Independent Impact of Eat, Sleep, Console Assessment on Neonatal Opioid Withdrawal Syndrome.

Compared with the Finnegan Neonatal Abstinence Scoring System (FNASS), the Eat, Sleep, Console (ESC) approach reduces pharmacotherapy and length of stay (LOS) for neonatal opioid withdrawal syndrome (NOWS) infants. The independent outcome contribution of ESC is unknown as the approach combines ESC assessment with additional management changes. Our objective was to evaluate ESC assessment's independent impact on outcomes compared with FNASS. We conducted a retrospective cohort study of in utero opioid-exposed infants ≥35 weeks gestation managed with FNASS versus ESC. Outcomes included pharmacotherapy initiation, LOS, length of pharmacotherapy, and emergency department visit/readmissions. Among 151 FNASS and 100 ESC managed infants, pharmacotherapy initiation (P = .47), LOS for all infants (P = .49), and LOS for pharmacologically treated infants (P = .68) were similar. Length of pharmacotherapy did not differ (P = .84). Emergency department evaluation/NOWS readmission was equally rare (P = .65). Using equivalent models of care, comparison of ESC and FNASS assessment tools showed no difference in NOWS outcomes.

NICU Versus Mother/Baby Unit Admission for Low-Acuity Infants Born at 35 Weeks' Gestation.

OBJECTIVES: To estimate the effect of NICU admission of low-acuity infants born at 35 weeks' gestation versus care in a mother/baby unit, on inpatient and outpatient medical outcomes. METHODS: This retrospective cohort study included 5929 low-acuity infants born at 350/7 to 356/7 weeks' gestation at 13 Kaiser Permanente Northern California hospitals with level II or level III NICUs between January 1, 2011, and December 31, 2021. Exclusion criteria included congenital anomalies and early respiratory support or antibiotics. We used multivariable regression and regression discontinuity analyses to control for confounding variables. RESULTS: Infants admitted to the NICU within 2 hours of birth (n = 862, 14.5%) had a 58 hour adjusted (98-hour unadjusted) longer length of stay. NICU admission was associated with an increased probability of a length of stay ≥96 hours (67% vs 21%; adjusted odds ratio [aOR], 4.94; 95% confidence interval [CI], 3.96-6.16). Regression discontinuity results suggested a similar (57 hour) increase in length of stay. Readmission risk, primarily for jaundice, was lower for those admitted to the NICU (3% vs 6%; aOR, 0.43; 95% CI, 0.27-0.69). Infants admitted to the NICU were slightly less likely to be receiving exclusive breast milk at 6-month follow-up (15% vs 25%; aOR, 0.73; 95% CI, 0.55-0.97; adjusted marginal risk difference -5%). CONCLUSIONS: Admitting low-acuity infants born at 35 weeks' gestation to the NICU was associated with decreased readmission, but with longer length of stay and decreased exclusive breast milk feeding at 6 months. Routine NICU admission may be unnecessary for low-acuity infants born at 35 weeks' gestation.

Accuracy of diagnostic codes for prenatal opioid exposure and neonatal opioid withdrawal syndrome.

OBJECTIVE: Determine the accuracy of diagnostic codes in identifying Prenatal Opioid Exposure (POE) and Neonatal Opioid Withdrawal Syndrome (NOWS). STUDY DESIGN: A cross-sectional study of 374,222 mother-infant dyads with delivery from 01/01/2010 to 12/31/2019. We ascertained maternal diagnostic codes for opioid use during pregnancy and infant diagnostic codes for drug exposure and withdrawal. We assessed sensitivity and positive predictive value (PPV) for POE and NOWS, defined using laboratory, pharmacy, and clinical data. RESULTS: Maternal codes had low sensitivity (36.4%) and PPV (34.7%) for POE. Infant codes for drug exposure were neither sensitive for POE (14%) nor NOWS (31.6%) and had low PPV. Codes for newborn withdrawal had low sensitivity (31.6%) for detecting NOWS, but high PPV (85%). Sensitivity improved (95.1%) for NOWS requiring pharmacologic treatment. CONCLUSIONS: Diagnostic codes identify POE and NOWS poorly. Improved case identification would include pharmacy and laboratory results, and clearly defined criteria for evidence of withdrawal.

