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Objective: In this proof-of-concept study, we aimed to develop deep-learning-based classifiers to identify rib fractures on frontal chest radiographs in children under 2 years of age. Methods: This retrospective study included 1311 frontal chest radiographs (radiographs with rib fractures, n = 653) from 1231 unique patients (median age: 4 m). Patients with more than one radiograph were included only in the training set. A binary classification was performed to identify the presence or absence of rib fractures using transfer learning and Resnet-50 and DenseNet-121 architectures. The area under the receiver operating characteristic curve (AUC-ROC) was reported. Gradient-weighted class activation mapping was used to highlight the region most relevant to the deep learning models’ predictions. Results: On the validation set, the ResNet-50 and DenseNet-121 models obtained an AUC-ROC of 0.89 and 0.88, respectively. On the test set, the ResNet-50 model demonstrated an AUC-ROC of 0.84 with a sensitivity of 81% and specificity of 70%. The DenseNet-50 model obtained an AUC of 0.82 with 72% sensitivity and 79% specificity. Conclusion: In this proof-of-concept study, a deep learning-based approach enabled the automatic detection of rib fractures in chest radiographs of young children with performances comparable to pediatric radiologists. Further evaluation of this approach on large multi-institutional data sets is needed to assess the generalizability of our results. Advances in knowledge: In this proof-of-concept study, a deep learning-based approach performed well in identifying chest radiographs with rib fractures. These findings provide further impetus to develop deep learning algorithms for identifying rib fractures in children, especially those with suspected physical abuse or non-accidental trauma.

Objective To assess the impact of the COVID-19 pandemic on physical abuse in young children, we compared the following before and during the pandemic: (1) skeletal survey volume, (2) percent of skeletal surveys revealing clinically unsuspected (occult) fractures, and (3) clinical severity of presentation. We hypothesized that during the pandemic, children with minor abusive injuries would be less likely to present for care, but severely injured children would present at a comparable rate to prepandemic times. We expected that during the pandemic, the volume of skeletal surveys would decrease but the percentage revealing occult fractures would increase and that injury severity would increase. Methods We conducted a retrospective study of children younger than 2 years undergoing skeletal surveys because of concern for physical abuse at a tertiary children's hospital. Subjects were identified by querying a radiology database during the March 15, 2019–October 15, 2019 (pre–COVID-19) period and the March 15, 2020–October 15, 2020 (COVID-19) period, followed by chart review to refine our population and abstract clinical and imaging data. Results Pre–COVID-19, 160 skeletal surveys were performed meeting the inclusion criteria, compared with 125 during COVID-19, representing a 22% decrease. No change was observed in identification of occult fractures (6.9% pre-COVID vs 6.4% COVID, P = 0.87). Clinical severity of presentation did not change, and child protective services involvement/referral decreased during COVID. Conclusions Despite a >20% decrease in skeletal survey performance early in the pandemic, the percent of skeletal surveys revealing occult fractures did not increase. Our results suggest that decreases in medical evaluations for abuse did not stem from decreased presentation of less severely injured children.

Child abuse is a global public health concern. Injuries from physical abuse may be clinically occult and not appreciable on physical examination. Imaging is therefore critical in identifying and do...

Trauma is the leading cause of morbidity and mortality in children, and rapid identification of organ injury is essential for successful treatment. Contrast-enhanced ultrasound (CEUS) is an appealing alternative to contrast-enhanced CT in the evaluation of children with blunt abdominal trauma, mainly with respect to the potential reduction of population-level exposure to ionizing radiation. This is particularly important in children, who are more vulnerable to the hazards of ionizing radiation than adults. CEUS is useful in hemodynamically stable children with isolated blunt low- to moderate-energy abdominal trauma to rule out solid organ injuries. It can also be used to further evaluate uncertain contrast-enhanced CT findings, as well as in the follow-up of conservatively managed traumatic injuries. CEUS can be used to detect abnormalities that are not apparent by conventional US, including infarcts, pseudoaneurysms and active bleeding. In this article we present the current experience from the use of CEUS for the evaluation of pediatric blunt abdominal trauma, emphasizing the examination technique and interpretation of major abnormalities associated with injuries in the liver, spleen, kidneys, adrenal glands, pancreas and testes. We also discuss the limitations of the technique and offer a review of the major literature on this topic in children, including an extrapolation of experience from adults.

