Predictive Validity of A Medication Adherence Measure in an Outpatient Setting

摘要

This study examines the psychometric properties and tests the concurrent and predictive validity of a structured, self-reported medication adherence measure in patients with hypertension. We also assessed various psychosocial determinants of adherence, such as knowledge, social support, satisfaction with care and complexity of the medical regimen. A total of 1367 patients participated in the study; mean age was 52.5 years, 40.8% were male, 76.5% were black, 51% graduated from high school, 26% were married, and 54.1% had income <$5,000. The eight-item medication adherence scale was reliable (α= 0.83) and significantly associated with blood pressure control (P<0.05). Using a cutpoint of less than 6, the sensitivity of the measure for identifying low versus higher adherers was estimated to be 93%, and the specificity was 53%. The medication adherence measure proved to be reliable with good concurrent and predictive validity in primarily low income, minority patients with hypertension, and might function as a screening tool in outpatient settings with other patient groups.