150 results on '"R. Croxford"'
Search Results
2. Clinical phenotype and risk factors for severe efavirenz-associated neurotoxicity amongst inpatients in Cape Town, South Africa
- Author
-
R. Croxford, Karen Cohen, Lubbe Wiesner, J. Scott, P. Arnab, and Sean Wasserman
- Subjects
Microbiology (medical) ,medicine.medical_specialty ,Efavirenz ,business.industry ,Neurotoxicity ,General Medicine ,medicine.disease ,lcsh:Infectious and parasitic diseases ,chemistry.chemical_compound ,Infectious Diseases ,chemistry ,Internal medicine ,Cape ,Medicine ,lcsh:RC109-216 ,business ,Clinical phenotype - Published
- 2020
3. Cardiovascular Disease Risk Factors and Outcomes Among a Primary Cardiovascular Disease Prevention Cohort with and Without COPD in Ontario, Canada: The Canbreathe/Canheart Study
- Author
-
Jacob A. Udell, P. Austin, J. Liu, D.S. Lee, D.D. Sin, A. Chu, A.S. Gershon, L.C. Maclagan, and R. Croxford
- Subjects
medicine.medical_specialty ,COPD ,business.industry ,Cohort ,Emergency medicine ,Disease risk ,Medicine ,Disease prevention ,business ,medicine.disease ,Ontario canada - Published
- 2020
- Full Text
- View/download PDF
4. Characteristics and Outcomes of People with Cardiovascular Diseases with and Without Chronic Obstructive Pulmonary Disease
- Author
-
A. Chu, R. Croxford, Jacob A. Udell, L.C. Maclagan, A.S. Gershon, Douglas S. Lee, D.D. Sin, and E.E. Cho
- Subjects
medicine.medical_specialty ,business.industry ,medicine ,Pulmonary disease ,Intensive care medicine ,business - Published
- 2020
- Full Text
- View/download PDF
5. The Impact of Compliance with Imaging Follow-up on Mortality After Endovascular Abdominal Aortic Aneurysm Repair: A Population Based Cohort Study
- Author
-
R. Croxford, C. de Mestral, Naomi Eisenberg, and Graham Roche-Nagle
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,Databases, Factual ,Computed Tomography Angiography ,030204 cardiovascular system & hematology ,Lower risk ,Aortography ,Risk Assessment ,Blood Vessel Prosthesis Implantation ,03 medical and health sciences ,Population based cohort ,Aortic aneurysm ,0302 clinical medicine ,Predictive Value of Tests ,Risk Factors ,medicine ,Humans ,030212 general & internal medicine ,Practice Patterns, Physicians' ,Aged ,Proportional Hazards Models ,Retrospective Studies ,Ultrasonography ,Aged, 80 and over ,Ontario ,business.industry ,Endovascular Procedures ,Ultrasound ,medicine.disease ,Abdominal aortic aneurysm ,Surgery ,Compliance (physiology) ,Treatment Outcome ,medicine.anatomical_structure ,Multivariate Analysis ,Practice Guidelines as Topic ,Cohort ,Patient Compliance ,Abdomen ,Female ,Guideline Adherence ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Aortic Aneurysm, Abdominal - Abstract
Objective Compliance with regular imaging follow-up after endovascular aortic aneurysm repair (EVAR) is inconsistent, and evidence of benefit from scheduled long-term surveillance is limited. This study sought to characterize the association between post-EVAR imaging frequency and long-term survival. Methods Using administrative health databases for the province of Ontario, Canada, a cohort of patients was identified who underwent EVAR between 2004 and 2014. Minimum appropriate imaging follow-up (MAIFU) was defined as a CT scan or ultrasound of the abdomen within 90 days of EVAR as well as every 15 months thereafter. Multivariate time to event analyses characterized the association between compliance with MAIFU over time and all-cause mortality. Results 4988 patients treated by EVAR were identified. Median follow-up was 3.4 years (IQR 2.0–5.3 years) and 90 day mortality was 1.6%. Among those who survived over 90 days, 87% (N = 4251 of 4902) underwent at least one CT scan or ultrasound of the abdomen within 90 days, but only 58% (N = 2859 of 4902) went on to meet MAIFU criteria. Infrequent imaging correlated with lower follow-up by a vascular surgeon, but not with infrequent primary care or specialist consultations. Consistently meeting MAIFU criteria was associated with a lower risk of death when compared with missing the first imaging follow-up within 90 days (HR 0.82, 95% CI 0.69–0.96, p = .014), or when compared with having first imaging follow-up within 90 days but subsequently not meeting MAIFU criteria (HR 0.78, 95% CI 0.68–0.91, p = .001). A larger proportion of the follow-up period meeting MAIFU criteria was associated with a lower risk of death. Conclusions These data support efforts to improve compliance with imaging surveillance after EVAR.
- Published
- 2017
- Full Text
- View/download PDF
6. The longitudinal relationship between hand, hip and knee osteoarthritis and cardiovascular events: a population-based cohort study
- Author
-
Ian Stanaitis, Peter Jüni, Lauren K. King, R. Croxford, Gillian A. Hawker, and Tetyana Kendzerska
- Subjects
Male ,medicine.medical_specialty ,Hand Joints ,Population ,Biomedical Engineering ,Myocardial Infarction ,Osteoarthritis ,Osteoarthritis, Hip ,Angina Pectoris ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Sex Factors ,Rheumatology ,medicine ,Myocardial Revascularization ,Humans ,Orthopedics and Sports Medicine ,030212 general & internal medicine ,Myocardial infarction ,Longitudinal Studies ,Mobility Limitation ,education ,Stroke ,Aged ,Proportional Hazards Models ,2. Zero hunger ,030203 arthritis & rheumatology ,Heart Failure ,Ontario ,education.field_of_study ,Primary Health Care ,business.industry ,Middle Aged ,Osteoarthritis, Knee ,medicine.disease ,Hospitalization ,Difficulty walking ,Cardiovascular Diseases ,Cohort ,Physical therapy ,Income ,Female ,business ,Emergency Service, Hospital ,Body mass index ,Cohort study - Abstract
Summary Objective In this population-based cohort study, we examined the association between the presence of symptomatic osteoarthritis (OA) and risk for cardiovascular (CV) events. Method A cohort aged ≥55 years recruited from 1996 to 98 was followed through provincial health administrative data to 2014. Demographics, joint complaints and functional limitations were collected. Hip, knee and hand OA were defined using a validated definition. Using Cox-regressions, the relationship between OA and a composite CV outcome (myocardial infarction (MI), stroke, angina, heart failure, revascularization) was assessed controlling for age, body mass index (BMI), sex, pre-existing metabolic factors, comorbidities, income status, primary care exposure and functional limitations. Results 18,490 participants were included: median age was 68 years, 60.3% were female; 24.4% met criteria for OA (10.0% hip, 15.3% knee, 16.0% hand), 16.3% self-reported limitation in grip and 25.4% in walking. Over a median 13.4 years, 31.9% experienced a CV event. Controlling for all but walking limitation, a dose–response relationship was observed between number of joints affected by knee/hip OA and CV risk (HR 2 hips/knees vs none: 1.13, 95% CI 1.03–1.23; 3+ hips/knees: 1.22, 95% CI 1.09–1.36). This relationship became non-significant additionally controlling for difficulty walking. Self-reported difficulty walking was associated with a 30% increased hazard for CV events. The effect of hand OA was not significant. Conclusion In a large population cohort, a greater burden of hip/knee OA was associated with higher CV risk; the relationship was explained by OA-related difficulty walking. Increased attention to management of OA with a view to improving mobility has potential to reduce CV events.
