OBJECTIVE: To assess whether a lower maximum dose of soybean oil lipid emulsion reduces bilirubin neurotoxicity measured by brainstem auditory evoked response (BAER) wave V latency. STUDY DESIGN: Single-center Bayesian r...OBJECTIVE: To assess whether a lower maximum dose of soybean oil lipid emulsion reduces bilirubin neurotoxicity measured by brainstem auditory evoked response (BAER) wave V latency. STUDY DESIGN: Single-center Bayesian randomized trial (NCT04584983; January 2021-January 2024) in a level IV neonatal intensive care unit. Infants born at <27 weeks or ≤750 grams were stratified by phototherapy regimen, randomized to 1.5 vs 3.0 g/kg/day maximum soybean oil lipid emulsion (Intralipid) doses through day 14. RESULTS: Of 143 eligible infants, 134 were enrolled (67 lower dose, 65 higher dose). Mean [SD] daily lipid administration was 1.1 [0.3] vs 1.96 [0.58] g/kg/day. Unbound bilirubin levels were similar between groups although values ≥30 and ≥40 nM occurred more often in the higher dose group (14.5% vs 28.6% and 6.5% vs 16.1%), even at low total serum bilirubin levels (3-8 mg/dL). Adjusted wave V latency did not differ between groups (7.36 ms [0.53] vs 7.22 ms [0.57], aMD: -0.14 [95% CrI -0.34, 0.06]), with no interaction with phototherapy dose. Clinical outcomes and growth were comparable. CONCLUSIONS: The lower maximum lipid dose did not reduce BAER wave V latency. Elevated unbound bilirubin levels occurred at the higher dose, suggesting the need for a multicenter safety trial in extremely preterm infants.
OBJECTIVE: To estimate the associations between time-to-transfer and hospitalization duration among neonates with severe congenital heart defects (CHDs). STUDY DESIGN: Retrospective, cross-sectional analysis of neonates...OBJECTIVE: To estimate the associations between time-to-transfer and hospitalization duration among neonates with severe congenital heart defects (CHDs). STUDY DESIGN: Retrospective, cross-sectional analysis of neonates with severe CHD, 2013-2021, who were reported to the Illinois Department of Public Health. The outcome was hospitalization duration, ie. time from birth to discharge from a surgical center. The exposure was time-to-transfer (four categories): birth at a surgical center (referent), not born at a surgical center and transferred at 0, 1-3, and after 3 days. Covariates included clinical and sociodemographic factors. Fine-Gray models estimated sub-distribution hazard ratios (sHRs) for discharge, accounting for competing risks. Restricted mean survival time summarized average hospitalization duration at different timepoint cutoffs. RESULTS: Among 1,391 neonates with severe CHD, 48.1% (669/1391) were not born at a cardiac surgical center. Of those who transferred, 43.4% (203/468) transferred at 0 days, 43.8% (205/468) transferred within 1-3 days, and 12.8% (60/468) transferred after 3 days. Median hospitalization duration was 23 (IQR 12-46) days. Compared with birth at a cardiac surgical center, transfer after 3 days was associated with slower rate of discharge over time (adjusted sHR 0.71, 95% CI 0.54-0.94) and longer hospitalization duration. CONCLUSIONS: For the substantial proportion of neonates with severe CHD who were not born at cardiac surgical centers, late transfer was associated with longer neonatal hospitalization duration.
