(778) Obstetrical patient comorbidity according to hospital volume of delivery: a retrospective cohort study

Our study objective is to determine whether obstetrical patients with more comorbidities are more likely cared for at hospitals with higher patient loads.

Study Design: A retrospective cohort study was conducted on all admissions with a delivery or maternal death from October 2015 to December 2019 from the American database Healthcare Cost and Utilization Project-Nationwide Inpatient Sample. The cohort was weighted to be representative of the entire population and births in the United States. The cohort was stratified using the validated Expanded Obstetric Comorbidity Scoring System, a tool designed to predict the risk of severe maternal morbidity. The cohort was divided in four categories of scores. The strata were then divided by hospital sizes at which the births were recorded. Frequencies were calculated for each sub-category of maternal comorbidity index and hospital size.

Results:

The cohort included 15,669,785 deliveries. Of those, 45.0% had a comorbidity score of 0, 19.2% had a score of 1-10, 19.2% had a score of 11-20 and 16.5% had a score of 21+. In hospitals with less than 500 deliveries annually, 48.2% had a score of 0, 20.2% had a score of 1-10, 18.40% had a score of 11-20 and 13.3% had a score of 21 or higher. In hospitals with 500-< 1000 deliveries annually, for the same score categories, the frequencies were as follow: 46.3%, 19.9%, 18.8% and 15.1%. In hospitals with 1000 to < 2000 deliveries, the frequencies were as follow: 44.5%, 19.1%, 19.4% and 17.0%. Lastly, in hospitals with >2000 deliveries, the frequencies were as follow: 44.1%, 18.7%, 18.7% and 17.8%.

Conclusion:

In conclusion, more than 50% of women delivering at American hospitals have comorbidity increasing the risk of severe maternal morbidity. As hospital volume of deliveries increases, the proportion of comorbid patients delivering also increases. Nonetheless, all hospital sizes care for patients of every risk level.