- Published
- 2017
7. The impact of hip and knee osteoarthritis and associated walking limitation on all-cause mortality: a population-based cohort study
- Author
-
Lauren K. King, A. Wall, Gillian A. Hawker, Tetyana Kendzerska, I. Stanaitis, and R. Croxford
- Subjects
030203 arthritis & rheumatology ,0301 basic medicine ,medicine.medical_specialty ,business.industry ,Biomedical Engineering ,Osteoarthritis ,medicine.disease ,03 medical and health sciences ,Population based cohort ,030104 developmental biology ,0302 clinical medicine ,Rheumatology ,Internal medicine ,Medicine ,Orthopedics and Sports Medicine ,business ,All cause mortality - Published
- 2016
- Full Text
- View/download PDF
8. Continental variations in IgA nephropathy among Asians
- Author
-
Peter C. Austin, Daniel C. Cattran, R. Croxford, Talerngsak Kanjanabuch, Chi-yuan Hsu, Suma Prakash, and A. I. Choi
- Subjects
Adult ,Male ,Nephrology ,medicine.medical_specialty ,Biopsy ,Renal function ,Kidney ,Article ,Nephropathy ,Asian People ,Prednisone ,Internal medicine ,medicine ,Humans ,Retrospective Studies ,Ontario ,Proteinuria ,business.industry ,Repeated measures design ,Glomerulonephritis, IGA ,General Medicine ,Thailand ,medicine.disease ,Immunology ,Female ,Morbidity ,medicine.symptom ,business ,Body mass index ,Glomerular Filtration Rate ,Kidney disease ,medicine.drug - Abstract
Background/Aims: Local variations in patient demographics and medical practice can contribute to differences in renal outcomes in patients with IgA nephropathy. We report the experiences of two groups of Asians with IgA nephropathy across continents. Materials and methods: We retrospectively examined two cohorts of Asian patients with IgA nephropathy from The King Chulalongkom Memorial Hospital registry, Thailand (1994 - 2005), and The Metropolitan Toronto Glomerulonephritis registry, Canada (1975 - 2006), and compared their baseline characteristics. Slope of estimated glomerular filtration rate (eGFR) in each group was approximated using separate repeated measures regression models for each country. Results: There were 152 Canadian and 76 Thai patients. At the time of first presentation, Thai patients were more likely to be female (63.2 vs. 44.1%, p = 0.01), have less baseline proteinuria (1.2 vs. 1.7 g/d, p = 0.08) and more likely to receive angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) (64.0 vs. 15.2%, p
- Published
- 2008
- Full Text
- View/download PDF
9. The impact of hand osteoarthritis and associated grip strength on all-cause mortality: a population-based cohort study
- Author
-
I. Stanaitis, R. Croxford, Gillian A. Hawker, Lauren K. King, A. Wall, and Tetyana Kendzerska
- Subjects
Population based cohort ,Grip strength ,medicine.medical_specialty ,Rheumatology ,business.industry ,Physical therapy ,Biomedical Engineering ,Medicine ,Orthopedics and Sports Medicine ,business ,Hand osteoarthritis ,All cause mortality - Published
- 2016
- Full Text
- View/download PDF
10. A Field Demonstration of the Efficacy of Bioremediation to Treat Oiled Shorelines Following the Sea Empress Incident
- Author
-
M. Jones, R.P. J. Swannell, M. Hagley, S Petch, D. Heath, D. Mitchell, R. Croxford, R. Milne, G. Lethbridge, Kenneth Lee, and David Jones
- Subjects
Phosphorus ,Environmental engineering ,chemistry.chemical_element ,General Medicine ,Human decontamination ,Fuel oil ,engineering.material ,Soil contamination ,Nutrient ,Bioremediation ,chemistry ,Environmental chemistry ,engineering ,Environmental Chemistry ,Environmental science ,Seawater ,Fertilizer ,Waste Management and Disposal ,Water Science and Technology - Abstract
Bioremediation was investigated as a method of treating a mixture of Forties Crude Oil and Heavy Fuel Oil stranded on Bullwell Bay, Milford Haven, UK after the grounding of the Sea Empress in 1996. A randomised block design in triplicate was used to test the efficacy of two bioremediation treatments: a weekly application of mineral nutrients dissolved in seawater and a single application of a slow-release fertilizer. Each treatment supplied an equivalent amount of nitrogen and phosphorus. Concentrations of residual hydrocarbons normalised to the biomarker 17α(H),21β(H)-hopane showed that after two months the oil was significantly (p
- Published
- 1999
- Full Text
- View/download PDF
11. The impact of hip, knee and hand osteoarthritis on the subsequent risk of cardiovascular events and all-cause mortality: a population-based cohort study
- Author
-
Tetyana Kendzerska, A. Wall, Gillian A. Hawker, Lauren K. King, I. Stanaitis, and R. Croxford
- Subjects
medicine.medical_specialty ,business.industry ,Biomedical Engineering ,body regions ,03 medical and health sciences ,Population based cohort ,0302 clinical medicine ,Rheumatology ,Internal medicine ,medicine ,Orthopedics and Sports Medicine ,030212 general & internal medicine ,business ,030217 neurology & neurosurgery ,All cause mortality ,Hand osteoarthritis - Published
- 2016
- Full Text
- View/download PDF
12. Hospital-acquired invasive group a streptococcal infections in Ontario, Canada, 1992-2000
- Author
-
R. Croxford, Peter Jessamine, Nick Daneman, Benjamin Schwartz, M. McArthur, A. E. Simor, D. E. Low, K. A. Green, Allison McGeer, and Gregory J. Tyrrell
- Subjects
Microbiology (medical) ,Adult ,Male ,medicine.medical_specialty ,Streptococcus pyogenes ,Population ,medicine.disease_cause ,law.invention ,Disease Outbreaks ,law ,Risk Factors ,Internal medicine ,Streptococcal Infections ,Case fatality rate ,medicine ,Humans ,Surgical Wound Infection ,education ,Fasciitis ,Intensive care medicine ,Prospective cohort study ,Child ,Aged ,Ontario ,education.field_of_study ,Cross Infection ,business.industry ,Streptococcus ,Outbreak ,medicine.disease ,Intensive care unit ,Infectious Diseases ,Population Surveillance ,Puerperal Infection ,Female ,business ,Postpartum period - Abstract
Background. A significant proportion of invasive group A streptococcal infections are hospital acquired. No large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals. Methods. We conducted prospective, population-based surveillance of invasive group A streptococcal infections in Ontario, Canada, from 1992 to 2000. Epidemiologic and microbiologic investigations were conducted to identify cross-transmission. Results. We identified 291 hospital-acquired cases (12.4%) among 2351 cases of invasive group A streptococcal disease. Hospital-acquired invasive group A streptococcal infections are heterogeneous, including surgical site (96 cases), postpartum (86 cases), and nonsurgical, nonobstetrical infections (109 cases). Surgical site infections affected 1 of 100,000 surgical procedures and involved all organ systems. Postpartum infections occurred at a rate of 0.7 cases per 10,000 live births and exhibited an excellent prognosis. Nonsurgical, nonobstetrical infections encompassed a broad range of infectious syndromes (case-fatality rate, 37%). Nine percent of cases were associated with in-hospital transmission. Transmission occurred from 3 of 142 patients with community-acquired cases of necrotizing fasciitis requiring intensive care unit (ICU) admission, compared with 1 of 367 patients with community-acquired cases without necrotizing fasciitis admitted to the ICU and 1 of 1551 patients with other cases (P
- Published
- 2004
13. Socio-economic status and surgery in children: myringotomies and tonsillectomies in Ontario, Canada, 1996-2000
- Author
-
R, Croxford, J, Friedberg, and P C, Coyte
- Subjects
Male ,Ontario ,Tympanic Membrane ,Adolescent ,Middle Ear Ventilation ,Health Services Accessibility ,Adenoidectomy ,Otitis Media ,Social Class ,Child, Preschool ,Humans ,Female ,Child ,Tonsillectomy - Abstract
To examine the relation between socio-economic status and (1) receipt of paediatric otolaryngological surgery, and (2) inclusion of adjuvant procedures.Using data on myringotomies with insertion of tympanostomy tube and tonsillectomies for all children in Ontario, Canada, from 1996 to 2000, and census data on socio-economic status, we examined the association between socio-economic status and (1) the probability of surgery (myringotomy or tonsillectomy), and (2) the probability that surgery was accompanied by an adjuvant procedure.Lower socio-economic status was associated with increased likelihood that a child's initial surgery was a tonsillectomy rather than a myringotomy (odds ratio per unit increase in the deprivation index = 1.09, p = 0.01, confidence interval 1.06-1.11), and with increased likelihood that those children having a myringotomy would undergo a tonsillectomy during the same hospitalization (odds ratio 1.14, p0.0001, confidence interval 1.11-1.16). Children from neighbourhoods with larger immigrant populations were less likely to receive either procedure (odds ratios per 1% increase in the proportion of immigrants = 0.97 (p0.0001, confidence interval 0.96-0.97) for myringotomies and 0.97 (p0.0001, confidence interval 0.97-0.98) for tonsillectomies).Socio-economic status was associated with treatment selection for the two most common paediatric surgical procedures. Further research should examine whether differences in treatment arise at the level of the primary care physician, the specialist, and/or are due to parental preference.
- Published
- 2004
14. 337 PATTERNS OF POPULATION USE OF TOTAL JOINT ARTHROPLASTY: FOCUS ON OUTCOMES FOLLOWING A SINGLE PRIMARY TJA IS TOO NARROW
- Author
-
G.A. Hawker and R. Croxford
- Subjects
medicine.medical_specialty ,Focus (computing) ,education.field_of_study ,Joint arthroplasty ,Rheumatology ,business.industry ,Population ,Physical therapy ,Biomedical Engineering ,Medicine ,Orthopedics and Sports Medicine ,business ,education - Published
- 2011
- Full Text
- View/download PDF
15. Expression of p210 and p190 BCR-ABL due to alternative splicing in chronic myelogenous leukaemia
- Author
-
B D, Lichty, A, Keating, J, Callum, K, Yee, R, Croxford, G, Corpus, B, Nwachukwu, P, Kim, J, Guo, and S, Kamel-Reid
- Subjects
Adult ,Aged, 80 and over ,Adolescent ,Reverse Transcriptase Polymerase Chain Reaction ,Fusion Proteins, bcr-abl ,Gene Expression ,Middle Aged ,Alternative Splicing ,Child, Preschool ,Leukemia, Myelogenous, Chronic, BCR-ABL Positive ,Humans ,RNA, Neoplasm ,Child ,Aged - Abstract
The hallmark of chronic myelogenous leukaemia (CML) is the presence of the Philadelphia chromosome and its resultant fusion message, BCR-ABL, and fusion protein, p210. Patients with CML in blast crisis, or with Philadelphia positive acute lymphoblastic leukaemia (ALL), can have a smaller BCR-ABL fusion transcript possessing only the first exon of BCR fused to ABL. This smaller transcript encodes a 190 kD protein which is more strongly transforming than the p210 protein derived from the larger CML-associated transcript. We performed RT-PCR on samples from CML patients in chronic phase to determine the frequency and mechanism of p190 and p210 co-expression and to see if this correlated with clinical indices. We examined the peripheral blood or marrow of 67 patients with CML and found that 35 of them expressed both transcripts whereas the remainder expressed the p210-encoding transcript exclusively. Additional PCR products of an intermediate size were also frequently detected and have been isolated and sequenced. Data from two of these products indicate that they are the result of alternative splicing and include variable combinations of BCR exons. We believe that the expression of the p190-encoding transcript in the chronic phase of CML is also due to alternative splicing. A comparison of patients co-expressing the p190- and p210-encoding transcripts with those patients who expressed only the p210-encoding transcript detected significantly higher white blood cell (WBC) counts and blast cell counts at time of testing as well as significantly higher white blood cell counts at diagnosis.
- Published
- 1998
16. Health-related quality of life after knee replacement
- Author
-
G, Hawker, J, Wright, P, Coyte, J, Paul, R, Dittus, R, Croxford, B, Katz, C, Bombardier, D, Heck, and D, Freund
- Subjects
Aged, 80 and over ,Male ,Reoperation ,Cross-Sectional Studies ,Treatment Outcome ,Socioeconomic Factors ,Patient Satisfaction ,Health Status ,Quality of Life ,Humans ,Female ,Arthroplasty, Replacement, Knee ,Aged - Abstract
A cross-sectional, community-based survey of a random sample of 1750 of 242,311 Medicare recipients was performed. The patients were at least sixty-five years old and had had a primary or revision knee replacement (either unilaterally or bilaterally) between 1985 and 1989. Three samples were surveyed separately: a national sample (to reflect the United States as a whole) and samples from Indiana and the western part of Pennsylvania (sites chosen for convenience to assess the validity of the findings for the national sample on a regional level). Each sample was stratified by race, age, residence (urban or rural), and the year of the procedure. Valid and reliable questionnaires were used to elicit the participants' assessments of pain, physical function, and satisfaction two to seven years after the knee replacement. Of the 1486 patients who were eligible for inclusion in the survey, 1193 (80.3 per cent) responded. The mean age of the respondents was 72.6 years. Eight hundred and forty-nine respondents (71.2 per cent) were white, and 849 (71.2 per cent) were women. The participants reported that they had little or no pain in the knee at the time of the survey, regardless of the age at the time of the knee replacement, the body-mass index, or the length of time since the knee replacement. After adjustment for potential confounding variables, predictors of better physical function after the replacement were an absence of problems with the contralateral knee, primary knee replacement (rather than revision) (Indiana sample only), and a lower body-mass index (Indiana and western Pennsylvania samples). Four hundred and fifteen (85.2 per cent) of the 487 patients in the national sample were satisfied with the result of the knee replacement. In what we believe to be the first community-based study of the outcome of knee replacement, patients reported having significant (p = 0.0001) and persistent relief of pain, improved physical function, and satisfaction with the result two to seven years postoperatively. The findings of the present study suggest that age and obesity do not have a negative impact on patient-relevant outcomes (pain and physical function). Dissemination of these findings has the potential to increase appropriate referrals for knee replacement and thereby reduce the pain and functional disability due to osteoarthrosis of the knee.