OBJECTIVE: To assess in neonates with hypoxic-ischemic encephalopathy (HIE) whether multimodal neuromonitoring, using near-infrared spectroscopy and amplitude-integrated electroencephalography (aEEG), correlates with cer...OBJECTIVE: To assess in neonates with hypoxic-ischemic encephalopathy (HIE) whether multimodal neuromonitoring, using near-infrared spectroscopy and amplitude-integrated electroencephalography (aEEG), correlates with cerebral injury observed on brain magnetic resonance imaging (MRI) as well as neurodevelopmental outcome. STUDY DESIGN: Neonates born at >35 weeks and >1800 gram undergoing therapeutic hypothermia were included in this prospective-retrospective, multicenter study. The aEEG pattern, cerebral tissue oxygenation (rScO), burden of rScO≥95%, arterial blood pressure, heart rate, and cerebrovascular autoregulation were monitored during therapeutic hypothermia and rewarming from 0-24, 24-48, 48-72, and 72-96 hours. Early cerebral MRI was assessed using a validated quali-quantitative score. Neurodevelopmental outcome was assessed using Bayley Scales of Infant Development (BSID-III) cognitive and motor scores at 24 months. RESULTS: In 128 neonates with a median Thompson score of 9, greater seizure burden (beta coefficient, B=3.21, 95% confidence interval limits, 95%CI [2.01, 4.41]), absent sleep-wake-cycling (B=-5.53, 95%CI [-8.29, -2.77]), and a higher burden of rScO≥95% (B=0.34, 95%CI [0.07, 0.61]) were associated with worse cerebral injury on MRI. Cognitive and motor scores inversely correlated with aEEG abnormalities, rScO, burden of rScO≥95%, and absent sleep-wake-cycling, whereas higher arterial blood pressures between 0-24 hours were associated with higher neurodevelopmental outcome scores. CONCLUSIONS: Combined abnormal aEEG characteristics and rScO, but not cerebrovascular autoregulation assessed as cerebral oximetry index or tissue oxygenation heart rate-reactivity index, correlated significantly with brain injury on MRI and neurodevelopmental outcome after HIE. These findings provide valuable clinical information and, in future studies, may support identification of infants who might benefit from adjuvant therapies.
REGISTRATION: Per Pfizer's policies on studies of Pfizer products, this study was posted on clinicaltrials.gov prior to analyses (NCT06923137). OBJECTIVE: To assess COVID-19 burden of disease, KP.2-adapted BNT162b2 COVID...REGISTRATION: Per Pfizer's policies on studies of Pfizer products, this study was posted on clinicaltrials.gov prior to analyses (NCT06923137). OBJECTIVE: To assess COVID-19 burden of disease, KP.2-adapted BNT162b2 COVID-19 vaccine uptake (2024-2025 formula), and vaccine effectiveness for children less than 5, 5-11, and 12-17 years of age. STUDY DESIGN: This retrospective cohort study used linked claims and vaccine registry data from California and Louisiana from August 22, 2024, to March 31, 2025. Inclusion criteria limited the sample to children without documented immunocompromised status and with complete demographic data. Vaccination status was treated as a time-varying exposure. The primary outcome was the composite of medically attended COVID-19 encounters in the emergency department (ED), urgent care (UC), or inpatient setting derived from administrative claims data. Analyses included incidence rates and, when possible, adjusted hazard ratios using Cox models. RESULTS: Among 2.6 million children aged less than 18 years who met inclusion criteria, approximately 2% received a single dose of the KP.2-adapted BNT162b2 COVID-19 vaccine. Median follow-up was 7.4 months. Vaccinated children were more likely to reside in California, have commercial insurance, and prior COVID-19 or influenza vaccination. Across age groups, the prevalence of underlying medical conditions was higher in children with medically attended COVID-19 (ED, UC, or inpatient setting). Vaccination was associated with significantly lower rates of medically-attended COVID-19 across all age strata, with an associated 43% vaccine effectiveness pooled across all children aged less than 18 years (95% CI: 10-64). CONCLUSION: KP.2-adapted BNT162b2 COVID-19 vaccine provided significant protection against emergency department, urgent care, and inpatient encounters for COVID-19 in children.
OBJECTIVE: To review rates of nirsevimab immunization for respiratory syncytial virus (RSV) among mother-newborn dyads admitted to a single tertiary medical center system. STUDY DESIGN: A retrospective study examined RSV...OBJECTIVE: To review rates of nirsevimab immunization for respiratory syncytial virus (RSV) among mother-newborn dyads admitted to a single tertiary medical center system. STUDY DESIGN: A retrospective study examined RSV immunization rates across admitted mother-infant dyads between November 2024-February 2025. Other collected data included gestational age, sex, delivery type, newborn medication receipt/declination, and maternal demographics. We analyzed specifically the relationship between RSV immunization and race and ethnicity, language, and other patient characteristics. RESULTS: Of 1156 mothers, 854 (74%) received the RSV vaccine during pregnancy. There were statistically significant differences in race and RSV vaccine receipt, with rates highest among Asian mothers (85%) and lowest among non-Hispanic Black mothers (59%). Among 302 newborns, 135 (55%) received nirsevimab during hospitalization. Differences in race and nirsevimab receipt were statistically significant, with uptake highest among Asian newborns (83%) and lowest among non-Hispanic White infants (47%). Secondary analyses showed significant associations between maternal and newborn RSV immunization and newborn medication acceptance, and between maternal RSV vaccination and maternal age, insurance type, and religion. CONCLUSIONS: Our study found substantial disparities in RSV immunization by race for mothers and infants. Some disparities were mitigated during the birth hospitalization, suggesting that the inpatient setting can effectively reduce health disparities. Given the effectiveness of RSV immunization addressing these disparities should be prioritized.
