Psychometric Properties of the CAHPS™ 1.0 Survey Measures

OBJECTIVES: Consumer surveys are being used increasingly to assess the quality of care provided by health plans, physician groups, and clinicians. The purpose of the Consumer Assessment of Health Plans Study (CAHPS) is to develop an integrated and standardized set of surveys designed to collect reliable and valid information about health plan performance from consumers. This article reports psychometric results for the CAHPS 1.0 survey items in samples of individuals with Medicaid or private health insurance coverage. METHODS: Reliability estimates for CAHPS 1.0 measures were estimated in a sample of 5,878 persons on Medicaid and 11,393 persons with private health insurance. Correlations of the CAHPS global rating of the health plan with willingness to recommend the plan and intention to re-enroll were estimated in a sample of 313 persons on Medicaid. The association of the rating of the health plan with ratings using a 5-point Excellent-to-Poor response scale also was investigated in the latter sample and in a sample of 539 persons with private health insurance. RESULTS: The CAHPS measures appeared to have good reliability, particularly at the health-plan level. Responses from 300 consumers per health plan tend to yield estimates that are reliable enough for health plan comparisons, especially among the privately insured. The global health plan rating was significantly correlated with consumers' willingness to recommend the plan to family and friends and to their intention to re-enroll in the plan if given a choice. CONCLUSIONS: The CAHPS 1.0 survey instrument appears to have excellent psychometric properties.