Rate-based calculation of failure to progress: A proposed quality improvement method

The rate of “failure to progress” as the indication for primary cesarean delivery used by the Joint Commission on Accreditation of Health Care Organizations is based upon the total number of cesareans performed for this indication divided by the total number of primary cesareans. This denominator includes a large number of patients who are not at risk for the diagnosis of failure to progress, including cases of malpresentation or multiple gestation in which cesarean is performed without trial of labor. Each of these variables may vary dramatically between individual physicians and institutions. Inclusion of patients not at risk for failure to progress results in a misclassification bias, which renders this rate less meaningful for purposes of comparison and trend assessment. We describe a simple method that bases the rate of failure to progress upon the population at risk for this diagnosis; that is, the total number of vaginal deliveries plus primary cesareans for failure to progress minus vaginal births after cesarean. Such a method controls for multiple differences in local practice standards and allows more meaningful assessment of trends and intra-institutional and inter-regional comparisons.