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The purpose of this study was to examine the content of physical activity inputs in Canadian family physician electronic medical records. Of 1 225 948 patients aged 18–64 years, a sample of 1535 patients’ charts were reviewed. A minority (n = 148; 9.6%) of patients had at least 1 mention of physical activity at any time. Insufficient information existed to determine physical activity domain (21.6%), purpose (50.0%), or meeting of guidelines (98.1%). Novelty: This study examines the physical activity content of what Canadian family physicians document in their electronic medical records.

Lay Summary Primary care providers can deliver tailored advice and support to patients who are overweight or have obesity. The 2020 Canadian Adult Obesity Practice Guideline for primary care providers recommended that patients’ waist circumference (WC) be measured if their height and weight place them in the overweight or Class I obesity category. The guideline does not recommend how often providers should measure WC nor describe how often this is measured in current practice. We reviewed electronic medical records (EMRs) of 707,819 Canadian adult patients aged 40 and older. Among them, 48.7% had 1 or more body mass index (BMI) recorded; 11.5% had at least 1 waist measurement recorded. Of those with a BMI classified as overweight or having Class I obesity, 23.7% had at least 1 WC measurement recorded, which differed by chronic disease. WC was documented in more patients who had diabetes mellitus (36.8%) than hypertension (26.1%), or osteoarthritis (24.3%). This difference may be reflective of more specific advice in diabetes guidelines. To our knowledge, this is the first study to describe documentation of WC measurement for patients who are overweight or have Class I obesity in Canadian primary care EMRs across obesity-related conditions.

The International Classification of Diseases, Ninth Revision (ICD-9) was released in the 1970s and adopted in Canada for physician billing claims in 1979 (CIHI n.d.b.; WHOamp; International Conference for the Ninth Revision of the International Classification of Diseases 1977). ICD-9 is no longer adequate for representing our modern healthcare environment and patient needs. We summarize the findings from a small survey of ICD-9 users across Canada - such as family physicians, researchers and decision makers - who describe the limitations of ICD-9 and the features that they would desire in a new or updated classification system.

Background: Research based in primary care suggests that hearing loss may be underreported as well as inconsistently recorded in patient histories. In this study, we aimed to develop and validate a case definition for hearing loss among older adults in primary care, using electronic medical records. Methods: We used data from adult patients aged 55 years and older from 13 practices in the Southern Alberta Primary Care Research Network database, part of the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), from Dec. 1, 2014, to Dec. 31, 2016. We developed a hearing loss case definition that was translated into an electronic algorithm. A record review was undertaken as the reference standard, followed by application of the algorithm to the sample. Validation metrics included sensitivity, specificity, positive predictive value and negative predictive value, as well as prevalence. We assessed risk factors using the Fisher exact test and odds ratios. Results: The sample included 1000 patients; 496 (49.6%) were female and the mean age was 67.5 (standard deviation 9.6) years. Sensitivity of the case definition algorithm was determined to be 87.3% (95% confidence interval [CI] 76.5%–94.4%) with specificity valued at 94.8% (95% CI 93.1%–96.1%). Positive and negative predictive values were 52.9% (95% CI 42.8%–62.8%) and 99.1% (95% CI 98.2%–99.6%), respectively. The prevalence of hearing loss within the sample was 6.3% (95% CI 4.9%–7.9%). Older age was a significant risk factor for hearing loss (t = 4.98, 95% CI 3.76–8.65). Men had greater odds of hearing loss than women (odds ratio 1.65, 95% CI 0.98–2.79). Interpretation: The validated case definition for hearing loss in community-based older adults had high sensitivity and specificity. It may be applied to surveillance and future epidemiologic research within the CPCSSN database.

