Associations of PM2.5 exposure with emergency department visits and readmissions among preterm infants with bronchopulmonary dysplasia.

OBJECTIVES: To quantify the association of ambient air pollution (particulate matter, PM2.5) exposure with medically attended acute respiratory illness among infants with bronchopulmonary dysplasia (BPD). STUDY DESIGN: Single center, retrospective cohort study of preterm infants with BPD in Metropolitan Philadelphia. Multivariable logistic regression quantified associations of annual mean PM2.5 exposure (per µg/m3) at the census block group level with medically attended acute respiratory illness, defined as emergency department (ED) visits or hospital readmissions within a year after first hospital discharge adjusting for age at neonatal intensive care unit (NICU) discharge, year, sex, race, insurance, BPD severity, and census tract deprivation. As a secondary analysis, we examined whether BPD severity modified the associations. RESULTS: Of the 378 infants included in the analysis, 189 were non-Hispanic Black and 235 were publicly insured. Census block PM2.5 level was not significantly associated with medically attended acute respiratory illnesses, ED visits, or hospital readmissions in the full study cohort. We observed significant effect modification by BPD grade; each 1 µg/m3 higher annual PM2.5 exposure was medically attended acute respiratory illness (adjusted odds ratio [aOR] 1.65, 95% CI: 1.06-2.63) among infants with Grade 1 BPD but not among infants with grade 3 BPD (aOR 0.83, 95% CI: 0.47-1.48) (interaction p = .024). CONCLUSIONS: Cumulative PM2.5 exposure in the year after NICU discharge was not significantly associated with medically attended acute respiratory illness among infants with BPD. However, infants with Grade 1 BPD had significantly higher odds with higher exposures. If replicated, these findings could inform anticipatory guidance for families of these infants to avoid outdoor activities during high pollution days after NICU discharge.

Environmental Determinants of Post-Discharge Acute Respiratory Illness among Preterm Infants with Bronchopulmonary Dysplasia.

OBJECTIVE: To analyze the association of components of the Centers for Disease Control and Prevention (CDC) Environmental Justice Index (EJI) with respiratory health outcomes among infants with bronchopulmonary dysplasia (BPD) within one year after discharge from the neonatal intensive care unit. METHODS: This was a retrospective cohort study of a cohort of preterm infants with BPD. Multivariable logistic regression models estimated associations of EJI and its components with medically attended acute respiratory illness, defined as an ED visit or inpatient readmission, within one year of discharge from the neonatal intensive care unit. A mediation analysis was conducted to evaluate how environmental injustice may contribute to racial disparities in acute respiratory illness. RESULTS: Greater EJI was associated with an increased risk of medically attended respiratory illness (per EJI standard deviation increment, aOR 1.38, 95% CI: 1.12-1.69). Of the index's components, the Environmental Burden Module's Air pollution domain had the greatest association (aOR 1.44, 95% CI: 1.44-2.61). With respect to individual indicators within the EJI, Diesel Particulate Matter (DSLPM) and Air Toxic Cancer Risk (ATCR) demonstrated the strongest relationship (aOR 2.06, 95% CI: 1.57-2.71 and aOR 2.10, 95% CI: 1.59-2.78, respectively). Among non-Hispanic Black infants, 63% experienced a medically attended acute respiratory illness as compared to 18% of non-Hispanic White infants. DSLPM mediated 39% of the Black-White disparity in medically attended acute respiratory illness (p = 0.004). CONCLUSIONS: Environmental exposures, particularly air pollution, are associated with post-discharge respiratory health outcomes among preterm infants with BPD after adjusting for clinical, demographic, and social vulnerability risk factors. Certain types of air pollutants, namely, DSLPM, are more greatly associated with acute respiratory illness. Environmental exposures may contribute to racial disparities in medically attended acute respiratory illness among infants with BPD.

Inter-hospital Variation in COVID-19 Era Pediatric Hospitalizations by Age Group and Diagnosis.