Time to positivity of blood cultures in neonatal late-onset bacteraemia.

OBJECTIVE: To determine the time to positivity (TTP) of blood cultures among infants with late-onset bacteraemia and predictors of TTP >36 hours. DESIGN: Retrospective cohort study. SETTING: 16 birth centres in two healthcare systems. PATIENTS: Infants with positive blood cultures obtained >72 hours after birth. OUTCOME: The main outcome was TTP, defined as the time interval from specimen collection to when a neonatal provider was notified of culture growth. TTP analysis was restricted to the first positive culture per infant. Patient-specific and infection-specific factors were analysed for association with TTP >36 hours. RESULTS: Of 10 235 blood cultures obtained from 3808 infants, 1082 (10.6%) were positive. Restricting to bacterial pathogens and the first positive culture, the median TTP (25th-75th percentile) for 428 cultures was 23.5 hours (18.4-29.9); 364 (85.0%) resulted in 36 hours. Excluding coagulase-negative staphylococci (CoNS), 275 of 294 (93.5%) cultures were flagged positive by 36 hours. In a multivariable model, CoNS isolation and antibiotic pretreatment were significantly associated with increased odds of TTP >36 hours. Projecting a 36-hour empiric duration at one site and assuming that all negative evaluations were associated with an empiric course of antibiotics, we estimated that 1164 doses of antibiotics would be avoided in 629 infants over 10 years, while delaying a subsequent antibiotic dose in 13 infants with bacteraemia. CONCLUSIONS: Empiric antibiotic administration in late-onset infection evaluations (not targeting CoNS) can be stopped at 36 hours. Longer durations (48 hours) should be considered when there is pretreatment or antibiotic therapy is directed at CoNS.

Use of Complete Blood Cell Count Components to Screen for Hereditary Spherocytosis in Neonates.

BACKGROUND AND OBJECTIVES: The neonatal hereditary spherocytosis (HS) index, defined as the mean corpuscular hemoglobin concentration divided by the mean corpuscular volume, has been proposed as a screening tool for HS in neonates. In a population of mostly white infants, an HS Index >0.36 was 97% sensitive and >99% specific. We evaluated the utility of the HS Index among a more racially and ethnically diverse population and determined if its discrimination varies with total serum bilirubin (TSB) levels. METHODS: Infants born at ≥35 weeks' gestation at 15 Kaiser Permanente Northern California hospitals from 1995 to 2015 were eligible (N = 670 272). Erythrocyte indices from the first complete blood count drawn at ≤7 days and TSB levels drawn at ≤30 days were obtained. Diagnoses of HS were confirmed via chart review. RESULTS: HS was confirmed in 79 infants, 1.2 per 10 000. HS was more common among infants of white and "other" race or ethnicity and among those with higher peak TSB levels. The area under the receiver operating characteristic curve for the HS Index was 0.84 (95% confidence interval 0.78-0.90). Likelihood ratios ranged from 10.1 for an HS Index ≥0.380 to 0.1 for an HS Index <0.310. Dichotomized at 0.36, the HS Index was 56% sensitive and 93% specific. Discrimination of the HS Index appeared best among infants with TSB levels <10 mg/dL. CONCLUSIONS: The HS Index, when obtained from a CBC drawn within the first week after birth, had only modest ability to alter the probability of HS.

Predicting the Need for Phototherapy After Discharge.

