Maternal comorbidity index and severe maternal morbidity during delivery hospitalizations in Texas, 2011-2014.

Abstract

Severe maternal morbidity (SMM) prevalence was 194.0 per 10000 deliveries in Texas in 2015. Chronic, behavioral, and pregnancy-induced conditions, as captured by a maternal comorbidity index, increase the risk for delivery-related morbidity and mortality. The objective of the study was to examine the association between maternal comorbidity index and SMM among delivery hospitalizations in Texas. Delivery-related hospitalizations among Texan women aged 15-49years were identified using the 2011-2014 Texas all-payer inpatient hospitalization public use data files (n=1434441). The primary outcome of interest was SMM, based on the Alliance for Innovation on Maternal Health's coding scheme. The exposure of interest was a maternal comorbidity index. Multivariable logistic regression model was used to examine the association between maternal comorbidity index and SMM. SMMprevalence remained consistent between 2011 and 2014 (196.0-197.0 per 10000 deliveries, P>.05; n=1434441). Nearly 40% of delivery-related hospitalizations had a maternal comorbidity index of at least 1, and the proportion of deliveries in the highest risk category of comorbidity index (≥5) increased by 12.0% from 2011 to 2014. SMMprevalence was highest among the youngest and oldest age groups. With each unit increase in maternal comorbidity index, the odds of SMM increase was 1.43 (95% CI 1.42-1.43). Maternal comorbidity index is associated with SMM; however, the low predictive power of the model suggests that other, unmeasured factors may influence SMM in Texas. These findings highlight a need to understand broader contextual factors (practitioner, facility, systems of care, and community) that may be associated with SMM to reduce maternal morbidity and mortality in Texas.