The extent of physician participation in Medicaid: a comparison of physician estimates and aggregated patient records.

This article compares two measures of the extent of physician participation in Medicaid programs. The first, which has been used in most research to date on the subject, is based on physician estimates of the proportion of their patients who are Medicaid patients. The second derives from encounter forms for a sample of visits to the interviewed physicians. The comparison shows that physicians in the sample tended to overestimate by 40 percent the extent of their Medicaid participation. Because the two measures are highly correlated, the analysis of the determinants of Medicaid participation was not affected by the measure used. However, since physicians tended to overstate the proportion of Medicaid patients in their practices, interview data should not be used to measure the amount of physician participation or to calculate elasticities for the effects of policy changes on the extent of participation.

Full and limited medicaid participation among pediatricians.

Participation in Medicaid by pediatricians is an important element in the access of low income children to health care. Factors that influence whether participating pediatricians choose to participate fully in the program or to limit their acceptance of Medicaid patients are identified and analyzed. Data were derived from interviews conducted with 814 pediatricians in 13 states. A multivariate analysis examining physician, practice, service area, and Medicaid policy characteristics indicates that policy factors are most influential in the physician's decision whether to participate fully in medicaid programs. Factors found to foster the willingness of pediatricians to participate fully in state Medicaid programs included more competitive levels of reimbursement, minimal delays in reimbursement, and eligibility and benefit policies that minimize interference with the exercise of medical judgment.