Inter-hospital variations in caesarean sections. A risk adjusted comparison in the Valencia public hospitals

Background-The aim of this study was to describe the variability in caesare an rates in the public hospitals in the Valencia Region, Spain, and to anal yse the association between caesarean sections and clinical and extra-clini cal factors. Methods-Analysis of data contained in the Minimum Basic Data Set (MBDS) com piled for all births in 11 public hospitals in Valencia during 1994-1995 (n =36 819). Bivariate and multivariate analyses were used to evaluate the ass ociation between caesarean section rates and specific risk factors. The mul tivariate model was used to construct predictions about caesarean rates for each hospital, for comparison with rates observed. Results-Caesarean rates were 17.6% (inter-hospital range: 14.7% to 25.0%), with ample variability between hospitals in the diagnosis of maternal-fetal risk factors (particularly dystocia and fetal distress), and the indicatio n for caesarean in the presence of these factors. Multivariate analysis sho wed that maternal-fetal risk factors correlated strongly with caesarean sec tion, although extra-clinical factors, such as the day of the week, also co rrelated positively. After adjusting for the risk factors, the inter-hospit al variation in caesarean rates persisted. Conclusions-Although certain limitations (imprecision of some diagnoses and information biases in the MBDS) make it impossible to establish unequivoca l conclusions, results show a high degree of variability among hospitals wh en opting for caesarean section. This variability cannot be justified by di fferences in obstetric risks.