Disparities in postpartum readmission by patient- and hospital-level social risk factors in the United States: a retrospective multistate analysis, 2015-2020.

BACKGROUND: Postpartum readmission is an area of focus for improving obstetric care and reducing costs. We examined disparities in all-cause 30-day postpartum readmission by patient- and hospital-level factors in the United States. METHODS: We conducted a retrospective cohort study using 2015-2020 records from the State Inpatient Databases from four states. Generalized linear mixed models were constructed to estimate the effects of individual patient- and hospital-level factors on adjusted odds of 30-day readmission after controlling for confounders. Stratified analyses by delivery and anesthesia type (New York only) and interaction models were performed. RESULTS: Black mothers were more likely than White mothers to be readmitted within 30-days postpartum (aOR 1.57, 95% CI 1.52 to 1.61). Mothers with public insurance had increased odds of readmission compared with those with private insurance (Medicare: aOR 2.13, 95% CI 1.95 to 2.32; Medicaid: aOR 1.14, 95% CI 1.11 to 1.17). Compared with mothers in the lowest income quartile, those in the highest quartile experienced a 14% lower odds of readmission (aOR 0.86, 95% CI 0.83 to 0.89). There were no significant associations between hospital-level characteristics and readmission. Black mothers were more likely to be readmitted regardless of delivery type and most combinations of delivery and anesthesia type. Black mothers from the highest income quartile were more likely to be readmitted than White mothers from the lowest income quartile. CONCLUSION: Substantial disparities in 30-day postpartum readmissions by patient-level social factors were observed, particularly amongst Black mothers. Action is needed to address and mitigate disparities in postpartum readmission.

United States rural residence is associated with increased acute maternal end-organ injury or mortality after birth: a retrospective multi-state analysis, 2007-2018.

BACKGROUND: Geographic-based healthcare determinants and choice of anesthesia have been shown to be associated with maternal morbidity and mortality. We explored whether differences in maternal outcomes based on maternal residence, and anesthesia type for cesarean and vaginal birth, exist. METHODS: This study was a retrospective multi-state analysis; patient residence was the predictor variable of interest and a composite binary measure of maternal end-organ injury or inpatient mortality was the primary outcome. Our secondary outcomes included a binary measure of anesthesia type for cesarean birth (general vs. neuraxial [NA]) and NA analgesia for vaginal birth (no NA vs. NA). Our predictor variable of interest was patient residency (reference category central metropolitan areas of >1 million population), fringe large metropolitan county, medium metropolitan, small metropolitan, micropolitan, and non-metropolitan or micropolitan county. RESULTS: Women residing in micropolitan (OR 1.17; 95% CI 1.09 to 1.27) and non-metropolitan or micropolitan counties (OR 1.14; 95% CI 1.04 to 1.24) had the highest adjusted increased odds of adverse maternal outcomes. Those residing in suburban, medium, and small metropolitan areas underwent general anesthesia less often during cesarean births than those residing in urban areas. Patients residing in micropolitan rural (OR 2.07; 95% CI 2.02 to 2.12) and non-metropolitan or micropolitan (2.25; 95% CI 2.16 to 2.34) counties underwent vaginal births without NA analgesia more than twice as often as those residing in urban areas. CONCLUSIONS: Rural-urban disparities in maternal end-organ damage and mortality exist and anesthesia choice may play an important role in these disparate outcomes.

Comparative performance of obstetric comorbidity indices within categories of race and ethnicity: an external validation study.

BACKGROUND: Existing obstetric comorbidity adjustment indices were created without explicitly accounting for sociodemographic diversity in the development populations, which could lead to imprecise estimates if these indices are applied to populations different from the ones in which they were developed. The objective of this study was to validate two obstetric comorbidity indices (one using severe maternal morbidity [SMM] and one using end-organ injury or mortality) within categories of race/ethnicity. METHODS: Delivery hospitalizations from the State Inpatient Databases for Florida, Maryland, Kentucky, Washington (2015-2018) and New York (2015-2016) were analyzed. Outcomes were modeled using logistic regression by category of race/ethnicity and overall, with each model having its respective index value as the covariate. Discrimination and calibration were assessed. RESULTS: There were 1 604 203 delivery hospitalizations, among which 1.6% experienced SMM and 0.4% had SMM excluding blood transfusions. Maternal end-organ injury or mortality was identified in 0.5% of cases. For the entire patient population, the area under the receiver operating curve (AUROC) was 0.72 (95% CI 0.71 to 0.72) and 0.75 (95% CI 0.75 to 0.76) for SMM and non-transfusion SMM, respectively. The AUROC for maternal end-organ injury or death was 0.65 (95% CI 0.65 to 0.66). All scores exhibited poor calibration across racial/ethnic groups. There was no substantial variation within categories of race/ethnicity in terms of index performance. CONCLUSION: Users of these indices should consider performance data in totality when choosing a measure for obstetric comorbidity adjustment. There were no marked differences in model performance observed across race/ethnicity groups within each index.

Patient race and racial composition of delivery unit associated with disparities in severe maternal morbidity: a multistate analysis 2007-2014.

BACKGROUND: High Black-serving delivery units and high hospital safety-net burden have been associated with poorer patient outcomes. We examine these hospital-level factors and their association with severe maternal morbidity (SMM), independently and as effect modifiers of patient-level factors. METHODS: Using the 2007-2014 State Inpatient Databases (Florida, New York, California, Maryland, Kentucky), we analyzed delivery hospitalizations. We constructed generalized linear mixed models with patient- and hospital-level variables (Black-serving delivery units: high: top 5th percentile; medium: 5th-25th percentile; low: bottom 75th percentile; hospital safety-net burden status defined by insurance status) and report adjusted odds ratios (aOR) and 99% confidence intervals (CI). We repeated our mixed models with stratification and interaction analysis. RESULTS: 6 879 332 delivery hospitalizations were included in the analysis. Deliveries at high (aOR 1.83; 99% CI 1.34 to2.50) or medium (aOR 1.27; 99% CI 1.10 to 1.46) Black-serving delivery units were more likely to have SMM than deliveries at low Black-serving delivery units. Hospital safety-net burden was not significantly associated with SMM. In stratified models by hospital category, deliveries of Black women were associated with an increase in SMM compared with deliveries of White women in all hospital categories. In interaction models, Black women giving birth in high Black-serving delivery units had more than twice the odds of White women in low Black-serving delivery units of experiencing SMM (aOR 2.42; 99% CI 1.90 to 3.08). CONCLUSION: The patient racial/ethnic composition of the delivery unit is associated with adjusted-odds of SMM, both independently and interactively with individual patient race.