IMPACT OF RISK-ADJUSTING CESAREAN DELIVERY RATES WHEN REPORTING HOSPITAL PERFORMANCE

Context.-Hospitals and health plans are often ranked on rates of cesar ean delivery, under the assumption that lower rates reflect more appro priate, more efficient care. However, most rankings do not account for patient factors that affect the likelihood of cesarean delivery. Obje ctive.-To compare hospital cesarean delivery rates before and after ad justing for clinical risk factors that increase the likelihood of cesa rean delivery. Design.-Retrospective cohort study, Setting.-Twenty-one hospitals in northeast Ohio. Patients.-A total of 26 127 women withou t prior cesarean deliveries admitted for labor and delivery from Janua ry 1993 through June 1995. Main Outcome Measures.-Hospital rankings ba sed on observed and risk-adjusted cesarean delivery rates. Results.-Th e overall cesarean delivery rate was 15.9% and varied (P<.001) from 6. 3% to 26.5% in individual hospitals. Adjusted rates varied from 8.4% t o 22.0%. The correlation between unadjusted and adjusted hospital rank ings (ie, 1-21) was only modest (R=0.35, P=.12). Whereas 7 hospitals w ere classified as outliers tie, had rates higher or lower [P<.05] than overall rate) on the basis of both unadjusted and adjusted rates, out lier status changed for 5 hospitals (24%), including 2 that changed fr om outliers to nonoutliers, 2 that changed from nonoutliers to outlier s, and 1 that changed from a high outlier to a low outlier. Conclusion s.-Cesarean delivery rates varied across hospitals in a single metropo litan region. However, rankings that fail to account for clinical fact ors that increase the risk of cesarean delivery may be methodologicall y biased and misleading to the public.