Journal Article

Competition and health plan performance: evidence from health maintenance organization insurance markets.

Scanlon DP, Swaminathan S, Chernew M, et al. Medical care. 2005;43:338-46.

This study of 341 health maintenance organizations found that plans in markets with greater competition showed inferior performance on three of six standard quality measures. While the cross-sectional design does not permit causal inferences, these findings argue against the frequently encountered view that greater competition will foster improvements in safety and quality of care.