Demographic and temporal trends in mental health and substance use services provided by primary care physicians in British Columbia, Canada.

Background: As the demand for mental health and substance use (MHSU) services increases, there will be an even greater need for health human resources to deliver this care. This study investigates how family physicians' (FP) contact volume, and more specifically, MHSU contact volume, is shaped by demographic trends among FPs in British Columbia, Canada. Methods: We used annual physician-level administrative billing data and demographic information on FPs in British Columbia between 1996 and 2017. This study analyzes trends in primary care service provision among graduating cohorts of FPs, FPs of different ages (as measured by years since graduation), and FPs practicing during different time periods. Additionally, analyses are stratified by FP sex to account for potential differences in labour supply patterns between male and female FPs. Results: Our results show that while FPs' overall contacts with patients decreased between 1996 and 2017, their annual number of MHSU contacts increased, which was largely driven by an increase in substance use visits. Demographically, the proportion of female FPs in the labour force rose over time. Observed trends were similar, though not identical in male and female FPs, as males tended to have higher overall contact volume (both total contacts and MHSU), but also steeper declines in contact volume in later careers. The number of contacts (both total and MHSU) changed across career stage - rising steadily from start to mid-career, peaking at 20–30 years in practice, and decreasing steadily thereafter. This was evident for all cohorts and consistent over the 21-year study period but flattened in amplitude over time. Our findings also point to potential cohort effects on labour supply. The inverse U-shaped career trend extended to MHSU contacts, but its peak seems to have shifted to a later career stage (peaking at 30–40 years of practice) over time. Conclusions: Our study shows changing dynamics in MHSU service delivery among FPs over time, across the life span and between FP sexes that are likely to influence access to care beyond simply the number of FPs. Given the healthcare needs of the population, these findings point to potential future changes in provision of MHSU services. [ABSTRACT FROM AUTHOR]