Variation in cesarean section rates among hospitals in Washington State.

OBJECTIVES: This study examined hospital characteristics and hospital population risk factors and their associations with hospital-specific cesarean section rates in Washington State. METHODS: Data were obtained from 1987 birth certificates. The study population included all hospitals that had 12 or more singleton live births. RESULTS: Hospital-specific cesarean section rates varied from 0% to 43% and were positively associated with proprietary ownership, size of delivery service, and the proportions of women who had complications or high-birthweight infants. The proportion of women who had late prenatal care was inversely associated with cesarean section rates. Although proprietary hospitals had higher cesarean section rates, their patient populations were lower risk than patients of public or teaching hospitals. CONCLUSIONS: Variation in cesarean section rates among hospitals cannot be fully explained by either hospital or patient population characteristics. A combined strategy may be necessary to lower unjustifiably high cesarean section rates.