BACKGROUND: Mitigation strategies and public responses to coronavirus disease 2019 (COVID-19) varied geographically and may have differentially affected burden of pediatric disease and hospitalization practices. We aimed to quantify hospital-specific variation in hospitalizations during the COVID-19 era. METHODS: Using Pediatric Health Information Systems data from 44 Children's Hospitals, this retrospective multicenter analysis compared hospitalizations of children (1 day-17 years) from the COVID-19 era (March 1, 2020-June 30, 2021) to prepandemic (January 1, 2017-December 31, 2019). Variation in the magnitude of hospital-specific decline between eras was determined using coefficients of variation (CV). Spearman's test was used to assess correlation of variation with community and hospital factors. RESULTS: The COVID-19 era decline in hospitalizations varied between hospitals (CV 0.41) and was moderately correlated with declines in respiratory infection hospitalizations (r = 0.69, P < .001). There was no correlation with community or hospital factors. COVID-19 era changes in hospitalizations for mental health conditions varied widely between centers (CV 2.58). Overall, 22.7% of hospitals saw increased admissions for adolescents, and 29.5% saw increases for newborns 1 to 14 days, representing significant center-specific variation (CV 2.30 for adolescents and 1.98 for newborns). CONCLUSIONS: Pandemic-era change in hospitalizations varied across institutions, partially because of hospital-specific changes in respiratory infections. Residual variation exists for mental health conditions and in groups least likely to be admitted for respiratory infections, suggesting that noninfectious conditions may be differentially and uniquely affected by local policies and hospital-specific practices enacted during the COVID-19 era.

County-Level Maternal Vulnerability and Preterm Birth in the US.

Importance: Appreciation for the effects of neighborhood conditions and community factors on perinatal health is increasing. However, community-level indices specific to maternal health and associations with preterm birth (PTB) have not been assessed. Objective: To examine the association of the Maternal Vulnerability Index (MVI), a novel county-level index designed to quantify maternal vulnerability to adverse health outcomes, with PTB. Design, Setting, and Participants: This retrospective cohort study used US Vital Statistics data from January 1 to December 31, 2018. Participants included 3 659 099 singleton births at 22 plus 0/7 to 44 plus 6/7 weeks of gestation born in the US. Analyses were conducted from December 1, 2021, through March 31, 2023. Exposure: The MVI, a composite measure of 43 area-level indicators, categorized into 6 themes reflecting physical, social, and health care landscapes. Overall MVI and theme were stratified by quintile (very low to very high) by maternal county of residence. Main Outcomes and Measures: The primary outcome was PTB (gestational age <37 weeks). Secondary outcomes were PTB categories: extreme (gestational age ≤28 weeks), very (gestational age 29-31 weeks), moderate (gestational age 32-33 weeks), and late (gestational age 34-36 weeks). Multivariable logistic regression quantified associations of MVI, overall and by theme, with PTB, overall and by PTB category. Results: Among 3 659 099 births, 298 847 (8.2%) were preterm (male, 51.1%; female, 48.9%). Maternal race and ethnicity included 0.8% American Indian or Alaska Native, 6.8% Asian or Pacific Islander, 23.6% Hispanic, 14.5% non-Hispanic Black, 52.1% non-Hispanic White, and 2.2% with more than 1 race. Compared with full-term births, MVI was higher for PTBs across all themes. Very high MVI was associated with increased PTB in unadjusted (odds ratio [OR], 1.50 [95% CI, 1.45-1.56]) and adjusted (OR, 1.07 [95% CI, 1.01-1.13]) analyses. In adjusted analyses of PTB categories, MVI had the largest association with extreme PTB (adjusted OR, 1.18 [95% CI, 1.07-1.29]). Higher MVI in the themes of physical health, mental health and substance abuse, and general health care remained associated with PTB overall in adjusted models. While the physical health and socioeconomic determinant themes were associated with extreme PTB, physical health, mental health and substance abuse, and general health care themes were associated with late PTB. Conclusions and Relevance: The findings of this cohort study suggest that MVI was associated with PTB even after adjustment for individual-level confounders. The MVI is a useful measure for county-level PTB risk that may have policy implications for counties working to lower preterm rates and improve perinatal outcomes.

