Comparing Administrative Data and Resident Assessment Instrument Data for Mental Health Surveillance in Home Care and Long-Term Care Populations.

OBJECTIVES: To compare mental illness prevalence, and agreement between mental illness measures, in home care (HC) and long-term care (LTC) using administrative definitions and Resident Assessment Instrument (RAI)-diagnoses. METHODS: Applying a common protocol to linked administrative-RAI datasets in Alberta, Manitoba, and Ontario, Canada, we selected adults receiving HC or LTC between 2012 and 2023. Cross-sectionally, we compared administrative definitions with RAI-diagnoses (depression, anxiety, bipolar disorder and schizophrenia) using kappa, sensitivity, specificity, positive and negative predictive value. We examined discordance-associated factors using multivariable logistic regression. RESULTS: Depression was the most prevalent mental illness (administrative data, HC: 29%-34% of 493,895 people; LTC: 21%-51% of 357,117 people). Prevalence estimates were consistently lower using RAI-diagnoses than administrative definitions. Agreement between data sources was moderate for depression (k = 0.33-0.57) and anxiety disorders (k = 0.35-0.63). Younger age, dementia, and more physician visits were associated with higher likelihood of discordance between data sources; male sex had a lower likelihood. CONCLUSION: While mental illness prevalence is high in HC and LTC populations, RAI-based estimates are lower than administrative data estimates. Discordance between data sources differs by individual characteristics. Concurrent comparison of RAI-diagnoses and administrative data to a gold standard clinical interview would clarify the optimal surveillance strategy.