Infants are at greatest risk of severe and fatal physical abuse yet they sometimes present for medical care multiple times with abusive injuries prior to being diagnosed with abuse and having protective actions taken. Efforts to identify these infants in a timely manner are critical to prevent repeated, escalating abuse and subsequent harm. Increasing the identification and evaluation of sentinel injuries has been highlighted as a strategy for improving timely detection of abuse in infants. Sentinel injuries are visible, minor, poorly explained injuries in young infants that raise concern for abuse. These injuries include cutaneous injuries such as bruising, subconjunctival hemorrhages and intra-oral injuries. Sentinel injuries can signal concurrent clinically occult but more serious injuries or precede more significant trauma from abuse. As such, sentinel injuries offer an opportunity to intervene and protect infants from further harm. A thorough physical exam is critical for detecting sentinel injuries. Imaging with skeletal survey and, when appropriate, neuroimaging are key components of the medical evaluation of sentinel injuries in these high-risk infants.

Infants who appear neurologically well and have fractures concerning for abuse are at increased risk for clinically occult head injuries. Evidence of excess variation in neuroimaging practices when abuse is suspected may indicate opportunity for quality and safety improvement.To quantify neuroimaging practice variation across children's hospitals among infants with fractures evaluated for abuse, with the hypothesis that hospitals would vary substantially in neuroimaging practices. As a secondary objective, factors associated with neuroimaging use were identified, with the hypothesis that age and factors associated with potential biases (ie, payer type and race or ethnicity) would be associated with neuroimaging use.This cross-sectional study included infants with a femur or humerus fracture or both undergoing abuse evaluation at 44 select US children's hospitals in the Pediatric Health Information System (PHIS) from January 1, 2016, through March 30, 2020, including emergency department, observational, and inpatient encounters. Included infants were aged younger than 12 months with a femur or humerus fracture or both without overt signs or symptoms of head injury for whom a skeletal survey was performed. To focus on infants at increased risk for clinically occult head injuries, infants with billing codes suggestive of overt neurologic signs or symptoms were excluded. Multivariable logistic regression was used to investigate demographic, clinical, and temporal factors associated with use of neuroimaging. Marginal standardization was used to report adjusted percentages of infants undergoing neuroimaging by hospital and payer type. Data were analyzed from March 2021 through January 2022.Covariates included age, sex, race and ethnicity, payer type, fracture type, presentation year, and hospital.Use of neuroimaging by CT or MRI.Of 2585 infants with humerus or femur fracture or both undergoing evaluations for possible child abuse, there were 1408 (54.5%) male infants, 1726 infants (66.8%) who were publicly insured, and 1549 infants (59.9%) who underwent neuroimaging. The median (IQR) age was 6.1 (3.2-8.3) months. There were 748 (28.9%) Black non-Hispanic infants, 426 (16.5%) Hispanic infants, 1148 (44.4%) White non-Hispanic infants. In multivariable analyses, younger age (eg, odds ratio [OR] for ages3 months vs ages 9 to12 months, 13.2; 95% CI, 9.54-18.2; P .001), male sex (OR, 1.47; 95% CI, 1.22-1.78; P .001), payer type (OR for public vs private insurance, 1.48; 95% CI, 1.18-1.85; P = .003), fracture type (OR for femur and humerus fracture vs isolated femur fracture, 5.36; 95% CI, 2.11-13.6; P = .002), and hospital (adjusted range in use of neuroimaging, 37.4% [95% CI 21.4%-53.5%] to 83.6% [95% CI 69.6%-97.5%]; P .001) were associated with increased use of neuroimaging, but race and ethnicity were not. Publicly insured infants were more likely to undergo neuroimaging (62.0%; 95% CI, 60.0%-64.1%) than privately insured infants (55.1%; 95% CI, 51.8%-58.4%) (P = .001).This study found that hospitals varied in neuroimaging practices among infants with concern for abuse. Apparent disparities in practice associated with insurance type suggest opportunities for quality, safety, and equity improvement.