Dementia is an increasing concern in many countries, especially in those experiencing rapid growth in the proportion of older adults in their population.This study aims to describe trends and demographic characteristics of incident dementia cases in community-dwelling older adults managed by primary care physicians.We used electronic medical records from the Canadian Primary Care Sentinel Surveillance Network database to conduct a retrospective analysis to determine the number of, and trends for, incident diagnoses of dementia. Age-standardized annual incidence rates were calculated. Participants in our cohort are Canadian community dwelling seniors aged 65+ years who were not diagnosed with dementia before baseline with at least six years of record at their primary care clinics.The cohort consisted of 39 067 patients of whom 57% were females; the mean (SD) follow-up was 8.4 (1.5) years. During follow-up, 4935 patients were diagnosed with dementia. The risk for dementia diagnosis increased with increasing age but decreased in the last four years among people aged 80 and older at baseline (P0.001). People with dementia were more likely to be females (P = 0.001) and urban residents (P0.001), they are less likely to be classified into the least deprived group (P = 0.012).The incidence of dementia diagnosis increased with age except in the oldest old in both sexes. This may be attributed to the effect of mortality competing risk. Future research on the association between risk factors and dementia should consider studying dementia among the oldest old separately to minimize bias.Dementias are conditions that may cause mental symptoms such as forgetfulness, confusion, or disorientation. As the population gradually ages, the number of dementia cases is also increasing. Among people aged 65 and over, the rate of dementia onset increases as people get older. However, among people aged 85 and over, the rate of developing dementia is slower, which might reflect that people who reach the age of 85 are usually healthier in general. Since family practitioners are normally the first contact when patients and their family notice symptoms, primary care plays an important role in diagnosing and managing dementia. Early recognizing dementia for early support is very helpful. According to our study, health-related information recorded in primary care in Canada is sufficient to be used for research. It is a valuable opportunity to study the characteristics of people with dementia, including their health conditions, risks and protective factors that may contribute to the development of the disease.

Chronic obstructive pulmonary disease (COPD) is a complex disease that is predicted to be the third most common cause of death by 2030. In Canada, the care and management of chronic conditions is largely provided by primary care providers. Although there is emerging research and initiatives that describe the prevalence of COPD in Canadian primary care settings, to our knowledge, there have been no efforts to use a large pan-Canadian database to analyze COPD as a risk factor for other common chronic conditions managed in primary care. We report the risk of developing comorbidities after the onset of COPD, that is, the extent to which COPD is a risk factor for developing common chronic conditions (heart failure, depression, anxiety, coronary artery disease, diabetes, anemia, hypertension, ischemic heart disease, underweight, and osteoporosis). After adjusting for age, sex, urban vs rural residence, and smoking status, the relative risks for patients with COPD at baseline were significantly higher for subsequent incidence of anemia, anxiety, diabetes, depression, heart failure, ischemic heart disease, lung cancer, osteoporosis, sleep apnea, underweight, and hypertension than patients without COPD. Using a cut-point of a 200% increase in relative risk as indicative of particular clinical relevance, COPD has a statistically and clinically significant association with developing lung cancer, becoming underweight, and developing heart failure.

Although asthma is one of the most common chronic conditions affecting Canadians, its epidemiologic characteristics and burden in primary care contexts are poorly understood. The aim of this study was to develop and validate a case definition to identify adults with asthma who consult family physicians and to estimate the prevalence of asthma in that setting in Canada. This validation study utilized a database of electronic medical records (EMRs) from the Southern Alberta Primary Care Research Network, a node of the Canadian Primary Care Sentinel Surveillance Network (SAPCReN-CPCSSN). The population included patients over age 17y of any gender and health status who had visited an SAPCReN-CPCSSN primary care provider during the period December 1, 2014−December 31, 2016. The validation of the case definition involved comparing a case-finding algorithm to caseness determined by an expert physician review of the records of 1000 patient in the CPCSSN database. The case definition, which included the ICD-9 code 493 and asthma-related text words, had 83.33% sensitivity (95% CI: 63.61–93.88%), 99.28% specificity (95% CI: 98.51–99.67%), a positive predictive value of 74.07% (95% CI: 55.03–87.14%), and a negative predictive value of 99.59% (95% CI: 98.93–99.86%). The prevalence of adult asthma in CPCSSN primary care practices in southern Alberta was 4.20% (95% CI: 4.09–4.31). The strong validation metrics suggest that this case definition is valid for both clinical and research purposes. The validated case definition may be used to improve patient care and improve understanding of the prevalence and burden of asthma in primary care in Canada.