BACKGROUND AND OBJECTIVES: Bilirubin screening before discharge is performed to identify neonates at risk for future hyperbilirubinemia. The American Academy of Pediatrics recommends using a graph of bilirubin levels by age (the Bhutani Nomogram) to guide follow-up and a different graph to determine phototherapy recommendations. Our objective was to evaluate predictive models that incorporate the difference between the last total serum bilirubin (TSB) before discharge and the American Academy of Pediatrics phototherapy threshold (Δ-TSB) to predict a postdischarge TSB above the phototherapy threshold by using a single graph. METHODS: We studied 148 162 infants born at ≥35 weeks' gestation at 11 Kaiser Permanente Northern California facilities from 2012 to 2017 whose TSB did not exceed phototherapy levels and who did not receive phototherapy during the birth hospitalization. We compared 3 logistic models (Δ-TSB; Δ-TSB-Plus, which included additional variables; and the Bhutani Nomogram) by using the area under the receiver operating characteristic curve (AUC) in a 20% validation subset. RESULTS: A total of 2623 infants (1.8%) exceeded the phototherapy threshold postdischarge. The predicted probability of exceeding the phototherapy threshold after discharge ranged from 56% for a predischarge Δ-TSB 0 to 1 mg/dL below the threshold to 0.008% for Δ-TSB >7 mg/dL below the threshold. Discrimination was better for the Δ-TSB model (AUC 0.93) and the Δ-TSB-Plus model (AUC 0.95) than for the Bhutani Nomogram (AUC 0.88). CONCLUSIONS: The use of Δ-TSB models had excellent ability to predict postdischarge TSB above phototherapy thresholds and may be simpler to use than the Bhutani Nomogram.

A simplified CD34+ based preharvest prediction tool for HPC(A) collection.

BACKGROUND: Hematopoietic stem cell transplantation is an important treatment that is dependent on the collection of sufficient CD34+ hematopoietic progenitor cells. The peripheral blood CD34 count (PB CD34+ counts) measured by flow cytometry can be used in predicting CD34+ stem cell yields hours before the completion of collection. Previously described formulas to predict the yield have used many different variables. As such, there is currently no consensus on an industry-standard algorithm or formula. STUDY DESIGN AND METHODS: Retrospective reviews of same-day PB CD34+ counts and the ensuing absolute CD34+ yields of mobilized donors (allogeneic and autologous) were used to develop and validate a formula using regression analysis to predict the CD34+ stem cell yield. A metric of prediction correlation, using root mean square error (RMSE), was used to assess the robustness of our prediction formula in addition to comparisons with two other published formulas, as well as subset analysis. RESULTS: A formula in the form of y = mxb with r = 0.95 and 95% confidence intervals was generated and validated. The ratio of actual to predicted yield demonstrated a high correlation coefficient (r = 0.96) with linear regression and overall RMSE of 228.4, which was lower than the two prior studies (calculated RMSE = 330.8 and 405.2). Subset analyses indicated male patients, lymphoma patients, and patients >60 years of age demonstrated lower RMSEs. CONCLUSION: We have demonstrated a simple yet robust formula that can be used prospectively to accurately predict the CD34+ stem cell yield in both autologous and allogeneic donors, which also accounts for recipient weight.

Time to Positivity of Neonatal Blood Cultures for Early-onset Sepsis.

BACKGROUND: In newborns at risk for early-onset sepsis, empiric antibiotics are often initiated while awaiting the results of blood cultures. The duration of empiric therapy can be guided by the time to positivity (TTP) of blood cultures. The objective of the study was to determine the TTP of neonatal blood cultures for early-onset sepsis and the factors which may impact TTP. METHODS: Observational study of blood cultures growing pathogenic species obtained within 72 hours of birth from infants born at 23-42 weeks gestation, at 19 hospitals in Northern California, Boston, and Philadelphia. TTP was defined as the time from blood culture collection to the time organism growth was reported by the microbiology laboratory. RESULTS: A total of 594 blood cultures growing pathogenic bacteria were identified. Group B Streptococcus and Escherichia coli accounted for 74% of blood culture isolates. Median TTP was 21.0 hours (interquartile range, 17.1-25.3 hours). Blood cultures were identified as positive by 24 hours after they were obtained in 68% of cases; by 36 hours in 94% of cases; and by 48 hours in 97% of cases. Neither the administration of maternal intrapartum antibiotic prophylaxis, gestational age <35 weeks, nor blood culture system impacted median TTP. CONCLUSIONS: Pathogens are isolated by 36 hours after blood culture collection in 94% of neonatal early blood cultures, regardless of maternal antibiotic administration. TTP information can inform decisions regarding the duration of empiric neonatal antibiotic therapies.