ImportanceInformation about the trend in illicit substance ingestions among young children during the pandemic is limited.ObjectivesTo assess immediate and sustained changes in overall illicit substance ingestion rates among children younger than 6 years before and during the COVID-19 pandemic and to examine changes by substance type (amphetamines, benzodiazepines, cannabis, cocaine, ethanol, and opioids) while controlling for differing statewide medicinal and recreational cannabis legalization policies.Design, Setting, and ParticipantsRetrospective cross-sectional study using an interrupted time series at 46 tertiary care children’s hospitals within the Pediatric Health Information System (PHIS). Participants were children younger than 6 years who presented to a PHIS hospital for an illicit substance(s) ingestion between January 1, 2017, and December 31, 2021. Data were analyzed in February 2023.ExposureAbsence or presence of the COVID-19 pandemic.Main Outcome(s) and Measure(s)The primary outcome was the monthly rate of encounters for illicit substance ingestions among children younger than 6 years defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code(s) for poisoning by amphetamines, benzodiazepines, cannabis, cocaine, ethanol, and opioids. The secondary outcomes were the monthly rate of encounters for individual substances.ResultsAmong 7659 children presenting with ingestions, the mean (SD) age was 2.2 (1.3) years and 5825 (76.0%) were Medicaid insured/self-pay. There was a 25.6% (95% CI, 13.2%-39.4%) immediate increase in overall ingestions at the onset of the pandemic compared with the prepandemic period, which was attributed to cannabis, opioid, and ethanol ingestions. There was a 1.8% (95% CI, 1.1%-2.4%) sustained monthly relative increase compared with prepandemic trends in overall ingestions which was due to opioids. There was no association between medicinal or recreational cannabis legalization and the rate of cannabis ingestion encounters.Conclusions and RelevanceIn this study of illicit substance ingestions in young children before and during the COVID-19 pandemic, there was an immediate and sustained increase in illicit substance ingestions during the pandemic. Additional studies are needed to contextualize these findings in the setting of pandemic-related stress and to identify interventions to prevent ingestions in face of such stress, such as improved parental mental health and substance treatment services, accessible childcare, and increased substance storage education.

To describe the percentage and characteristics of children aged24 months with non-motor vehicle crash (MVC)-related injuries who undergo a skeletal survey and have occult fractures.We performed a retrospective chart review of a stratified, systematic random sample of 1769 children aged24 months with non-MVC-related bruises, burns, fractures, abdominal injuries, and head injuries at 4 children's hospitals between 2008 and 2012. Sampling weights were assigned to each child to allow for representative hospital-level population estimates. Logistic regression models were used to test for associations between patient characteristics with outcomes of skeletal survey completion and occult fracture identification.Skeletal surveys were performed in 46.3% of children aged 0 to 5 months, in 21.1% of those aged 6 to 11 months, in 8.0% of those aged 12 to 17 months, and in 6.2% of those aged 18 to 24 months. Skeletal surveys were performed most frequently in children with traumatic brain injuries (64.7%) and rib fractures (100%) and least frequently in those with burns (2.1%) and minor head injuries (4.4%). In adjusted analyses, older age, private insurance, and reported history of accidental trauma were associated with decreased skeletal survey use (P ≤ .001 for all). The prevalence of occult fractures on skeletal surveys ranged from 24.6% in children aged 0 to 5months to 3.6% in those aged 18 to 24 months, and varied within age categories based on the presenting injury (P.001).The high rate of occult fractures in infants aged 0 to 5 months underscores the importance of increasing the use of skeletal surveys in this population. Further research is needed to identify the injury characteristics of older infants and toddlers most at risk for occult fractures.

Objectives The aim of this study was to evaluate cervical magnetic resonance imaging (MRI) and computed tomography (CT) practices and cervical spine injuries among young children with non-motor vehicle crash (MVC)-associated traumatic brain injury (TBI). Methods We performed a retrospective study of a stratified, systematic random sample of 328 children younger than 2 years with non-MVC-associated TBI at 4 urban children's hospitals from 2008 to 2012. We defined TBI etiology as accidental, indeterminate, or abuse. We reported the proportion, by etiology, who underwent cervical MRI or CT, and had cervical abnormalities identified. Results Of children with non-MVC-associated TBI, 39.4% had abusive head trauma (AHT), 52.2% had accidental TBI, and in 8.4% the etiology was indeterminate. Advanced cervical imaging (CT and/or MRI) was obtained in 19.1% of all children with TBI, with 9.3% undergoing MRI and 11.7% undergoing CT. Cervical MRI or CT was performed in 30.9% of children with AHT, in 11.7% of accidental TBI, and in 10.7% of indeterminate-cause TBI. Among children imaged by MRI or CT, abnormal cervical findings were found in 22.1%, including 31.3% of children with AHT, 7.1% of children with accidental TBI, and 0% of children with indeterminate-cause TBI. Children with more severe head injuries who underwent cervical imaging were more likely to have cervical injuries. Conclusions Abusive head trauma victims appear to be at increased risk of cervical injuries. Prospective studies are needed to define the risk of cervical injury in children with TBI concerning for AHT and to inform development of imaging guidelines.