Background Cardiovascular disease (CVD) is a major cause of morbidity and mortality in Canada. Assessment and management of CVD risk is essential in reducing disease burden. This includes both clinical risk factors and socioeconomic factors, though few studies report on socioeconomic status in relation to CVD risk and treatment. The primary objective of this study was to estimate the cardiovascular risk of patients attending primary care practices across Canada; secondly, to evaluate concordance with care indicators suggested by current clinical practice guidelines for statin prescribing according to patients’ cardiovascular risk and socioeconomic status. Methods This cross-sectional observational study used the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) database, which is comprised of clinical data from primary care electronic medical records. Patients aged 35-75y with at least one visit to their primary care provider between 2012 and 2016 were included. Patients were assigned to a CVD risk category (high, medium, low) and a deprivation quintile was calculated for those with full postal code available. Descriptive analyses were used to determine the proportion of patients in each risk category. Logistic regression was used to evaluate the consistency of statin prescribing according to national clinical guidelines by risk category and deprivation quintile. Results A total of 324,526 patients were included. Of those, 116,947 (36%) of patients were assigned to a high CVD risk category, primarily older adults, males, and those with co-morbidities. There were statistically significant differences between least (quintile 1) and most (quintile 5) deprived socioeconomic quintiles, with those at high CVD risk disproportionately in Q5 (odds ratio 1.4). Overall, 48% of high-risk patients had at least one statin prescription in their record. Patients in the lower socioeconomic groups had a higher risk of statin treatment which deviated from clinical guidelines. Conclusions Primary care patients who are at high CVD risk are more often male, older, have more co-morbidities and be assigned to more deprived SES quintiles, compared to those at low CVD risk. Additionally, patients who experience more challenging socioeconomic situations may be less likely to receive CVD treatment that is consistent with care guidelines.

Objectives: This paper explores the role of immigrant-serving agencies in facilitating access to dementia services and supports provided by dementia service agencies (particularly the health author...

The relationship between individuals living with dementia and their caregivers is important and can impact their dementia journey. However, limited national longitudinal data exists about the caregiver-person living with dementia dyad. Availability of such data would provide important information about joint trajectories and help to better identify the needs of caregivers and persons living with dementia across the dementia journey. The objective of this study was to develop a linked national longitudinal database of persons living with dementia and their caregivers. The Canadian Primary Care Sentinel Surveillance Network (CPCSSN) extracts and de-identifies clinical data from electronic medical records (EMR) from approximately 2 million patients across Canada. CPCSSN data is used to identify persons living with dementia and caregivers willing to participate in the study. CPCSSN data from participating dyads are linked (e.g., chronic and mental health conditions, diagnoses, laboratory test results) and additional information about the experiences of persons living with dementia and their caregivers (e.g., ethnicity, amount and type of care provided, burden, availability of support) are collected yearly using surveys. The growing database contains linked, de-identified, comprehensive information about persons living with dementia and their caregivers that will become a rich source of data for researchers, clinicians, and policymakers. Specifics around how the database was developed, and lessons learned will be discussed as these findings can be used as a template to develop similar linked health surveillance databases.

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have shown cardiorenal benefits independent of their glucose-lowering effects among persons living with type 2 diabetes mellitus (T2DM). In this study, we describe the proportion of persons with T2DM eligible to receive and currently receiving these agents based on their risk criteria for cardiorenal events.This study was a cross-sectional analysis of primary care electronic medical records, in southern Alberta, of persons with T2DM who had at least 1 encounter with their primary care provider between December 31, 2018, to December 31, 2020. A descriptive and multivariate logistic regression analysis was conducted to examine clinical and demographic determinants of being prescribed one of the new treatments.Our study sample included 11,939 persons living with T2DM, among whom 66.3% had a cardiorenal indication for SGLT2i or GLP-1 RA use. In the secondary and primary prevention subsamples, 19.4% and 16.6% of persons were prescribed SGLT2i or GLP-1 RA, respectively, compared with 20.0% of those with no specific cardiorenal indication. Several person-level characteristics, such as age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.96 to 0.97), male sex (OR, 1.37; 95% CI, 1.21 to 1.55) and glycated hemoglobin (OR, 1.29; 95% CI, 1.24 to 1.34), were associated with being prescribed SGLT2i or GLP-1 RA.Low rates of SGLT2i or GLP-1 RA use and minimal differences between high-risk and no cardiorenal indication subsamples suggest the presence of barriers to prescribing these medications in a primary care setting. Action to highlight the indications for, and improve access to agents with, cardiorenal benefits will be required to achieve better outcomes for people with T2DM in primary care.

