1. Thus, the existence of a causal connection is an open question. A study of the 1977 California birth cohort found that the CS rate was inversely related to perinatal mortality, adjusted for birthweight and other factors,'5 but the results were dominated by heterogeneity among the types of hospital, and the findings probably represent the unadjusted confounding effects of socioeconomic status. Thus, it remains unclear what the optimal
2. The physician factor in cesarean birth rates;Goyert, G.L.; Bottoms, S.F.; Treadwell, M.C.; Nehra, P.C.;N Engl J Med,1989
3. Comparisons of national cesarean section rates;Notzon, F.C.; Placek, P.J.; Taffel, S.M.;N Engl Jf Med,1987
4. Variations in operative delivery rates;Lomas, J.; Enkin, M.;Effective care in pregnancy and childbirth,1989
5. Population Censuses and Surveys. Hospital inpatient enquiry. Maternity tables 1982-1985;Department of Health and Social Security, Office of;(Series,1988