- Published
- 1998
17. Variation in rheumatologists' and family physicians' perceptions of the indications for and outcomes of knee replacement surgery
- Author
-
P C, Coyte, G, Hawker, R, Croxford, C, Attard, and J G, Wright
- Subjects
Adult ,Observer Variation ,Treatment Outcome ,Knee Joint ,Rheumatology ,Osteoarthritis ,Humans ,Practice Patterns, Physicians' ,Family Practice ,Knee Prosthesis ,Retrospective Studies - Abstract
To assess agreement among rheumatologists and family physicians (FP) about the indications for knee replacement (KR) referral, use of nonsurgical management options, and perceived outcomes of KR, and to determine the relationship between these opinions and the number of patients seen with severe osteoarthritis (OA) of the knee.98 adult rheumatologists and a random sample of 250 FP in Ontario, Canada were surveyed. Of the practising and traceable rheumatologists and FP, 70.0 and 5.16% responded, respectively.FP disagreed on how 28 of 32 patient factors affected their KR referral decision, while rheumatologists disagreed on 26 of these 32 factors (p = 0.03). Rheumatologists and FP consistently disagreed on the use of 8 of 10 treatments for knee OA (p = 0.37). While rheumatologists and FP reported similar KR outcomes, FP were less in agreement (p = 0.03). Clinical disagreement for the indications for KR (p0.0001) and KR outcomes (p0.0001) were greater among FP than among orthopedic surgeons who were surveyed in a prior study. Clinical disagreement about the indications for KR was greater among rheumatologists than among surgeons (p = 0.04), but there was no difference in perceived KR incomes (p = 0.18).Referring physicians disagreed on the indications for KR referral an on the treatments for knee arthritis, but were in general agreement regarding KR outcomes. Clinical disagreement was greater among FP than among rheumatologists, who in turn reported more disagreement than orthopedic surgeons. Explanations for these difference in perceptions should be the focus of research, but guidelines specifically tailored for each physician specialty may be required to reduce clinical uncertainty.
- Published
- 1996
18. Risk factors in elective laparoscopic cholecystectomy for conversion to open cholecystectomy
- Author
-
J R, Sanabria, S, Gallinger, R, Croxford, and S M, Strasberg
- Subjects
Adult ,Male ,Patients ,Decision Trees ,Age Factors ,Gallbladder Diseases ,Middle Aged ,Severity of Illness Index ,Postoperative Complications ,Cholecystectomy, Laparoscopic ,Predictive Value of Tests ,Risk Factors ,Humans ,Cholecystectomy ,Female - Abstract
Most cholecystectomies can be performed using a laparoscopic approach. However, 3 to 10 percent of laparoscopic cholecystectomies (LC) must be converted to open cholecystectomies (OC) and preoperative factors that predict risk for conversion are still not defined.Preoperative and intraoperative data were collected and analyzed from 628 patients who were scheduled for elective LC by two surgeons in an academic institution. Logistic regression was performed on data from two groups of patients: LC completed, 596 patients (95 percent) and LC converted, 32 patients (5 percent).Elective LC was accomplished with no common bile duct injuries, low morbidity rate (7.3 percent), and zero mortality rate. Both patient and surgeon factors predicted conversion from LC to OC. Older patients (65 years of age or older, (p0.01), males (p0.01), and patients with multiple attacks (ten or more) of biliary colic (p0.01), or a documented history of acute cholecystitis (p0.01) had a greater risk for conversion. Both surgeons had higher rates of conversion (p0.05) during the learning phase (fewer than 50 LC) of their experience.Risk factors for conversion may be predicted and awareness of these factors should help in the selection of the appropriate procedure for patients and in selection of cases for resident training.
- Published
- 1994
19. Portal-enteric Pancreas Transplantation: A More Physiologic Approach
- Author
-
A. Carpentier, Alan W. Hemming, Paul D. Greig, Dave L. Bigam, M. S. Cattral, J. Karpinsky, R. Croxford, Linda Wright, and Juan Ramon Sanabria
- Subjects
Transplantation ,Pathology ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,medicine ,Pancreas transplantation ,business - Published
- 1999
- Full Text
- View/download PDF
20. The economic burden of disabling hip and knee osteoarthritis (OA) from the perspective of individuals living with this condition.
- Author
-
S. Gupta, G. A. Hawker, A. Laporte, R. Croxford, and P. C. Coyte
- Published
- 2005
- Full Text
- View/download PDF
21. Reducing vascular access morbidity: a comparative trial of two vascular access monitoring strategies.
- Author
-
C.E. Lok, C. Bhola, R. Croxford, and R.M.A. Richardson
- Subjects
THROMBOSIS ,FISTULA ,ARTERIAL catheterization - Abstract
Background. Thrombosis is the primary cause of access failure in polytetrafluoroethylene grafts and arteriovenous fistulas. It can lead to significant patient and access morbidity and mortality, and is difficult to prevent medically. Intervention is largely limited to maximizing access patency by detecting culprit lesions early and intervening with angioplasty or surgical revision. The most efficacious monitoring strategy is undetermined. Methods. This 3 year prospective study took advantage of a change in monitoring strategy used in a large dialysis centre to compare the efficacy of two methods used to monitor grafts and fistulas in order to prevent access thrombosis. Accesses were monitored using Duplex ultrasonography in year 1, while the saline ultrasound dilution technique (Transonic) became the primary monitoring strategy in year 3 (year 2 was a transition year). Risk factors for thrombosis were determined using multivariate survival analysis, and the performance of Duplex ultrasonography and Transonic monitoring was assessed. Results. A total of 303 656 access days at risk were assessed, with 344, 385 and 425 accesses in years 1, 2 and 3, respectively. The total thrombosis rate was 1.01/1000 access days in year 1 compared with 0.66/1000 access days in year 3. This was accomplished despite a reduction in procedure rates of 55% for angiograms, 13% for angioplasties and 31% for thrombolysis. Conclusion. Low flow rates detected using Transonic monitoring were associated with increased thrombosis, while stenosis detected using Duplex ultrasonography was not a strong predictor of incipient thrombosis; however, these different access characteristics were compared using monitoring techniques that may be ideal in different clinical situations. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
22. Bromocriptine suppression of dispersed pituitary lactotrophs from estrogen-pretreated rats: a quantitative electron microscopic study
- Author
-
K. Kovacs, John V. Milligan, R. Croxford, and D. J. McComb
- Subjects
Male ,medicine.medical_specialty ,Physiology ,medicine.drug_class ,Cytoplasmic Granules ,Cell morphology ,Prolactin cell ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Incubation ,Bromocriptine ,Cell Nucleus ,Pharmacology ,Hyperplasia ,Chemistry ,Granule (cell biology) ,Estrogens ,General Medicine ,Prolactin ,Rats ,Pituitary Hormones ,Endocrinology ,Estrogen ,Pituitary Gland ,Ultrastructure ,medicine.drug - Abstract
Dispersed rat lactotrophs were treated with bromocriptine (10−10 M) for either 30 min or 3 h to investigate its effect on cell morphology using light and electron microscopy and ultrastructural morphometry. After 30 min, lactotrophs treated with bromocriptine exhibited an increase in storage granule size (p < 0.05). Crinophagy was also evident and a significant increase in lysosome volume density was observed (p < 0.001). However, no significant change in prolactin content in the media was detected until 3 h of incubation in bromocriptine (p < 0.05). At this time a nonsignificant decrease in Golgi region volume density was also observed.
- Published
- 1982
- Full Text
- View/download PDF
23. Opiate-seeking behavior under conditions of methadone detoxification and removal
- Author
-
G. Singer, J. Jethwa, C. Madden, J. Jagoda, and R. Croxford
- Subjects
Adult ,Male ,business.industry ,Heroin Dependence ,Conditioning, Classical ,Medicine (miscellaneous) ,Self Administration ,medicine.disease ,Substance abuse ,Detoxification ,Anesthesia ,Medicine ,Humans ,Female ,Opiate ,business ,Methadone ,medicine.drug - Abstract
This study was carried out to determine whether heroin-dependent persons, having completed methadone detoxification, can be maintained on an inert substance which has previously been associated with methadone. Forty heroin-dependent men and women were randomly allocated to either a “standard detoxification” group or a cordial sub-stitution group. Results showed that subjects administered methadone-associated cordial after methadone detoxification could not be retained at the clinic for a time significantly beyond that of subjects in the standard detoxification group despite the inability of the subjects to accurately estimate methadone dosage. The role of cognitive factors is discussed.
- Published
- 1986
24. Some functional and morphological characteristics of an acutely dispersed purified cell suspension of rat lactotrophs prepared with Percoll
- Author
-
D. J. McComb, R. Croxford, N. Ryan, and John V. Milligan
- Subjects
Pharmacology ,Male ,endocrine system ,Chromatography ,Physiology ,General Medicine ,Cell Separation ,Biology ,Centrifugation, Isopycnic ,Suspension culture ,Prolactin ,Rats ,Prolactin cell ,Immunoenzyme Techniques ,Microscopy, Electron ,Adrenocorticotropic Hormone ,Pituitary Gland, Anterior ,Physiology (medical) ,Growth Hormone ,Male rats ,Animals ,Percoll ,Thyrotropin-Releasing Hormone - Abstract
A cell suspension containing more than 90% lactotrophs can be prepared from enzymically dispersed adenohypophyses obtained from male rats pretreated with estradiol. The lactotrophs are separated from the mixed cell population by centrifugation on a discontinuous density gradient prepared from a commercial preparation of colloidal silica (Percoll, Pharmacia). The method allows isopycnic separation of these delicate cells under very mild conditions; normal ionic strength and normal pH were maintained throughout the gradient, centrifugal acceleration did not exceed 1600 × g, and all procedures were done at room temperature. Histological verification that at least 90% of the cells were lactotrophs was done using specific immunoperoxidase staining. The functional capability of the lactotrophs was established by measuring the dose–response to the dopamine agonist bromocriptine and to thyrotropin-releasing hormone (TRH). Bromocriptine decreased spontaneous release in a dose-related way over the concentration range of 10−10 to 10−8 M. TRH, which causes an in vivo release of prolactin (PRL) in estrogen-primed rats, produced a dose-related increase in the release of PRL over the concentration range of 3 × 10−10 to 3 × 10−8 M after the high spontaneous release had been previously reduced by bromocriptine (3 × 10−8 M).