We describe how the out-of-plane dielectric polarizability of monolayer graphene influences the electrostatics of bilayer graphene -- both Bernal (BLG) and twisted (tBLG). We compare the polarizability value computed using density functional theory with the output from previously published experimental data on the electrostatically controlled interlayer asymmetry potential in BLG and data on the on-layer density distribution in tBLG. We show that monolayers in tBLG are described well by polarizability $\alpha_{exp} = 10.8 \unicode{x212B}^3$ and effective out-of-plane dielectric susceptibility $\epsilon_z = 2.5$, including their on-layer electron density distribution at zero magnetic field and the inter-layer Landau level pinning at quantizing magnetic fields., Comment: 4 pages

Background Polypharmacy, often defined as the concomitant use of ≥ 5 medications, has been identified as a significant global public health threat. Aging and multimorbidity are key drivers of polypharmacy and have been linked to a broad range of adverse health outcomes and mortality. Patients with chronic kidney disease (CKD) are particularly at high risk of polypharmacy and use of potentially inappropriate medications given the numerous risk factors and complications associated with CKD. The aim of this systematic review will be to assess the prevalence of polypharmacy among adult patients with CKD, and the potential association between polypharmacy and adverse health outcomes within this population. Methods/design We will search empirical databases such as MEDLINE, Embase, Cochrane Library, CINAHL, Web of Science, and PsycINFO and grey literature from inception onwards (with no language restrictions) for observational studies (e.g., cross-sectional or cohort studies) reporting the prevalence of polypharmacy in adult patients with CKD (all stages including dialysis). Two reviewers will independently screen all citations, full-text articles, and extract data. Potential conflicts will be resolved through discussion. The study methodological quality will be appraised using an appropriate tool. The primary outcome will be the prevalence of polypharmacy. Secondary outcomes will include any adverse health outcomes (e.g., worsening kidney function) in association with polypharmacy. If appropriate, we will conduct random effects meta-analysis of observational data to summarize the pooled prevalence of polypharmacy and the associations between polypharmacy and adverse outcomes. Statistical heterogeneity will be estimated using Cochran’s Q and I2 index. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., sex, kidney replacement therapy, multimorbidity). Discussion Given that polypharmacy is a major and a growing public health issue, our findings will highlight the prevalence of polypharmacy, hazards associated with it, and medication thresholds associated with adverse outcomes in patients with CKD. Our study will also draw attention to the prognostic importance of improving medication practices as a key priority area to help minimize the use of inappropriate medications in patients with CKD. Systematic review registration PROSPERO registration number: [CRD42020206514].

According to Landau's Fermi liquid theory, the main properties of the quasiparticle excitations of an electron gas are embodied in the effective mass $m^*$, which determines the energy of a single quasiparticle, and the Landau interaction function, which indicates how the energy of a quasiparticle is modified by the presence of other quasiparticles. This simple paradigm underlies most of our current understanding of the physical and chemical behavior of metallic systems. The quasiparticle effective mass of the three-dimensional homogeneous electron gas has been the subject of theoretical controversy and there is a lack of experimental data. In this work, we deploy diffusion Monte Carlo (DMC) methods to calculate $m^*$ as a function of density for paramagnetic and ferromagnetic three-dimensional homogeneous electron gases. The DMC results indicate that $m^*$ decreases when the density is reduced, especially in the ferromagnetic case. The DMC quasiparticle energy bands exclude the possibility of a reduction in the occupied bandwidth relative to that of the free-electron model at density parameter $r_s=4$, which corresponds to Na metal., Comment: Accepted for the publication

In Canada , 70% of paediatric asthma is managed in primary care. Different collection methods and venues produce a range of values for prevalence and patient demographics. We aimed to (1) describe both of these as seen in primary care in Canada using the national primary care database of the Canadian Primary Care Sentinel Surveillance Network which contains data from 1.8 million patients9 electronic medical records (2) the characteristics of children with asthma in Canada and (3) aspects of the management in primary care. We conducted a cross-sectional study of asthma in children between the ages of 1 and 17 in 2016 and the medications that they were prescribed. We used a validated search algorithm to extract data on children with asthma who had no gaps in the diagnosis greater than 3 years. The prevalence of asthma in this primary care cohort in 2016 was 18.07% (N=44,679). 52% males. Median age was 9 with a mean of 9.4. The median age of onset of the asthma was 7 years (mean 7.1). Prevalence reached a trough at age 12 and peaked at age 4 in both sexes and again in girls at age 17. Boys out numbered girls at all ages up to age 15. Twice as many girls had asthma onset at 16 or at 17 than did boys. Prevalence in the 1-3 year age group was 13%, before 6 was 17% and between 12 and 18 years was 20% Half the children had no recorded prescription for asthma in 2016. 13% had only ever had salbutamol as therapy. 66% had EVER had an ICS (7% in a combination inhaler) 1% had ever had prednisone . Though 26% had seen the physician in the last 12 months, only 4% had a recorded visit for asthma. Despite a high prevalence of childhood asthma , only 1% had severe asthma. Visits were irregular. More structure is needed.