Abusive intra-abdominal injuries are less common than other types of injuries, such as fractures and bruises, identified in victims of child physical abuse, but they can be deadly. No single abdominal injury is pathognomonic for abuse, but some types and constellations of intra-abdominal injuries are seen more frequently in abused children. Identification of intra-abdominal injuries can be important clinically or forensically. Injuries that do not significantly change clinical management can still elevate a clinician's level of concern for abuse and thereby influence subsequent decisions affecting child protection efforts. Abusive intra-abdominal injuries can be clinically occult, necessitating screening laboratory evaluations to inform decisions regarding imaging. Once detected, consideration of developmental abilities of the child, type and constellation of injuries, and the forces involved in any provided mechanism of trauma are necessary to inform assessments of plausibility of injury mechanisms and level of concern for abuse. Here we describe the clinical, laboratory and imaging evaluation of the abdomen in the setting of suspected child abuse.

Infants are at greatest risk of severe and fatal physical abuse yet they sometimes present for medical care multiple times with abusive injuries prior to being diagnosed with abuse and having protective actions taken. Efforts to identify these infants in a timely manner are critical to prevent repeated, escalating abuse and subsequent harm. Increasing the identification and evaluation of sentinel injuries has been highlighted as a strategy for improving timely detection of abuse in infants. Sentinel injuries are visible, minor, poorly explained injuries in young infants that raise concern for abuse. These injuries include cutaneous injuries such as bruising, subconjunctival hemorrhages and intra-oral injuries. Sentinel injuries can signal concurrent clinically occult but more serious injuries or precede more significant trauma from abuse. As such, sentinel injuries offer an opportunity to intervene and protect infants from further harm. A thorough physical exam is critical for detecting sentinel injuries. Imaging with skeletal survey and, when appropriate, neuroimaging are key components of the medical evaluation of sentinel injuries in these high-risk infants.

Objective The primary objective of this study was to determine the prevalence of (a) additional injuries, (b) abuse as determined by a standardized scale, and (c) reports to child protective services (CPS) among children younger than 5 years in whom a rib fracture was the first presenting injury concerning for abuse. Methods A retrospective study of children younger than 5 years diagnosed with rib fractures at a tertiary pediatric hospital between 2007 and 2018 was performed. Children in motor vehicle crashes, hospitalized after birth, or with previously diagnosed metabolic bone disease were excluded. We included only those children whose rib fractures were the first presenting injury. Demographic and clinical information was abstracted from the records. Prevalence of additional injuries, a diagnosis of abuse, and a report to CPS were calculated. Associations between patient demographic and clinical characteristics and the outcomes of interest were examined. Results Of the 67 cases included, additional injuries concerning for abuse were identified in 40 (60%), and 58% were deemed likely or definite abuse. Reports to CPS were filed in 72% of cases. Posterior rib fractures, multiple rib fractures, and presence of rib fractures of multiple ages were all associated with presence of additional injuries and classification as definite or likely abuse (all P ≤ 0.05). Conclusions The presence of a rib fracture in young children is associated with a high likelihood of additional concerning injuries and should prompt a thorough evaluation for child abuse.