OBJECTIVE: To determine whether blood-based biomarkers in the first days of life could specifically predict cerebral palsy (CP) and/or cognitive/language delay in infants with moderate-severe HIE. STUDY DESIGN: A seconda...OBJECTIVE: To determine whether blood-based biomarkers in the first days of life could specifically predict cerebral palsy (CP) and/or cognitive/language delay in infants with moderate-severe HIE. STUDY DESIGN: A secondary analysis of the High Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, which examined erythropoietin as an adjunct to therapeutic hypothermia for moderate-severe HIE. Recruitment took place in the United States from 2017-2019. Analysis focused on 180 infants with biomarker measurements performed at baseline, day 2, and day 4 of life. Outcomes assessed were: a diagnosis of CP at 2 years; Bayley III cognitive/language scores <85 and, separately, <70 at 2 years. MRI of the brain was performed on day 4-6 of life. RESULTS: Mean gestational age was 39.0 weeks and 68 (44%) were female. After adjusting for multiple comparisons, 5 biomarkers: Tau, GFAP, VEGF, MIP-1b, and IL-13 were significantly altered in the CP group. On day 2 of life, Tau resulted in a receiver operating characteristic area under the curve (AUC) of 0.902 (95% CI 0.812-0.992), specificity 91%, sensitivity 88%, performing as well as detailed MRI scoring (AUC 0.90 [95% CI 0.80-1.0]). A different set of biomarkers showed altered expression in those with cognitive/language delay; Tau, UCH-L1, S100B, and NSE, with the best prediction seen with Tau on day 2 of life (AUC 0.669 [95% CI 0.564-0.774], sensitivity 40%, specificity 92%). CONCLUSIONS: Tau on day 2 of life demonstrated excellent prognostic value for CP in this cohort with moderate-severe HIE and gave similar prediction to detailed MRI score on day of life 4-6. Patterns of neurospecific biomarker perturbations were different for the prediction of cognitive/language delay, but Tau on day 2 remained the best performing biomarker.
OBJECTIVE: To assess long-term effects of mild head injury (MHI) during childhood on school grades and high school eligibility. STUDY DESIGN: Children with MHI aged 6-16 years at the time of injury were followed up with...OBJECTIVE: To assess long-term effects of mild head injury (MHI) during childhood on school grades and high school eligibility. STUDY DESIGN: Children with MHI aged 6-16 years at the time of injury were followed up with register linkage and compared with their siblings in their total school grade score, grades in mathematics and Swedish language, as well as high school eligibility at the end of compulsory school. Patients were analyzed according to their recovery level at 3 months post MHI using their Glasgow Outcome Scale Extended score. Educational outcomes were analyzed using generalized estimating equations with adjustment for relevant covariates using the genmod procedure in SAS®. RESULTS: This study included 663 MHI patients and 1003 siblings. The MHI patients (34% female) had a mean age at injury of 12.2 years and a mean follow-up time of 3.8 years. This study was not able to detect any significant difference in school grades or high school eligibility for MHI patients with a good recovery level when compared with the siblings. However, patients with a poorer recovery level at m3onths post MHI showed a lower total grade score mean compared with the siblings. CONCLUSIONS: Children with no sequelae 3 months after MHI perform similarly to their siblings in later school performance. However, children with poorer short-term recovery levels show poorer long term school performance than their siblings.
