Restrictions on provider access in health plans and socioeconomic status.

Objective: To model the socioeconomic determinants of restrictions on provider access and choices in health plans.

Data Sources: Data from the 1996-97 Community Tracking Study are used. Publicly available enrollee data including enrollee reports of health care plan characteristics are linked with restricted use data with insurer reports of health plan characteristics.

Study Design: This is an observational study. A mixed multinomial logit model is used to model the enrollees' choice between health plans, each plan being treated as a bundle of attributes formed from restrictions on provider access.

Principal Findings: There are important differences between the enrollee responses and the insurer reports, which may be due to poor information dissemination on the part of health plans and/or lack of attention on the part of enrollees. There is no evidence of selection into plans with restrictive attributes on the basis of observed health status but there is evidence of selection on the basis of race, ethnicity, gender and other socioeconomic characteristics. Determinants of plan supply, i.e., employment characteristics, are the most important determinants of plan attribute choices.

Conclusion: The finding suggests that plan designs optimized using "objective" knowledge and with the best intentions may not receive favorable reviews from enrollees because enrollees have different perceptions of these plans.