Multiply robust causal inference of the restricted mean survival time difference.

2023

9622802231211009

11/2023

1477-0334

The hazard ratio (HR) remains the most frequently employed metric in assessing treatment effects on survival times. However, the difference in restricted mean survival time (RMST) has become a popular alternative to the HR when the proportional hazards assumption is considered untenable. Moreover, independent of the proportional hazards assumption, many comparative effectiveness studies aim to base contrasts on survival probability rather than on the hazard function. Causal effects based on RMST are often estimated via inverse probability of treatment weighting (IPTW). However, this approach generally results in biased results when the assumed propensity score model is misspecified. Motivated by the need for more robust techniques, we propose an empirical likelihood-based weighting approach that allows for specifying a set of propensity score models. The resulting estimator is consistent when the postulated model set contains a correct model; this property has been termed multiple robustness. In this report, we derive and evaluate a multiply robust estimator of the causal between-treatment difference in RMST. Simulation results confirm its robustness. Compared with the IPTW estimator from a correct model, the proposed estimator tends to be less biased and more efficient in finite samples. Additional simulations reveal biased results from a direct application of machine learning estimation of propensity scores. Finally, we apply the proposed method to evaluate the impact of intrapartum group B streptococcus antibiotic prophylaxis on the risk of childhood allergic disorders using data derived from electronic medical records from the Children's Hospital of Philadelphia and census data from the American Community Survey.

10.1177/09622802231211009

Stat Methods Med Res

37965684

Knowledge, Attitudes, and Perceptions about Antibiotic Stewardship Programs among Neonatology Trainees.

2023

893-897

06/2023

1098-8785

OBJECTIVE: Antibiotic stewardship should be an essential component of neonatology training as neonatal intensive care units (NICU) have unique stewardship needs. Our aim was to assess neonatology fellowship trainees' knowledge, attitudes, and perceptions about antibiotic stewardship to inform sustainable curriculum development.

STUDY DESIGN: We distributed an electronic survey to neonatology fellows in the United States over 4 months (January-April 2018) via Accreditation Council for Graduate Medical Education program directors.

RESULTS: Of 99 programs in the United States with an estimated 700 fellows, 159 (23%) fellows from 52 training programs (53%) responded to the survey and 139 (87%) provided analyzed responses. Majority of respondents were training in southern (59; 42%) and northeastern (43; 31%) regions and were equally spread across all 3 years of training. One hundred (72%) respondents reported an antibiotic stewardship program (ASP) in their institution. While 86% (120/139) were able to identify the components of an ASP, 59% (82/139) either did not or were unsure if they had received antibiotic stewardship training during fellowship.Furthermore, while answering case studies, 124 (89%) respondents identified the optimal antibiotic for methicillin susceptible (MSSA) infection and 69 (50%) respondents chose appropriate empiric antibiotics for neonatal meningitis. Notably, fellowship training year was not significantly related to the proportion of incorrect knowledge responses ( = 0.40). Most survey respondents (81; 59%) identified small group sessions as the most useful teaching format, while others chose audit and feedback of individual prescribing behavior (52; 38%) and didactic lectures (52; 38%). Finally, ninety-five (69%) respondents preferred trainee-led ASP interventions targeting focal areas such as antifungal and surgical prophylaxis.

CONCLUSION: Antibiotic stewardship is a critical part of neonatology training. Neonatology fellows report variation in access to ASP during their training. Fellows prefer dedicated trainee-led interventions and stewardship curriculum taught within small group settings to promote targeted NICU ASP.

KEY POINTS: · Most neonatology programs expose trainees to internal or external antibiotic stewardship programs.. · Over half of fellow trainees are unsure about receiving targeted antibiotic stewardship training.. · Most neonatology fellows prefer a trainee-led antibiotic stewardship intervention..

10.1055/s-0041-1732418

Am J Perinatol

34282573

Diagnostic Performance and Patient Outcomes With C-Reactive Protein Use in Early-Onset Sepsis Evaluations.

2023

98-104.e6

05/2023

1097-6833

OBJECTIVES: To determine performance of C-reactive protein (CRP) in the diagnosis of early-onset sepsis, and to assess patient outcomes with and without routine use of CRP.