- Published
- 1982
25. Electric strength of liquid-filled plastics tape insulation
- Author
-
R. Croxford
- Subjects
Electric strength ,Materials science ,Composite number ,General Engineering ,Insulator (electricity) ,General Medicine ,Dielectric ,Impulse (physics) ,Silicone oil ,chemistry.chemical_compound ,chemistry ,medicine ,Composite material ,Mineral oil ,medicine.drug - Abstract
The paper describes electrical-breakdown experiments performed on thin, flat packs of plastics film impregnated with mixtures of dielectric liquids of different composition. Using this technique, it is possible to distinguish the direct effect of the ratio of the liquid and solid relative permittivities on the electric strength of the composite from the characteristics of particular materials. It is shown that the impulse electric strength of the composite depends only on the stress in the liquid at the breakdown site and its electric strength, but, for mineral oil or silicone oil alone, the composite may have a considerably greater electric strength than expected on this basis. The magnitude of the increase is governed by the solid.
- Published
- 1973
- Full Text
- View/download PDF
26. Analogue of cylindrically symmetric fields using teledeltos paper
- Author
-
R. Croxford
- Subjects
Engineering ,business.industry ,General Engineering ,Electrical engineering ,General Medicine ,business ,Teledeltos - Published
- 1967
- Full Text
- View/download PDF
27. Opioid toxicity deaths in Indigenous people who experienced incarceration in Ontario, Canada 2015-2020: a whole population retrospective cohort study.
- Author
-
Butsang T, Owl N, Butler A, Sabourin H, Croxford R, Gislason L, and Kouyoumdjian FG
- Abstract
Background: While Indigenous people are overrepresented in Canada's prisons and in the toxic drug supply crisis, we lack data on the harms related to opioids for Indigenous people with experiences of incarceration. We aimed to examine opioid toxicity deaths in Indigenous peoples who experienced incarceration and to compare opioid toxicity mortality rates with rates for people with no incarceration., Methods: This retrospective cohort study linked correctional data for all people who were incarcerated in provincial correctional facilities and coronial data for all people who died from opioid toxicity in Ontario, Canada between 2015 and 2020. We calculated opioid mortality rates for Indigenous people who experienced incarceration and for people who did not experience incarceration using publicly available population data and calculated age-standardized mortality rates for Indigenous and non-Indigenous people who experienced incarceration compared with people who did not experience incarceration., Findings: Of 14,885 Indigenous people who experienced incarceration, 2% (N = 242) died from opioid toxicity in custody or post-release, representing 2.9% of all opioid toxicity deaths in Ontario during this period. The crude opioid toxicity mortality rate per 100 person-years was 0.53 for Indigenous females and 0.36 for Indigenous males who experienced incarceration, compared with 0.0060 for females and 0.0132 for males who did not experience incarceration. Rates of opioid toxicity death were highest in the month post-release for Indigenous people who experienced incarceration, at 1.13 per 100 person-years. Standardized for age and compared with people with no incarceration, the mortality ratio was 81.0 (95% CI 62.1-100.0) for Indigenous females who experienced incarceration and 23.6 (95% CI 20.1-27.1) for Indigenous males who experienced incarceration. The SMRs for Indigenous and non-Indigenous females who experienced incarceration were not significantly different, at 81.0 compared with 76.4, and were significantly different for Indigenous and non-Indigenous males who experienced incarceration, at 23.6 compared with 28.5., Interpretation: This whole-population study identified a substantial and inequitable burden of opioid toxicity death for Indigenous people who experienced incarceration, similar to the burden for non-Indigenous people who experienced incarceration. The large burden is particularly concerning in the context of the overrepresentation of Indigenous people in correctional facilities. Focus is warranted to prevent substance use harms for Indigenous people, including through community- and custody-based interventions to support health., Funding: Canadian Institutes of Health Research through the Canadian Research Initiative in Substance Misuse (SMN-139150 and REN-181677)., Competing Interests: We declare no competing interests., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
28. Mixed nontuberculous mycobacteria in an immunocompromised patient with probable progressive multifocal leukoencephalopathy.
- Author
-
Opperman C, Scott J, Steyn J, Singh S, Ghebrekristos Y, Croxford R, Warren R, Esmail A, Ghielmetti G, and Goosen W
- Abstract
Objectives: Nontuberculous mycobacteria (NTM) are increasingly recognized opportunistic pathogens found ubiquitously in the environment. The presence of multiple NTM species at the site of disease complicates diagnosis and treatment., Case and Management: A 40-year-old patient who tested positive for HIV, with an absolute clusters of differentiation 4+ T-cell count of 3 cells/µl and cryptococcaemia, presented with hemoptysis, productive cough, and weight loss. Mixed NTM species, including Mycobacterium kansasii and Mycobacterium chelonae, were detected by the GenoType Mycobacterium Common Mycobacteria line probe assay from respiratory specimens, with Mycobacterium avium bacteremia also identified in the same month. An empirical regimen of azithromycin, ethambutol, isoniazid, and rifabutin was initiated to address recurrent positive cultures with M. kansasii and the NTM bacteremia. Despite this treatment, the patient experienced neurologic deterioration, was diagnosed with probable progressive multifocal leukoencephalopathy, and subsequently died., Additional Investigation: Advanced diagnostic techniques, including Sanger sequencing, Deeplex Myc-TB in combination with short-read next-generation sequencing, and targeted amplicon-based Oxford Nanopore Technologies long-read sequencing, revealed the presence of mixed NTM species in two retrospective stored cultures, with variations in primer binding affinity among the M. kansasii and M. avium ., Conclusion: This case highlights the individualized considerations required to manage a patient with mixed NTM infection and the need for multi-target diagnostic approaches., Competing Interests: The authors have no competing interest to declare., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
29. Impact of the coronavirus disease 2019 pandemic on equity of access to hip and knee replacements: a population-level study.
- Author
-
Ekhtiari S, Pincus D, Croxford R, Gatley JM, Khoshbin A, Atrey A, Paterson JM, and Ravi B
- Subjects
- Humans, Pandemics, Health Services Accessibility, COVID-19 epidemiology, Arthroplasty, Replacement, Knee, Arthroplasty, Replacement, Hip
- Abstract
Purpose: The COVID-19 pandemic had innumerable impacts on healthcare delivery. In Canada, this included limitations on inpatient capacity, which resulted in an increased focus on outpatient surgery for non-emergent cases such as joint replacements. The objective of this study was to assess whether the pandemic and the shift towards outpatient surgery had an impact on access to joint replacement for marginalized patients., Methods: Data from Ontario's administrative healthcare databases were obtained for all patients undergoing an elective hip or knee replacement between January 1, 2018 and August 31, 2021. All surgeries performed before March 15, 2020 were classified as "pre-COVID," while all procedures performed after that date were classified as "post-COVID." The Ontario Marginalization Index domains were used to analyze proportion of marginalized patients undergoing surgery pre- and post-COVID., Results: A total of 102,743 patients were included-42,812 hip replacements and 59,931 knee replacements. There was a significant shift towards outpatient surgery during the post-COVID period (1.1% of all cases pre-COVID to 13.2% post-COVID, p < 0.001). In the post-COVID cohort, there were significantly fewer patients from some marginalized groups, as well as fewer patients with certain co-morbidities, such as congestive heart failure and chronic obstructive pulmonary disease., Conclusion: The most important finding of this population-level database study is that, compared to before the COVID-19 pandemic, there has been a change in the profile of patients undergoing hip and knee replacements in Ontario, specifically across a range of indicators. Fewer marginalized patients are undergoing joint replacement surgery since the COVID-19 pandemic. Further monitoring of access to joint replacement surgery is required in order to ensure that surgery is provided to those who are most in need., (© 2023. The Author(s) under exclusive licence to SICOT aisbl.)
- Published
- 2024
- Full Text
- View/download PDF
30. Opioid toxicity deaths in Black persons who experienced provincial incarceration in Ontario, Canada 2015-2020: A population-based study.
- Author
-
Owusu-Bempah A, Nicholson HL Jr, Butler A, Croxford R, and Kouyoumdjian FG
- Subjects
- Humans, Analgesics, Opioid adverse effects, Ontario epidemiology, Prisons, Prisoners, Opioid-Related Disorders epidemiology
- Abstract
Objective: In the context of mass incarceration and the opioid toxicity crisis in North America, there is a lack of data on the burden of opioid toxicity deaths in Black persons who experience incarceration. We aimed to describe absolute and relative opioid toxicity mortality for Black persons who experienced incarceration in Ontario, Canada between 2015 and 2020., Methods: We linked data for all persons incarcerated in provincial correctional facilities and all persons who died from opioid toxicity in Ontario between 2015 and 2020, and accessed public data on population sizes. We described the characteristics of Black persons who were incarcerated and died from opioid toxicity, and calculated absolute mortality rates, as well as age-standardized mortality rates compared with all persons in Ontario not incarcerated during this period., Results: Between 2015 and 2020, 0.9% (n = 137) of 16,177 Black persons who experienced incarceration died from opioid toxicity in custody or post-release, for an opioid toxicity death rate of 0.207 per 100 person years. In the two weeks post-release, the opioid toxicity death rate was 1.34 per 100 person years. Standardized for age and compared with persons not incarcerated, the mortality ratio (SMR) was 17.8 (95%CI 16.4-23.1) for Black persons who experienced incarceration., Conclusions: We identified a large, inequitable burden of opioid toxicity death for Black persons who experience incarceration in Ontario, Canada. Work is needed to support access to culturally appropriate prevention and treatment in custody and post-release for persons who are Black, and to prevent incarceration and improve determinants of health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
31. The impact of COVID-19 on opioid toxicity deaths for people who experience incarceration compared to the general population in Ontario: A whole population data linkage study.