ObjectiveTo describe the process for linking electronic medical record (EMR) and administrative data in Alberta and examine the advantages and limitations of utilising linked data for hypertension surveillance.MethodsDe-identified EMR data from 323 primary care providers contributing to the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) in Alberta were used. Mapping files from each contributing provider were generated from their EMR to facilitate linkage to administrative data within the provincial health data warehouse. Deterministic linkage was conducted using valid personal healthcare number (PHN) with age and/or sex. Characteristics of patients and providers in the linked cohort were compared with population-level sources. Criteria used to define hypertension in both sources were examined.ResultsData were successfully linked for 6307 hypertensive patients (96.2% of eligible patients) from 49 contributing providers. Non-linkages from invalid PHN (n=246) occurred more for deceased patients and those with fewer primary care encounters, with differences due to type of EMR and patient EMR status. The linked cohort had more patients who were female, >60 years and residing in rural areas compared to the provincial healthcare registry. Family physicians were more often female and medically trained in Canada compared to all physicians in Alberta. Most patients (>97%) had ≥1 record in the registry, pharmacy, emergency/ambulatory care and claims databases; 44.3% had ≥1 record in the hospital discharge database.ConclusionEMR-administrative data linkage has the potential to enhance hypertension surveillance. The current linkage process in Alberta is limited and subject to selection bias. Processes to address these deficiencies are under way.

Background: Electronic medical records (EMR) are commonly used in primary care to document patient measurements including height and weight that are then used to produce body mass index (BMI) scores. However, little is known about the proportion of waist circumference (WC) documentation compared to BMI and the characteristics of patients with these measures. This study used a pan-Canadian research database, sourced from primary care EMRs, to describe BMI and WC documentation in primary care. Methods: A retrospective cohort design of primary care providers participating in the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), this study presented descriptive, observational findings of EMR inputs. Frequencies and percentages of median BMI and WC documentation in CPCSSN EMRs and patient demographic characteristics are compared. Results: Of 707,819 Canadian patients aged of 40 or older, at least one BMI input was recorded for 58.6% and 11.5% had WC notations. The majority of patients (98.1%) with at least one WC measurement also had a BMI measurement while conversely 19.2% of patients with at least one BMI measurement also had a WC measurement. The most common median BMI category was overweight (36.9%) and median WC was 95.0 centimetres (IQR = 21.5).Conclusions: This study reports the documentation of obesity and overweight in select Canadian primary care EMRs infrequently recorded WC when compared to BMI. Future studies should examine the frequency and categories of anthropometric measurements in people with commonly managed chronic conditions and whether BMI and WC inputs are missing at random. Trial registration: Not applicable for this study.

BACKGROUND: To date, there has been no validated method to identify cases of pelvic floor disorders in primary care electronic medical record (EMR) data. We aimed to develop and validate symptom-based case definitions for urinary incontinence, fecal incontinence and pelvic organ prolapse in women, for use in primary care epidemiologic or clinical research. METHODS: Our retrospective study used EMR data from the Southern Alberta Primary Care Research Network (SAPCReN) and the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) in southern Alberta. Trained researchers remotely reviewed a random sample of EMR charts of women aged 18 years or older from 6 rural and urban clinics to validate case definitions for urinary incontinence, fecal incontinence and pelvic organ prolapse. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and estimated SAPCReN prevalence as appropriate. RESULTS: Charts of 900 women were included. Sensitivity was 81.9% (95% confidence interval [CI] 75.1–87.2) for urinary incontinence, 61.2% (95% CI 46.2–74.5) for fecal incontinence, and 51.8% (95% CI 40.6–62.8) for pelvic organ prolapse. Corresponding specificity values were 71.9% (95% CI 68.4–75.1), 99.2% (95% CI 98.2–99.6) and 98.8% (95% CI 97.7–99.4), PPVs 40.6% (95% CI 35.4–46.0), 81.1% (95% CI 64.3–91.4) and 81.1% (95% CI 67.6–90.1), and NPVs 94.4% (95% CI 92.1–96.1), 97.8% (95% CI 96.5–98.6) and 95.3% (95% CI 93.6–96.6). The SAPCReN-observed prevalence for urinary incontinence was 29.7% (95% CI 29.3–30.0), but the adjusted prevalence was 2.97%. INTERPRETATION: The case definition for urinary incontinence met our standard for validity (sensitivity and specificity > 70%), and the case definitions for fecal incontinence and pelvic organ prolapse had PPVs greater than 80%. The urinary incontinence definition may be used in epidemiologic research, and those for fecal incontinence and pelvic organ prolapse may be used in quality-improvement studies or creation of disease registries. Our symptom-based case definitions could also be adapted for research in other EMR settings.