BACKGROUND: Abusive head injuries in infants may be occult but clinically or forensically important. Data conflict regarding yield of neuroimaging in detecting occult head injuries in infants evaluated for physical abuse, with prior studies identifying yields of 4.3–37.3 %. OBJECTIVES: (1) To quantify yield of computed tomography or magnetic resonance imaging in identification of occult head injuries in infants with concerns for physical abuse and (2) to evaluate risk factors for occult head injuries. PARTICIPANTS AND SETTING: We conducted a retrospective, stratified, random systematic sample of 529 infants < 12 months evaluated for physical abuse at 4 urban children’s hospitals in the United States from 2008–2012. Infants with signs or symptoms suggesting head injury or skull fracture on plain radiography (N = 359), and infants without neuroimaging (N = 1) were excluded. METHODS: Sampling weights were applied to calculate proportions of infants with occult head injuries. We evaluated for associations between hypothesized risk factors (age < 6 months, rib or extremity fracture, facial bruising) and occult head injury using chi-square tests. RESULTS: Of 169 neurologically normal infants evaluated for abuse, occult head injury was identified in 6.5 % (95 % CI: 2.6, 15.8). Infants < 6 months were at higher risk (9.7 %; 95 % CI: 3.6, 23.3) than infants 6–12 months (1.0 %; 95 % CI: 1.3, 20.2). Rib fracture, extremity fracture and facial bruising were not associated with occult head injury. CONCLUSIONS: Occult head injuries were less frequent than previously reported in some studies, but were identified in 1 in 10 infants

Abusive head trauma (AHT) is the leading cause of fatal child physical abuse. Victims may initially present with clinically occult AHT without overt signs of head trauma or with only subtle, nonspecific symptoms, which can make timely recognition of AHT challenging. Research has shown missed opportunities for early detection of AHT in the medical setting are common and can lead to repeated injury. Neuroimaging is needed to diagnose clinically occult AHT but is not without risk. Researchers have worked to understand the yield of neuroimaging in detection of clinically occult AHT and to identify risk factors, yet findings have varied widely across studies. Identifying which children undergoing physical abuse evaluations are at highest risk of clinically occult AHT is key to development of evidence-based imaging decision support tools for clinicians. Here we discuss the recent literature, identify potential reasons for variation across studies, and offer opportunities for future research.

OBJECTIVES The aim of this study was to evaluate the effectiveness of clinical pathway implementation and quality improvement (QI) interventions to increase the percentage of infants with extremity fractures undergoing evaluation for suspected physical abuse, including skeletal survey (SS), and consultation with social work, and/or Child Protection Team. METHODS Charts were retrospectively reviewed to establish percentage of infants less than 12 months old with extremity fractures undergoing an SS and consultation during the prepathway (January 1, 2012 to December 31, 2013) and postpathway (January 1, 2014 to June 30, 2015) periods. Using an Ishikawa framework, key process drivers were identified and additional QI interventions (clinical decision support and provider education) were developed and implemented. Impact of QI interventions on study metrics during active QI (July 1, 2015 to June 30, 2016) and post-QI periods (July 1, 2016 to December 31, 2016) was monitored using statistical process control charts. Logistic regression assessed predictors of obtaining an SS, consultation use, and occult fracture detection. RESULTS Skeletal survey use pre- and postpathway averaged 40%, surpassing 60% on average during active QI and post-QI periods. Consultation performance averaged 46% pre- and postpathway, increasing to nearly 67% during active QI; consultation performance decreased during post-QI to 60%. A lack of trauma history and presence of femur or humerus fracture were associated with increased SS use and consultation (both P < 0.001). Overall 20% of SS revealed occult fractures.

Three-dimensional (3-D) printing is gaining terrain in medical education, presurgical evaluation and recently as forensic evidence in court. Physicians, including radiologists, often provide expert testimony in court cases involving children with rib fractures and other injuries concerning for child physical abuse. Effectively communicating the complexities of fractures and other skeletal findings to nonmedical personnel using standard radiology studies can be challenging, especially during medical courtroom testimony. For this reason, we printed two 3-D models of the rib cage from the chest computed tomography (CT) scans of two patients with suspected non-accidental injury. The patients also had available chest radiographs. The DICOM (Digital Imaging and Communications in Medicine) data were 3-D reconstructed and segmented using two attenuation thresholds. We removed unwanted structures and printed them on a commercially available scanner. A pediatric radiologist, blinded to clinical data, reviewed both 3-D models, identified all rib lesions and classified them according to their healing stage. We compared the 3-D models and the chest radiograph against the chest CT as the standard of care. We convened a meeting with the Child Protection Team at out institution to get their feedback and opinions about the models. From our observations of our experts, three spontaneous interactions were observed. Instinctively, the experts picked up and grasped the models, rotating them, feeling them and angling them to better visualize the fractures from multiple angles. The experts expressed a willingness to consider using the models in court.

