Karen E Bremner’s research while affiliated with University Health Network and other places

Introduction: Malignant Pleural Effusion (MPE) is common in advanced malignancy. Data are needed on health care utilization and costs. Methods: This population-based retrospective cohort study included patients aged ≥18 years with an MPE diagnosed between January 1, 2004 and December 31, 2018. We described the incidence and prevalence of MPE from 2004 to 2018, and trends in hospital admissions, emergency department (ED) visits, and pleural-based procedures. In patients diagnosed with MPE from 2006 to 2016 we estimated 2-year health care costs (2018 US dollars) from the public payer perspective. Results: The annual incidence and prevalence of MPE increased from 5,090 and 14,579 in 2004 to 6,977 and 23,204 in 2018, respectively. Annual mortality among prevalent patients decreased from 32% to 28%. In 2004, 57% of patients were hospitalized, decreasing to 50% in 2018. ED visits increased (59% to 61%). From 2004 to 2018, the number of patients who had insertions of thoracostomy tube (2,211 to 3,664) and tunnelled pleural catheter (383 to 1,164) increased. The number of patients receiving pleurodesis declined (565 to 284). No change occurred in the number of patients receiving video-assisted thoracoscopy (range 140 - 208/year). Between 2004 and 2016, 76,190 patients were diagnosed with MPE (mean age 71.2; 52% female). The median (interquartile range) health care cost during follow-up was $45,641 ($23,237-$86,700), with$19,753 ($9,590-$38,746) for inpatient hospitalization. Conclusion: Hospitalization and temporizing MPE procedures are associated with high costs. This population-based study may guide clinicians and policy makers to improve MPE management and reduce health care costs.

Background There is no widely accepted framework to guide the development of condition-specific preference-based instruments (CSPBIs) that includes both de novo and from existing non-preference-based instruments. The purpose of this study was to address this gap by reviewing the published literature on CSPBIs, with particular attention to the application of item response theory (IRT) and Rasch analysis in their development. Methods A scoping review of the literature covering the concepts of all phases of CSPBI development and evaluation was performed from MEDLINE, Embase, PsychInfo, CINAHL, and the Cochrane Library, from inception to December 30, 2022. Results The titles and abstracts of 1,967 unique references were reviewed. After retrieving and reviewing 154 full-text articles, data were extracted from 109 articles, representing 41 CSPBIs covering 21 diseases or conditions. The development of CSPBIs was conceptualized as a 15-step framework, covering four phases: 1) develop initial questionnaire items (when no suitable non-preference-based instrument exists), 2) establish the dimensional structure, 3) reduce items per dimension, 4) value and model health state utilities. Thirty-nine instruments used a type of Rasch model and two instruments used IRT models in phase 3. Conclusion We present an expanded framework that outlines the development of CSPBIs, both from existing non-preference-based instruments and de novo when no suitable non-preference-based instrument exists, using IRT and Rasch analysis. For items that fit the Rasch model, developers selected one item per dimension and explored item response level reduction. This framework will guide researchers who are developing or assessing CSPBIs.

Introduction The aim of our study was to assess the initial impact of COVID-19 on total publicly-funded direct healthcare costs and health services use in two Canadian provinces, Ontario and British Columbia (BC). Methods This retrospective repeated cross-sectional study used population-based administrative datasets, linked within each province, from January 1, 2018 to December 27, 2020. Interrupted time series analysis was used to estimate changes in the level and trends of weekly resource use and costs, with March 16–22, 2020 as the first pandemic week. Also, in each week of 2020, we identified cases with their first positive SARS-CoV-2 test and estimated their healthcare costs until death or December 27, 2020. Results The resources with the largest level declines (95% confidence interval) in use in the first pandemic week compared to the previous week were physician services [Ontario: -43% (-49%,-37%); BC: -24% (-30%,-19%) (both p<0.001)] and emergency department visits [Ontario: -41% (-47%,-35%); BC: -29% (-35%,-23%) (both p<0.001)]. Hospital admissions declined by 27% (-32%,-23%) in Ontario and 21% (-26%,-16%) in BC (both p<0.001). Resource use subsequently rose but did not return to pre-pandemic levels. Only home care and dialysis clinic visits did not significantly decrease compared to pre-pandemic. Costs for COVID-19 cases represented 1.3% and 0.7% of total direct healthcare costs in 2020 in Ontario and BC, respectively. Conclusions Reduced utilization of healthcare services in the overall population outweighed utilization by COVID-19 patients in 2020. Meeting the needs of all patients across all services is essential to maintain resilient healthcare systems.

