Potentially inappropriate drug prescriptions and risk of hospitalization among older, Italian, nursing home residents: the ULISSE project.

BACKGROUND: Potentially inappropriate medications in older patients increase the risk of adverse drug events, which are an important cause of hospital admission and death among hospitalized patients. Little information is available about the prevalence of potentially inappropriate drug prescriptions (PIDPs) and the related health adverse outcomes among nursing home (NH) residents.

OBJECTIVE: To estimate the prevalence of PIDPs and the association with adverse outcomes in NH residents.

METHODS: A total of 1716 long-term residents aged >or=65 years participating in the ULISSE (Un Link Informatico sui Servizi Sanitari Esistenti per l'anziano [A Computerized Network on Health Care Services for Older People]) project were evaluated using a standardized comprehensive geriatric assessment instrument, i.e. the interResident Assessment Instrument Minimum Data Set. A thorough evaluation of residents' drug use, medical diagnoses and healthcare resource utilization was performed. A PIDP was defined according to the most recent update of the Beers criteria.

RESULTS: Almost one out of two persons (48%) had at least one PIDP and almost one out of five had two or more PIDPs (18%). Residents with a higher number of PIDPs had a higher likelihood of being hospitalized. Compared with residents without PIDPs, those with two or more PIDPs at baseline had a higher probability of being hospitalized (hazard ratio 1.73; 95% CI 1.14, 2.60) during the following 12 months. Risk of PIDP was positively associated with the total number of drugs and diseases, but negatively with age. PIDPs defined according to specific conditions (n = 780; 55%) were slightly more frequent than PIDPs based on single medications irrespective of specific indication (n = 639; 45%).

CONCLUSIONS: PIDP is a significant problem among Italian NH residents. There is an urgent need for intervention trials to test strategies to reduce inappropriate drug use and its associated adverse health outcomes.