An assessment of different components of patient medication knowledge.

Different components of drug knowledge (i.e., knowledge of the drug purpose, regimen, action if a dose is missed, and common side effects) were examined in 187 ambulatory cardiovascular patients in order to determine whether the components were similar enough to be considered interchangeable in representing drug knowledge. Patients and physicians were interviewed in a family practice setting and their responses compared for each cardiovascular drug the patient was taking. Scores were highest for knowledge of the drug regimen and purpose, fewer patients were correct about the appropriate action if a dose were missed, and only a small number could accurately identify common side effects associated with their drug therapy. The comparison of patient responses to each of the knowledge measures indicated that there was little consistency in response across the various types of knowledge. The differences in the measures were supported further by regression equations that showed different relationships between a set of independent variables and knowledge of drug purpose and regimen, respectively. The study findings suggest that a partial explanation for inconsistencies of research about drug knowledge may be the way this concept is measured.