OBJECTIVE: To validate a case definition for speech and language disorders in community-dwelling older adults and to determine the prevalence of speech and language disorders in a primary care population. DESIGN: This is a combined case definition validation and cross-sectional prevalence study. Chart review was considered the reference standard and was used to estimate prevalence. This study used de-identified electronic medical record data from participating SAPCReN-CPCSSN (Southern Alberta Primary Care Research Network–Canadian Primary Care Sentinel Surveillance Network) primary care clinics. SETTING: Southern Alberta. PARTICIPANTS: Men and women aged 55 years and older who had visited a SAPCReN-CPCSSN physician or nurse practitioner at least once in the 2 years before the beginning of the study. MAIN OUTCOME MEASURES: Validation analysis included estimation of sensitivity, specificity, positive predictive value, and negative predictive value. Prevalence was the other main outcome measure. RESULTS: The prevalence of speech and language disorders within the sample of 1384 patients was 1.2%. The case definition had a favourable specificity (99.9%, 95% CI 99.6% to 100.0%), positive predictive value (75.6%, 95% CI 25.4% to 96.6%), and negative predictive value (99.0%, 95% CI 98.8% to 99.2%). Sensitivity was not sufficient for validity (18.8%, 95% CI 4.05% to 45.6%). CONCLUSION: The case definition did not meet an acceptable standard for validity and thus cannot be used for future epidemiologic research. However, owing to the case definition’s high positive predictive value, it might be useful for clinical purposes and for cohort studies. Finally, while the case definition did not prove valid, this study has provided a conservative estimate of prevalence (1.2%) given the case definition’s high specificity.

Dementia is a common, progressive, chronic condition associated with cognitive impairment, particularly in seniors. In the absence of a cure, much attention is focused on providing care for people with the disease and support for their families and friends who provide most of the care. As the condition changes, the care needs of people with dementia change too. The result is typically a long series of transitions in health status, locations, organizations, practices, and people. This chapter introduces aspects of the lived experience, management, and epidemiology of dementia and some of the significant transitions that people with the disease and their caregivers frequently encounter. It then considers some research designed to identify factors associated with good transitions in dementia care and finally to discuss the nature of “good” itself, in the context of living with dementia.

© 2020 American Physical Society. We report diffusion quantum Monte Carlo (DMC) and many-body GW calculations of the electronic band gaps of monolayer and bulk hexagonal boron nitride (hBN). We find the monolayer band gap to be indirect. GW predicts much smaller quasiparticle gaps at both the single-shot G0W0 and the partially self-consistent GW0 levels. In contrast, solving the Bethe-Salpeter equation on top of the GW0 calculation yields an exciton binding energy for the direct exciton at the K point in close agreement with the DMC value. Vibrational renormalization of the electronic band gap is found to be significant in both the monolayer and the bulk. Taking vibrational effects into account, DMC overestimates the band gap of bulk hBN, while GW theory underestimates it.