STUDY DESIGN: This was a retrospective cohort study of infants admitted to 2 neonatal intensive care units. CRP was used routinely in early-onset sepsis evaluations during 2009-2014; this period was used to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed early-onset sepsis. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014.

RESULTS: From 2009 to 2014, 10 134 infants were admitted; 9103 (89.8%) had CRP and 7549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9%, and positive likelihood ratio 4.12 in diagnosis of early-onset sepsis. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n = 4977) and without (n = 5135) routine use of CRP, we observed lower rates of early-onset sepsis evaluation (74.5% vs 50.5%), antibiotic initiation (65.0% vs 50.8%), and antibiotic prolongation in the absence of early-onset sepsis (17.3% vs 7.2%) in the later period. Rate and timing of early-onset sepsis detection, transfer to a greater level of care, and in-hospital mortality were not different between periods.

CONCLUSIONS: CRP diagnostic performance was not sufficient to guide decision-making in early-onset sepsis. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.

10.1016/j.jpeds.2022.12.007

J Pediatr

36529283

Higher body mass index after intrapartum antibiotic exposure in children persists over 10-years.

2023

e13035

04/2023

2047-6310

Exposure to intrapartum antibiotic prophylaxis to reduce perinatal group B streptococcal disease was associated with increased childhood body mass index (BMI) persisting to age 10 years compared to no exposure (Δ BMI at 10 years: vaginal delivery 0.14 kg/m , caesarean 0.40 kg/m ).

10.1111/ijpo.13035

Pediatr Obes

37026509

Maternal and Newborn Hospital Outcomes of Perinatal SARS-CoV-2 Infection: A National Registry.

2023

02/2023

1098-4275

OBJECTIVES: The American Academy of Pediatrics National Registry for the Surveillance and Epidemiology of Perinatal coronavirus disease 2019 (COVID-19) (NPC-19) was developed to provide information on the effects of perinatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS: National Registry for the Surveillance and Epidemiology of Perinatal COVID-19 participating centers entered maternal and newborn data for pregnant persons who tested positive for SARS-CoV-2 infection between 14 days before and 10 days after delivery. Incidence of and morbidities associated with maternal and newborn SARS-CoV-2 infection were assessed.

RESULTS: From April 6, 2020 to March 19, 2021, 242 centers in the United States centers reported data for 7524 pregnant persons; at the time of delivery, 78.1% of these persons were asymptomatic, 18.2% were symptomatic but not hospitalized specifically for COVID-19, 3.4% were hospitalized for COVID-19 treatment, and 18 (0.2%) died in the hospital of COVID-related complications. Among 7648 newborns, 6486 (84.8%) were tested for SARS-CoV-2, and 144 (2.2%) were positive; the highest rate of newborn infection was observed when mothers first tested positive in the immediate postpartum period (17 of 125, 13.6%). No newborn deaths were attributable to SARS-CoV-2 infection. Overall, 15.6% of newborns were preterm: among tested newborns, 30.1% of polymerase chain reaction-positive and 16.2% of polymerase chain reaction-negative were born preterm (P < .001). Need for mechanical ventilation did not differ by newborn SARS-CoV-2 test result, but those with positive tests were more likely to be admitted to a NICU.

CONCLUSIONS: Early in the pandemic, SARS-CoV-2 infection was acquired by newborns at variable rates and without apparent short-term effects. During a period that preceded widespread availability of vaccines, we observed higher than expected numbers of preterm births and maternal in-hospital deaths.

10.1542/peds.2022-059595

Pediatrics

36995183

Diagnostic performance and patient outcomes with C-reactive protein use in early-onset sepsis evaluations.

2022

12/2022

1097-6833

OBJECTIVES: To determine performance of C-reactive protein (CRP) in diagnosis of early-onset sepsis (EOS), and to assess patient outcomes with and without routine use of CRP.

STUDY DESIGN: Retrospective cohort study of infants admitted to two neonatal intensive care units. CRP was routinely used in EOS evaluations during 2009-2014; this period was utilized to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed EOS. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014.

