Measuring Adherence in a Community-Based Elderly Population

Abstract

OBJECTIVE: To examine the reliability and validity of the Medication Adherence Individual Review-Screening Tool (MedAdhIR-ST) for assessing medication adherence in a community-dwelling elderly population. DESIGN: A prospective, observational pilot study comparing the reliability and validity of the MedAdhIR-ST and the Medication Adherence Questionnaire (MAQ). SETTING: Independent senior-housing apartments and senior centers in Wake County, North Carolina. PARTICIPANTS: Eligible subjects included individuals 60 years of age or older who were living in the community and managing their own medication regimens. INTERVENTIONS: Each subject was asked to participate in two assessment visits, two weeks (+/- 3 days) apart, in which the questions of the MedAdhIR-ST and MAQ were administered. MAIN OUTCOME MEASURE: Medication adherence. RESULTS: Both tools showed moderate-to-high test/retest reliability in the study population (correlation coefficient of 0.632 for MAQ, and 0.699 for MedAdhIR-ST), and moderate internal consistency (Cronbach's a of 0.551 and 0.584, respectively). Moderate concordance in the ability to assess adherence was observed between MedAdhIR-ST and MAQ (positive correlation coefficient of 0.450). When compared with refill records, MedAdhIR-ST was slightly more sensitive (67% vs. 43%) and specific (60% vs. 50%) for detecting adherence and nonadherence, respectively, compared with MAQ. Exploratory factor analysis indicated that MedAdhIR-ST is multidimensional. CONCLUSION: MedAdhIR-ST appears to be a reliable and valid tool for screening nonadherence in a community-dwelling elderly population.