The Impact of Hospital Delivery Volumes of Newborns Born Very Preterm on Mortality and Morbidity.

OBJECTIVE: To examine if the annual patient volume of infants born very preterm (VPT, gestational age <32 weeks) at a hospital is associated with neonatal mortality and morbidity. STUDY DESIGN: We performed an observational, secondary data analysis using a 20-year panel of birth certificates linked to hospital discharge abstracts, including transfers in California, Michigan, Missouri, Oregon, Pennsylvania, and South Carolina from 1996 through 2015. The study included all in-hospital VPT deliveries (N=208,261). Study outcomes were in-hospital mortality or serious morbidity (intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, or bronchopulmonary dysplasia), attributed to the hospital of birth. Poisson regression models estimated the risk-adjusted relative risk (RR) for mortality and serious morbidity across different patient volume categories within a given hospital using hospital fixed effects. RESULTS: The risk of mortality and serious morbidity for VPT infants increased as the number of infants born VPT at a hospital decreased. Compared with VPT delivery volumes >100 infants per year, the risk of mortality increased when a given hospital had VPT delivery volumes < 60 per year, ranging from a RR of 1.13 (95% C.I. 1.02-1.25) for volumes between 50 to 59 to 1.39 (1.19-1.62) for VPT volumes <10, and the risk of mortality or serious morbidity increased when a given hospital had VPT volumes <100, ranging from a RR of 1.05 (1.02-1.08) for volumes between 90 to 99 and 1.27 (1.19-1.36) for VPT volumes <10. CONCLUSIONS: These results suggest that, for VPT infants, the risk of both mortality and mortality or serious morbidity is increased as the VPT volume within a given hospital declines.

County-level Structural Vulnerabilities in Maternal Health and Geographic Variation in Infant Mortality.

OBJECTIVE: To evaluate whether community factors that differentially affect the health of pregnant people contribute to geographic differences in infant mortality across the United States. STUDY DESIGN: This retrospective cohort study sought to characterize the association of a novel composite measure of county-level maternal structural vulnerabilities, the Maternal Vulnerability Index (MVI), with risk of infant death. We evaluated 11,456,232 singleton infants born at 22 0/7 through 44 6/7 weeks' gestation from 2012 to 2014. Using county-level MVI, which ranges from 0-100, multivariable mixed effects logistic regression models quantified associations per 20-point increment in MVI, with odds of death clustered at the county level and adjusted for state, maternal, and infant covariates. Secondary analyses stratified by the social, physical, and health exposures that comprise the overall MVI score. Outcome was also stratified by cause of death. RESULTS: Odds of death were higher among infants from counties with the greatest maternal vulnerability (0.62% in highest quintile vs 0.32% in lowest quintile, [p<0.001]). Odds of death increased 6% per 20-point increment in MVI (aOR: 1.06, 95% CI 1.04, 1.07). The effect estimate was highest with theme of mental health and substance use (aOR 1.08; 95% CI 1.06, 1.09). Increasing vulnerability was associated with six of seven causes of death. CONCLUSIONS: Community-level social, physical, and healthcare determinants indicative of maternal vulnerability may explain some of the geographic variation in infant death, regardless of cause of death. Interventions targeted to county-specific maternal vulnerabilities may reduce infant mortality.

Association between stillbirth and severe maternal morbidity.