RESULTS: From 2009-2014, 10,134 infants were admitted; 9,103 (89.8%) had CRP and 7,549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9% and positive likelihood ratio 4.12 in diagnosis of EOS. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n=4,977) and without (n=5,135) routine use of CRP, we observed lower rates of EOS evaluation (74.5% vs. 50.5%), antibiotic initiation (65.0% vs. 50.8%), and antibiotic prolongation in the absence of EOS (17.3% vs. 7.2%) in the later period. Rate and timing of EOS detection, transfer to a higher level of care, and in-hospital mortality were not different between periods.

CONCLUSIONS: CRP diagnostic performance was not sufficient to guide decision-making in EOS. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.

10.1016/j.jpeds.2022.12.007

J Pediatr

36529283

Comparison of Maternal and Neonatal Antibody Levels After COVID-19 Vaccination vs SARS-CoV-2 Infection.

2022

e2240993

11/2022

2574-3805

Importance: Pregnant persons are at an increased risk of severe COVID-19 from SARS-CoV-2 infection, and COVID-19 vaccination is currently recommended during pregnancy.

Objective: To ascertain the association of vaccine type, time from vaccination, gestational age at delivery, and pregnancy complications with placental transfer of antibodies to SARS-CoV-2.

Design, Setting, and Participants: This cohort study was conducted in Pennsylvania Hospital in Philadelphia, Pennsylvania, and included births at the study site between August 9, 2020, and April 25, 2021. Maternal and cord blood serum samples were available for antibody level measurements for maternal-neonatal dyads.

Exposures: SARS-CoV-2 infection vs COVID-19 vaccination.

Main Outcomes and Measures: IgG antibodies to the receptor-binding domain of the SARS-CoV-2 spike protein were measured by quantitative enzyme-linked immunosorbent assay. Antibody concentrations and transplacental transfer ratios were measured after SARS-CoV-2 infection or receipt of COVID-19 vaccines.

Results: A total of 585 maternal-newborn dyads (median [IQR] maternal age, 31 [26-35] years; median [IQR] gestational age, 39 [38-40] weeks) with maternal IgG antibodies to SARS-CoV-2 detected at the time of delivery were included. IgG was detected in cord blood from 557 of 585 newborns (95.2%). Among 169 vaccinated persons without SARS-CoV-2 infection, the interval from first dose of vaccine to delivery ranged from 12 to 122 days. The geometric mean IgG level among 169 vaccine recipients was significantly higher than that measured in 408 persons after infection (33.88 [95% CI, 27.64-41.53] arbitrary U/mL vs 2.80 [95% CI, 2.50-3.13] arbitrary U/mL). Geometric mean IgG levels were higher after vaccination with the mRNA-1273 (Moderna) vaccine compared with the BNT162b2 (Pfizer/BioNTech) vaccine (53.74 [95% CI, 40.49-71.33] arbitrary U/mL vs 25.45 [95% CI, 19.17-33.79] arbitrary U/mL; P < .001). Placental transfer ratios were lower after vaccination compared with after infection (0.80 [95% CI, 0.68-0.93] vs 1.06 [95% CI, 0.98-1.14]; P < .001) but were similar between the mRNA vaccines (mRNA-1273: 0.70 [95% CI, 0.55-0.90]; BNT162b2: 0.85 [95% CI, 0.69-1.06]; P = .25). Time from infection or vaccination to delivery was associated with transfer ratio in models that included gestational age at delivery and maternal hypertensive disorders, diabetes, and obesity. Placental antibody transfer was detectable as early as 26 weeks' gestation. Transfer ratio that was higher than 1.0 was present for 48 of 51 (94.1%) births at 36 weeks' gestation or later by 8 weeks after vaccination.

Conclusions and Relevance: This study found that maternal and cord blood IgG antibody levels were higher after COVID-19 vaccination compared with after SARS-CoV-2 infection, with slightly lower placental transfer ratios after vaccination than after infection. The findings suggest that time from infection or vaccination to delivery was the most important factor in transfer efficiency.

10.1001/jamanetworkopen.2022.40993

JAMA Netw Open

36350652

Group B Streptococcus Infection in Extremely Preterm Neonates and Neurodevelopmental Outcomes at 2 Years.

