Mental health and substance use disorders at delivery hospitalization and readmissions after delivery discharge

Background: The objective was to assess mental health and substance use disorders (MSUD) at delivery hospi-talization and readmissions after delivery discharge.Methods: This is a population-based retrospective cohort study of persons who had a delivery hospitalization during January to September in the 2019 Nationwide Readmissions Database. We calculated 90-day readmission rates for MSUD and non-MSUD, overall and stratified by MSUD status at delivery. We used multivariable logistic regressions to assess the associations of MSUD type, patient, clinical, and hospital factors at delivery with 90-day MSUD readmissions.Results: An estimated 11.8% of the 2,697,605 weighted delivery hospitalizations recorded MSUD diagnoses. The 90-day MSUD and non-MSUD readmission rates were 0.41% and 2.9% among delivery discharges with MSUD diagnoses, compared to 0.047% and 1.9% among delivery discharges without MSUD diagnoses. In multivariable analysis, schizophrenia, bipolar disorder, stimulant-related disorders, depressive disorders, trauma-and stressor-related disorders, alcohol-related disorders, miscellaneous mental and behavioral disorders, and other specified substance-related disorders were significantly associated with increased odds of MSUD readmissions. Three or more co-occurring MSUDs (vs one MSUD), Medicare or Medicaid (vs private) as the primary expected payer, lowest (vs highest) quartile of median household income at residence zip code level, decreasing age, and longer length of stay at delivery were significantly associated with increased odds of MSUD readmissions.Conclusion: Compared to persons without MSUD at delivery, those with MSUD had higher MSUD and non-MSUD 90-day readmission rates. Strategies to address MSUD readmissions can include improved postpartum MSUD follow-up management, expanded Medicaid postpartum coverage, and addressing social determinants of health.