Case-mix adjusted odds ratios as an alternative way to compare hospital performances.

The purpose of this study was to compare two different methods to describe C-section variability among hospital units: case-mix adjusted ORs and case-mix adjusted rates. About 41,755 deliveries without previous C-section occurred in 60 hospitals in 2001 were analysed. Logistic regression was used to produce both adjusted rates and ORs by maternity unit. The two methods showed similar rankings, however ORs estimates were more precise and proved to be a useful tool to describe C-section variability across hospitals.