BACKGROUND: Severe maternal morbidity has been increasing in the past few decades. Few studies have examined the risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries. OBJECTIVE: This study aimed to examine the prevalence and risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries during delivery hospitalization as a primary outcome and during the postpartum period as a secondary outcome. STUDY DESIGN: This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from California (2008-2018), Michigan (2008-2020), Missouri (2008-2014), Pennsylvania (2008-2014), and South Carolina (2008-2020). Relative risk regression analysis was used to examine the crude and adjusted relative risks of severe maternal morbidity along with 95% confidence intervals among individuals with stillbirths vs individuals with live-birth deliveries, adjusting for birth year, state of residence, maternal sociodemographic characteristics, and the obstetric comorbidity index. RESULTS: Of the 8,694,912 deliveries, 35,012 (0.40%) were stillbirths. Compared with individuals with live-birth deliveries, those with stillbirths were more likely to be non-Hispanic Black (10.8% vs 20.5%); have Medicaid (46.5% vs 52.0%); have pregnancy complications, including preexisting diabetes mellitus (1.1% vs 4.3%), preexisting hypertension (2.3% vs 6.2%), and preeclampsia (4.4% vs 8.4%); have multiple pregnancies (1.6% vs 6.2%); and reside in South Carolina (7.4% vs 11.6%). During delivery hospitalization, the prevalence rates of severe maternal morbidity were 791 cases per 10,000 deliveries for stillbirths and 154 cases per 10,000 deliveries for live-birth deliveries, whereas the prevalence rates for nontransfusion severe maternal morbidity were 502 cases per 10,000 deliveries for stillbirths and 68 cases per 10,000 deliveries for live-birth deliveries. The crude relative risk for severe maternal morbidity was 5.1 (95% confidence interval, 4.9-5.3), whereas the adjusted relative risk was 1.6 (95% confidence interval, 1.5-1.8). For nontransfusion severe maternal morbidity among stillbirths vs live-birth deliveries, the crude relative risk was 7.4 (95% confidence interval, 7.0-7.7), whereas the adjusted relative risk was 2.0 (95% confidence interval, 1.8-2.3). This risk was not only elevated among individuals with stillbirth during the delivery hospitalization but also through 1 year after delivery (severe maternal morbidity adjusted relative risk, 1.3; 95% confidence interval, 1.1-1.4; nontransfusion severe maternal morbidity adjusted relative risk, 1.2; 95% confidence interval, 1.1-1.3). CONCLUSION: Stillbirth was found to be an important contributor to severe maternal morbidity.

A multi-state analysis on the effect of deprivation and race on PICU admission and mortality in children receiving Medicaid in United States (2007-2014).

INTRODUCTION: In the United States (US), racial and socioeconomic disparities have been implicated in pediatric intensive care unit (PICU) admissions and outcomes, with higher rates of critical illness in more deprived areas. The degree to which this persists despite insurance coverage is unknown. We investigated whether disparities exist in PICU admission and mortality according to socioeconomic position and race in children receiving Medicaid. METHODS: Using Medicaid data from 2007-2014 from 23 US states, we tested the association between area level deprivation and race on PICU admission (among hospitalized children) and mortality (among PICU admissions). Race was categorized as Black, White, other and missing. Patient-level ZIP Code was used to generate a multicomponent variable describing area-level social vulnerability index (SVI). Race and SVI were simultaneously tested for associations with PICU admission and mortality. RESULTS: The cohort contained 8,914,347 children (23·0% Black). There was no clear trend in odds of PICU admission by SVI; however, children residing in the most vulnerable quartile had increased PICU mortality (aOR 1·12 (95%CI 1·04-1·20; p = 0·0021). Black children had higher odds of PICU admission (aOR 1·04; 95% CI 1·03-1·05; p < 0·0001) and higher mortality (aOR 1·09; 95% CI 1·02-1·16; p = 0·0109) relative to White children. Substantial state-level variation was apparent, with the odds of mortality in Black children varying from 0·62 to 1·8. CONCLUSION: In a Medicaid cohort from 2007-2014, children with greater socioeconomic vulnerability had increased odds of PICU mortality. Black children were at increased risk of PICU admission and mortality, with substantial state-level variation. Our work highlights the persistence of sociodemographic disparities in outcomes even among insured children.

Racial and Ethnic Disparities in Sudden Unexpected Infant Death Among US Infants Born Preterm.