Incremental Cost of Prematurity by Week of Gestational Age.

Objective This study was aimed to compare health care costs and utilization at birth through 1 year, between preterm and term infants, by week of gestation. Methods A cross-sectional study of infants born at ≥ 23 weeks of gestational age (GA) at Kaiser Permanente Northern California facilities between 2000 and 2011, using outcomes data from an internal neonatal registry and cost estimates from an internal cost management database. Adjusted models yielded estimates for cost differences for each GA group. Results Infants born at 25 to 37 weeks incur significantly higher birth hospitalization costs and experience significantly more health care utilization during the initial year of life, increasing progressively for each decreasing week of gestation, when compared with term infants. Among all very preterm infants (≤ 32 weeks), each 1-week decrease in GA is associated with incrementally higher rates of mortality and major morbidities. Conclusion We provide estimates of potential cost savings that could be attributable to interventions that delay or prevent preterm delivery. Cost differences were most extreme at the lower range of gestation (≤ 30 weeks); however, infants born moderately preterm (31-36 weeks) also contribute substantially to the burden, as they represent a higher proportion of total births.

Automated early detection of obstetric complications: theoretic and methodologic considerations.

Compared with adults who are admitted to general medical-surgical wards, women who are admitted to labor and delivery services are at much lower risk of experiencing unexpected critical illness. Nonetheless, critical illness and other complications that put either the mother or fetus at risk do occur. One potential approach to prevention is to use automated early warning systems, such as those used for nonpregnant adults. Predictive models that use data extracted in real time from electronic records constitute the cornerstone of such systems. This article addresses several issues that are involved in the development of such predictive models: specification of temporal characteristics, choice of denominator, selection of outcomes for model calibration, potential uses of existing adult severity of illness scores, approaches to data processing, statistical considerations, validation, and options for instantiation. These have not been addressed explicitly in the obstetrics literature, which has focused on the use of manually assigned scores. In addition, this article provides some results from work in progress to develop 2 obstetric predictive models with the use of data from 262,071 women who were admitted to a labor and delivery service at 15 Kaiser Permanente Northern California hospitals between 2010 and 2017.

Hyperbilirubinemia, Phototherapy, and Childhood Asthma.

OBJECTIVES: Our aim was to quantify the associations of both hyperbilirubinemia and phototherapy with childhood asthma using a population-based cohort with total serum bilirubin (TSB) levels. METHODS: Retrospective cohort study of infants born at ≥35 weeks' gestation in the Kaiser Permanente Northern California health system (n = 109 212) from 2010 to 2014. Cox models were used to estimate hazard ratios (HRs) for a diagnosis of asthma. RESULTS: In the study, 16.7% of infants had a maximum TSB level of ≥15 mg/dL, 4.5% of infants had a maximum TSB level of ≥18 mg/dL, and 11.5% of infants received phototherapy. Compared with children with a maximum TSB level of 3 to 5.9 mg/L, children with a TSB level of 9 to 11.9 mg/dL, 12 to 14.9 mg/dL, and 15 to 17.9 mg/dL were at an increased risk for asthma (HR: 1.22 [95% confidence interval (CI): 1.11-1.3], HR: 1.18 [95% CI: 1.08-1.29], and HR: 1.30 [95% CI: 1.18-1.43], respectively). Children with a TSB level of ≥18 mg/dL were not at an increased risk for asthma (HR: 1.04; 95% CI: 0.90-1.20). In propensity-adjusted analyses, phototherapy was not associated with asthma (HR: 1.07; 95% CI: 0.96-1.20). CONCLUSIONS: Modest levels of hyperbilirubinemia were associated with an increased risk of asthma, but an association was not seen at higher levels. No dose-response relationship was seen. Using phototherapy to prevent infants from reaching these modest TSB levels is unlikely to be protective against asthma.

Accuracy of international classification of diseases, ninth revision, codes for postpartum hemorrhage among women undergoing cesarean delivery.

