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Post-Transformation Update: Volume as an Indicator for Outcomes for Severe Maternal Morbidity in the Military Health
Teresa L Russell1,2,3, Amanda Banaag1,2,3, Elizabeth H Lee1,2,4
1Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
Background:
Hospital delivery volume has been linked to severe maternal morbidity (SMM), which increases medical costs, readmissions, hospital stays, and mortality risk. During Fiscal Years (FY) 2019-2023, the Military Health System (MHS) rolled out a new electronic health record, merged facilities under Defense Health Agency (DHA) management, and weathered the COVID-19 pandemic. This study aimed to examine the association between delivery volume and odds of SMM and 30-day readmissions for deliveries at U.S. military hospitals for FY 2019-2023.
Methods:
This cross-sectional study analyzed healthcare claims data from MHS beneficiary women aged 15-54 years delivering FY 2019-2023. Delivery volume was measured using International Classification of Diseases-10 (ICD-10) and Medicare Severity-Diagnosis Related Group codes. Military hospitals were grouped into quartiles by volume over the study period. SMM was measured by 21 ICD-10 indicators (any/none). Any postpartum readmission (yes/no) to the same hospital within 30 days of discharge was included. Covariables included hospital identifier and maternal comorbidities and demographics associated with each delivery. Stepwise logistic regression was performed.
Results:
Women delivering at hospitals in the lowest, lower-middle, and highest volume quartiles had significantly lower (19-30%) odds of SMM compared with the upper-middle quartile (p < 0.05). Those delivering at lower and lower-middle quartile hospitals had significantly higher (29-46%) odds of 30-day readmissions compared with the upper-middle quartile (p < 0.05), with no significant difference found among those in the highest quartile.
Conclusions:
Delivery volume was significantly associated with SMM and 30-day readmission odds among MHS deliveries FY 2019-2023. This differs from previous FY 2015-2018 findings, therefore concurrent effects of the DHA transition and COVID-19 pandemic cannot be ruled out.
