Development of the purposeful action medication-taking questionnaire.

This three-phase study describes the development and psychometric properties of the Medication-Taking Questionnaire (MTQ) to measure the purposeful action domain (reasons individuals decide to accept medication treatment) in the medication adherence model for hypertension. During Phase I, items were evaluated for content validity and clarity. Item analysis, internal consistency, and exploratory factor analysis were preformed during Phase II to finalize the MTQ: Purposeful Action as 12 items and 2 subscales (treatment benefits and medication safety). Phase III evaluated the MTQ: Purposeful Action for temporal stability and construct validity. The final version MTQ: Purposeful Action demonstrated good internal consistency, temporal stability, and construct validity. The MTQ: Purposeful Action appears to have good psychometric characteristics that represent the decision-making process for adherence in medication treatment for hypertension.