OBJECTIVE: To investigate among US infants born at <37 weeks gestation (a) racial and ethnic disparities in sudden unexpected infant death (SUID) and (b) state variation in SUID rates and non-Hispanic Black (NHB)-non-Hispanic White (NHW) SUID disparity ratio. METHODS: In this retrospective cohort analysis of linked birth and death certificates from 50 states from 2005 to 2014, SUID was defined by the following International Classification of Diseases, 9th or 10th edition, codes listed on death certificates: (7980, R95 or Recode 135; ASSB: E913, W75 or Recode 146; Unknown: 7999 R99 or Recode 134). Multivariable models were used to assess the independent association between maternal race and ethnicity and SUID, adjusting for several maternal and infant characteristics. The NHB-NHW SUID disparity ratios were calculated for each state. RESULTS: Among 4 086 504 preterm infants born during the study period, 8096 infants (0.2% or 2.0 per 1000 live births) experienced SUID. State variation in SUID ranged from the lowest rate of 0.82 per 1000 live births in Vermont to the highest rate of 3.87 per 1000 live births in Mississippi. Unadjusted SUID rates across racial and ethnic groups varied from 0.69 (Asian/Pacific Islander) to 3.51 (NHB) per 1000 live births. In the adjusted analysis, compared with NHW infants, NHB and Alaska Native/American Indian preterm infants had greater odds of SUID (aOR, 1.5;[95% CI, 1.42-1.59] and aOR, 1.44 [95% CI, 1.21-1.72]) with varying magnitude of SUID rates and NHB-NHW disparities across states. CONCLUSIONS: Significant racial and ethnic disparities in SUID among preterm infants exist with variation across US states. Additional research to identify the drivers of these disparities within and across states is needed.

Risk of Extreme, Moderate, and Late Preterm Birth by Maternal Race, Ethnicity, and Nativity.

OBJECTIVES: To explore the relative risks of preterm birth-both overall and stratified into 3 groups (late, moderate, and extreme prematurity)-associated with maternal race, ethnicity, and nativity (ie, birthplace) combined. STUDY DESIGN: This was a retrospective cross-sectional cohort study of women delivering a live birth in Pennsylvania from 2011 to 2014 (n = 4 499 259). Log binomial and multinomial regression analyses determined the relative risks of each strata of preterm birth by racial/ethnic/native category, after adjusting for maternal sociodemographic, medical comorbidities, and birth year. RESULTS: Foreign-born women overall had lower relative risks of both overall preterm birth and each strata of prematurity when examined en bloc. However, when considering maternal race, ethnicity, and nativity together, the relative risk of preterm birth for women in different racial/ethnic/nativity groups varied by preterm strata and by race. Being foreign-born appeared protective for late prematurity. However, only foreign-born White women had lower adjusted relative risks of moderate and extreme preterm birth compared with reference groups. All ethnic/native sub-groups of Black women had a significantly increased risk of extreme preterm births compared with US born non-Hispanic White women. CONCLUSIONS: Race, ethnicity, and nativity contribute differently to varying levels of prematurity. Future research involving birth outcome disparities may benefit by taking a more granular approach to the outcome of preterm birth and considering how nativity interacts with race and ethnicity.

Acute Kidney Injury Associated with Late-Onset Neonatal Sepsis: A Matched Cohort Study.

OBJECTIVES: To determine incidence and severity of acute kidney injury (AKI) within 7 days of sepsis evaluation and to assess AKI duration and the association between AKI and 30-day mortality. STUDY DESIGN: Retrospective, matched cohort study in a single-center level IV neonatal intensive care unit. Eligible infants underwent sepsis evaluations at ≥72 hours of age during calendar years 2013-2018. Exposed infants (cases) were those with culture-proven sepsis and antimicrobial duration ≥5 days. Nonexposed infants (controls) were matched 1:1 to exposed infants based on gestational and corrected gestational age, and had negative sepsis evaluations with antibiotic durations <48 hours. AKI was defined by modified neonatal Kidney Disease Improving Global Outcomes criteria. Statistical analysis included Mann-Whitney and χ2 tests, multivariable logistic regression, and Kaplan-Meier time-to-event analysis. RESULTS: Among 203 episodes of late-onset sepsis, 40 (20%) developed AKI within 7 days after evaluation, and among 193 episodes with negative cultures, 16 (8%) resulted in AKI (P = .001). Episodes of sepsis also led to greater AKI severity, compared with nonseptic episodes (P = .007). The timing of AKI onset and AKI duration did not differ between groups. Sepsis was associated with increased odds of developing AKI (aOR, 3.0; 95% CI, 1.5-6.2; P = .002). AKI was associated with increased 30-day mortality (aOR, 4.5; 95% CI, 1.3-15.6; P = .017). CONCLUSIONS: Infants with late-onset sepsis had increased odds of AKI and greater AKI severity within 7 days of sepsis evaluation, compared with age-matched infants without sepsis. AKI was independently associated with increased 30-day mortality. Strategies to mitigate AKI in critically ill neonates with sepsis may improve outcomes.

