Comparing variation in hospital rates of cesarean delivery among low-risk women using 3 different measures

This report describes the development of a measure of low-risk cesarean delivery by the Society for Maternal-Fetal Medicine (SMFM). Safely lowering the cesarean delivery rate is a priority for maternity care clinicians and health care delivery systems. Therefore, hospital quality assurance programs are increasingly tracking cesarean delivery rates among low-risk pregnancies. Two commonly used definitions of "low risk" are available, the Joint Commission (JC) and the Agency for Healthcare Research and Quality (AHRQ) measures, but these measures are not clinically comprehensive. We sought to refine the definition of the low-risk cesarean delivery rate to enhance the validity of the metric for quality measurement. We created this refined definition-called the SMFM definition-and compared it to the JC and AHRQ measures using claims-based data from the 2011 Nationwide Inpatient Sample of >863,000 births in 612 hospitals. Using these definitions, we calculated means and interquartile ranges (25th-75th percentile range) for hospital low-risk cesarean delivery rates, stratified by hospital size, teaching status, urban/rural location, and payer mix. Across all hospitals, the mean low-risk cesarean delivery rate was lowest for the SMFM definition (12.65%), but not substantially different from the JC and AHRQ measures (13.12% and 13.29%, respectively). We empirically examined the SMFM definition to ensure its validity and utility. This refined definition performs similarly to existing measures and has the added advantage of clinical perspective, enhanced face validity, and ease of use.