Is there an association between inappropriate prescription drug use and adherence in discharged elderly patients?

Background: Inappropriate prescription drug (IPD) use is very common among older patients. However, its impact on medication continuity and adherence after hospitalization has not been researched, with little known regarding readmissions and mortality.

Objective: To investigate the prevalence and clinical characteristics of patients discharged with IPDs and examine whether use of these drugs is related to medication continuity and adherence 1 month postdischarge as well as to readmissions and mortality 3 months postdischarge.

Methods: Clinical and demographic data, postdischarge medication modification, and adherence were prospectively obtained on interview of 212 unselected elderly (aged > or = 65 y) patients or, if necessary, their caregivers. Nonadherence was defined as the percentage of drug doses less than or equal to 70% or greater than or equal to 110%. Medication appropriateness was assessed retrospectively using the Beers' criteria.

Results: Use of IPDs occurred in 43.5% and 44.4% of patients on admission and discharge, respectively. At discharge, the numbers of IPDs and prescribed drugs were correlated (R = 0.39; p < 0.01). No relationship was found between IPDs at discharge and age, sex, functional and cognitive status, number of chronic diseases, and reason for admission. Sixty percent of patients who were nonadherent to at least one drug had at least one IPD, compared with 37.4% of the adherent patients (p = 0.008). Nonadherence to at least one drug increased as the number of IPDs on discharge increased (p = 0.004). No relationship was found between IPD use and postdischarge medication modifications, readmissions, and mortality.

Conclusions: A high number of hospitalized elderly patients are discharged with IPDs that are directly correlated with the number of prescribed drugs at discharge and postdischarge nonadherence. Further studies are needed to assess the impact of postdischarge IPD use on health outcome, and healthcare providers should work to decrease its prevalence.