Medication adherence in elderly patients receiving home health services following hospital discharge

OBJECTIVE: To assess prevalence and risk factors for medication under- and overadherence in a two-week period following hospital discharge in adults greater than or equal to 65 years. DESIGN: Prospective, cohort study. SETTING: Three home healthcare agencies in Madison, Wisconsin, and surrounding vicinity. PARTICIPANTS: One hundred forty-seven older participants taking three or more medications who were hospitalized for medical illness, received home nursing after discharge, acid completed the two-week interview. MEASUREMENTS: The main outcome measures were having at least one medication with less than 70% adherence (underadherence) and having at least one medication with more than 120% adherence (overadherence) based on pill counts. RESULTS: Forty-five (30.6%) participants were underadherent and 27 (18.4%) participants were overadherent with at least one medication. In a multivariate model, underadherence was predicted by poor cognition (OR 2.5; 95% CI 1.02 to 6.10) and higher medication use (OR 1.16; 95% CI 1.03 to 1.31, for each 1-unit increase in number of medications). Both poor cognition and low education were significantly associated with overadherence in univariate analysis; however, neither variable was significant once included in the multivariate model. CONCLUSIONS: Under- and overadherence to medications is common after hospital discharge. Poor cognition and a greater number of medications were associated with underadherence. Poor cognition and lower education were markers for overadherence; however, further study is needed to determine whether these are independent predictors. Patients who have impaired cognition or are taking a greater number of medications after hospitalization may benefit from targeted interventions to monitor and improve medication compliance.