The prevalence, trends and determinants of mental health disorders in older Australians living in permanent residential aged care: Implications for policy and quality of aged care services.

Mental health disorders are a major health concern in older people and are associated with a higher risk of disability, frailty and early mortality. This study aimed to conduct a contemporary population-based assessment of the prevalence, trends and factors associated with mental health disorders in individuals who are living in permanent residential aged care (PRAC) in Australia. A retrospective cross-sectional study was conducted using national data from the Registry of Senior Australians, a national cohort of older Australians who had aged care eligibility assessment and entered PRAC between 2008 and 2016. Stepwise multivariate logistic regression modeling was applied to identify factors associated with mental health disorders. Of 430,862 individuals included in this study, 57.8% had at least one mental health disorder. The prevalence of depression, phobia/anxiety and psychosis were as follows: 46.2% (95% confidence interval = [46.0%, 46.3%]), 14.9% (95% confidence interval = [14.8%, 15.0%]) and 9.7% (95% confidence interval = [9.6%, 9.8%]), respectively. The likelihood of having a mental health disorder was higher for those who were (adjusted odds ratio [95% confidence interval]) relatively younger, specifically for every 10-year increment in age, the odds of having mental health disorders was 44.0% lower (0.56, [0.55, 0.56]); female (1.33 [1.32, 1.35]); having increasing numbers of physical health comorbidities, 6-10 (1.26 [1.24, 1.29]) or 11-15 (1.48 [1.45, 1.51]) or more than 15 (1.64 [1.58, 1.71]) compared to people having less than five comorbidities; having limitations related to health care tasks (1.05 [1.04, 1.07]), meals (1.04 [1.02, 1.05]) or social and community participation (1.10 [1.08, 1.12]). The burden of mental health disorders in older Australians living in PRAC was high and individuals with these conditions tend to be younger, with several physical comorbidities and/or functional limitations. Understanding the profile of individuals with mental health disorders at entry into PRAC can be used as evidence for baseline resource allocation for this population and evaluation of future needs of mental health services.