Background:Residential mobility influences cumulative environmental exposures over the life course, yet few national datasets capture these dynamics across multiple exposure domains. This paper describes the development of the Residential Mobility Exposome File (ReMEF) and the cohort profile. Data and methods:The ReMEF integrates individual-level residential histories from linked census and administrative data with annually resolved spatial measures of ambient air pollution, built and green environment characteristics, and ambient temperature. Annual k-means clustering was applied within each domain to classify exposures into three levels (low, medium, or high), followed by a temporal dominance rule to derive five-year exposure biographies. The analytical cohort included individuals aged 25 to 89 years with stable pre-baseline residence, enabling assessment of residential mobility patterns and exposure trajectories. Results:The ReMEF framework offers a scalable approach for leveraging residential mobility as a quasi-experimental feature of observational data. The standardized trichotomy (low, medium, high) applied across domains allows for comparability between different types of exposures. Residential mobility varied substantially by population group and socioeconomic characteristics. Certain racialized populations had relatively higher mobility, while First Nations and Inuit individuals were less likely to move. Distinct exposure biographies were observed across environmental domains, with racialized and immigrant populations more frequently residing in higher ambient air pollution clusters. Interpretation:The ReMEF provides a resource analytical file and is useful for natural experiments that aim to leverage residential mobility to examine cumulative, multi-domain environmental exposures and disparities over time. The analytical file creation code is available upon request, and it can be recreated using the source data following approval.
Background:Previous research has shown that Black adults in Canada experience higher cause-specific mortality and differential rates of diagnosis and hospitalization compared with White adults. These disparities may reflect underlying differences in access to health care. This study assesses whether inequalities in access to primary and pharmaceutical health care exist between Black and White adults in Canada. Data and methods:This study used pooled data from the annual Canadian Community Health Survey from 2015 to 2019. Access to care was measured through indicators of primary care access and insurance for prescription medicine. Inequalities were assessed through crude and adjusted differences between Black and White adults, and counterfactual decomposition methods were applied to identify the contributions of specific factors to observed inequalities. Results:Primary care access and insurance for prescription medicine were significantly lower for Black adults aged 25 years and older, compared with White adults in the same age group, from 2015 to 2019. About three-quarters of the differences in having a regular health care provider and insurance for prescription medicine were explained by population differences in the levels of measured covariates, including demographic, immigrant, and socioeconomic factors. By contrast, less than one-third of the difference in going to a doctor's office for care of a minor problem was explained by model covariates. Interpretation:Much of the measured inequality between Black and White adults in having a regular health care provider and insurance for prescription medicine was attributable to differences in demographic factors, immigrant status, and socioeconomic variables. However, these factors explained less of the inequality in visiting a doctor's office for care of a minor problem. Notably, socioeconomic factors - including educational attainment, occupational skill level, and household income - represent modifiable determinants that may be amenable in reducing the observed disparity.
Background:Canada's population is aging rapidly, with implications for the health care system, including increasing demand for specialist care. However, few studies have examined factors associated with specialist care use, difficulty accessing such care, and the relationship between access difficulties and unmet health care needs among middle-aged (45 to 64 years) and older (65 years or older) adults. Data and methods:Data from the 2024 Survey on Health Care Access and Experiences - Primary and Specialist Care were used to identify factors associated with specialist care use, difficulty accessing specialist care, and to examine the relationship between access difficulties and unmet health care needs. Drawing on a nationally representative sample of 23,473 Canadians aged 45 or older, multivariable logistic regression analyses were conducted separately for middle-aged and older adults. Results:In 2024, 38.5% of Canadians aged 45 or older used specialist care, 27.8% experienced access difficulties, and 18.0% reported unmet health care needs. Older adults (65 years or older) were more likely than middle-aged adults (45 to 64 years) to use specialist care (42.9% versus 35.1%) but less likely to report difficulty accessing it (24.6% versus 30.2%). Having a greater number of chronic conditions or a disability was associated with both specialist care use and greater difficulty accessing specialist care among middle-aged and older adults. Experiencing difficulties accessing specialist care was strongly associated with a higher likelihood of having unmet health care needs among middle-aged (6.2 times) and older (14.0 times) adults. Interpretation:The study underscores the importance of accounting for multiple factors, such as age, gender, immigrant status, multimorbidity, disability, and access to a primary health care provider, when examining access to care.
Background:Breast cancer is the most commonly diagnosed cancer among women in Canada. Breast density substantially influences breast cancer risk and mammography performance. However, OncoSim-Breast, a Canadian microsimulation model representing breast cancer control, including cancer onset, screening, and survival, has not previously explicitly accounted for breast density. This study describes the incorporation of density-specific parameters into the OncoSim-Breast model. Data and methods:Breast density-specific inputs were integrated into OncoSim-Breast using data from five Canadian provinces. Three key parameters - prevalence, relative risk of breast cancer, and digital mammography performance (sensitivity and specificity) - were estimated by age group and breast density category, following the American College of Radiology's Breast Imaging Reporting and Data System (BI-RADS) classification (categories A to D). Calibration experiments and internal validations were conducted to ensure the updated OncoSim-Breast model aligned with observed data from the Canadian Cancer Registry. Results:The prevalence of dense breasts declined with age: BI-RADS categories C and D accounted for 58% of women younger than 50 years and 26% of those aged 70 and older. Digital mammography sensitivity also decreased with increasing density: among women younger than 50 years, sensitivity was 88% for Category A and 69% for Category D. The updated OncoSim-Breast model accurately replicated age-specific incidence, age-adjusted incidence, and stage distribution based on historical data from the Canadian Cancer Registry (2010 to 2019). Interpretation:Incorporating breast density-specific parameters substantially improved the accuracy and policy relevance of OncoSim-Breast. The updated model provides a validated tool to inform screening policy decisions for Canadian women, allowing consideration for the effect of the variability of breast density among women.
Background:Previous work has noted variability in cancer incidence and cancer-related outcomes according to place of residence. This study examined geographic variability in the incidence and mortality of breast cancer among females in Canada. Data and methods:Data from the 2021 Canadian Cancer Registry (breast cancer incidence) and the Canadian Vital Statistics - Death database (breast cancer mortality) were examined across provinces and territories, community sizes, and peer groups (i.e., clusters of health regions with similar socioeconomic and demographic characteristics). Age-standardized incidence rates (ASIRs) and age-standardized mortality rates (ASMRs) per 100,000 females per year and their rate ratios were calculated, as well as age group-specific and age-standardized stage-specific incidence rates. Results:From 2010 to 2020, the invasive breast cancer ASIR was 140.1 per 100,000 females annually, with marked geographic and community variation. Mean age at diagnosis was 62.7 years, and it was lowest in northern and remote regions. Three-quarters of cases were stages I and II, though stage-specific ASIRs varied. Overall ASIRs were highest in peer groups B (urban centres with large immigrant and racialized populations) and D (rural regions in Quebec, Ontario and the Prairies). They were lowest in peer groups F (Northern and remote regions with young populations), G (Montréal, Toronto, and Vancouver), and H (urban centres in Ontario and British Columbia). From 2010 to 2022, the ASMR was 28.3 per 100,000, highest in rural Eastern Peer Group E and lowest in large urban centres. Interpretation:The study found significant variability in female breast cancer incidence and mortality across the geographical classifications considered, highlighting the need for a closer look at regional- and individual-level factors and their respective associations with cancer incidence and outcomes.
