Solmaz Setayeshgar

Background: Stroke mortality rates have declined in recent decades; however, data on contemporary drivers of this trend are limited. This study compared the contribution of trends in stroke event rates and 30-day case fatality to declines in stroke mortality from 2002 to 2018. Methods: Linked hospitalization and mortality data were obtained from Western Australia (WA), England, New Zealand, British Columbia (BC), and Ontario. Age-standardized and age-specific stroke mortality and event rates and 30-day case fatality were calculated and age-adjusted trends estimated from Poisson and binomial regression models. The relative contribution of trends in stroke events and 30-day case fatality to trends in stroke mortality were calculated. Results: There were 2 248 242 stroke events identified. Age-adjusted reductions in event rates ranged from −0.96%/year [95% confidence interval (CI) − 1.22, 0.70%] in men in WA to −2.51%/year (95% CI −2.61, −2.40%) in women in Ontario. Age-standardized 30-day case fatality was highest in England in 2002 (men 43.7%, women 45.5%), but declined at a greater rate than in other jurisdictions. Declines in stroke mortality ranged from −3.3%/year to −5.5%/year. Reductions in 30-day case fatality were the major contributor to declines in stroke mortality [range: men, 63.5% (Ontario)–80.9% (England); women, 55.3% (BC)–73.1% (England)]. In people aged <65 years, stroke mortality declines were almost completely driven by reductions in 30-day case fatality with increasing or attenuated event rates among those aged 35–64 years. Conclusion: Improvements in 30-day case fatality had a greater impact on stroke mortality than trends in event rates, suggesting that further gains could be achieved with targeted prevention. Adverse trends in event rates in people aged <65 years could signal future increases in stroke mortality.

Background: Stroke remains a leading cause of death in British Columbia (BC), Canada. Understanding whether mortality declines are driven by prevention (reduced incidence) or improved survival (treatment) can inform public health and acute care planning. Methods: We conducted a population-based study of 123,075 stroke events from 2002 to 2022 among BC residents aged 35–110 years, using linked administrative datasets. We calculated age-standardized rates of stroke events, 30-day case fatality and mortality, stratifying the rates by sex, age, income and geography. Regression models estimated temporal changes and relative contributions of declining event rates and case fatality to mortality reductions. Results: Age-standardized stroke event rates declined by 33% in females (208–140 per 100,000) and 25% in males (248–187) but increased among adults aged 35–54 (+14% females, +27% males). Females experienced a higher burden of stroke events as pre-admission deaths, particularly among 85+. Case fatality fell by 22% in females (40–31 per 100 events) and 15% in males (37–32), with the greatest improvements in younger adults. Mortality declined by 53% in females (72–34 per 100,000) and 43% in males (72–41) primarily driven by declines in case fatality. Disparities by sex, income and geography persisted. Conclusion: Improved survival is the main driver of declining stroke mortality in BC, particularly in recent years. Socioeconomic, sex and age disparities persist, warranting focused strategies to address inequities and the rising stroke burden among younger populations.

Background: Canada has one of the highest per capita greenhouse gas (GHG) emissions, with healthcare contributing ~5% of the total. Pressurised metered-dose inhalers (pMDIs) are significant contributors due to their use of hydrofluorocarbon propellants. While propellant-free dry powder inhalers (DPIs) and soft mist inhalers (SMIs) are available, their adoption remains limited. This population-based study evaluates inhaler dispensation trends in British Columbia (BC), Canada, projects future dispensation and emissions over the next decade, and explores mitigation strategies through pMDI substitution. Methods: Historical inhaler dispensation data (2015–2022) from BC were analysed using negative binomial models to assess trends, project future usage and emissions (2023–2032) and evaluate four substitution scenarios replacing pMDIs with low-GHG alternatives or DPIs/SMIs. Emissions were estimated by inhaler type, sex, age and health region, with uncertainties addressed through Monte Carlo simulation for the projected values. Results: An average of 2.1 million inhalers are dispensed annually in BC, with pMDIs comprising 64% of total inhaler use but contributing 98% of the ~30 000 tonnes of GHG emissions. There was regional variation and older populations contributed disproportionately, reflecting burden of disease. From 2015 to 2022 (excluding 2020 and 2021, the COVID-19 years), pMDI dispensations decreased by 1% annually while DPI/SMI dispensations increased by 5%. Projections show that, without intervention, emissions could rise to ~37 000 tonnes by 2032, varying by age group. All substitution scenarios, by replacing pMDIs with DPIs/SMIs, could reduce emissions by up to 42%. Conclusion: High quality, guideline-directed diagnosis and management of respiratory disease is known to improve health and reduce emissions. Building on these benefits, our analysis shows that substituting pMDIs with lower-emission inhalers, when guided by policy and clinical decisions that prioritise patient safety and preference, can significantly reduce healthcare-related GHG emissions.