OBJECTIVE: To evaluate risk factors for mortality and discharge timing in preterm infants born before 35 weeks' gestational age (GA) with congenital heart disease (CHD). STUDY DESIGN: Retrospective cohort study using Chi...OBJECTIVE: To evaluate risk factors for mortality and discharge timing in preterm infants born before 35 weeks' gestational age (GA) with congenital heart disease (CHD). STUDY DESIGN: Retrospective cohort study using Children's Hospitals Neonatal Consortium data from 2010-2024. Infants <35 weeks' GA with CHD were included. Primary and secondary outcomes were in-hospital mortality and post-menstrual age (PMA) at discharge. CHD subtypes were categorized as compromised systemic output, sustained cyanosis, or congestive heart failure. Multivariable generalized linear mixed models were used. RESULTS: Among 11,261 preterm infants with CHD, mortality was 13.7%. Significant interactions between CHD subtype and gestational age were observed. Among infants with congestive heart failure, those 30-32 weeks' GA had higher mortality compared with <27 weeks' GA (adjusted odds ratio [aOR] 1.46, 95% confidence interval [CI], 1.06-2.02, p=0.012), and those 27-29 weeks GA had lower mortality odds compared with 30-32 weeks (aOR 0.69, 95% CI, 0.52-0.90, p=0.002). Surgical necrotizing enterocolitis, delivery room intubation, and trisomy 21 were the strongest mortality predictors (aOR 3.12, 2.69 and 2.27, respectively; all p<0.001). Higher GA was associated with earlier PMA at discharge (-2.4 weeks for 30-32 weeks GA vs <27 weeks GA; p<0.001). CONCLUSIONS: Short-term outcomes vary by CHD subtype and comorbidities. Older GA was unrelated to inpatient mortality. Potentially modifiable factors such as necrotizing enterocolitis and infections could inform care. Future work incorporating prenatal decisions and surgical timing is needed.
OBJECTIVE: To assess the safety of 20-valent pneumococcal conjugate vaccine (PCV20) in children in the United States using data from the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous surveillance...OBJECTIVE: To assess the safety of 20-valent pneumococcal conjugate vaccine (PCV20) in children in the United States using data from the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous surveillance system. STUDY DESIGN: We searched VAERS for reports of adverse events (AEs) following PCV20 in children aged 0 - 17 years who received PCV20 from June 22, 2023, through January 24, 2025. We reviewed reports and available medical records for all serious reports and for adverse events of special interest (AESIs; seizures, anaphylaxis, hypotonic hyporesponsive episode, Kawasaki disease). We used empirical Bayesian data mining to identify AEs that were disproportionally reported. RESULTS: VAERS received 1,040 reports after receipt of PCV20 in children 0-17 years; 107 (10.3%) were serious, which included 26 (2.5%) death reports. In 970 (93.3%) reports, PCV20 was concomitantly administered with another vaccine. The most reported AEs were fever (109, 10.4%), rash (75, 7.2%), urticaria (68, 6.5%), and injection site erythema (54, 5.2%). The most commonly reported AESI was seizures (42, 4.0%). Empirical Bayesian data mining revealed disproportionate reporting for "wrong product administered," but no adverse health events were associated with this vaccination error. CONCLUSIONS: Most reports following PCV20 administration in children were non-serious. The most common AEs were local and systemic reactions, consistent with pre-licensure clinical trials.
OBJECTIVE: To determine the association between salivary substance P (SP) concentration and aspiration on videofluoroscopic swallow study (VFSS) in children with oropharyngeal dysphagia. STUDY DESIGN: We recruited childr...OBJECTIVE: To determine the association between salivary substance P (SP) concentration and aspiration on videofluoroscopic swallow study (VFSS) in children with oropharyngeal dysphagia. STUDY DESIGN: We recruited children <2 years of age who underwent VFSS within 3 months of study enrollment. Saliva samples were collected using absorbent collection devices and SP levels were measured by ELISA. We used student's t-test to compare levels between subjects with and without aspiration. Exploratory receiver operating characteristic (ROC) analyses were used to determine optimal cut-off values and calculate sensitivity and specificity compared with gold-standard VFSS results. A subgroup analysis included only subjects with saliva collected within 1 month of VFSS. RESULTS: The cohort included 50 subjects with age 8.16 ± 0.83 months at sample collection. SP concentrations were 344.7 ± 42.9 pg/ml for patients with aspiration compared with 105.7 ± 40.5 pg/ml for those without aspiration (p<0.001). On ROC analysis, area under the curve (AUC) was 0.868 (95% CI 0.721-1.0, p<0.001). A cutoff of 65 pg/ml provided 97% sensitivity (95% CI 86-99%) and 75% specificity (95% CI 43-95%) for predicting aspiration on VFSS. In a subgroup analysis with 29 subjects who had VFSS within 1 month of sample collection, AUC was 0.964 (95% CI 0.98-1.0, p<0.001). A cutoff of 63.2 pg/ml provided 100% sensitivity (95% CI 85-100%) and 83.3% specificity (95% CI 36-100%) for predicting aspiration on VFSS. CONCLUSIONS: Salivary substance P concentrations were found to be significantly higher in children with aspiration. Salivary substance P may represent an early candidate biomarker that could be used to predict risk of aspiration in infants and toddlers.