BACKGROUND: Determining the accuracy of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes for postpartum hemorrhage (PPH) is vital for reaching valid conclusions about the epidemiology of PPH. Our primary objectives were to assess the performance characteristics of ICD-9 PPH codes against a reference standard using estimated blood loss (EBL) among a cohort undergoing Cesarean delivery. STUDY DESIGN AND METHODS: We analyzed maternal discharge and EBL data from women who underwent Cesarean delivery at Kaiser Permanente Northern California facilities between 2010 and 2013. We defined PPH as an EBL of at least 1000 mL. In a secondary analysis, ICD-9 performance characteristics were assessed using an EBL of at least 1500 mL to classify severe PPH. RESULTS: We identified 35,614 hospitalizations for Cesarean delivery. Using EBL of at least 1000 mL as the "gold standard," PPH codes had a sensitivity of 27.8%, specificity of 97%, positive predictive value (PPV) of 74.5%, and a negative predictive value (NPV) of 80.9%. The prevalence of a PPH code (9%) was lower than the prevalence using a blood loss of at least 1000 mL (24%). Using a reference standard of EBL of at least 1500 mL, PPH codes had a sensitivity of 61.7%, specificity of 93.8%, PPV of 34.2%, and NPV of 97.9%. CONCLUSION: PPH ICD-9 codes have high specificity, moderately high PPVs and NPVs, and low sensitivity. An EBL of at least 1500 mL as a reference standard has higher sensitivity. Our findings suggest that, for women undergoing Cesarean delivery, quality improvement efforts are needed to enhance PPH ICD-9 coding accuracy in administrative data sets.

Effectiveness of Respiratory Syncytial Virus Immunoprophylaxis in Reducing Bronchiolitis Hospitalizations Among High-Risk Infants.

We sought to determine the real-world effectiveness of respiratory syncytial virus (RSV) immunoprophylaxis in a population-based cohort to inform policy. The study population included infants born during 1996-2008 and enrolled in the Kaiser Permanente Northern California integrated health-care delivery system. During the RSV season (November-March), the date of RSV immunoprophylaxis administration and the following 30 days were defined as RSV immunoprophylaxis protected period(s), and all other days were defined as unprotected period(s). Numbers of bronchiolitis hospitalizations were determined using International Classification of Diseases, Ninth Revision, codes during RSV season. We used a proportional hazards model to estimate risk of bronchiolitis hospitalization when comparing infants' protected period(s) with unprotected period(s). Infants who had ever received RSV immunoprophylaxis had a 32% decreased risk of bronchiolitis hospitalization (adjusted hazard ratio = 0.68, 95% confidence interval: 0.46, 1.00) when protected periods were compared with unprotected periods. Infants with chronic lung disease (CLD) had a 52% decreased risk of bronchiolitis hospitalization (adjusted hazard ratio = 0.48, 95% confidence interval: 0.25, 0.94) when protected periods were compared with unprotected periods. Under the new 2014 American Academy of Pediatrics (AAP) guidelines, 48% of infants eligible for RSV immunoprophylaxis on the basis of AAP guidelines in place at birth would no longer be eligible, but nearly all infants with CLD would remain eligible. RSV immunoprophylaxis is effective in decreasing hospitalization. This association is greatest for infants with CLD, a group still recommended for receipt of RSV immunoprophylaxis under the new AAP guidelines.

Prevalence of infant bronchiolitis-coded healthcare encounters attributable to RSV.

