title: Risk-adjustment of cesarean delivery rates: a practical method for use in quality improvement.
abstract: Risk-adjustment of cesarean birthrates has been hampered by inadequacies in the existing secondary data sources or by the need for extensive chart review. This study presents an efficient risk-adjustment model for cesarean birth, based on easily retrievable ICD-9 codes and clinical risk factors least influenced by physician practice style. Data are presented for mothers undergoing 7322 deliveries from 1997-1998 at a large academic medical center with a cesarean birth rate of 15.9%. Multiple logistic regression was used to predict the likelihood of cesarean delivery controlled for maternal age, 10 risk factors identified through ICD-9 coding, and 3 additional clinical variables (nulliparity, birth weight, and gestational age) derived from a perinatal (birth certificate) database. All risk factors were significant predictors of cesarean birth, producing an area under the receiver-operating characteristic curve of 0.86 and a 60-fold increase in cesarean delivery from highest to lowest deciles of predicted risk. This methodology can be used widely for quality improvement without the need for extensive chart review.
authors.affiliation: Division of Maternal and Fetal Medicine, Northwestern University Medical School, Chicago, Ill., USA. amp066@northwestern.edu
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Joe
authors.initials: J
authors.lastname: Feinglass
authors.forename: Larry M
authors.initials: LM
authors.lastname: Manheim
mesh_terms: D000046:Academic Medical Centers / Q000592:standards*; D000328:Adult; D002585:Cesarean Section / Q000592:standards / Q000706:statistics & numerical data*; D002641:Chicago; D017598:Efficiency, Organizational; D005260:Female; D006801:Humans; D016015:Logistic Models; D011247:Pregnancy; D011336:Probability; D020379:Risk Adjustment; D012307:Risk Factors; D017749:Total Quality Management