OBJECTIVE: To evaluate criteria associated with intensive care unit (ICU) utilization among children admitted to the intensive care unit (ICU) after elective congenital lung malformation (CLM) surgery. STUDY DESIGN: A re...OBJECTIVE: To evaluate criteria associated with intensive care unit (ICU) utilization among children admitted to the intensive care unit (ICU) after elective congenital lung malformation (CLM) surgery. STUDY DESIGN: A retrospective study of children undergoing elective CLM resection between 2016 and 2023 was conducted. Factors analyzed included demographics and perioperative details. ICU utilization was defined by the occurrence of 1 or more of the following: vasopressor support, continued need for mechanical ventilation due to failure to extubate in the operating room (OR), reintubation, continuous positive airway pressure use, extracorporeal membrane oxygenation support, or continuous monitoring due to concerns about hemodynamic instability. RESULTS: 87 patients were included. The predominant diagnoses were congenital pulmonary airway malformation (34), and intralobar (30) and extralobar (8) sequestrations. Postoperatively, 26.4% (23) were admitted to the floor and 73.6% (64) to the ICU. Only 9% (8) had ICU utilization. Although a prenatal diagnosis and younger age at resection (median 0.75 years, IQR: 0.60, 1.15) were associated with ICU admission, factors associated with ICU utilization included thoracoscopic converted to open surgery (p=0.023), higher estimated blood loss (p=0.018), longer total time in the OR (p=0.027), and failure to extubate (p=0.001). No patients admitted to the floor postoperatively required transfer to the ICU. CONCLUSION: Only 9% of patients undergoing elective CLM resection required ICU utilization. Factors contributing to ICU utilization postoperatively included operative approach, estimated blood loss, total time in the OR, and failure to extubate. Customizing patient disposition based on these factors could minimize ICU resource utilization while maintaining patient safety. Congenital lung malformations (CLM) represent a spectrum of developmental anomalies which occur during fetal development. These malformations are further classified into different types such as congenital pulmonary airway malformation (CPAM), intralobar and extralobar pulmonary sequestration, congenital lobar overinflation, bronchial atresia, and others. The incidence of CLM is reported to range from 1 in 1,000 to 1/35 000. Large registries in the United Kingdom have documented an increase in the incidence of CLMs to 4.15 per 10,000 between 2008 and 2012. This inc rease in incidence is largely due to the advances in prenatal ultrasound and fetal diagnosis. Approximately 80% of CLMs are diagnosed prenatally, mostly during routine second trimester ultrasound screening. These lesions can exhibit varying clinical courses, with some being symptomatic at birth yet most remain asymptomatic. Most CLMs are eventually managed with surgical resection via thoracotomy or thoracoscopy either in the neonatal period for those symptomatic at birth or electively between 4 and 6 months of age due to the purported risk of later infection or malignancy. The minimally invasive thoracoscopic approach is the preferred surgical approach for the resection of asymptomatic CLM..
OBJECTIVES: To evaluate parental experiences following diagnosis of a cancer predisposition syndrome (CPS) in childhood and to assess parental perspectives on population-based genomic newborn screening (gNBS) for CPS. ST...OBJECTIVES: To evaluate parental experiences following diagnosis of a cancer predisposition syndrome (CPS) in childhood and to assess parental perspectives on population-based genomic newborn screening (gNBS) for CPS. STUDY DESIGN: Participants were guardians of children diagnosed with a CPS by age 8, for whom cancer surveillance was recommended, and who had no history of cancer before the CPS diagnosis. Participants completed a demographic survey, genetic knowledge assessment and a semi-structured qualitative interview. Thematic analysis was performed on interview transcripts. Clinical data was abstracted from medical records. RESULTS: We enrolled 25 parents of children with 7 different CPS, including Li-Fraumeni syndrome (43%), familial adenomatous polyposis (14%), nevoid basal cell carcinoma syndrome (11%) and Beckwith-Weidemann syndrome (11%). Parents characterized receiving a CPS diagnosis as emotionally challenging but also felt empowered by engagement in proactive cancer surveillance. They identified logistical, emotional, physical, and financial burdens of surveillance; however, most perceived that these burdens were outweighed by the medical and emotional advantages. The majority endorsed implementation of gNBS for pediatric cancer risk. CONCLUSIONS: Parents of presymptomatic children with a CPS experience both psychological distress and benefits following a genetic diagnosis. Despite the burdens of surveillance, parents express support for early genomic identification of cancer risk. These findings have implications for the care of children with CPS and inform implementation of population-based gNBS for CPS.