Black-White disparities in maternal in-hospital mortality according to teaching and Black-serving hospital status.

BACKGROUND: Maternal mortality is higher among Black than White people in the United States. Whether Black-White disparities in maternal in-hospital mortality during the delivery hospitalization vary across hospital types (Black-serving vs nonBlack-serving and teaching vs nonteaching) and whether overall maternal mortality differs across hospital types is not known. OBJECTIVE: The aims of this study were to determine whether risk-adjusted Black-White disparities in maternal mortality during the delivery hospitalization vary by hospital types (this is analysis of disparities in mortality within hospital types) and compare risk-adjusted in-hospital maternal mortality among Black-serving and nonBlack-serving teaching and nonteaching hospitals regardless of race (this is an analysis of overall mortality across hospital types). STUDY DESIGN: We performed a population-based, retrospective cohort study of 5,679,044 deliveries among Black (14.2%) and White patients (85.8%) in 3 states (California, Missouri, and Pennsylvania) from 1995 to 2009. A hospital discharge disposition of "death" defined maternal in-hospital mortality. Black-serving hospitals had at least 7% Black obstetrical patients (top quartile). We performed risk adjustment by calculating expected death rates using predictions from logistic regression models incorporating sociodemographics, rurality, comorbidities, multiple gestations, gestational age at delivery, year, state, and mode of delivery. We calculated risk-adjusted risk ratios of mortality by comparing observed-to-expected ratios among Black and White patients within hospital types and then examined mortality across hospital types, regardless of patient race. We quantified the proportion of Black-White disparities in mortality attributable to delivering in Black-serving hospitals using causal mediation analysis. RESULTS: There were 330 maternal deaths among 5,679,044 patients (5.8 per 100,000). Black patients died more often (11.5 per 100,000) than White patients (4.8 per 100,000) (relative risk, 2.38; 95% confidence interval, 1.89-2.98). Examination of Black-White disparities revealed that after risk adjustment, Black patients had significantly greater risk of death (adjusted relative risk, 1.44; 95% confidence interval, 1.17-1.79) and that the disparity was similar within each of the hospital types. Comparison of mortality, regardless of race, across hospital types revealed that among teaching hospitals, mortality was similar in Black-serving and nonBlack-serving hospitals. However, among nonteaching hospitals, mortality was significantly higher in Black-serving vs nonBlack-serving hospitals (adjusted relative risk, 1.47; 95% confidence interval, 1.15-1.87). Notably, 53% of Black patients delivered in nonteaching, Black-serving hospitals compared with just 19% of White patients. Among nonteaching hospitals, 47% of Black-White disparities in maternal in-hospital mortality were attributable to delivering at Black-serving hospitals. CONCLUSION: Maternal in-hospital mortality during the delivery hospitalization among Black patients is more than double that of White patients. Our data suggest this disparity is caused by excess mortality among Black patients within each hospital type, in addition to excess mortality in nonteaching, Black-serving hospitals where most Black patients deliver. Addressing downstream effects of racism to achieve equity in maternal in-hospital mortality will require transparent reporting of quality metrics by race to reduce differential care and outcomes within hospital types, improvements in care delivery at Black-serving hospitals, overcoming barriers to accessing high-quality care among Black patients, and eventually desegregation of healthcare.

Surface mining and low birth weight in central appalachia.