- Author
-
Butler A, Croxford R, McLeod KE, Gomes T, Orkin AM, Bondy SJ, and Kouyoumdjian FG
- Subjects
- Male, Female, Humans, Analgesics, Opioid adverse effects, Ontario epidemiology, Retrospective Studies, Pandemics, Correctional Facilities, Opioid-Related Disorders epidemiology, Prisoners, COVID-19 epidemiology
- Abstract
Background: To inform preparedness and population health action, we need to understand the effects of COVID-19 on health inequities. In this study, we assess the impact of COVID-19 on opioid toxicity deaths among people who experience incarceration compared to others in the general population in Ontario, Canada., Methods: We conducted a retrospective cohort study for the period of January 1, 2015 to December 31, 2020. We accessed and linked coronial data on all opioid toxicity deaths in Ontario with correctional data for people aged 18 years and older who were incarcerated in a provincial correctional facility. We used data from the Statistics Canada Census to calculate whole population rates. We used an interrupted time series design and segmented regression to assess for change in the level or rate of increase in deaths due to opioid toxicity coinciding with the COVID-19 pandemic. We compared the impact of COVID-19 on the opioid toxicity death rates for people exposed and not exposed to incarceration., Results: Rates of opioid toxicity death increased with a linear positive slope in both persons exposed to incarceration and those not exposed over the study period. The start of COVID-19 measures coincided with a marked upward shift in the trend lines with modification of the effect of COVID-19 by both sex and exposure to incarceration. For persons exposed to incarceration, the risk ratio (RR) was 1.50 (95%CI 1.35-1.69) for males and 1.21 (95%CI 1.06-1.42) for females, and for persons not exposed to incarceration, the RR was 1.25 (95%CI 1.13-1.38) for males and not significant for females., Conclusions: COVID-19 substantially exacerbated the risk of opioid toxicity death, impacting males and females who experienced incarceration more than those who had not, with an immediate stepwise increase in risk but no change in the rate of increase of risk over time. Public health work, including pandemic preparedness, should consider the specific needs and circumstances of people who experience incarceration., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Butler et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
- Full Text
- View/download PDF
32. Health status and health-care utilization among men recently released from a superjail: a matched prospective cohort study.
- Author
-
Matheson FI, McLuhan A, Croxford R, Hahmann T, Ferguson M, and Mejia-Lancheros C
- Subjects
- Adult, Male, Humans, Prospective Studies, Canada, Medical Records, Patient Acceptance of Health Care, Health Status
- Abstract
Purpose: Continuity of care and access to primary care have been identified as important contributors to improved health outcomes and reduced reincarceration among people who are justice-involved. While the disproportionate burden of health concerns among incarcerated populations is well documented, less is known about their health service utilization, limiting the potential for effective improvements to current policy and practice. This study aims to examine health status and health care utilization among men recently released from a superjail in a large metropolitan area to better understand patterns of use, risk factors and facilitators., Design/methodology/approach: Participants included adult men (n = 106) matched to a general population group (n = 530) in Ontario, Canada, linked to medical records (88.5% linkage) to examine baseline health status and health utilization three-months post-release. The authors compared differences between the groups in baseline health conditions and estimated the risk of emergency department, primary care, inpatient hospitalization and specialist ambulatory care visits., Findings: Superjail participants had a significantly higher prevalence of respiratory conditions, mental illness, substance use and injuries. Substance use was a significant risk factor for all types of visits and emergency department visits were over three times higher among superjail participants., Originality/value: This empirical case is illustrative of an emerging phenomenon in some regions of the world where emergency departments serve as de facto "walk-in clinics" for those with criminal justice involvement. Strategic approaches to health services are required to meet the complex social and health needs and disparities in access to care experienced by men released from custody., (© Emerald Publishing Limited.)
- Published
- 2023
- Full Text
- View/download PDF
33. Quantifying COPD as a risk factor for cardiac disease in a primary prevention cohort.
- Author
-
Maclagan LC, Croxford R, Chu A, Sin DD, Udell JA, Lee DS, Austin PC, and Gershon AS
- Subjects
- Humans, Cohort Studies, Retrospective Studies, Risk Factors, Primary Prevention, Ontario epidemiology, Cardiovascular Diseases complications, Cardiovascular Diseases epidemiology, Cardiovascular Diseases diagnosis, Myocardial Infarction epidemiology, Pulmonary Disease, Chronic Obstructive complications, Pulmonary Disease, Chronic Obstructive epidemiology
- Abstract
Background: Despite COPD being a risk factor for cardiovascular disease (CVD) and knowing that risk stratification for CVD primary prevention is important, little is known about the real-world risk of CVD among people with COPD with no history of CVD. This knowledge would inform CVD management for people with COPD. The current study aimed to examine the risk of major adverse cardiovascular events (MACE) (including acute myocardial infarction, stroke or cardiovascular death) in a large, complete real-world population with COPD without previous CVD., Methods: We conducted a retrospective population cohort study using health administrative, medication, laboratory, electronic medical record and other data from Ontario, Canada. People without a history of CVD with and without physician-diagnosed COPD were followed between 2008 and 2016, and cardiac risk factors and comorbidities compared. Sequential cause-specific hazard models adjusting for these factors determined the risk of MACE in people with COPD., Results: Among ∼5.8 million individuals in Ontario aged ≥40 years without CVD, 152 125 had COPD. After adjustment for cardiovascular risk factors, comorbidities and other variables, the rate of MACE was 25% higher in persons with COPD compared with those without COPD (hazard ratio 1.25, 95% CI 1.23-1.27)., Conclusions: In a large real-world population without CVD, people with physician-diagnosed COPD were 25% more likely to have a major CVD event, after adjustment for CVD risk and other factors. This rate is comparable to the rate in people with diabetes and calls for more aggressive CVD primary prevention in the COPD population., Competing Interests: Conflict of interest: D.D. Sin reports having received small honoraria from GSK, AstraZeneca and Boehringer Ingelheim, and is Deputy Chief Editor of the European Respiratory Journal. A.S. Gershon is on the Editorial Board of the European Respiratory Journal. All other authors have nothing to disclose., (Copyright ©The authors 2023. For reproduction rights and permissions contact permissions@ersnet.org.)
- Published
- 2023
- Full Text
- View/download PDF
34. Severe efavirenz associated neurotoxicity: A retrospective cohort study.
- Author
-
Arnab P, Croxford R, Scott J, Perumal S, Mohammed Z, Wiesner L, Cohen K, and Wasserman S
- Abstract
Background: Efavirenz (EFV) is associated with neuropsychiatric symptoms. Severe neurotoxicity has been reported but the clinical phenotype and risk factors are poorly defined., Objectives: To characterise clinical presentations, risk factors and outcomes to help clinicians recognise severe neurotoxicity earlier., Method: The authors retrospectively identified adults with supratherapeutic EFV concentrations (> 4 mg/L) obtained during routine clinical care in Cape Town, South Africa. Clinical and laboratory data at the time of EFV quantification were extracted from medical records. Logistic regression was performed to identify associations with neuropsychiatric symptoms, and with severe neurotoxicity., Results: Eighty one patients were included; 62 with neuropsychiatric manifestations (most frequently ataxia [ n = 20] and psychomotor slowing [ n = 24]); and 19 with hepatotoxicity. Overall, 28 (34.6%) were male, 49 (60.5%) had concomitant isoniazid exposure, and median EFV concentration was 12.1 mg/L (interquartile range [IQR]: 6.6-20.0). Neuropsychiatric symptoms were associated with longer duration of EFV therapy, adjusted odds ratio (aOR) 1.3/180-day increment (95% confidence interval [CI]: 1.0-1.7); higher EFV concentrations, aOR 1.2/1 mg/L increase (95% CI: 1.0-1.4) and isoniazid exposure, aOR 8.2 (95% CI: 2.5-26.7). Severe neuropsychiatric symptoms occurred in 47 (75%) patients at a median of 5.9 months (IQR: 2.1-40.8) after EFV initiation. Severe symptoms odds were 1.2-fold higher (95% CI: 1.1-1.4) per 1 mg/L increase in EFV concentration. Symptoms resolved completely within 1 month in 25 (76%) patients with severe neurotoxicity who discontinued EFV., Conclusion: A concentration-effect relationship for severe neurotoxicity exists, which occurred late and resolved in most patients after EFV discontinuation., Contribution: The authors highlighted clinical heterogeneity and morbidity of EFV-associated neurotoxicity., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article., (© 2023. The Authors.)
- Published
- 2023
- Full Text
- View/download PDF
35. Radiotherapy planning of spine and pelvis using single-energy metal artifact reduction corrected computed tomography sets.
- Author
-
Ignatius D, Alkhatib Z, Rowshanfarzad P, Goodall S, Ibrahim M, Hirst A, Croxford R, Dass J, and Sabet M
- Abstract
Metal artifacts produce incorrect Hounsfield units and impact treatment planning accuracy. This work evaluates the use of single-energy metal artifact reduction (SEMAR) algorithm for treatment planning by comparison to manual artifact overriding. CT datasets of in-house 3D-printed spine and pelvic phantoms with and without metal insert(s) and two treated patients with metal implants were analysed. CT number accuracy improved with the use of SEMAR filter: root mean square deviation (RMSD) from reference (without metal) reduced by 35.4 in spine and 98.8 in hip. The plan dose volume histograms (DVHs) and dosimetric measurements showed comparable results. SEMAR reconstruction improved planning efficiency., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023 Published by Elsevier B.V. on behalf of European Society of Radiotherapy & Oncology.)
- Published
- 2023
- Full Text
- View/download PDF
36. Cost-effectiveness of second-line ipilimumab for metastatic melanoma: A real-world population-based cohort study of resource utilization.
- Author
-
Lu B, Dai WF, Croxford R, Isaranuwatchai W, Beca J, Menjak IB, Petrella TM, Mittmann N, Earle CC, Gavura S, Mercer RE, Hanna TP, and Chan KKW
- Subjects
- Humans, Ipilimumab, Cost-Benefit Analysis, Retrospective Studies, Cohort Studies, Ontario epidemiology, Quality of Life, Melanoma drug therapy, Melanoma pathology
- Abstract
Background: The efficacy-effectiveness gap between randomized trial and real-world evidence regarding the clinical benefit of ipilimumab for metastatic melanoma (MM) has been well characterized by previous literature, consistent with initial concerns raised by health technology assessment agencies (HTAs). As these differences can significantly impact cost-effectiveness, it is critical to assess the real-world cost-effectiveness of second-line ipilimumab versus non-ipilimumab treatments for MM., Methods: This was a population-based retrospective cohort study of patients who received second-line non-ipilimumab therapies between 2008 and 2012 versus ipilimumab treatment between 2012 and 2015 (after public reimbursement) for MM in Ontario. Using a 5-year time horizon, censor-adjusted and discounted (1.5%) costs (from the public payer's perspective in Canadian dollars) and effectiveness were used to calculate incremental cost-effectiveness ratios (ICERs) in life-years gained (LYGs) and quality-adjusted life years (QALYs), with bootstrapping to capture uncertainty. Varying the discount rate and reducing the price of ipilimumab were done as sensitivity analyses., Results: In total, 329 MM were identified (Treated: 189; Controls: 140). Ipilimumab was associated with an incremental effectiveness of 0.59 LYG, incremental cost of $91,233, and ICER of $153,778/LYG. ICERs were not sensitive to discounting rate. Adjusting for quality of life using utility weights resulted in an ICER of $225,885/QALY, confirming the original HTA estimate prior to public reimbursement. Reducing the price of ipilimumab by 100% resulted in an ICER of $111,728/QALY., Conclusion: Despite its clinical benefit, ipilimumab as second-line monotherapy for MM patients is not cost-effective in the real world as projected by HTA under conventional willingness-to-pay thresholds., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)
- Published
- 2023
- Full Text
- View/download PDF
37. Investigating Associations Between Access to Rheumatology Care, Treatment, Continuous Care, and Healthcare Utilization and Costs Among Older Individuals With Rheumatoid Arthritis.
