The relationship between the rising cesarean delivery and postpartum readmission rates

OBJECTIVE: This study seeks to determine if the increasing rate of postpartum readmissions is related to the increasing rate of cesarean delivery. STUDY DESIGN: Readmitted patients were identified in the State Inpatient Databases of California, Florida and New York from 2004 to 2011. Relevant maternal comorbidities, pregnancy complications and intrapartum events were collected using ICD-9 diagnosis and procedure codes. The effects of cesarean delivery were first examined via univariate logistic regression to calculate the odds of readmission by year for patients who had delivered via cesarean section. Then, we used multivariate logistic regression models to isolate the effect of mode of delivery on the odds of readmission by adjusting for the effects of patient demographics, hospital characteristics and maternal comorbidities. RESULTS: Nearly one million deliveries were identified each year, and 600 000 deliveries per year met inclusion criteria. During this time, the readmission rate increased from 1.72 to 2.16%, and the cesarean delivery rate increased from 30.4 to 33.9%. The odds of readmission for patients delivered via cesarean section decreased yearly, from 1.343 (95% CI: 1.295 to 1.392) in 2004 to 1.046 (95% CI: 1.012 to 1.108) in 2011. In a multivariate model, the odds based on year were 1.032 (95% CI: 1.030 to 1.035), demonstrating an increased odds of readmission over time. When cesarean delivery was added to the model, this odds estimate did not change (OR: 1.031, 95% CI: 1.028 to 1.035), suggesting it did not account for the increased odds of readmission over time, even though cesarean delivery rates increased. However, when maternal comorbidities were added to the model, the odds ratio for year became insignificant (OR: 1.001, 95% CI: 0.998 to 1.005), suggesting that they accounted for the increasing rate of readmissions. CONCLUSIONS: The increasing cesarean delivery rate does not explain the increasing rate of postpartum readmissions. Rather, the increasing postpartum readmission rate appears to be related to maternal comorbidities.