Provider distribution and variations in statewide cesarean section rates

Cesarean section rates vary among states from approximately 15% to over 26% of all deliveries. Since it is unlikely that patient factors alone contrib ute to this wide variation, other non-clinical factors that are unique to e ach state must influence cesarean section decisions. To explore if provider workforce and specialty was associated with differences in statewide cesar ean rates, we compared statewide cesarean rates for 1996 with (1) the volum e of deliveries in a state per board-certified obstetrician; (2) percentage of deliveries performed in the state by nurse midwives, and (3) the percen tage of family physicians in the state performing obstetrics. In a linear r egression model that adjusted for state rurality and median income, we foun d that only the percentage of family physicians participating in obstetrics was related to cesarean delivery rates. As the percentage of family physic ians offering obstetric services increased in a state, the rate of cesarean delivery for that state declined. This effect appeared to be independent o f other provider effects, state rurality, or statewide income. Family physi cian participation in obstetrics is unlikely to be the cause for lower cesa rean rates, but is likely a marker for a medical environment and practice s tyle that supports non-operative obstetric care.