Impact of Inappropriate Drug Use on Hospitalizations, Mortality, and Costs in Older Persons and Persons with Dementia: Findings from the SNAC Study

BACKGROUND: Inappropriate drug use (IDU) is an important risk factor for adverse outcomes in older persons. We aimed to investigate IDU and the risk of hospitalizations and mortality in older persons and in persons with dementia and to estimate the costs of IDU-related hospitalizations. METHODS: We analyzed 4108 individuals aged ≥60 years from the Swedish National Study on Aging and Care (SNAC) data from Kungsholmen and Nordanstig (2001–2004). IDU was assessed by indicators developed by the Swedish National Board of Health and Welfare. Hospitalizations and mortality data were collected from Swedish registers. Regression models were used to investigate associations between IDU, hospitalizations, and mortality in the whole population and in the subpopulation of persons with dementia (n = 319), after adjustment for sociodemographics, physical functioning, and co-morbidity. Costs for hospitalizations were derived from the Nord-Diagnose Related Group cost database. RESULTS: IDU was associated with a higher risk of hospitalization [adjusted odds ratio (OR) = 1.46; 95 % confidence interval (CI) 1.18–1.81] and mortality [adjusted hazard ratio (HR) = 1.15; 95 % CI 1.01–1.31] within 1 year in the whole study population and with hospitalization (adjusted OR = 1.88; 95 % CI 1.03–3.43) in the subpopulation of persons with dementia, after adjustment for confounding factors. There was also a tendency for higher costs for hospitalizations with IDU than without IDU, although this was not statistically significant. CONCLUSIONS: Our findings suggest that IDU is associated with an increased risk of hospitalization in older persons and in persons with dementia. IDU is also associated with mortality among older persons. These findings highlight the need for cautious prescribing of long-acting benzodiazepines, anticholinergic drugs, concurrent use of three or more psychotropic drugs and drug combinations that may lead to serious drug–drug interactions to older patients. Further studies are needed to investigate the association between IDU and costs for hospitalizations.