- Author
-
Barber CEH, Lacaille D, Croxford R, Barnabe C, Marshall DA, Abrahamowicz M, Xie H, Aviña-Zubieta JA, Esdaile JM, Hazlewood GS, Faris P, Katz S, MacMullan P, Mosher D, and Widdifield J
- Subjects
- Humans, Female, Aged, Male, Delivery of Health Care, Patient Acceptance of Health Care, Ontario, Rheumatology, Arthritis, Rheumatoid drug therapy
- Abstract
Objective: To examine the association between rheumatologist access, early treatment, and ongoing care of older-onset rheumatoid arthritis (RA) and healthcare utilization and costs following diagnosis., Methods: We analyzed data from a population-based inception cohort of individuals aged > 65 years with RA in Ontario, Canada, diagnosed between 2002 and 2014 with follow-up to 2019. We assessed 4 performance measures in the first 4 years following diagnosis, including access to rheumatology care, yearly follow-up, timely treatment, and ongoing treatment with a disease-modifying antirheumatic drug. We examined annual healthcare utilization, mean direct healthcare costs, and whether the performance measures were associated with costs in year 5., Results: A total of 13,293 individuals met inclusion criteria. The mean age was 73.7 (SD 5.7) years and 68% were female. Total mean direct healthcare cost per individual increased annually and was CAD $13,929 in year 5. All 4 performance measures were met for 35% of individuals. In multivariable analyses, costs for not meeting access to rheumatology care and timely treatment performance measures were 20% (95% CI 8-32) and 6% (95% CI 1-12) higher, respectively, than where those measures were met. The main driver of cost savings among individuals meeting all 4 performance measures were from lower complex continuing care, home care, and long-term care costs, as well as fewer hospitalizations and emergency visits., Conclusion: Access to rheumatologists for RA diagnosis, timely treatment, and ongoing care are associated with lower total healthcare costs at 5 years. Investments in improving access to care may be associated with long-term health system savings., (Copyright © 2023 by the Journal of Rheumatology.)
- Published
- 2023
- Full Text
- View/download PDF
38. Understanding COVID-19 Risk in Patients With Immune-Mediated Inflammatory Diseases: A Population-Based Analysis of SARS-CoV-2 Testing.
- Author
-
Eder L, Croxford R, Drucker AM, Mendel A, Kuriya B, Touma Z, Johnson SR, Cook R, Bernatsky S, Haroon N, and Widdifield J
- Subjects
- Adult, Humans, SARS-CoV-2, Cohort Studies, COVID-19 Testing, Immunomodulating Agents, Ontario epidemiology, Iritis, COVID-19 diagnosis, COVID-19 epidemiology, Arthritis, Rheumatoid epidemiology, Inflammatory Bowel Diseases, Multiple Sclerosis epidemiology
- Abstract
Objective: To investigate the incidence of and factors associated with SARS-CoV-2 testing and infection in immune-mediated inflammatory disease (IMID) patients versus matched non-IMID comparators from the general population., Methods: We conducted a population-based, matched cohort study among adult residents from Ontario, Canada, from January 2020 to December 2020. We created cohorts for the following IMIDs: rheumatoid arthritis (RA), psoriasis, psoriatic arthritis, ankylosing spondylitis, systemic autoimmune rheumatic diseases, multiple sclerosis (MS), iritis, inflammatory bowel disease (IBD), polymyalgia rheumatica, and vasculitis. Each patient was matched with 5 patients without IMIDs based on sociodemographic factors. We estimated the incidence of SARS-CoV-2 testing and infection in IMID patients and non-IMID patients. Multivariable logistic regressions assessed odds of SARS-CoV-2 infection., Results: We studied 493,499 patients with IMIDs and 2,466,946 patients without IMIDs. Patients with IMIDs were more likely to have at least 1 SARS-CoV-2 test versus patients without IMIDs (27.4% versus 22.7%), but the proportion testing positive for SARS-CoV-2 was identical (0.9% in both groups). Overall, IMID patients had 20% higher odds of being tested for SARS-CoV-2 (odds ratio 1.20 [95% confidence interval 1.19-1.21]). The odds of SARS-CoV-2 infection varied across IMID groups but was not significantly elevated for most IMID groups compared with non-IMID comparators. The odds of SARS-CoV-2 infection was lower in IBD and MS and marginally higher in RA and iritis., Conclusion: Patients across all IMIDs were more likely to be tested for SARS-CoV-2 versus those without IMIDs. The risk of SARS-CoV-2 infection varied across disease subgroups., (© 2021 American College of Rheumatology.)
- Published
- 2023
- Full Text
- View/download PDF
39. System-level performance measures of access to rheumatology care: a population-based retrospective study of trends over time and the impact of regional rheumatologist supply in Ontario, Canada, 2002-2019.
- Author
-
Barber CEH, Lacaille D, Croxford R, Barnabe C, Marshall DA, Abrahamowicz M, Xie H, Avina-Zubieta JA, Esdaile JM, Hazlewood G, Faris P, Katz S, MacMullan P, Mosher D, and Widdifield J
- Abstract
Objective: To determine whether there were improvements in rheumatology care for rheumatoid arthritis (RA) between 2002 and 2019 in Ontario, Canada, and to evaluate the impact of rheumatologist regional supply on access., Methods: We conducted a population-based retrospective study of all individuals diagnosed with RA between January 1, 2002 and December 31, 2019. Performance measures evaluated were: (i) percentage of RA patients seen by a rheumatologist within one year of diagnosis; and (ii) percentage of individuals with RA aged 66 years and older (whose prescription drugs are publicly funded) dispensed a disease modifying anti-rheumatic drug (DMARD) within 30 days after initial rheumatologist visit. Logistic regression was used to assess whether performance improved over time and whether the improvements differed by rheumatology supply, dichotomized as < 1 rheumatologist per 75,000 adults versus ≥1 per 75,000., Results: Among 112,494 incident RA patients, 84% saw a rheumatologist within one year: The percentage increased over time (adjusted odds ratio (OR) 2019 vs. 2002 = 1.43, p < 0.0001) and was consistently higher in regions with higher rheumatologist supply (OR = 1.73, 95% CI 1.67-1.80). Among seniors who were seen by a rheumatologist within 1 year of their diagnosis the likelihood of timely DMARD treatment was lower among individuals residing in regions with higher rheumatologist supply (OR = 0.90 95% CI 0.83-0.97). These trends persisted after adjusting for other covariates., Conclusion: While access to rheumatologists and treatment improved over time, shortcomings remain, particularly for DMARD use. Patients residing in regions with higher rheumatology supply were more likely to access care but less likely to receive timely treatment., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
40. Initial health care costs for COVID-19 in British Columbia and Ontario, Canada: an interprovincial population-based cohort study.
- Author
-
Tsui TCO, Zeitouny S, Bremner KE, Cheung DC, Mulder C, Croxford R, Del Giudice L, Lapointe-Shaw L, Mendlowitz A, Wong WWL, Perlis N, Sander B, Teckle P, Tomlinson G, Walker JD, Malikov K, McGrail KM, Peacock S, Kulkarni GS, Pataky RE, and Krahn MD
- Subjects
- British Columbia epidemiology, Cohort Studies, Female, Health Care Costs, Humans, Male, Middle Aged, Ontario epidemiology, SARS-CoV-2, COVID-19 epidemiology
- Abstract
Background: COVID-19 imposed substantial health and economic burdens. Comprehensive population-based estimates of health care costs for COVID-19 are essential for planning and policy evaluation. We estimated publicly funded health care costs in 2 Canadian provinces during the pandemic's first wave., Methods: In this historical cohort study, we linked patients with their first positive SARS-CoV-2 test result by June 30, 2020, in 2 Canadian provinces (British Columbia and Ontario) to health care administrative databases and matched to negative or untested controls. We stratified patients by highest level of initial care: community, long-term care, hospital (without admission to the intensive care unit [ICU]) and ICU. Mean publicly funded health care costs for patients and controls, mean net (attributable to COVID-19) costs and total costs were estimated from 30 days before to 120 days after the index date, or to July 31, 2020, in 30-day periods for patients still being followed by the start of each period., Results: We identified 2465 matched people with a positive test result for SARS-CoV-2 in BC and 28 893 in Ontario. Mean age was 53.4 (standard deviation [SD] 21.8) years (BC) and 53.7 (SD 22.7) years (Ontario); 55.7% (BC) and 56.1% (Ontario) were female. Net costs in the first 30 days after the index date were $22 010 (95% confidence interval [CI] 19 512 to 24 509) and $15 750 (95% CI 15 354 to 16 147) for patients admitted to hospital, and $65 828 (95% CI 58 535 to 73 122) and $56 088 (95% CI 53 721 to 58 455) for ICU patients in BC and Ontario, respectively. In the community and long-term care settings, net costs were near 0. Total costs for all people, from 30 days before to 30 days after the index date, were $22 128 330 (BC) and $175 778 210 (Ontario)., Interpretation: During the first wave, we found that mean costs attributable to COVID-19 were highest for patients with ICU admission and higher in BC than Ontario. Reducing the number of people who acquire COVID-19 and severity of illness are required to mitigate the economic impact of COVID-19., Competing Interests: Competing interests: None declared., (© 2022 CMA Impact Inc. or its licensors.)
- Published
- 2022
- Full Text
- View/download PDF
41. "Bring the Hoses to Where the Fire Is!": Differential Impacts of Marginalization and Socioeconomic Status on COVID-19 Case Counts and Healthcare Costs.