Background Children and adolescents necessitating hospitalization for physical health conditions are at high risk for mental health conditions; however, the prevalence of mental health conditions and symptoms among hospitalized children and adolescents is uncertain. The objective of this study was to determine the proportion of hospitalized children and adolescents who have diagnosed mental health disorders or undiagnosed mental health problems. Methods In this single-center point prevalence study of hospitalized children between the ages of 4 and 21 years, patients or their parents reported known mental health diagnoses and use of services using the Services Assessment for Children and Adolescent, and they reported patient mental health symptoms using the Pediatric Symptom Checklist, 17-item form (PSC-17). Results Of 229 eligible patients, 119 agreed to participate. Demographic characteristics of patients who enrolled were not statistically significantly different from those of patients who declined to participate. Among participants, 26% (95% confidence interval [CI], 18%–35%) reported a known mental health diagnosis. On the PSC-17, 29% (95% CI, 21%–38%) of participants had a positive screen for mental health symptoms. Of those with a positive screen, 38% (95% CI, 21%–55%) had no known mental health diagnosis, and 26% (95% CI, 12%–43%) had not received ambulatory mental health services in the 12 months before hospitalization. Conclusions Mental health conditions and symptoms are common among patients hospitalized in a tertiary children's hospital, and many affected patients are not receiving ambulatory mental health services.

Objective Cervical imaging practices are poorly understood in young children with traumatic brain injury (TBI). We therefore sought to identify child-level and hospital-level factors associated with performance of cervical imaging of children with TBI from falls and abusive head trauma (AHT) and to describe across-hospital variation in cervical imaging performance. We hypothesized that imaging decisions would be influenced by hospital volume of young injured children. Methods We performed a retrospective study of children younger than 2 years of age with TBI from 2009 to 2013 in the Premier Perspective Database. After adjustment for observed patient characteristics, we evaluated variation in advanced cervical imaging (computed tomography or magnetic resonance imaging) in children with AHT and TBI from falls. Results Of 2347 children with TBI, 18.7% were from abuse and 57.1% were from falls. Fifteen percent of children with TBI underwent advanced cervical imaging. Moderate or severe head injuries were associated with increased odds of cervical imaging in AHT (odds ratio 7.10; 95% confidence interval 2.75, 18.35) and falls (odds ratio 2.25; 95% confidence interval 1.19, 4.27). There was no association between annual hospital volume of injured children and cervical imaging performance. The adjusted probability of imaging across hospitals ranged from 4.3% to 84.3% in AHT and 3.1 to 39.0% in TBI from falls ( P Conclusions These results highlight variation across hospitals in adjusted probability of cervical imaging in AHT (nearly 20-fold) and TBI from falls (over 10-fold) not explained by observed patient characteristics. This variation suggests opportunities for further research to inform imaging practices.

OBJECTIVES: To describe the disposition of young children diagnosed with physical abuse in the emergency department (ED) setting and identify factors associated with the decision to discharge young abused children. STUDY DESIGN: We performed a retrospective cross-sectional study of children less than 2 years of age diagnosed with physical abuse in the 2006-2012 Nationwide Emergency Department Sample. National estimates were calculated accounting for the complex survey design. We developed a multivariable logistic regression model to evaluate the relationship between payer type and discharge from the ED compared with admission with adjustment for patient and hospital factors. RESULTS: Of the 37 655 ED encounters with a diagnosis of physical abuse among children less than 2 years of age, 51.8% resulted in discharge, 41.2% in admission, 4.3% in transfer, 0.3% in death in the ED, and 2.5% in other. After adjustment for age, sex, injury type, and hospital characteristics (trauma designation, volume of young children, and hospital region), there were differences in discharge decisions by payer and injury severity. The adjusted percentage discharged of publicly insured children with minor/moderate injury severity was 56.2% (95% CI 51.6, 60.7). The adjusted percentages discharged were higher for both privately insured children at 69.9% (95% CI 64.4, 75.5) and self-pay children at 72.9% (95% CI 67.4, 78.4). The adjusted percentages discharged among severely injured children did not differ significantly by payer. CONCLUSIONS: The majority of ED visits for young children diagnosed with abuse resulted in discharge. The notable differences in disposition by payer warrant further investigation.Copyright © 2016 Elsevier Inc. All rights reserved. Language: en