BACKGROUND: Surface mining has become a significant method of coal mining in the Central Appalachian region of the eastern United States alongside the traditional underground mining. Concerns have been raised about the health effects of this surface mining, particularly mountaintop removal mining where coal is mined upon steep mountaintops by removing the mountaintop through clearcutting forests and explosives. METHODS: We used a control group design with a pretest and a posttest to assess the associations of surface mining in Central Appalachia with low birth weight and other adverse birth outcomes. The pretest period is 1977-1989, a period of low surface mining activity. We consider three posttest periods: 1990-1998, 1999-2011 and 2012-2017, with 1999-2011 as the primary analysis and the other periods as secondary analyses. Surface mining in Central Appalachia increased after 1989, partly resulting from the Clean Air Act Amendments of 1990 which made surface mining in Appalachia more financially attractive. For the primary analysis, we fit a logistic regression model of the primary outcome (low birth weight, <2500 g) on dummy variables for county and year; individual level maternal/infant covariates (maternal race, maternal age, infant sex and whether birth was a multiple birth); and the amount of surface mining during the year of the birth in the maternal county of residence. RESULTS: Our analysis sample consisted of 783,328 infants -- 482,284 infants born from 1977 to 2017 to women residing in substantial surface mining activity counties and 301,044 infants born from 1977 to 2017 to women residing in matched control counties. Compared to the pre-period of low surface mining from 1977 to 1989, for the primary analysis posttest period of 1999-2011, there was an estimated relative increase in low birth weight in surface mining counties compared to matched control counties that was not statistically significant (odds ratio for a 5 percentage point increase in area disturbed by surface mining: 1.07, 95% confidence interval (0.96, 1.20), p-value: .22). For the secondary analysis posttest period of 1990-1998, there was no increase (odds ratio: 0.91, 95% confidence interval: (0.74, 1.13), p-value: .41). For the secondary analysis posttest period of 2012-2017, there was a statistically significant relative increase (odds ratio: 1.28, 95% confidence interval: (1.08, 1.50), p-value: .004). Qualitatively similar results were found for the outcomes of very low birth weight, preterm birth and small-for-gestational age. CONCLUSIONS: We examined the hypothesis that surface mining activity in Central Appalachia contributes to low birth weight using an observational study. We found evidence in secondary analyses that surface mining was associated with low birth weight in the 2012-2017 time period and potentially beginning in the early to mid 2000's. Evidence for an association was not found prior to 2000. A potential explanation for this pattern of association is that surface mining caused an increase in low birth weight but its onset was delayed. Future research is needed to clarify the findings and if replicated, identify the mechanism necessary to mitigate the impacts of mining on adverse birth outcomes.

Socioeconomic barriers to prenatal diagnosis of critical congenital heart disease.

OBJECTIVE: The study was designed to assess the impact of socioeconomic barriers on the rate of prenatal diagnosis of critical congenital heart disease (CCHD). METHODS: This was a retrospective review of the Medicaid analytic extract (MAX) dataset, a national Medicaid administrative claims database with linked maternal-infant claims, from 2007 to 2012. Infants with CCHD were identified by searching for International Classification of Diseases (ICD) 9 codes and Procedural Coding System (PCS) codes for CCHD within the first 6 months after the delivery date. Multivariate logistic regression was used to evaluate the effect of maternal and socioeconomic factors on the prenatal diagnosis rate. RESULTS: There were 4702 mother-infant dyads included in the analysis. The prenatal diagnosis rate of CCHD was 27.9%. Factors independently associated with odds of prenatal diagnosis of CCHD were presence of maternal diabetes (OR, 2.055; P < .001), ZIP code level median household income (OR, 1.005; P = .015), sonographer labor quotient (OR, 1.804; P = .047), the year of the delivery (OR, 1.155; P < .001), and needing a view other than a 4 chamber or outflow tract view to obtain the diagnosis (OR, 0.383; P < .001). CONCLUSION: Maternal health, diabetes, socioeconomic factors, and access to sonographers impacts prenatal diagnosis of CCHD.

Identifying individual hospital levels of maternal care using administrative data.

BACKGROUND: The goal of regionalized perinatal care, specifically levels of maternal care, is to improve maternal outcomes through risk-appropriate obstetric care. Studies of levels of maternal care are limited by current approaches to identify a hospital's level of care, often relying on hospital self-reported data, which is expensive and challenging to collect and validate. The study objective was to develop an empiric approach to determine a hospital's level of maternal care using administrative data reflective of the patient care provided and apply this approach to describe the levels of maternal care available over time. METHODS: Retrospective cohort study of mother-infant dyads who delivered in California, Missouri, and Pennsylvania hospitals from 2000 to 2009. Linked mother-infant administrative records with an infant born at 24-44 weeks' gestation and a birth weight of 400-8000 g were included. Using the American College of Obstetricians and Gynecologists and the Society for Maternal Fetal Medicine descriptions of levels of maternal care, four levels were classified based on the appropriate location of care for patients with specific medical or pregnancy conditions. Individual hospitals were assigned a level of maternal care annually based on the volume of patients who delivered reflective of the four classified levels as determined by International Classification of Diseases and Current Procedural Terminology. RESULTS: Based on the included 6,895,000 mother-infant dyads, the obstetric hospital levels of maternal care I, II, III and IV were identified. High-risk patients more frequently delivered in hospitals with higher level maternal care, accounting for 8.9, 10.9, 13.8, and 16.9% of deliveries in level I, II, III and IV hospitals, respectively. The total number of obstetric hospitals decreased over the study period, while the proportion of hospitals with high-level (level III or IV) maternal care increased. High-level hospitals were located in more densely populated areas. CONCLUSION: Identification of the level of maternal care, independent of hospital self-reported variables, is feasible using administrative data. This empiric approach, which accounts for changes in hospitals over time, is a valuable framework for perinatal researchers and other stakeholders to inexpensively identify measurable benefits of levels of maternal care and characterize where specific patient populations receive care.

