Association between hospital-level cesarean delivery rates and severe maternal morbidity and unexpected newborn complications.

Abstract

INTRODUCTION\nWhile there are many indications for a cesarean delivery (CD), the optimal CD rate is unknown. Neonatal and maternal morbidity have largely not been considered in the generation of hospital-level CD rate targets.\n\n\nOBJECTIVE\nWe sought to examine if widely adopted and reported markers of maternal and neonatal morbidity were associated with hospital CD rates to provide context for potential comparison and consideration for defining CD rate targets. We hypothesized that hospitals with higher CD rates would have increased rates of SMM, though we were less certain of the associations with unexpected newborn complications.\n\n\nMATERIALS AND METHODS\nThis is a cross-sectional, ecological study using data from the 2016 Nationwide Readmission Database of hospitals with at least 100 deliveries per year. The exposure of interest was hospital cesarean delivery rate. The outcomes were 1) severe maternal morbidity (SMM) with and without transfusion, in accordance with the Centers for Disease Control and Prevention s definition; and 2) neonatal morbidity, defined using The Joint Commission s Perinatal Quality metric of moderate and severe unexpected newborn complications (UNCs) among term, singleton, non-anomalous neonates. Prior to assuming a single linear relationship to model the associations between morbidity and CD rates, the Joinpoint Regression Program was used to examine for potential splines in the relationships with both SMM (with and without transfusion) and severe and moderate unexpected newborn complications. Poisson regression models were then used to determine the association between morbidity and cesarean delivery rates.\n\n\nRESULTS\nThe analysis included 831,111 deliveries from 621 hospitals. The mean cesarean delivery rate was 30.5%. The median SMM rate was 1.40 per 100 deliveries (interquartile rage (IQR) 0.71, 2.21 per 1,000 deliveries). Excluding transfusion, the median SMM rate was 0.47 per 100 deliveries (IQR 0.22, 0.73 per 100 deliveries). The median rate of severe and moderate UNCs was 1.01 per 100 low-risk newborns (IQR 0.64, 1.69 per 100 low-risk newborns) and 1.79 per 1,000 low-risk newborns (IQR 0.94, 2.93 per 100 low-risk newborns). In the unadjusted analysis, every percentage point increase in a hospital s cesarean delivery rate was associated with a 3.4% (95% confidence interval (CI) 2.3-4.4%) and a 2.3% (95% CI 1.0-3.5%) increase in SMM including and excluding transfusion. After adjustment for case mix and hospital factors, only the relationship with SMM including transfusion remained significant: 3.3% (95% CI 1.7-4.9%) increase in SMM per every percentage point increase in the cesarean delivery rate. There was no observed association between cesarean delivery rates and UNCs.\n\n\nCONCLUSIONS AND RELEVANCE\nSMM and UNCs occur in less than 5 in 100 births. Findings from this analysis of hospitals with CD rates ranging 6.8 to 56.3% suggest that those with lower CD rates have lower SMM, which includes transfusion, and similar UNCs compared to hospitals with higher CD rates. This work may provide helpful context to providers, hospitals, and policymakers who are measuring and reporting outcomes. Particularly relevant to neonatal morbidity, the Joint Commission manual notes that the unexpected newborn complication metric was specifically designed to be compared against maternal-focused metrics, like cesarean delivery rates. More work is needed to define and identify appropriate measures of maternal and neonatal morbidity for these types of comparisons.