2022

1405-1415

10/2022

1537-6591

BACKGROUND: This study was performed to determine the incidence of group B Streptococcus (GBS) disease among extremely preterm infants and assess to risk of death or neurodevelopmental impairment (NDI) at a corrected age of 18-26 months.

METHODS: In this observational cohort study of infants enrolled in a multicenter registry, the incidence of GBS disease was assessed in infants born in 1998-2016 at 22-28 weeks' gestation and surviving for >12 hours. The composite outcome, death or NDI, was assessed in infants born in 1998-2014 at 22-26 weeks' gestation. Infection was defined as GBS isolation in blood or cerebrospinal fluid culture at ≤72 hours (early-onset disease [EOD]) or >72 hours (late-onset disease [LOD]) after birth. Using Poisson regression models, the outcome was compared in infants with GBS disease, infants infected with other pathogens, and uninfected infants.

RESULTS: The incidence of GBS EOD (2.70/1000 births [95% confidence interval (CI), 2.15-3.36]) and LOD (8.47/1000 infants [7.45-9.59]) did not change significantly over time. The adjusted relative risk of death/NDI was higher among infants with GBS EOD than in those with other infections (adjusted relative risk, 1.22 [95% CI, 1.02-1.45]) and uninfected infants (1.44 [1.23-1.69]). Risk of death/NDI did not differ between infants with GBS LOD and comparator groups. GBS LOD occurred at a significantly later age than non-GBS late-onset infection. Among infants surviving >30 days, the risk of death was higher with GBS LOD (adjusted relative risk, 1.90 [95% CI, 1.36-2.67]), compared with uninfected infants.

CONCLUSIONS: In a cohort of extremely preterm infants, the incidence of GBS disease did not change during the study period. The increased risk of death or NDI with GBS EOD, and of death among some infants with GBS LOD, supports the need for novel preventive strategies for disease reduction.

CLINICAL TRIALS REGISTRATION: NCT00063063.

10.1093/cid/ciac222

Clin Infect Dis

35323895

Breast Milk and Saliva for Postnatal Cyto†megalovirus Screening among Very Low Birth Weight Infants.

2022

904-910

11/2022

1532-0987

BACKGROUND: The optimal approach to managing postnatal cytomegalovirus disease (pCMV) among very low birth weight (VLBW) infants remains unknown. Methods to facilitate screening are needed.

OBJECTIVE: Determine whether mother's milk and infant saliva can be used to reliably identify maternal cytomegalovirus (CMV) serostatus and detect infant pCMV acquisition.

METHODS: This was a single-center, prospective cohort study of VLBW infants, and their mothers, born between 2017 and 2020. Maternal milk samples were tested for CMV immunoglobulin G (IgG) using a CMV glycoprotein B binding enzyme-linked immunosorbent assay and the results were compared with maternal serum CMV IgG results. Biweekly paired saliva and urine samples were collected from infants born to mothers with positive or unknown CMV serostatus. Saliva samples were tested for CMV DNA by quantitative real-time polymerase chain reaction (PCR) and compared with urine CMV qualitative PCR results obtained from a clinical laboratory.

RESULTS: Among 108 infants without congenital CMV included in the study, 10 (9%) acquired pCMV. Both milk and blood CMV serology results were available for 70 mothers. Maternal milk antibody testing had a sensitivity of 97.2% (95% CI: 85.5-99.9%) and specificity of 91.2% (95% CI: 76.3-98.1%) in establishing CMV serostatus. Paired serially collected saliva and urine samples (n = 203) were available for 66 infants. Saliva PCR had a sensitivity of 30.0% (95% CI: 6.7-65.2%) and specificity of 92.7% (95% CI: 88.1-96.0%) in detecting pCMV acquisition.

CONCLUSIONS: Maternal breast milk is a reliable alternative sample to determine CMV serostatus. Serial testing of infant saliva was not adequately sensitive for identifying pCMV acquisition in preterm infants.

10.1097/INF.0000000000003671

Pediatr Infect Dis J

36102681

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

2022

583-588

11/2022

1468-2052

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.

10.1136/archdischild-2021-323416

Arch Dis Child Fetal Neonatal Ed

35273079