Medication Utilization at School Age for Children Born Preterm.

We explored medication use by children born preterm at 5-8 years of age. Compared with children born at full term, children born preterm had higher medication use that included most therapeutic classifications. Although asthma and chronic lung disease influenced use, prematurity remained an independent risk factor.

Preventive Health Care Utilization Among Mother-infant Dyads With Medicaid Insurance in the Year Following Birth.

BACKGROUND: Following birth, women may access preventive care in adult settings or, with their infants, in pediatric settings. Preventive care can improve future birth outcomes and long-term health, particularly for women with health risks. METHODS: This cohort study linked mother-infant Medicaid claims from 12 states for 2007-2011 births. Pregnancy claims identified health risk categories: maternal cardiovascular (diabetes, hypertension, pre-eclampsia, obesity), maternal mental health (depression, anxiety), and premature birth. Claims for 1 year following birth identified adult and pediatric preventive visits. Logistic regression assessed the relationship between visits and risks, adjusting for maternal demographics, perinatal health care utilization, year, and state. RESULTS: Of 594,888 mother-infant dyads with Medicaid eligibility for 1 year following birth, 36% had health risks. In total, 38% of all dyads, and 33% with health risks, had no adult preventive visits. Dyads had a median of 1 (IQR, 0-2) adult and 3 (IQR, 2-5) pediatric preventive visits. A total of 72% of dyads had more preventive visits in pediatric than adult settings. In regression, preterm birth was associated with lower odds of any adult preventive visits [odds ratio (OR), 0.97; 95% confidence interval (CI), 0.95-0.99], and maternal health risks with higher odds (cardiovascular OR, 1.19; 95% CI, 1.18-1.21; mental health OR, 1.87; 95% CI, 1.84-1.91), compared with dyads without risk. CONCLUSIONS: Maternal health risks were associated with increased adult preventive visits, but 38% of dyads had no adult preventive visits in the year following birth. Most dyads had more opportunities for preventive care in pediatric settings than adult settings.

Prematurity as an Independent Risk Factor for the Development of Pulmonary Disease.

OBJECTIVES: To determine if premature infants without bronchopulmonary dysplasia (BPD) are at similar risk for developing pulmonary morbidity as compared with those with BPD and if there are differences in management of care. STUDY DESIGN: We retrospectively abstracted information from our electronic medical record from January 1, 2006, to December 31, 2015, for primary care patients born at <30 weeks of gestation (n = 811). Multivariate models determined the impact of BPD on a diagnosis of respiratory disease, respiratory medications, subspecialty visits, and emergency department use or hospitalizations after adjusting for gestational age, sex, insurance type, and race. RESULTS: Infants with BPD were more likely to be diagnosed with asthma than those without BPD (75% vs 60%; OR, 1.8; 95% CI, 1.27-2.54), but not all respiratory conditions (OR, 1.56; 95% CI, 0.7-3.51), and were more likely to be referred to a pulmonologist (relative risk, 5.98; 95% CI, 4.1-8.74). Infants with BPD were more likely to be hospitalized for respiratory conditions than those without BPD (50% vs 30%; relative risk, 2.44; 95% CI, 1.73-3.45). CONCLUSIONS: Although infants with BPD were more likely to have a diagnosis of asthma and be readmitted for respiratory conditions, 60% of infants without BPD were also diagnosed with asthma and 30% were readmitted. There were significant differences in the management of patients, including time to pulmonary referral and prescription rates for inhaled corticosteroids. Practitioners should consider all patients born prematurely at high risk for respiratory morbidity.