Lakshminrusimha S, Yoder BA, Chowdhury D
… +16 more, Das A, Kirpalani H, Dhawan MA, Snyder JM, Fraga MV, Konduri GG, McNamara PJ, Klein J, Ambalavanan N, Rau CA, Lally KP, Nelin LD, Cotten CM, Higgins RD, Keszler M, milrinone in CDH subcommittee
OBJECTIVE: To assess accuracy of prediction of oxygenation index (OI=mean airway pressure*FiO*100÷PaO) with a non-invasive alternative, oxygen saturation index (OSI= FiO*100÷SpO) in a prospectively collected multicenter...OBJECTIVE: To assess accuracy of prediction of oxygenation index (OI=mean airway pressure*FiO*100÷PaO) with a non-invasive alternative, oxygen saturation index (OSI= FiO*100÷SpO) in a prospectively collected multicenter cohort of children with congenital diaphragmatic hernia (CDH) with substantial degree of hypoxemia (OI≥10 or OSI≥5). STUDY DESIGN: This secondary analysis of the Milrinone in CDH Trial studied 61 subjects with OI≥10 or OSI≥5 at randomization. Prospectively collected arterial blood gas (ABG) data with PaO and preductal and postductal SpO were used to compare all OI and preductal OSI, all OI and postductal OSI, preductal OI/OSI only and postductal OI/OSI, by simple linear and quadratic regression modelling. RESULTS: Indwelling arterial lines were present in 61 of 66 randomized subjects (51 as umbilical arterial lines). There were 572 matched pairs of PaO-SpO data. Repeated measures correlation (95% CI) between all OI and preductal OSI by linear regression was 0.82 (0.79,0.85; n=61 patients, 572 samples), and between OI and OSI with SpO matched from the same preductal or postductal sites as the ABG were 0.97 (9.91,0.89) and 0.86 (0.84,0.89) respectively. The relationship between preductal OI and OSI was described best by the quadratic equation, OI=0.3*OSI+0.1*OSI+2.4 (4 patients, 22 samples) and postductal OI and OSI by OI=0.6*OSI +0.08*OSI+2.6 (54 patients, 477 samples). There was no difference in quasi-likelihood under the independence model information criterion (QlCu) between linear and quadratic models (461 vs 462 respectively). Use of site-specific (preductal vs postductal) quadratic equations captured the non-linear relationship but did not improve QlCu. CONCLUSION: Non-invasive OSI values correlate well with OI. The use of OSI based on preductal SpO may be a suitable alternate strategy for clinical trials even if post-ductal arterial access is available.
OBJECTIVES: To develop an online pediatric electrocardiogram (ECG) educational intervention, d to examine pediatricians' diagnostic skill development as they progressed to achieve a performance-based standard, and to det...OBJECTIVES: To develop an online pediatric electrocardiogram (ECG) educational intervention, d to examine pediatricians' diagnostic skill development as they progressed to achieve a performance-based standard, and to determine the frequency of pediatric ECG findings at highest risk for diagnostic error. METHODS: This multicenter, prospective cohort study included a convenience sample of pediatricians. There were 400 cases in the intervention, and for each case, participants first determined whether an actionable abnormality was present or absent. If present, participants categorized abnormalities as rate/rhythm, anatomical/technical, or Q-wave/repolarization, and selected the most appropriate specific diagnosis from a drop-down list of options. Immediate feedback was provided after each case, and practice continued until a minimal passing standard was achieved. RESULTS: A total of 345 pediatricians performed 46,649 pediatric ECG case interpretations. Initial accuracy was 82.1% in identifying ECG with actionable findings, 70.9% for correct categorization of actionable findings, and 45.2% for selecting most actionable specific diagnosis. There were learning gains for each of these diagnostic tasks: +14.6% (95% CI 13.1, 15.8), +15.0% (95% CI 13.2, 16.8), and +19.8% (95% CI 17.5, 22.1), respectively. Furthermore, 65% achieved the minimal passing standard in a median of 325 cases (IQR 198, 496) or 6.5 hours (IQR 3.4, 10.0) of practice. Among the 46,649 case interpretations, 7,675 (16.5%) were incorrect interpretations. ECG findings consistent with ventricular hypertrophy, Brugada sign, prolonged QTc, and ischemia/pericarditis were among the most challenging diagnoses. CONCLUSION: Structured practice with feedback can feasibly improve pediatrician ECG interpretation skills and derive data to identify ECG findings prone to diagnostic error.