Background Hypertension is a common chronic condition affecting nearly a quarter of Canadians. Hypertension surveillance in Canada typically relies on administrative data and/or national surveys. Routinely-captured data from primary care electronic medical records (EMRs) are a complementary source for chronic disease surveillance, with longitudinal patient-level details such as sociodemographics, blood pressure, weight, prescribed medications, and behavioural risk factors. As EMR data are generated from patient care and administrative tasks, assessing data quality is essential before using for secondary purposes. This study evaluated the quality of primary care EMR data from one province in Canada within the context of hypertension surveillance. Methods We conducted a cross-sectional, descriptive study using primary care EMR data collected by two practice-based research networks in Alberta, Canada. There were 48,377 adults identified with hypertension from 53 clinics as of June 2018. Summary statistics were used to examine the quality of data elements considered relevant for hypertension surveillance. Results Patient year of birth and sex were complete, but other sociodemographic information (ethnicity, occupation, education) was largely incomplete and highly variable. Height, weight, body mass index and blood pressure were complete for most patients (over 90%), but a small proportion of outlying values indicate data inaccuracies were present. Most patients had a relevant laboratory test present (e.g. blood glucose/glycated hemoglobin, lipid profile), though a very small proportion of values were outside a biologically plausible range. Details of prescribed antihypertensive medication, such as start date, strength, dose, frequency, were mostly complete. Nearly 80% of patients had a smoking status recorded, though only 66% had useful information (i.e. categorized as current, past, or never), and less than half had their alcohol use described; information related to amount, frequency or duration was not available. Conclusions Blood pressure and prescribed medications in primary care EMR data demonstrated good completeness and plausibility, and contribute valuable information for hypertension epidemiology and surveillance. The use of other clinical, laboratory, and sociodemographic variables should be used carefully due to variable completeness and suspected data errors. Additional strategies to improve these data at the point of entry and after data extraction (e.g. statistical methods) are required.

Alpha1-antitrypsin deficiency (AATD) is a manageable cause of COPD. Although prevalence rates vary with ethnicity, it is estimated to be 2% in COPD cohorts. In high-risk groups, however, prevalence rises to 5%. Testing for AATD in COPD patients is recommended by national guidelines, but in developed countries with low prevalence it is much more effective to test those who develop COPD before age 65, or who develop COPD despite never having smoked. In this study, we aimed to identify high-risk patients in a primary care electronic database in southern Alberta, Canada and to test if an electronic reminder would increase the number of tests performed in a group of primary care physicians (PCPs). We notified 224 PCPs of the eligible patients in their practice and reminded them to test patients with a simple 2-page leaflet of the national guidelines. We searched the database for tests performed up to January 2018 as well as tests performed after January 2018 when notification was sent by email. Prior to the intervention, 1879 tests had been performed by the PCPs, but only 300 of these patients had algorithm-defined COPD. The total number of tests had risen each year from 10 in 2005 to 248 in 2016. The top 5 testers among PCPs had together tested 29 patients under age 40, 143 patients between the ages of 31 and 60, and 7 patients over age 60. For each of these 5 testers, the numbers tested peaked in 2009 and 2014 (average 8.5 and 9.7, respectively) but dropped to

This cross-sectional study assesses chronic kidney disease management in Canadian primary care practices to identify care gaps to guide development and implementation of national quality improvement initiatives., Key Points Question What is the current status of chronic kidney disease management in Canadian primary care practice settings? Findings In this cross-sectional study of 46 162 individuals with moderate to severe chronic kidney disease who received care in primary care practices in Canada, 4 of 12 quality indicators were met by 75% or more of the study cohort. Guideline-recommended care relating to monitoring and testing for albuminuria and recommended medication use were identified as gaps in management of chronic kidney disease. Meaning The findings suggest that although most patients received high-quality care, there are gaps in treatment that may be key priority areas for quality improvement., Importance Although patients with chronic kidney disease (CKD) are routinely managed in primary care settings, no nationally representative study has assessed the quality of care received by these patients in Canada. Objective To evaluate the current state of CKD management in Canadian primary care practices to identify care gaps to guide development and implementation of national quality improvement initiatives. Design, Setting, and Participants This cross-sectional study leveraged Canadian Primary Care Sentinel Surveillance Network data from January 1, 2010, to December 31, 2015, to develop a cohort of 46 162 patients with CKD managed in primary care practices. Data analysis was performed from August 8, 2018, to July 31, 2019. Main Outcomes and Measures The study examined the proportion of patients with CKD who met a set of 12 quality indicators in 6 domains: (1) detection and recognition of CKD, (2) testing and monitoring of kidney function, (3) use of recommended medications, (4) monitoring after initiation of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs), (5) management of blood pressure, and (6) monitoring for glycemic control in those with diabetes and CKD. The study also analyzed associations of divergence from these quality indicators. Results The cohort comprised 46 162 patients (mean [SD] age, 69.2 [14.0] years; 25 855 [56.0%] female) with stage 3 to 5 CKD. Only 4 of 12 quality indicators were met by 75% or more of the study cohort. These indicators were receipt of an outpatient serum creatinine test within 18 months after confirmation of CKD, receipt of blood pressure measurement at any time during follow-up, achieving a target blood pressure of 140/90 mm Hg or lower, and receiving a hemoglobin A1c test for monitoring diabetes during follow-up. Indicators in the domains of detection and recognition of CKD, testing and monitoring of kidney function (specifically, urine albumin to creatinine ratio testing), use of recommended medications, and appropriate monitoring after initiation of treatment with ACEIs or ARBs were not met. Only 6529 patients (18.4%) with CKD received a urine albumin test within 6 months of CKD diagnosis, and 3954 (39.4%) had a second measurement within 6 months of an abnormal baseline urine albumin level. Older age (≥85 years) and CKD stage 5 were significantly associated with not satisfying the criteria for the quality indicators across all domains. Across age categories, younger patients (aged 18-49 years) and older patients (≥75 years) were less likely to be tested for albuminuria (314 of 1689 patients aged 18-49 years [18.5%], 1983 of 11 919 patients aged 75-84 years [61.6%], and 614 of 5237 patients aged ≥85 years [11.7%] received the urine albumin to creatinine ratio test within 6 months of initial estimated glomerular filtration rate

