Rates of outpatient mental health service use and relocation among female military spouses: a matched retrospective cohort study

Introduction: In Canada, non-serving spouses of military members experience frequent geographic mobility and other military lifestyle dimensions that may cause a greater need for mental health services and barriers to their use, relative to civilians. Our team’s previous work has documented less frequent use of mental health services for female military spouses in Ontario. In this study, we updated our team’s previous investigation of mental health services use among civilian, female Canadian Armed Forces (CAF) spouses in Ontario with an additional decade of data and a more sophisticated approach to comparing rates of use. We also investigated the impact of relocations on mental health services use, and whether the impact of a move is different for CAF spouses compared with matched civilians. Methods: This was a matched retrospective cohort study comparing female CAF spouses posted to Ontario between 01/01/2008 and 12/31/2019 with Ontario female civilians using administrative health data. CAF female spouses were hard-matched to civilians in Ontario 5:1 without replacement on age at index, sex, and geography. Participants were followed until 03/31/2023 or death. Outcomes included mental-health related emergency department (ED) visits, primary care visits, and psychiatrist visits. Estimated relative rates were adjusted for income quintile, index year, and geography using Andersen-Gill recurrent event regression models comparing female military spouses and female Ontarians. Effect modification by age, income, and region were investigated. We also estimated relative rates adjusted for a time- varying exposure of relocations >100km using Andersen-Gill models. Results: The cohort included 6,183 female CAF spouses and 30,915 civilians. Crude mental health-related ED visit rates for female CAF spouses and matched female Ontarians were 16 and 22 per 1000 person- years (crude RR 0.72, 95% CI 0.64-0.82). Corresponding data for primary care visits, and psychiatrist visits were 385 and 571 per 1000 person-years (crude RR 0.67, 95% CI 0.66-0.69), and 82 and 209 per 1000 person-years (crude RR 0.39, 95% CI 0.37-0.41), respectively. After adjusting for confounders, the rates of mental health services use for CAF female military spouses were significantly lower relative to female civilians across all measures. We did not observe significant heterogeneity by age but did identify differences in the association by income and region of the province. Conclusions: Information on how mental health services were accessed by civilian CAF spouses in the public health system can inform the planning and delivery of mental health services. Research is needed to understand why rates of mental health services use and relocation events were lower, and whether they reflected unmet need among female spouses, differences in the epidemiology of common mental disorders between CAF spouses and the civilian population, or a greater use of federally funded mental health services or those paid for privately by employment health insurance.