Does mental illness history affect primary care chronic disease management in older adults? A population-based propensity score-matched study.

Background: Older adults living with physical chronic conditions and comorbid mental illness have more complex care needs, and may experience side effects of treatment for mental illness that can exacerbate physical conditions. There is a need to examine variation in health service use and chronic disease management in the context of treatment for mental illness.

Objective: We compared evidence-informed management of diabetes, heart failure and chronic obstructive pulmonary disease (COPD) amongst older adults based on history of mental illness treatment.

Design/setting: We conducted a population-based propensity score-matched study in British Columbia, Canada, using health administrative data from 1 April 2020 to 31 March 2023.

Subjects: Older adults (aged ≥65) registered for provincial health insurance and diagnosed with diabetes, heart failure and/or COPD.

Methods: Within each chronic disease subgroup, propensity scores (matching for age, sex, rurality and neighbourhood income quintile) paired individuals 1:1 based on mental illness history. Differences in health service utilisation and chronic disease management outcomes were assessed from P-values.

Results: Older adults with mental illness history had more primary care contacts, virtual visits and contacts with their usual primary care provider and specialists. However, they also had fewer labs/testing and a lower likelihood of being dispensed drugs for their chronic condition than those without mental illness history.

Conclusion: Despite more frequent contact with primary care, older adults with mental illness may face barriers to receiving comparable chronic disease management. These findings underscore the need for more integrated, multidisciplinary care models that address both mental and physical health needs.