 1.1; 95% CI, 1.0-1.1), highest mean number of prescribed medications (14.2; 95% CI, 14.2-14.3 vs [lowest] 4.9; 95% CI, 4.9-4.9), highest rate of death (6.6%; 95% CI, 6.3%-6.9% vs [lowest] 0.1%; 95% CI, <0.1%-0.2%), and highest rate of placement in a long-term care facility (2.0%; 95% CI, 1.8%-2.2% vs [lowest] <0.1%; 95% CI, <0.1%-0.1%). Patients seen by infectious disease specialists had the highest complexity as assessed by the other 5 markers: rate of a mental health condition (29%; 95% CI, 28%-29% vs [lowest] 14%; 95% CI, 14%-14%), mean number of physician types (5.5; 95% CI, 5.5-5.6 vs [lowest] 2.1; 95% CI, 2.1-2.1), mean number of physicians (13.0; 95% CI, 12.9-13.1 vs [lowest] 3.8; 95% CI, 3.8-3.8), mean days in hospital (15.0; 95% CI, 14.9-15.0 vs [lowest] 0.4; 95% CI, 0.4-0.4), and mean emergency department visits (2.6; 95% CI, 2.6-2.6 vs [lowest] 0.5; 95% CI, 0.5-0.5). When types of physician were ranked according to patient complexity across all 9 markers, the order from most to least complex was nephrologist, infectious disease specialist, neurologist, respirologist, hematologist, rheumatologist, gastroenterologist, cardiologist, general internist, endocrinologist, allergist/immunologist, dermatologist, and family physician., Conclusion and Relevance: Substantial differences were found in 9 different markers of patient complexity across different types of physician, including medical subspecialists, general internists, and family physicians. These findings have implications for medical education and health policy.

Aims: Patients with chronic kidney disease (CKD) have been under-represented in stable ischaemic heart disease (SIHD) trials despite their heightened risk of cardiovascular mortality. We examine associations between kidney disease, treatment selection, and long-term survival in patients with SIHD., Methods and Results: SIHD patients with angiographically significant stenosis (≥70%) were categorized by renal function [dialysis-dependent, severe CKD [estimated glomerular filtration rate (eGFR) < 30], mild-moderate CKD (eGFR 30-59), and no CKD (eGFR ≥ 60)] and by treatment groups [revascularization ≤3 months of angiogram (percutaneous coronary intervention or coronary artery bypass surgery) vs. medical therapy]. The association between renal function category and treatment on long-term survival was examined and adjusted for differences in age, sex, co-morbidities, and coronary anatomy. Of the 17 910 SIHD patients, 0.7% (n = 118) were dialysis-dependent, 1.2% (n = 215) severe CKD, 12.0% (n = 2157) mild-moderate CKD, and 86.1% (n = 15420) no CKD. The presence of CKD was associated with significantly lower adjusted odds of receiving revascularization [reference no CKD: dialysis-dependent: odds ratio (OR) 0.52 (0.35, 0.79), severe (non-dialysis) CKD: OR 0.54 (0.40, 0.73), and mild-moderate CKD: OR 0.80 (0.71, 0.89)]. Over a median follow-up of 8.0 (interquartile range 3.2) years, patients with progressive CKD had higher long-term mortality (dialysis-dependent, 53.4%; severe CKD, 30.2%; mild-moderate CKD, 22.2%; no CKD, 11.9%, Ptrend < 0.0001). Revascularization was associated with improved long-term survival [adjusted hazard ratio (HR): dialysis-dependent: HR 0.29 (0.15, 0.55), severe CKD: HR 0.63 (0.36, 1.08), mild-moderate CKD: HR 0.49 (0.40, 0.60), and no CKD: HR 0.47 (0.42, 0.52)] (Pinteraction < 0.001)., Conclusion: In SIHD, the presence of CKD was accompanied by lower revascularization rates and a higher risk of mortality. However, revascularization in CKD was associated with improved long-term survival.