Incidence Trends and Risk Factor Variation in Severe Intraventricular Hemorrhage across a Population Based Cohort.

OBJECTIVE: To quantify the current burden of severe intraventricular hemorrhage (IVH), describe time trends in severe IVH, identify IVH-associated risk factors, and determine the contribution of mediating factors. STUDY DESIGN: The retrospective cohort included infants 220/7-316/7 weeks of gestation without severe congenital anomalies, born at hospitals in the California Perinatal Quality Care Collaborative between 2005 and 2015. The primary study outcome was severe (grade III or IV) IVH. RESULTS: Of 44 028 infants, 3371 (7.7%) had severe IVH. The incidence of severe IVH decreased significantly across California from 9.7% in 2005 to 5.9% in 2015. After stratification by gestational age, antenatal steroid exposure was the only factor associated with a decreased odds of severe IVH for all gestational age subgroups. Other factors, including delivery room intubation, were associated with an increased odds of severe IVH, though significance varied by gestational age. Factors analyzed in the mediation analysis accounted for 45.6% (95% CI 38.7%-71.8%) of the reduction in severe IVH, with increased antenatal steroid administration and decreased delivery room intubation mediating a significant proportion of this decrease, 19.4% (95% CI 13.9%-27.5%) and 27.3% (95% CI 20.3%-39.2%), respectively. The unaccounted proportion varied by gestational age. CONCLUSIONS: The incidence of severe IVH decreased across California, associated with changes in antenatal steroid exposure and delivery room intubation. Maternal, patient, and delivery room factors accounted for less than one-half of the decrease in severe IVH. Study of other factors, specifically neonatal intensive care unit and hospital-level factors, may provide new insights into policies to reduce severe IVH.

Mental Health of Mothers of Infants with Neonatal Abstinence Syndrome and Prenatal Opioid Exposure.

BACKGROUND: The prevalence of opioid use during pregnancy is increasing. Two downstream effects are neonatal abstinence syndrome (NAS), a postnatal withdrawal syndrome, and long-term prenatal opioid exposure (LTPOE) without documented withdrawal symptoms in the infant. Mental health characteristics of mothers of infants with NAS and LTPOE have not been described. METHODS: Using linked maternal and infant Medicaid claims and birth certificate data, we analyzed 15,571 infants born to Medicaid-insured women 15-24 years old in a mid-Atlantic city from 2007 to 2010. Pairwise comparisons with multinomial logistic regression, adjusting for maternal and infant covariates, were performed. We compared four mental health conditions among mothers of infants with NAS, infants with LTPOE without NAS, and controls: depression, anxiety, bipolar disorder, and schizophrenia. RESULTS: The prevalence of depression among mothers of infants with NAS, infants with LTPOE, and controls was 26, 21.1, and 5.5% respectively. Similar results were found for anxiety. In multivariable analysis, mothers of infants with NAS and LTPOE had approximately twice the depression risk as controls, while mothers of infants with LTPOE had 2.2 times the bipolar disorder risk and 4.6 times the schizophrenia risk as controls. The overall risk of mental health conditions in mothers of infants with NAS and LTPOE was similar. DISCUSSION: Mothers of infants with LTPOE who did not develop NAS are at similarly high risk for mental health conditions as mothers of infants with NAS, and both are at higher risk than controls. Therefore, those mothers of infants who did not develop symptoms of NAS despite LTPOE may be a vulnerable population that needs additional mental health support in the post-partum period.

Comparing the Contributions of Acute and Postacute Care Facility Characteristics to Outcomes After Hospitalization for Hip Fracture.