Racial and ethnic disparities in outcomes after NICU discharge: An equity-focused model.

Significant racial and ethnic disparities exist in birth outcomes and complications related to prematurity. However, little is known about racial and ethnic variations in health outcomes after premature infants are discharged from the neonatal intensive care unit (NICU). We propose a novel, equity-focused conceptual model to guide future evaluations of post-discharge outcomes that centers on a multi-dimensional, comprehensive view of health, which we call thriving. We then apply this model to existing literature on post-discharge inequities, revealing a need for rigorous analysis of drivers and strength-based, longitudinal outcomes.

Birth Hospital Length of Stay and Rehospitalization During COVID-19.

OBJECTIVES: To determine if birth hospitalization length of stay (LOS) and infant rehospitalization changed during the coronavirus disease 2019 (COVID-19) era among healthy, term infants. METHODS: Retrospective cohort study using Epic's Cosmos data from 35 health systems of term infants discharged ≤5 days of birth. Short birth hospitalization LOS (vaginal birth <2 midnights; cesarean birth <3 midnights) and, secondarily, infant rehospitalization ≤7 days after birth hospitalization discharge were compared between the COVID-19 (March 1 to August 31, 2020) and prepandemic eras (March 1 to August 31, 2017, 2018, 2019). Mixed-effects models were used to estimate adjusted odds ratios (aORs) comparing the eras. RESULTS: Among 202 385 infants (57 110 from the COVID-19 era), short birth hospitalization LOS increased from 28.5% to 43.0% for all births (vaginal: 25.6% to 39.3%, cesarean: 40.1% to 61.0%) during the pandemic and persisted after multivariable adjustment (all: aOR 2.30, 95% confidence interval [CI] 2.25-2.36; vaginal: aOR 2.12, 95% CI 2.06-2.18; cesarean: aOR 3.01, 95% CI 2.87-3.15). Despite shorter LOS, infant rehospitalizations decreased slightly during the pandemic (1.2% to 1.1%); results were similar in adjusted analysis (all: aOR 0.83, 95% CI 0.76-0.92; vaginal: aOR 0.82, 95% CI 0.74-0.91; cesarean: aOR 0.87, 95% CI 0.69-1.10). There was no change in the proportion of rehospitalization diagnoses between eras. CONCLUSIONS: Short infant LOS was 51% more common in the COVID-19 era, yet infant rehospitalization within a week did not increase. This natural experiment suggests shorter birth hospitalization LOS among family- and clinician-selected, healthy term infants may be safe with respect to infant rehospitalization, although examination of additional outcomes is needed.

Racial Segregation and Intraventricular Hemorrhage in Preterm Infants.

BACKGROUND: Intraventricular hemorrhage (IVH) disproportionately affects black neonates. Other conditions that are more common in black neonates, including low birth weight and preterm delivery, have been linked with residential racial segregation (RRS). In this study, we investigated the association between RRS and IVH. METHODS: A retrospective cohort of neonates born between 24 and 32 weeks' gestation was constructed by using birth certificates linked to medical records from California, Missouri, and Pennsylvania between 1995 and 2009. Dissimilarity, a measure of RRS indicating the proportion of minorities in the census tract of the mother in comparison to the larger metropolitan area, was linked to patient data, yielding a cohort of 70 775 infants. Propensity score analysis matched infants born to mothers living in high segregation to those living in less segregated areas on the basis of race, sociodemographic factors, and medical comorbidities to compare the risk of developing IVH. RESULTS: Infants born to mothers in the most segregated quartile had a greater risk of developing IVH compared with those in the lowest quartile (12.9% vs 10.4%; P < .001). In 17 918 pairs matched on propensity scores, the risk of developing IVH was greater in the group exposed to a segregated environment (risk ratio = 1.08, 95% confidence interval: 1.01-1.15). This effect was stronger for black infants alone (risk ratio = 1.16; 95% confidence interval: 1.03-1.30). CONCLUSIONS: RRS is associated with an increased risk of IVH in preterm neonates, but the effect size varies by race. This association persists after balancing for community factors and birth weight, representing a novel risk factor for IVH.