Psychometric properties of the CAHPS 1.0 survey measures. Consumer Assessment of Health Plans Study

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.

Special issues addressed in the CAHPS survey of Medicare managed care beneficiaries. Consumer Assessment of Health Plans Study

OBJECTIVES

This article describes the process through which the MMC survey was developed and examines issues in using this survey with Medicare beneficiaries that have implications for all CAHPS surveys. These include the ability of Medicare beneficiaries to use MMC navigational features, whether access measures are meaningful for this population, and whether beneficiaries' familiarity with managed care influences their health plan assessments.

BACKGROUND

The Health Care Financing Administration (HCFA) is mandated to provide comparative plan information, based partly on consumer surveys, to Medicare beneficiaries. The Consumer Assessments of Health Plans Study (CAHPS) is an integrated set of tested, standardized surveys of health plan enrollees. To meet its goal, HCFA has invested in the development of a CAHPS survey of beneficiaries enrolled in Medicare Managed Care plans (MMC).

METHODS

Cognitive interviews were completed with 31 Medicare beneficiaries. A field test also was conducted with beneficiaries to examine patterns of survey response. A sample of 956 eligible individuals was selected from six health plans. Using a combination of mail and telephone data collection, 663 (69%) questionnaires were completed. This article provides selective results from these tests.

RESULTS

The use of screening questions, skip instructions, and tailored "not applicable" response options appeared to facilitate the response task. Some CAHPS access questions were not meaningful to Medicare beneficiaries. The data do not support the need to adjust for length of plan enrollment.

CONCLUSION

Analyses suggested changes to improve the MMC survey and to make other CAHPS surveys consistent with these changes.

In situ microviscoelastic measurements by polarization-interferometric monitoring of indentation depth

new type of computer-controlled instrument has been developed to measure microviscoelastic properties of thin materials. It can independently control and measure indentation loads and depths in situ revealing information about material creep and relaxation. Sample and indenter positions are measured with a specially designed polarization interferometer. Indenter loadings can be varied between 0.5 and 10 g and held constant to +/-41 mg. The resulting indentation depths can be measured in situ to +/-1.2 nm. The load required to maintain constant indentation depths from 0.1 to 5.0 microim can be measured in situ to +/-3.3 mg and the depth held constant to +/-15 nm.