Health Profiles, Health Services Use, and Transition to Dementia in Inpatients With Late-Life Depression and Other Mental Illnesses

Abstract

ObjectivesDepression has been reported as a risk factor for dementia. We compared health and health service use profiles in older people hospitalized with late-life depression and older people hospitalized with other mental illnesses and examined the transition to dementia. DesignA retrospective population-based study using linked administrative health data over 11 years. Setting and ParticipantsThe sample includes 55,717 inpatients age 65+ years with depression and 104,068 inpatients age 65+ years with other mental illnesses in New South Wales, Australia. MethodsThe risk of subsequent dementia under consideration of sociodemographics, comorbidities, and health service use was analyzed with logistic regression. ResultsThe most prominent differences were the rates of delirium and self-harm with a 6 times lower rate of delirium and an 8 times higher rate of self-harm in people with late-life depression compared with those with other mental illness. Inpatients with late-life depression had an increased risk of subsequent dementia by 12% and received a dementia diagnosis at a younger age compared with inpatients with other mental illnesses. Besides depression only 3 other conditions, delirium, diabetes, and cerebrovascular accidents, were associated with an increased dementia risk. Other factors associated with an increased dementia risk were longer hospital stays, low socioeconomic status, male sex, and older age. Conclusions and ImplicationsResults from this study lead to a better understanding of the risk for dementia and of differences in health profiles and health services use in older people with depression compared with those with other mental illnesses. Our findings highlight the importance of the clinical management and prevention of self-harm and delirium in older people.