Psychometric Properties of an Instrument to Assess Medicare Beneficiaries’ Prescription Drug Plan Experiences

Using data from 335,249 Medicare beneficiarieswho responded to the 2007 MedicareConsumer Assessment of Healthcare Providersand Systems (CAHPS®) survey, alongwith data from 22 cognitive interviews, weinvestigated the reliability and validity ofan instrument designed to assess beneficiaries’experiences with their prescription drugplans. Composite measures derived from theinstrument had acceptable internal consistencyand sufficient plan­level reliability toinform consumer choice, quality improvement,and payor oversight. These measureswere positively associated with members’overall rating of the plan and their willingnessto recommend the plan. Moreover, eachwas independently useful in predicting beneficiaries’global ratings of their plan. Thisinstrument can be an important tool forhelping beneficiaries to choose a plan thatbest meets their needs.