OBJECTIVE: To quantify the contribution of acute versus postacute care factors to survival and functional outcomes after hip fracture. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using Medicare data; subjects included previously ambulatory nursing home residents hospitalized for hip fracture between 2005 and 2009. METHODS: We used logistic regression to measure the associations of hospital and nursing home factors with functional and survival outcomes at 30 and 180 days among patients discharged to a nursing facility; we quantified the contribution of hospital versus nursing home factors to outcomes by the ω statistic. RESULTS: Among 45,996 hospitalized patients, 1814 (3.9%) died during hospitalization. A total of 42,781 (93%) were discharged alive to a nursing home. Of these, 12,126 (28%) died within 180 days and 20,479 (48%) died or were newly unable to walk within 180 days. Hospital characteristics were not consistently associated with outcomes. Multiple nursing home characteristics predicted 30- and 180-day outcomes, including bed count, chain membership, and performance on selected quality measures. Nursing home factors explained 3 times more variation in the odds of 30-day mortality than did hospital factors [ω, hospital vs. nursing home: 0.32; 95% confidence interval (CI), 0.11, 0.96], 7 times more variation in the odds of 180-day mortality (ω: 0.15; 95% CI, 0.04, 0.61), and 8 times more variation in the odds of 180-day death or new dependence in locomotion (ω: 0.12; 95% CI, 0.05, 0.31). CONCLUSIONS: Nursing home factors explain a larger proportion of the variation in clinical outcomes following hip fracture than do hospital factors.

The Association of NICU Strain with Neonatal Mortality and Morbidity.

Objective: To examine the association of admission NICU strain with neonatal mortality and morbidity. Study Design: 2008-2021 South Carolina cohort using linked vital statistics and discharge data of 22-44 weeks GA infants, born at hospitals with ≥ level 2 unit and ≥5 births of infants <34 weeks GA/year. The exposure was tertiles of admission NICU strain, defined as the sum of infants <44 weeks GA with a congenital anomaly plus all infants born <33 weeks GA at midnight on the day of birth. We used Poisson generalized linear mixed models to examine the association of exposure to strain with the primary outcome of a composite of mortality and term and preterm morbidities adjusting for patient and hospital characteristics. Results: We studied 64,647 infants from 30 hospitals. High strain was associated with increased risk of mortality and morbidity adjusting for patient/hospital factors (aIRR 1.07, 95% CI 1.01 - 1.12). Conclusion: NICU strain is associated with increased adverse outcomes.

The impact of volume and neonatal level of care on outcomes of moderate and late preterm infants.

OBJECTIVE: Evaluate the relationship of neonatal unit level of care (LOC) and volume with mortality or morbidity in moderate-late preterm (MLP) (32-36 weeks' gestation) infants. DESIGN: Retrospective cohort study of 650,865 inborn MLP infants in 4976 hospitals-years using 2003-2015 linked administrative data from 4 states. Exposure was combined neonatal LOC and MLP annual volume. The primary outcome was death or morbidity (respiratory distress syndrome, severe intraventricular hemorrhage, necrotizing enterocolitis, sepsis, infection, pneumothorax, extreme length of stay) with components as secondary outcomes. Poisson regression models adjusted for patient characteristics with a random effect for unit were used. RESULTS: In adjusted models, high-volume level 2 units had a lower risk of the primary outcome compared to low-volume level 3 units (aIRR 0.90 [95% CI 0.83-0.98] vs. aIRR 1.13 [95% CI 1.03-1.24], p < 0.001) CONCLUSION: MLP infants had improved outcomes in high-volume level 2 units compared to low-volume level 3 units in adjusted analysis.

Who's in the NICU? A population-level analysis.

OBJECTIVE: To understand the characteristics of infants admitted to US NICUs. STUDY DESIGN: 2006-2014 linked birth certificate and hospital discharge data for potentially viable deliveries in Pennsylvania and South Carolina were used. NICU admissions were identified using revenue codes. NICU-admitted infants were categorized by gestational age (GA), birthweight, and condition severity (for GA 35+ weeks). We also assessed total patient days and trends over time. RESULTS: 12% of infants were admitted to a NICU; 13.6% were GA < 32 weeks (45.3% of total days); 36.1% were GA 32-36 weeks (31.2% of total days); and 50.4% were GA 37+ weeks (23.5% of total days). 20% of admissions were for infants with GA 35+ weeks and mild conditions. Admissions increased numerically from 11.2% (2006) to 13.0% (2014), with increases among infants 35+ weeks. CONCLUSION: Most NICU admissions are for infants 35+ weeks GA, many with mild conditions who may be accommodated in well-baby units.