Visualizing Delivery Catchment Area for Severe Maternal Morbidity in Harris County, Texas, 2016 [25T

Abstract

INTRODUCTION: Severe maternal morbidity (SMM) reflects complex, multi-level factors. In Texas, the SMM rate was 17.0 per 1,000 deliveries in 2016. In this exploratory case study, we describe SMM by ZIP Code for select hospitals in the Texas county with the highest delivery volume, to highlight differences in SMM at a granular level. METHODS: Using Texas all-payer inpatient hospitalization data for 2011-2016, delivery-related hospitalizations were classified as SMM based on 21 ICD-10-CM diagnosis and procedure codes. Using ArcGIS Desktop, SMM was mapped at (1) maternal residence ZIP Code for Harris County, and (2) maternal residence ZIP Code and hospital level for two hospitals with the lowest and two hospitals with the highest SMM rates. RESULTS: SMM remained consistent during 2011-2016 in Harris County (15.4-23.4 per 1,000 deliveries, P>.05). Among the 125 ZIP Codes with at least 100 deliveries in 2016, over one-third had SMM higher than the state rate. In the four hospitals included in this study, the SMM rate ranged from 1.9 to 33.8 per 1,000 deliveries. The hospital with the highest SMM rate included deliveries from a wide catchment area, while the other three hospitals had a relatively concentrated delivery catchment area. CONCLUSION: In this exploratory study, we observed differences in SMM across hospital and community settings, which reflects complex factors, including patient preexisting conditions, hospital quality of care and community characteristics. Our findings can help generate additional research to gain in-depth understanding of the relative contribution of these multi-level factors to SMM and inform development of risk adjustment approaches for SMM.