- Author
-
Cheung DC, Bremner KE, Tsui TCO, Croxford R, Lapointe-Shaw L, Giudice LD, Mendlowitz A, Perlis N, Pataky RE, Teckle P, Zeitouny S, Wong WWL, Sander B, Peacock S, Krahn MD, Kulkarni GS, and Mulder C
- Subjects
- Female, Health Care Costs, Humans, Male, Middle Aged, Ontario epidemiology, Retrospective Studies, Social Class, COVID-19 epidemiology
- Abstract
Objectives: Local health leaders and the Director General of the World Health Organization alike have observed that COVID-19 "does not discriminate." Nevertheless, the disproportionate representation of people of low socioeconomic status among those infected resembles discrimination. This population-based retrospective cohort study examined COVID-19 case counts and publicly funded healthcare costs in Ontario, Canada, with a focus on marginalization., Methods: Individuals with their first positive severe acute respiratory syndrome coronavirus 2 test from January 1, 2020 to June 30, 2020, were linked to administrative databases and matched to negative/untested controls. Mean net (COVID-19-attributable) costs were estimated for 30 days before and after diagnosis, and differences among strata of age, sex, comorbidity, and measures of marginalization were assessed using analysis of variance tests., Results: We included 28 893 COVID-19 cases (mean age 54 years, 56% female). Most cases remained in the community (20 545, 71.1%) or in long-term care facilities (4478, 15.5%), whereas 944 (3.3%) and 2926 (10.1%) were hospitalized, with and without intensive care unit, respectively. Case counts were skewed across marginalization strata with 2 to 7 times more cases in neighborhoods with low income, high material deprivation, and highest ethnic concentration. Mean net costs after diagnosis were higher for males ($4752 vs $2520 for females) and for cases with higher comorbidity ($1394-$7751) (both P < .001) but were similar across levels of most marginalization dimensions (range $3232-$3737, all P ≥ .19)., Conclusions: This study suggests that allocating resources unequally to marginalized individuals may improve equality in outcomes. It highlights the importance of reducing risk of COVID-19 infection among marginalized individuals to reduce overall costs and increase system capacity., (Copyright © 2022. Published by Elsevier Inc.)
- Published
- 2022
- Full Text
- View/download PDF
42. A Population-Based Study Evaluating Retention in Rheumatology Care Among Patients With Rheumatoid Arthritis.
- Author
-
Barber CEH, Lacaille D, Croxford R, Barnabe C, Marshall DA, Abrahamowicz M, Xie H, Avina-Zubieta JA, Esdaile JM, Hazlewood G, Faris P, Katz S, MacMullan P, Mosher D, and Widdifield J
- Abstract
Objective: The study objective was to assess adherence to system-level performance measures measuring retention in rheumatology care and disease modifying anti-rheumatic drug (DMARD) treatment in rheumatoid arthritis (RA)., Methods: We used a validated health administrative data case definition to identify individuals with RA in Ontario, Canada, between 2002 and 2014 who had at least 5 years of potential follow-up prior to 2019. During the first 5 years following diagnosis, we assessed whether patients were seen by a rheumatologist yearly and the proportion dispensed a DMARD yearly (in those aged ≥66 for whom medication data were available). Multivariable logistic regression analyses were used to estimate the odds of remaining under rheumatologist care., Results: The cohort included 50,883 patients with RA (26.1% aged 66 years and older). Over half (57.7%) saw a rheumatologist yearly in all 5 years of follow-up. Sharp declines in the percentage of patients with an annual visit were observed in each subsequent year after diagnosis, although a linear trend to improved retention in rheumatology care was seen over the study period (P < 0.0001). For individuals aged 66 years or older (n = 13,293), 82.1% under rheumatologist care during all 5 years after diagnosis were dispensed a DMARD annually compared with 31.0% of those not retained under rheumatology care. Older age, male sex, lower socioeconomic status, higher comorbidity score, and having an older rheumatologist decreased the odds of remaining under rheumatology care., Conclusion: System-level improvement initiatives should focus on maintaining ongoing access to rheumatology specialty care. Further investigation into causes of loss to rheumatology follow-up is needed., (© 2022 The Authors. ACR Open Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)
- Published
- 2022
- Full Text
- View/download PDF
43. COVID-19 Hospitalizations, Intensive Care Unit Stays, Ventilation, and Death Among Patients With Immune-mediated Inflammatory Diseases Compared to Controls.
- Author
-
Eder L, Croxford R, Drucker AM, Mendel A, Kuriya B, Touma Z, Johnson SR, Cook R, Bernatsky S, Haroon N, and Widdifield J
- Subjects
- Cohort Studies, Hospitalization, Humans, Intensive Care Units, Male, Ontario epidemiology, Prostate-Specific Antigen, Arthritis, Psoriatic epidemiology, Arthritis, Rheumatoid complications, COVID-19 epidemiology, Iritis complications, Multiple Sclerosis, Vasculitis complications
- Abstract
Objective: To investigate coronavirus disease 2019 (COVID-19) hospitalization risk in patients with immune-mediated inflammatory diseases (IMIDs) compared with matched non-IMID comparators from the general population., Methods: We conducted a population-based, matched cohort study using health administrative data from January to July 2020 in Ontario, Canada. Cohorts for each of the following IMIDs were assembled: rheumatoid arthritis (RA), psoriasis, psoriatic arthritis (PsA), ankylosing spondylitis, systemic autoimmune rheumatic diseases (SARDs), multiple sclerosis (MS), iritis, inflammatory bowel disease, polymyalgia rheumatica, and vasculitis. Each patient was matched with 5 non-IMID comparators based on sociodemographic factors. We compared the cumulative incidence of hospitalizations for COVID-19 and their outcomes between IMID and non-IMID patients., Results: A total of 493,499 patients with IMID (417 hospitalizations) and 2,466,946 non-IMID comparators (1519 hospitalizations) were assessed. The odds of being hospitalized for COVID-19 were significantly higher in patients with IMIDs compared with their matched non-IMID comparators (matched unadjusted odds ratio [OR] 1.37, adjusted OR 1.23). Significantly higher risk of hospitalizations was found in patients with iritis (OR 1.46), MS (OR 1.83), PsA (OR 2.20), RA (OR 1.42), SARDs (OR 1.47), and vasculitis (OR 2.07). COVID-19 hospitalizations were associated with older age, male sex, long-term care residence, multimorbidity, and lower income. The odds of complicated hospitalizations were 21% higher among all IMID vs matched non-IMID patients, but this association was attenuated after adjusting for demographic factors and comorbidities., Conclusion: Patients with IMIDs were at higher risk of being hospitalized with COVID-19. This risk was explained in part by their comorbidities., (© 2022 by the Journal of Rheumatology.)
- Published
- 2022
- Full Text
- View/download PDF
44. Health Care Use, Costs, and Survival Trajectory of Home Mechanical Insufflation-Exsufflation.
- Author
-
Rose L, Fisher T, Pizzuti R, Amin R, Croxford R, Dale CM, Goldstein R, Katz S, Leasa D, McKim D, Nonoyama M, Tandon A, and Gershon A
- Subjects
- Cohort Studies, Cough, Delivery of Health Care, Health Care Costs, Humans, Retrospective Studies, Insufflation
- Abstract
Background: Despite expert recommendations for use, limited evidence identifies effectiveness of mechanical insufflation-exsufflation (MI-E) in addressing respiratory morbidity and resultant health care utilization and costs for individuals with neuromuscular disorders. We examined the impact of provision of publicly funded MI-E devices on health care utilization, health care costs, and survival trajectory., Methods: This is a retrospective pre/post cohort study linking data on prospectively recruited participants using MI-E to health administrative databases to quantify outcomes., Results: We linked data from 106 participants (8 age < 15 y) and determined annualized health care use pre/post device. We found no difference in emergency department (ED) visit or hospital admission rates. Following MI-E approval, participants required fewer hospital days (median [interquartile range] [IQR]) 0 [0-9] vs 0 [0-4], P = .03). Rates of physician specialist visits also decreased (median IQR 7 [4-11] vs 4 [2-7], P < .001). Conversely, rates of home care nursing and homemaking/personal support visits increased. Following MI-E, total costs were lower for 59.4%, not different for 13.2%, and higher for 27.4%. Physician billing costs decreased whereas home care costs increased. Regression modeling identified pre-MI-E costs were the most important predictor of costs after approval. At 12 months, 23 (21.7%) participants had died. Risk of death was higher for those using more medical devices (hazard ratio 1.12, [95% CI 1.02-1.22]) in the home., Conclusions: Provision of publicly funded MI-E devices did not influence rates of ED visits or hospital admission but did shift health care utilization and costs from the acute care to community sector. Although increased community costs negated cost savings from physician billings, evidence suggests costs savings from reduced hospital days and fewer specialist visits. Risk of death was highest in individuals requiring multiple medical technologies., Competing Interests: The authors disclose a relationship with IQVIA Canada., (Copyright © 2022 by Daedalus Enterprises.)
- Published
- 2022
- Full Text
- View/download PDF
45. Patterns of pre-operative opioid use affect the risk for complications after total joint replacement.
- Author
-
Ravi B, Pincus D, Croxford R, Leroux T, Paterson J, Hawker G, and Redelmeier DA
- Subjects
- Aged, Arthroplasty, Replacement, Hip adverse effects, Female, Humans, Male, Ontario, Pain, Postoperative, Preoperative Care methods, Retrospective Studies, Risk Factors, Analgesics, Opioid therapeutic use, Arthroplasty, Replacement, Knee adverse effects, Knee Joint surgery, Postoperative Complications prevention & control
- Abstract
Preoperative opioid use has been shown to increase the risk for complications following total joint arthroplasty (TJA); however, these studies have not always accounted for differences in co-morbidities and socio-demographics between patients that use opioids and those that do not. They have also not accounted for the variation in degree of pre-operative use. The objective of this study was to determine if preoperative opioid use is associated with risk for surgical complications after TJA, and if this association varied by degree of use. Population-based retrospective cohort study. Older adult patients undergoing primary TJA of the hip, knee and shoulder for osteoarthritis between 2002 and 2015 in Ontario, Canada were identified. Using accepted definitions, patients were stratified into three groups according to their preoperative opioid use: no use, intermittent use and chronic use. The primary outcome was the occurrence of a composite surgical complication (surgical site infection, dislocation, revision arthroplasty) or death within a year of surgery. Intermittent and chronic users were matched separately to non-users in a 1:1 ratio, matching on TJA type plus a propensity score incorporating patient and provider factors. Overall, 108,067 patients were included in the study; 10% (N = 10,441) used opioids on a chronic basis before surgery and 35% (N = 37,668) used them intermittently. After matching, chronic pre-operative opioid use was associated with an increased risk for complications after TJA (HR 1.44, p = 0.001) relative to non-users. Overall, less than half of patients undergoing TJA used opioids in the year preceding surgery; the majority used them only intermittently. While chronic pre-operative opioid use is associated with an increased risk for complications after TJA, intermitted pre-operative use is not., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
