Estimates of ethnic disparities across a variety of preventive screening tests vary depending on whether the estimates are based on Medicare claims records or on patient self-reports. A study published today in the open access journal BMC Health Services Research reveals that ethnic disparities in preventive screening procedures, such as Pap smear and cholesterol testing, are larger when estimated using Medicare claims than when using surveys of patients. The reasons for this discrepancy are unclear, but they may have profound policy implications, in the allocation of national resources to eliminate health care disparities, and potentially in the use of claims data to monitor quality of care.
Kevin Fiscella and colleagues from the University of Rochester School of Medicine and Dentistry in Rochester, New York collaborated with colleagues from the University of California School of Medicine in Sacramento, California. Fiscella et al. analysed patient surveys of the last preventive procedures that they had received and compared them with matched Medicare claims for these patients. A total of 49,645 records were analysed. The procedures included those commonly used to screen for disease, such as PSA testing for prostate cancer; Pap smear testing for precancerous and cancerous cervical lesions, cholesterol testing, mammography screening for breast cancer and colorectal cancer screening tests. In addition, the team examined receipt of influenza vaccination.
The results of Fiscella et al.'s study show that, with the exception of PSA testing, ethnic disparities in the preventive procedures analysed were larger when based on Medicare claims than when using patients' self-reports. After adjusting for age, gender, income, educational level, and health status, the results show that minorities are more likely to report receipt of a preventive procedure in the absence of a submitted Medicare claim, thus minimizing the gap in these procedures between different ethnic groups.
The authors write: "It is not clear whether higher rates of self-report in the absence of a claim represent a greater tendency among minorities to "over-report" across many procedures or whether these findings represent suboptimal Medicare billing by providers who serve minorities."
They recommend further studies to clarify the causes of discrepancies in disparity estimates based on patient self-report and claims data.
Journal
BMC Health Services Research