AIM: We sought to determine the proportion of bronchiolitis episodes attributable to respiratory syncytial virus (RSV) among ICD-9 coded infant bronchiolitis episodes which were tested for RSV. METHODS: Bronchiolitis healthcare encounters were extracted from Kaiser Permanente Northern California databases for years 2006 to 2009. We used ICD-9 codes for bronchiolitis to capture bronchiolitis-related healthcare encounters including hospital admissions (Hospitalization), emergency department visits (EDV), and outpatient visits (OPV). We reported the monthly proportion of RSV-positive bronchiolitis episodes among tested bronchiolitis episodes. We used logistic regression to assess association between bronchiolitis episodes and patient demographic and health care characteristics. We also used logistic regression to assess association between decision to test and patient demographics and health care characteristics. RESULTS: Among 10,411 ICD-9 coded infant bronchiolitis episodes, 29% were RSV tested. Fifty one percent of those tested were RSV positive. Between December and February, and in infants ≤6 months, the proportion of bronchiolitis episodes that were attributable to RSV was 77.2% among hospitalized episodes, 78.3% among EDV episodes, and 60.9% among OPV episodes, respectively. The proportion of RSV-positive bronchiolitis episodes varied based upon infant age at diagnosis, level of health care service used, and time of the year of the episode. CONCLUSION: Estimation of the proportion of ICD-9 coded bronchiolitis episodes attributable to RSV is more specific when restricting to bronchiolitis episodes during peak months, younger infant age, and those requiring higher level of healthcare.

Health Care Utilization in the First Month After Birth and Its Relationship to Newborn Weight Loss and Method of Feeding.

OBJECTIVE: Guidelines recommend closer outpatient follow-up for exclusively breastfed newborns, especially those with pronounced weight loss, because of increased risk of hyperbilirubinemia and dehydration that might require readmission. Our objective was to determine how feeding method and weight loss are associated with neonatal health care utilization. METHODS: A retrospective cohort study conducted at Northern California Kaiser Permanente hospitals in 2009-2013 assessed 143,889 neonates to study the inpatient method of feeding as well as inpatient and outpatient weights. The main outcome measures were inpatient and outpatient health care utilization in the 30 days after birth. RESULTS: Newborn weight loss and feeding method were both associated with utilization. Exclusively breastfed newborns had higher readmission rates than those exclusively formula fed for both vaginal (4.3% compared to 2.1%) (P < .001) and cesarean deliveries (2.1% compared to 1.5%) (P = .025). Those exclusively breastfed also had more neonatal outpatient visits compared to those exclusively formula fed for both vaginal (means of 3.0 and 2.3, P < .001) and cesarean deliveries (means of 2.8 and 2.2, P < .001). Among vaginally delivered newborns of all feeding types, newborns with weight loss >10% at discharge had a relative risk of readmission of 1.10 (95% confidence interval [CI],1.00, 1.20) compared to those with <8% weight loss at discharge; among the subset weighed as inpatients or outpatients between 48 and 72 hours, those with >10% weight loss between 48-72 hours had a relative risk of readmission of 2.11 (95% CI, 1.95, 2.26) compared to those with <8% weight loss at 48-72 hours. CONCLUSIONS: Exclusive breastfeeding and weight loss are associated with increased neonatal health care utilization. Improving clinical management of exclusively breastfed neonates with pronounced weight loss might reduce health care utilization.

Outcomes of Admissions for Preterm Labor.

Objective This study aims to quantitate the incidence of preterm labor (PTL) admissions and determine the frequency and predictors of preterm delivery (PTD) during these admissions. Study Design Retrospective cohort of singleton pregnancies within Kaiser Permanente Northern California, 2001 to 2011. PTL admissions were defined as inpatient encounters > 24 hours with an International Classification of Diseases, 9th Revision code for PTL. Results Total study population was 365,897 with PTL admission rate 11%. PTD occurred in 85% of pregnancies with PTL admission. Delivery occurred within 48 hours of admission in 96% ≥34 weeks, 67% 31 to 33 weeks, and 51.9% <31 weeks. Predictors of delivery during PTL admission included gestational age 34 to 36 weeks (adjusted odds ratio [aOR], 6.90), chorioamnionitis (aOR, 105.58), and preterm rupture of membranes (aOR 19.29). Conclusion We demonstrate a high rate of PTD per PTL admission in a highly integrated health care system. More work is needed to determine optimal practices for hospitalization and treatment of women diagnosed with PTL.

A Quantitative, Risk-Based Approach to the Management of Neonatal Early-Onset Sepsis.