46. Early invasive coronary angiography and acute ischaemic heart failure outcomes.
- Author
-
Kosyakovsky LB, Austin PC, Ross HJ, Wang X, Abdel-Qadir H, Goodman SG, Farkouh ME, Croxford R, Lawler PR, Spertus JA, and Lee DS
- Subjects
- Aged, Aged, 80 and over, Coronary Angiography, Female, Humans, Male, Treatment Outcome, Coronary Artery Disease, Heart Failure diagnostic imaging, Myocardial Infarction, Percutaneous Coronary Intervention
- Abstract
Aims: While myocardial ischaemia plays a major role in the pathogenesis of heart failure (HF), the indications for coronary angiography during acute HF are not established. We determined the association of early coronary angiography during acute HF hospitalization with 2-year mortality, cardiovascular death, HF readmissions, and coronary revascularization., Methods and Results: In a two-stage sampling process, we identified acute HF patients who presented to 70 emergency departments in Ontario (April 2010 to March 2013) and determined whether they underwent early coronary angiography within 14 days after presentation using administrative databases. After clinical record review, we defined a cohort with acute ischaemic HF as patients with at least one factor suggesting underlying ischaemic heart disease, including previous myocardial infarction, troponin elevation, or angina on presentation. We oversampled patients undergoing angiography. We used inverse-probability-of-treatment weighting (IPTW) to adjust for baseline differences. Of 7239 patients with acute HF, 2994 met inclusion criteria [median age 75 (interquartile range 65-83) years; 40.9% women]. Early angiography was performed in 1567 patients (52.3%) and was associated with lower all-cause mortality [hazard ratio (HR) 0.74, 95% confidence interval (CI) 0.61-0.90, P = 0.002], cardiovascular death (HR 0.72, 95% CI 0.56-0.93, P = 0.012), and HF readmissions (HR 0.84, 95% CI 0.71-0.99, P = 0.042) after IPTW. Those undergoing early angiography experienced higher rates of percutaneous coronary intervention (HR 2.58, 95% CI 1.73-3.86, P < 0.001) and coronary artery bypass grafting (HR 2.94, 95% CI 1.75-4.93, P < 0.001) within 2 years., Conclusions: Early coronary angiography was associated with lower all-cause mortality, cardiovascular death, HF readmissions, and higher rates of coronary revascularization in acute HF patients with possible ischaemia., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2021
- Full Text
- View/download PDF
47. Physician Factors Associated with Inappropriate Vitamin B12 Prescribing in Ontario, Canada.
- Author
-
Silverstein WK, Lin Y, Dharma C, Croxford R, and Cheung MC
- Subjects
- Canada, Humans, Inappropriate Prescribing, Ontario epidemiology, Physicians, Vitamin B 12
- Published
- 2021
- Full Text
- View/download PDF
48. Characteristics and Outcomes of Women Developing Heart Failure After Early Stage Breast Cancer Chemotherapy: A Population-Based Matched Cohort Study.
- Author
-
Abdel-Qadir H, Tai F, Croxford R, Austin PC, Amir E, Calvillo-Argüelles O, Ross H, Lee DS, and Thavendiranathan P
- Subjects
- Adult, Anthracyclines pharmacology, Antibiotics, Antineoplastic adverse effects, Breast Neoplasms complications, Breast Neoplasms epidemiology, Cardiotoxicity etiology, Cohort Studies, Female, Heart Failure diagnosis, Humans, Middle Aged, Trastuzumab administration & dosage, Breast Neoplasms drug therapy, Drug Therapy, Drug-Related Side Effects and Adverse Reactions etiology, Heart Failure drug therapy, Trastuzumab pharmacology
- Abstract
Background: The prognosis of heart failure (HF) after early stage breast cancer (EBC) treatment with anthracyclines or trastuzumab is not well-characterized., Methods: Using administrative databases, women diagnosed with HF after receiving anthracyclines or trastuzumab for EBC in Ontario during 2007 to 2017 (the EBC-HF cohort) were categorized by cardiotoxic exposure (anthracycline alone, trastuzumab alone, sequential therapy with both agents) and matched on age with ≤3 cancer-free HF controls to compare baseline characteristics. To study prognosis after HF onset, we conducted a second match on age plus important HF prognostic factors. The cumulative incidence function was used to describe risk of hospitalization or emergency department visits (hospital presentations) for HF and cardiovascular death., Results: A total of 804 women with EBC developed HF after anthracyclines (n=312), trastuzumab (n=112), or sequential therapy (n=380); they had significantly fewer comorbidities than 2411 age-matched HF controls. After the second match, the anthracycline-HF cohort had a similar 5-year incidence of HF hospital presentations (16.5% [95% CI, 12.0%-21.7%]) as controls (17.1% [95% CI, 14.4%-20.1%]); the 5-year incidence was lower than matched controls for the trastuzumab-HF (9.7% [95% CI, 4.7%-16.9%]; controls 16.4% [95% CI, 12.1%-21.3%]; P =0.03) and sequential-HF cohorts (2.7% [95% CI, 1.4%-4.8%]; controls 10.8% [95% CI, 8.9%-13.0%]; P <0.001). At 5 years, the incidence of cardiovascular death was 2.9% (95% CI, 1.2%-5.9%) in the anthracycline-HF cohort vs. 9.5% (95% CI, 6.9%-12.6%) in controls, and 1.7% (0.6%-3.7%) for women developing HF after trastuzumab vs. 4.3% (95% CI, 3.1-5.8%) for controls., Conclusions: Women developing HF after cardiotoxic EBC chemotherapy have fewer comorbidities than cancer-free women with HF; trastuzumab-treated women who develop HF have better prognosis than matched HF controls.
- Published
- 2021
- Full Text
- View/download PDF
49. Real-world, population-based cohort study of toxicity and resource utilization of second-line ipilimumab for metastatic melanoma in Ontario, Canada.
- Author
-
Dai WF, Beca J, Croxford R, Isaranuwatchai W, Menjak IB, Petrella TM, Mittmann N, Earle CC, Gavura S, Mercer RE, Hanna TP, and Chan KKW
- Subjects
- Aged, Female, Gastrointestinal Diseases chemically induced, Heart Diseases chemically induced, Hospitalization statistics & numerical data, Humans, Immune Checkpoint Inhibitors adverse effects, Immune Checkpoint Inhibitors therapeutic use, Ipilimumab adverse effects, Male, Melanoma mortality, Melanoma pathology, Middle Aged, Neoplasm Metastasis, Ontario, Retrospective Studies, Skin Neoplasms mortality, Skin Neoplasms pathology, Survival Rate, Ipilimumab therapeutic use, Melanoma drug therapy, Population Surveillance methods, Skin Neoplasms drug therapy
- Abstract
Second-line ipilimumab has been publicly funded in Ontario for metastatic melanoma (MM) since September 2012. We examined real-world toxicity of second-line ipilimumab compared to standard second-line treatments prior to funding. MM patients who received systemic treatment from April 2005 to March 2015 were included. Patients receiving second-line ipilimumab after September 2012 were considered as cases, and those who received second-line treatment prior to the funding date were included as historical controls. Outcomes assessed include treatment-related mortality, any-cause hospital visits, ipilimumab-related hospital visits and specialist visits (eg, endocrinologists, ophthalmologists, gastroenterologists, rheumatologists and respirologists), which were captured from up to 30 and/or 90 days after end of second-line treatment. Inverse probability of treatment weighting was used to adjust for baseline differences between groups. Odds ratios (ORs) from logistic regressions and rate ratios (RRs) from rate regressions were used to assess differences between groups. We identified 329 MM patients who received second-line treatments (ipilimumab: 189; controls: 140). Ipilimumab was associated greater any-cause (60.1% vs 45.7%; OR = 1.81; P value = .019) and ipilimumab-related (47.2% vs 31.9%; OR = 1.91; P value = .011) hospital visits. Adjusting for different follow-up days, ipilimumab was associated with higher rates of all-cause (RR = 1.56 [95%CI: 1.12-2.16]), and ipilimumab-related (RR = 2.18 [95% CI: 1.45-3.27]) hospital visits. Patients receiving ipilimumab were more likely to visit specialist involved in immunotherapy toxicity management (23.5% vs 13.7%; P value = .04). Compared to historical second-line treatments, second-line ipilimumab was associated with more health service utilization (specifically hospital visits and specialist visits), suggestive of potentially increased toxicity in the real world., (© 2020 Union for International Cancer Control.)
- Published
- 2021
- Full Text
- View/download PDF
50. Days Spent at Home before Death from Cancer for Immigrants and Long-Term Residents in Ontario, Canada.
- Author
-
Engelhart S, Cheung M, Croxford R, and Singh S
- Subjects
- Adult, Cohort Studies, Female, Humans, Male, Ontario, Emigrants and Immigrants, Neoplasms, Terminal Care
- Abstract
Background: Time at home before death is an emerging patient-centered metric of quality end-of-life care. It is unknown if immigrants who die from cancer in Ontario spend less time at home near the end of life. Objective: Compare the number of days at home (DAH) in the last six months of life for immigrants and long-term residents (LTRs) who die from cancer. Methods: Population-based cohort study (January 1, 2005 to December 31, 2013) using administrative databases. Participants were adults (≥18 years) who died from cancer in Ontario. Immigrants were defined as those who immigrated from 1985 onward. The outcome was DAH in the last six months of life. Analysis included univariate and multivariable regression, adjusting for patient and disease characteristics. Subgroup analyses assessed DAH by immigration class, time since immigration, and region of birth. Sensitivity analyses excluded patients with breast and prostate cancer to examine for sex differences. Results: Seventy-two thousand nine hundred eighty-eight individuals (3988 immigrants) were identified. Immigrants spent fewer DAH in the last six months (unadjusted 162 days vs. 164 days, p < 0.001). This remained statistically significant after adjusting ( p = 0.0087). DAH varied by immigration class and region of birth. Sensitivity analyses suggest a sex difference in end-of-life time spent at home. Conclusions: Immigrants who die from cancer in Ontario spend fewer DAH before death than LTRs. This may be due to patient preferences, inequitable access to services, or availability of local relatives for support. Further research is needed to understand the causes of this association.
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.