Measuring adherence in a community-based elderly population

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.

A prospective, observational pilot study comparing the reliability and validity of the MedAdhIR-ST and the Medication Adherence Questionnaire (MAQ).

Independent senior-housing apartments and senior centers in Wake County, North Carolina.

Eligible subjects included individuals 60 years of age or older who were living in the community and managing their own medication regimens.

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.

Medication adherence.

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.

MedAdhIR-ST appears to be a reliable and valid tool for screening nonadherence in a community-dwelling elderly population.