Importance: Current algorithms for management of neonatal early-onset sepsis (EOS) result in medical intervention for large numbers of uninfected infants. We developed multivariable prediction models for estimating the risk of EOS among late preterm and term infants based on objective data available at birth and the newborn's clinical status. Objectives: To examine the effect of neonatal EOS risk prediction models on sepsis evaluations and antibiotic use and assess their safety in a large integrated health care system. Design, Setting, and Participants: The study cohort includes 204 485 infants born at 35 weeks' gestation or later at a Kaiser Permanente Northern California hospital from January 1, 2010, through December 31, 2015. The study compared 3 periods when EOS management was based on (1) national recommended guidelines (baseline period [January 1, 2010, through November 31, 2012]), (2) multivariable estimates of sepsis risk at birth (learning period [December 1, 2012, through June 30, 2014]), and (3) the multivariable risk estimate combined with the infant's clinical condition in the first 24 hours after birth (EOS calculator period [July 1, 2014, through December 31, 2015]). Main Outcomes and Measures: The primary outcome was antibiotic administration in the first 24 hours. Secondary outcomes included blood culture use, antibiotic administration between 24 and 72 hours, clinical outcomes, and readmissions for EOS. Results: The study cohort included 204 485 infants born at 35 weeks' gestation or later: 95 343 in the baseline period (mean [SD] age, 39.4 [1.3] weeks; 46 651 male [51.0%]; 37 007 white, non-Hispanic [38.8%]), 52 881 in the learning period (mean [SD] age, 39.3 [1.3] weeks; 27 067 male [51.2%]; 20 175 white, non-Hispanic [38.2%]), and 56 261 in the EOS calculator period (mean [SD] age, 39.4 [1.3] weeks; 28 575 male [50.8%]; 20 484 white, non-Hispanic [36.4%]). In a comparison of the baseline period with the EOS calculator period, blood culture use decreased from 14.5% to 4.9% (adjusted difference, -7.7%; 95% CI, -13.1% to -2.4%). Empirical antibiotic administration in the first 24 hours decreased from 5.0% to 2.6% (adjusted difference, -1.8; 95% CI, -2.4% to -1.3%). No increase in antibiotic use occurred between 24 and 72 hours after birth; use decreased from 0.5% to 0.4% (adjusted difference, 0.0%; 95% CI, -0.1% to 0.2%). The incidence of culture-confirmed EOS was similar during the 3 periods (0.03% in the baseline period, 0.03% in the learning period, and 0.02% in the EOS calculator period). Readmissions for EOS (within 7 days of birth) were rare in all periods (5.2 per 100 000 births in the baseline period, 1.9 per 100 000 births in the learning period, and 5.3 per 100 000 births in the EOS calculator period) and did not differ statistically (P = .70). Incidence of adverse clinical outcomes, including need for inotropes, mechanical ventilation, meningitis, and death, was unchanged after introduction of the EOS calculator. Conclusions and Relevance: Clinical care algorithms based on individual infant estimates of EOS risk derived from a multivariable risk prediction model reduced the proportion of newborns undergoing laboratory testing and receiving empirical antibiotic treatment without apparent adverse effects.

Patterns and predictors of severe postpartum anemia after Cesarean section.

BACKGROUND: Postpartum anemia is associated with maternal and perinatal morbidity. Population-level data may inform guideline development for postpartum anemia screening. Our objectives were to evaluate the associations between potential predictors (predelivery anemia and postpartum hemorrhage [PPH]) with severe postpartum anemia after Cesarean section. STUDY DESIGN AND METHODS: Data were collected from 70,939 hospitalizations for Cesarean section performed at Kaiser Permanente Northern California facilities between 2005 and 2013. Severe postpartum anemia was defined as a hemoglobin (Hb) level of less than 8 g/dL before hospital discharge. Using multivariable logistic regression, we assessed the associations between predelivery anemia and PPH with severe postpartum anemia. Distributions of these characteristics among women with severe postpartum anemia were evaluated. RESULTS: The overall rate of severe postpartum anemia was 7.3% (95% confidence interval [CI], 7.1%-7.4%). Severe postpartum anemia was strongly associated with a predelivery Hb level between 10 and 10.9 g/dL (adjusted odds ratio [aOR], 5.4; 95% CI, 4.89-5.91), predelivery Hb level of less than 10 g/dL (aOR, 30.6; 95% CI, 27.21-34.6), and PPH (aOR, 8.45; 95% CI, 7.8-9.16). The proportions of women with severe postpartum anemia were highest for those experiencing PPH but no predelivery anemia (12.2%; 95% CI, 11.0%-13.6%) and those who did not incur PPH nor predelivery anemia (10.7%; 95% CI, 9.6%-12.0%). CONCLUSIONS: Our findings suggest that PPH and predelivery anemia are strong independent risk factors for severe postpartum anemia. Optimization of patients' Hb before delivery may reduce the incidence of severe anemia after Cesarean section.

