Managed care market share and cesarean section rates in the United States:Is there a link?

Objective: After peaking during the early 1980s, cesarean section rates in the United States have been falling for the last decade. At the same time, managed care enrollment has increased dramatically, This study examines whe ther managed care penetration in local markets is associated with lower ces arean section rates in those geographic area. Study Design: A cross-sectional comparison of cesarean section rates and he alth maintenance organization (HMO) market penetration in 61 selected metro politan areas in the United States was conducted. National birth certificat e data for 1996 were used to calculate crude and race-adjusted cesarean sec tion rates for residents in each area. Results: No relationship between overall cesarean section rates in the metr opolitan areas and managed care penetration was observed. Subanalyses of ra cial groups demonstrated the existence of a weak association between manage d care penetration and cesarean section rates for white women (21.2% for th e highest quartile of HMO penetration, compared with 19.1% for the lowest q uartile; P = .03), but not for African-Americans or other minorities. Conclusions: Managed care penetration in a market may have an association w ith cesarean section rates for white women, but the strength of this relati onship is small. Even if managed care delivery systems reduce cesarean sect ion rates in their own populations, this change is likely to have only a sm all impact on overall cesarean rates. HMO penetration is unlikely to influe nce national cesarean section rates, nor does it appear to explain state va riations in these rates.