In older people with chronic kidney disease (CKD) and comorbidities, the risk of death or disability may overshadow the risk of kidney failure. To help refine this we did a retrospective population-based cohort study to evaluate the relative likelihood of adverse outcomes as functions of age and comorbidity burden among 47,228 adults with severe non-dialysis dependent CKD. We identified comorbidities using 29 validated algorithms applied to administrative data and assessed death, end-stage renal disease (ESRD), cardiovascular disease (CVD) events, and long-term care. Over five years of follow-up, 53.4% of participants died, 24.1% had a CVD event, 14.3% were placed into long-term care and 5.3% developed ESRD. Death was 145 times more likely and 11 times more likely than ESRD for participants aged 80 years or more and 60-79 years, respectively; long-term care was 30 times more likely and 1.7 times as likely as ESRD for participants aged 80 years or more and 60-79 years, respectively. Increasing comorbidity burden was similarly associated with increased risk of death and long-term care placement but reduced the likelihood of ESRD, and the risks of increasing age were similarly incremental. Thus, among patients with severe CKD, older age and/or higher comorbidity burden, death and long-term care placement are markedly more likely than ESRD. Hence, clinicians, patients and families should all consider the relative magnitude of these risks when making decisions about renal replacement., (Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Health-related quality of life (HRQOL) assessment is an important health outcome for measuring the efficacy of treatments and interventions for coronary artery disease (CAD). HRQOL is known to improve over the first year after interventions for CAD, but there is limited knowledge of the changes in HRQOL beyond 1 year. We investigated heterogeneity in long-term trajectories of HRQOL in patients with CAD., Methods and Results: Data were obtained from 6226 patients identified from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease with at least 1-vessel CAD who underwent their first catheterization between 2006 and 2009. HRQOL was assessed using the Seattle Angina Questionnaire, a 19-item disease-specific measure of HRQOL for patients with CAD. Group-based trajectory analysis was used to identify various subgroups of Seattle Angina Questionnaire trajectories over time while adjusting for missing data through a longitudinal multiple imputation model. Multinomial logistic regression was used to identify the predictors of differences among the identified subgroups. Our analysis revealed significant improvements in HRQOL across all the 5 domains of Seattle Angina Questionnaire overtime for the whole data. Multitrajectory analyses revealed 4 HRQOL trajectory subgroups including high (25.1%), largely increased (32.3%), largely decreased (25.0%), and low (17.6%) trajectories. Age, sex, body mass index, diabetes mellitus, previous history of myocardial infarction, smoking, depression, anxiety, type of treatment received, and perceived social support were significant predictors of differences among these trajectory subgroups., Conclusions: This study highlights variations in longitudinal trajectories of HRQOL in patients with CAD. Despite overall improvements in HRQOL, about a quarter of our cohort experienced a significant decline in their HRQOL over the 5-year period. Understanding these HRQOL trajectories may help personalize prognostic information, identify patients and HRQOL domains on which clinical interventions are most beneficial, and support treatment decisions for patients with CAD., (© 2018 American Heart Association, Inc.)

