Mental Illness Prevalence Among Ontario Home Care Clients: Variation by Urban/Rural Residence and Deprivation Measures: Prévalence de la maladie mentale chez les clients de soins à domicile en Ontario : variation selon la résidence urbaine/rurale et

Background Degree of rurality and neighbourhood deprivation are important factors in understanding variation in mental illness across populations, but epidemiological data on their relevance to mental illness in home care (HC) clients are limited. We estimated the prevalence of several mental illnesses by these characteristics and their interaction effects among HC clients and matched community comparators in Ontario, Canada. Method We conducted a repeated cross-sectional study using linked health administrative data. HC recipients aged ≥18 years were matched to community comparators on demographics, dementia, and comorbidity. Within each study sample, prevalence estimates were calculated and compared across urban/rural residence and binary measures of the 4 dimensions of the Canadian Index of Multiple Deprivation (CIMD). Outcomes were derived with validated case definitions for any mental illness, mood/anxiety disorders, depression and anxiety (with/without drug claims), schizophrenia, bipolar disorder, and suicide attempt. Prevalence ratios (PRs: 95% CIs) were estimated with modified Poisson regression models adjusted for relevant covariates. Results We included 479,064 urban- and 72,862 rural-residing HC clients (mean age 73.2 and 72.4 years, respectively). Mental illnesses were less common in rural than urban clients (e.g., any mental illness 31.3% vs. 39.4%), with adjusted PRs between 0.80 and 0.87. Prevalence estimates were significantly higher among clients in areas more marginalized in residential instability and ethno-cultural composition, with more pronounced adjusted PRs for clients in urban than rural settings (e.g., PR [more vs. less marginalized residential instability] for any mental illness: 1.12 (1.12, 1.13) for urban and 1.07 (1.04, 1.10) for rural clients, P < 0.001). In matched community comparators, we observed similar patterns by urban/rural and deprivation measures though mental illness prevalence was significantly lower overall. Conclusions Mental illnesses are common among HC clients and vary regionally. Incorporating geographic and socioeconomic indicators into mental health surveillance systems offers insight into mental health disparities that may warrant more targeted interventions.