Using Medicaid Claims Data to Evaluate a Large Physician Fee Increase

Health Services Research
August 1994
Fox, M.H. and K.L. Phua

OBJECTIVE. This study demonstrates the use of Medicaid claims data in order to evaluate a threefold fee increase in physician fees for deliveries ($265 to $795), which the Maryland Medicaid program implemented in 1986. DATA SOURCES AND STUDY SETTING. The study used Maryland Medicaid claims data for years of service 1985-1988, and was done at the Maryland Department of Health and Mental Hygiene with the help of a Robert Wood Johnson, Health Care Financing and Organization (HCFO) grant. STUDY DESIGN. Overall, our design is that of a pre-test, post-test with multiple observation points both before and after the fee increase. We measured participation in three ways, corresponding to three different units of analysis. With the county-quarter year as unit of analysis, we followed a panel of providers over 16 quarters for each county in the state to determine changes in the number of delivering providers. With the individual provider as the unit of analysis, we identified effects on their Medicaid caseload between years that may have been influenced by the fee increase. Finally, we looked at continuously enrolled Medicaid women who delivered to determine the effects of the fee increase on site and volume of prenatal care. DATA COLLECTION/EXTRACTION METHODS. Analytic files for each unit of analysis were compiled from previously extracted Medicaid claims files using standard statistical software packages. PRINCIPAL FINDINGS. Using techniques described, we were able to get an in-depth picture of overall responsiveness to the intervention. We found a moderate influence of the fee increase on overall participation, less than what we would have predicted. CONCLUSIONS. Administrative data can be used to construct efficient, yet sophisticated evaluations of major policy changes. Findings from our evaluation suggest a moderate effect of the fee increase on overall participation. However, raising fees to the level of private third party payers does not in itself guarantee equal access to private physician health care for Medicaid mothers.

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