Background: Metropolitan versus nonmetropolitan status and area median income may independently affect care for and outcomes of acute coronary syndromes. We sought to determine whether location of care modifies the association among area income, receipt of cardiac catheterization, and mortality following an acute coronary syndrome in a universal health care system., Methods and Results: We studied a cohort of 14 012 acute coronary syndrome patients admitted to cardiology services between April 18, 2004, and December 31, 2011, in southern Alberta, Canada. We used multivariable logistic regression to determine the odds of cardiac catheterization within 1 day and 7 days of admission and the odds of 30-day and 1-year mortality according to area median household income quintile for patients presenting at metropolitan and nonmetropolitan hospitals. In models adjusting for area income, patients who presented at nonmetropolitan facilities had lower adjusted odds of receiving cardiac catheterization within 1 day of admission (odds ratio 0.22, 95% CI 0.11-0.46, P<0.001). Among nonmetropolitan patients, when examined by socioeconomic status, each incremental decrease in income quintile was associated with 10% lower adjusted odds of receiving cardiac catheterization within 7 days (P<0.001) and 24% higher adjusted odds of 30-day mortality (P=0.008) but no significant difference for 1-year mortality (P=0.12). There were no differences in adjusted mortality among metropolitan patients., Conclusion: Within a universal health care system, the association among area income and receipt of cardiac catheterization and 30-day mortality differed depending on the location of initial medical care for acute coronary syndromes. Care protocols are required to improve access to care and outcomes in patients from low-income nonmetropolitan communities., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Using a community-based cohort we sought to investigate the association between change in estimated glomerular filtration rate (eGFR) and risk of incident cardiovascular disease including congestive heart failure (CHF), acute myocardial infarction (AMI), and stroke., Methods: We identified 479,126 adults without a history of cardiovascular disease who had at least 3 outpatient eGFR measurements over a 4 year period in Alberta, Canada. Change in eGFR was estimated as the absolute annual rate of change (categorized as ≤-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, and ≥5 mL/min/1.73 m2/year). In a sensitivity analysis we also estimated change as the annual percentage change (categorized as ≤-7, -6 to -5, -4 to -3, -2 to -1, 0, 1 to 2, 3 to 4, 5 to 6, and ≥7%/year). The adjusted risk of incident CHF, AMI, and stroke associated with each category of change in eGFR was estimated, using no change in eGFR as the reference,, Results: There were 2622 (0.6%) CHF, 3463 (0.7%) AMI, and 2768 (0.6%) stroke events over a median follow-up of 2.5 years. Compared to participants with stable eGFR, those with the greatest decline (≤-5 mL/min/1.73 m2/year) had more than a two-fold increased risk of CHF (HR 2.57; 95% CI: 2.28 to 2.89). Risk for AMI and stroke was increased by 31% and 29%, respectively. After adjusting for the last eGFR at the end of the accrual period, the observed association remained significantly higher for CHF but diminished for AMI and stroke. A similar pattern was observed when change in eGFR was quantified as annual percentage change., Conclusion: In this large community-based cohort, we observed that a declining eGFR was associated with an increased risk of CHF, AMI, and stroke. However, when the risk of CVD events was adjusted for the last eGFR measurement, decline in eGFR per se was no longer associated with increased risk of AMI or stroke, and the association with CHF remained significant but was attenuated. These results demonstrate the importance of monitoring change in eGFR over time to improve cardiovascular risk prognostication., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Background: Multimorbidity is common and associated with poor clinical outcomes and high health care costs. Administrative data are a promising tool for studying the epidemiology of multimorbidity. Our goal was to derive and apply a new scheme for using administrative data to identify the presence of chronic conditions and multimorbidity., Methods: We identified validated algorithms that use ICD-9 CM/ICD-10 data to ascertain the presence or absence of 40 morbidities. Algorithms with both positive predictive value and sensitivity ≥70% were graded as "high validity"; those with positive predictive value ≥70% and sensitivity <70% were graded as "moderate validity". To show proof of concept, we applied identified algorithms with high to moderate validity to inpatient and outpatient claims and utilization data from 574,409 people residing in Edmonton, Canada during the 2008/2009 fiscal year., Results: Of the 40 morbidities, we identified 30 that could be identified with high to moderate validity. Approximately one quarter of participants had identified multimorbidity (2 or more conditions), one quarter had a single identified morbidity and the remaining participants were not identified as having any of the 30 morbidities., Conclusions: We identified a panel of 30 chronic conditions that can be identified from administrative data using validated algorithms, facilitating the study and surveillance of multimorbidity. We encourage other groups to use this scheme, to facilitate comparisons between settings and jurisdictions.