Introduction We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies. Method We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 million) in Canada with universal healthcare coverage. We created two cohorts of COVID-19 hospitalisations based on date of admission: annual cohort (March 2020 to February 2021) and peak cohort (Omicron era; first 10 weeks of 2022). For comparison, we created influenza annual and peak cohorts using three historical periods years to capture varying severity and circulating strains: 2009/2010, 2015/2016 and 2016/2017. We estimated hospitalisation rates per 100 000 population. Results COVID-19 and influenza hospitalisation rates by age group were ‘J’ shaped. The population rate of COVID-19 hospital admissions in the annual cohort (mostly unvaccinated; public health restrictions in place) was significantly higher than influenza among individuals aged 30–69 years, and comparable to the severe influenza year (2016/2017) among 70+. In the peak COVID-19 cohort (mostly vaccinated; few restrictions in place), the hospitalisation rate was comparable with influenza 2016/2017 in all age groups, although rates among the unvaccinated population were still higher than influenza among 18+. Among people aged 5–17 years, COVID-19 hospitalisation rates were lower than/comparable to influenza years in both cohorts. The COVID-19 hospitalisation rate among 0–4 years old, during Omicron, was higher than influenza 2015/2016 and 2016/2017 and lower than 2009/2010 pandemic. Conclusions During first Omicron wave, COVID-19 hospitalisation rates were significantly higher than historical influenza hospitalisation rates for unvaccinated adults but were comparable to influenza for vaccinated adults. For children, in the context of high infection levels, hospitalisation rates for COVID-19 were lower than 2009/2010 H1N1 influenza and comparable (higher for 0–4) to non-pandemic years, regardless of the vaccine status.

Objective To compare the population rate of COVID-19 and influenza hospitalizations by age, COVID-19 vaccine status and pandemic phase. Design Observational retrospective study Setting Residents of British Columbia (population 5.3 million), Canada Participants Hospitalized patients due to COVID-19 or historical influenza Main outcome measures This population based study in a setting with universal healthcare coverage, used COVID-19 case and hospital data for COVID-19 and influenza. Admissions were selected from March 2020 to February 2021 for the annual cohort and the first 8 weeks of 2022 for the peak cohort of COVID-19 (Omicron era). Influenza annual and peak cohorts were from three years with varying severity: 2009/10, 2015/16, and 2016/17. We estimated hospitalization rates per 100,000 population by age group. Results Similar to COVID-19 with median age 66 (Q1-Q3 44-80), influenza 2016/17 mostly affected older adults, with median age 78 (64-87). COVID-19 and influenza 2016/17 hospitalization rate by age group were “J” shaped. The rates for mostly unvaccinated COVID-19 patients in 2020/21 in the context of public health restrictions were significantly higher than influenza among individuals 30 to 69 years of age, and comparable to a severe influenza year (2016/17) among 70+. In early 2022 (Omicron peak), rates primarily due to COVID-19 among vaccinated adults were comparable with influenza 2016/17 in all age groups while rates among unvaccinated COVID-19 patients were still higher than influenza among 18+. In the pediatric population, COVID-19 hospitalization rates were similar to or lower than influenza. Conclusions Our paper highlighted the greater population-level impact of COVID-19 compared with influenza in terms of adult hospitalizations, especially among those unvaccinated. However, influenza had greater impact than COVID-19 among <18 regardless of vaccine status or the circulating variant.

Introduction In randomized controlled trials, single-dose efficacy against SARS-CoV-2 illness exceeded 90% for mRNA vaccines (BNT162b2 and mRNA-1273), and 75% for ChAdOx1. In British Columbia (BC), Canada second doses were deferred up to 16 weeks and ChAdOx1 was only initially recommended for adults 55 years of age and older. We compared single-dose vaccine effectiveness (VE) during the spring 2021 wave in BC when Alpha and Gamma variants of concern (VOC) predominated. Methods VE was estimated against infection and hospitalization by test-negative design: cases were RT-PCR test-positive for SARS-CoV-2 and controls were test-negative. Adults 50-69 years old with specimen collection between April 4 and May 22 (weeks 14-20) were included. Variant-specific VE was estimated between weeks 17-20 when genetic characterization of all case viruses was performed, primarily through whole genome sequencing. Results VE analyses included 7,116 (10%) cases and 60,958 controls. Three-quarters of vaccinated participants received mRNA vaccine (60% BNT162b2, 15% mRNA-1273) and 25% received ChAdOx1. Half of genetically characterized viruses were Alpha, with 38% Gamma, 4% Delta and 8% non-VOCs. Single-dose VE against any infection was 75% (95%CI: 72-78) for BNT162b2, 82% (95%CI: 76-87) for mRNA-1273 and 61% (95%CI: 54-66) for ChAdOx1. VE against hospitalization was 83% (95%CI: 76-89), 85% (95%CI: 63-94) and 96% (95%CI: 86-99), respectively. VE against Alpha vs. Gamma infections did not differ among mRNA (78%;95%CI: 73-82 and 80%;95%CI: 74-85) or ChAdOx1 (66%;95%CI: 57-74 and 60%;95%CI: 48-69) recipients. Conclusions A single dose of mRNA vaccine reduced the SARS-CoV-2 infection risk by at least 75%, including infections due to early VOC. Although effectiveness of a single dose of ChAdOx1 was lower at 60% against infection, just one dose of any vaccine reduced the hospitalization risk by more than 80%. In the context of constrained vaccine supplies, these findings have implications for global vaccine deployment to reduce the overall burden of infections and hospitalizations due to SARS-CoV-2.