Background: As First Nations Peoples are a priority focus of Canada's commitment to eliminating hepatitis C virus (HCV) as a public health threat, understanding individuals' progression from diagnosis to cure can guide prioritization of elimination efforts. We sought to characterize and identify gaps in the HCV care cascade for Status First Nations peoples in Ontario. Methods: In this retrospective cohort study, a partnership between the Ontario First Nations HIV/AIDS Education Circle and academic researchers, HCV testing records (1999-2018) for Status First Nations peoples in Ontario were linked to health administrative data. We defined the cascade of care as 6 stages, as follows: tested positive for HCV antibody, tested for HCV RNA, tested positive for HCV RNA, HCV genotyped, initiated treatment and achieved sustained viral response (SVR). We mapped the care cascade from 1999 to 2018, and estimated the number and proportion of people at each stage. We stratified analyses by sex, diagnosis date and location of residence. We used Cox regression to analyze the secondary outcomes, namely the associations between undergoing HCV RNA testing and initiating treatment, and demographic and clinical predictors. Results: By Dec. 31, 2018, 4962 people tested positive for HCV antibody. Of those testing positive, 4118 (83.0%) were tested for HCV RNA, with 2480 (60.2%) testing positive. Genotyping was completed in 2374 (95.7%) of those who tested positive for HCV RNA, with 1002 (42.2%) initiating treatment. Nearly 80% (n = 801, 79.9%) of treated people achieved SVR, with 34 (4.2%) experiencing reinfection or relapse. Undergoing testing for HCV RNA was more likely among people in older age categories (within 1 yr of antibody test; adjusted hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.19-1.41, among people aged 41-60 yr; adjusted HR 1.47, 95% CI 1.18-1.81, among people aged > 60 yr), those living in rural areas (adjusted HR 1.20, 95% CI 1.10-1.30), those with an index date after Dec. 31, 2013 (era of treatment with direct-acting antiviral regimens) (adjusted HR 1.99, 95% CI 1.85-2.15) and those with a record of substance use or addictive disorders (> 1 yr after antibody test; adjusted HR 1.38, 95% CI 1.18-1.60). Treatment initiation was more likely among people in older age categories at index date (adjusted HR 1.32, 95% CI 1.15-1.50, among people aged 41-60 yr; adjusted HR 2.62, 95% CI 1.80-3.82, among people aged > 60 yr) and those with a later diagnosis year (adjusted HR 2.71, 95% CI 2.29-3.22). Interpretation: In comparison with HCV testing and diagnosis, a substantial gap in treatment initiation remains among Status First Nations populations in Ontario. Elimination efforts that prioritize linkage to care and integration with harm reduction and substance use services are needed to close gaps in HCV care among First Nations populations in Ontario.

Background: Direct-acting antiviral agents (DAAs) have transformed chronic hepatitis C (CHC) treatment. Continued affordable access to DAAs requires updated cost-effectiveness analyses (CEA). Utility is a preference-based measure of health-related quality of life (HRQoL) used in CEA. This study evaluated the impact of DAAs on utilities for patients with CHC in two clinical settings. Methods: This prospective longitudinal study included patients aged ≥18 years, diagnosed with CHC and scheduled to begin DAA treatment, from two tertiary care hospital clinics and four community clinics in Toronto, Calgary, and Montreal. Patients completed two utility instruments (EQ-5D-5L and Health Utilities Index 2/3 (HUI2/3)) before treatment, 6 weeks after treatment initiation, and 12 weeks and one year after treatment completion. We measured utilities for all patients, and for hospital-based and community-based groups. Results: Between 2017 and 2020, 209 patients (126 hospital-based, 83 community-based; average age 53 years; 65% male) were recruited, and 143 completed the 1-year post-treatment assessment. Pre-treatment, utilities were (mean±standard deviation) 0.77±0.21 (EQ-5D-5L), 0.69±0.24 (HUI2) and 0.58±0.34 (HUI3). The mean changes at 1-year post-treatment were 0.035, 0.038 and 0.071, respectively. While utilities for hospital-based patients steadily improved, utilities for the community-based cohort improved between baseline and 12-weeks post-treatment, but decreased thereafter. Discussion: This study suggests that utilities improve after DAA treatment in patients with CHC in a variety of settings. However, community-based patients may face challenges related to comorbid health and social conditions that are not meaningfully addressed by treatment. Our study is essential for valuing health outcomes in CHC-related CEA.