Due to their unique 2D nature, charge carriers in semiconducting transition metal dichalcogenides (TMDs) exhibit strong unscreened Coulomb interactions and sensitivity to defects and impurities. The versatility of van der Waals layer stacking allows spatially separating electrons and holes between different TMD layers with staggered band structure, yielding interlayer few-body excitonic complexes whose nature is still debated. Here we combine quantum Monte Carlo calculations with spectrally and temporally resolved photoluminescence (PL) measurements on a top- and bottom-gated MoSe2/WSe2 heterostructure, and identify the emitters as impurity-bound interlayer excitonic complexes. Using independent electrostatic control of doping and out-of-plane electric field, we demonstrate control of the relative populations of neutral and charged complexes, their emission energies on a scale larger than their linewidth, and an increase of their lifetime into the microsecond regime. This work unveils new physics of confined carriers and is key to the development of novel optoelectronics applications.

To determine the stability of warfarin anticoagulation using a nationally representative sample of Canadian primary care patients and providers.Prospective cohort study.Primary care practices associated with the Canadian Primary Care Sentinel Surveillance Network.Adult warfarin users with 7 or more evaluable international normalized ratio (INR) readings.International normalized ratio time in therapeutic range (TTR) determined using the Rosendaal method; TTR above 75% was considered good INR control and TTR below 60% was considered poor INR control. The primary outcome was the proportion of all warfarin users (using an INR target range of 2.0 to 3.5) with good INR control during their first year taking warfarin who have poor INR control the following year. Secondary outcomes included the TTR using an INR target of 2.0 to 3.0 when restricted to patients with known atrial fibrillation (AF) or venous thromboembolism (VTE); and the proportion of INR values below the target of 2.0 and above the targets of 3.0 and 3.5 in the year before the availability of other oral anticoagulants.Among 18 303 adult warfarin users (mean age of 71.0 years, 46.6% female), the median TTR (INR target range of 2.0 to 3.5) was 77.4% (interquartile range of 64.6% to 86.4%). The TTR was above 75% in 56.0% of patients and below 60% in 19.3% of patients. Of those exhibiting good INR control in year 1 of anticoagulation therapy, only 10.2% had poor control the following year. When restricted to patients with known AF or VTE (89.7% with AF and 13.5% with VTE), and assuming an INR target range of 2.0 to 3.0, the TTR was 67.8% (interquartile range of 54.8% to 77.9%). Of these patients, 27.9% had INR values below 2.0, and 19.4% and 8.6% had values above 3.0 and 3.5, respectively.Primary care warfarin management produces a TTR comparable to that in randomized trials, with out-of-range INR values 3 times more likely to predispose to thrombosis (INR of2.0) than to hemorrhage (INR of3.5). A history of good INR control does predict future INR stability and meaningfully informs decisions to switch established warfarin users onto newer agents.