Respiratory syncytial virus immunoprophylaxis in high-risk infants and development of childhood asthma.

BACKGROUND: Respiratory syncytial virus (RSV) lower respiratory tract infection is implicated in asthma development. RSV immunoprophylaxis during infancy is efficacious in preventing RSV-related hospitalizations and has been associated with decreased wheezing in the first years of life. OBJECTIVE: We investigated whether greater adherence to immunoprophylaxis in infants at high risk for severe RSV would be associated with decreased childhood asthma. METHODS: We conducted a retrospective cohort investigation including children born from 1996-2003 who were enrolled in Kaiser Permanente Northern California or Tennessee Medicaid and eligible to receive RSV immunoprophylaxis. Asthma was defined at 4.5 to 6 years of age by using asthma-specific health care visits and medication fills. We classified children into immunoprophylaxis eligibility groups and calculated adherence (percentage receipt of recommended doses). We used a set of statistical strategies (multivariable logistic regression and propensity score [PS]-adjusted and PS-matched analyses) to overcome confounding by medical complexity because infants with higher adherence (≥70%) have higher prevalence of chronic lung disease, lower birth weight, and longer nursery stays. RESULTS: By using multivariable logistic regression and PS-adjusted models in the combined group, higher adherence to RSV immunoprophylaxis was not associated with decreased asthma. However, in PS-matched analysis, treated children with 70% or greater adherence had decreased odds of asthma compared with those with 20% or less adherence (odds ratio, 0.62; 95% CI, 0.50-0.78). CONCLUSIONS: This investigation of RSV immunoprophylaxis in high-risk children primarily found nonsignificant associations on prevention of asthma in specific preterm groups. Our findings highlight the need for larger studies and prospective cohorts and provide estimates of potential preventive effect sizes in high-risk children.

Weight Change Nomograms for the First Month After Birth.

OBJECTIVE: Clinicians expect newborns to surpass birth weight by age 10 to 14 days, yet few studies have examined the natural history of weight change in the weeks after birth. We sought to determine the distribution of weight loss and subsequent regain during the first month, the proportion not surpassing birth weight by 14 and 21 days, and whether findings differed by delivery mode. METHODS: For 161 471 singleton neonates delivered at ≥36 weeks' gestation at Kaiser Permanente Northern California Medical Centers between 2009 and 2013 and weighing 2000 to 5000 g at birth, we extracted daily weights from inpatient electronic records and weights from outpatient visits in the first month. Quantile regression appropriate for repeated measures was used to estimate percentiles of weight change as a function of time after birth, stratified by delivery mode. RESULTS: After exclusions, weight data were analyzed from 143 889 newborns (76% born vaginally). Based on percentile estimates, 50% of newborns were at or above birth weight at 9 and 10 days after vaginal and cesarean delivery, respectively. Among those delivered vaginally, 14% and 5% were not back to birth weight by 14 and 21 days, respectively. For those delivered by cesarean, 24% and 8% were not back to birth weight by 14 and 21 days, respectively. CONCLUSIONS: It is not uncommon for newborns to be below birth weight 10 to 14 days after delivery. A larger percentage of newborns delivered by cesarean had yet to regain birth weight at every time point through 1 month.