Sustaining the gains: Reducing unnecessary computed tomography scans in pediatric trauma patients.

BACKGROUND/PURPOSE: "Pan-scanning" pediatric blunt trauma patients leads to exposure to harmful radiation and increased healthcare costs without improving outcomes. We aimed to reduce computed tomography (CT) scans that are not indicated (NI) by imaging guidelines for injured children. METHODS: In July 2017, our Pediatric Trauma Center prospectively implemented validated imaging guidelines to direct CT imaging for trauma activations and consultations for children younger than 16 years old with blunt traumatic injuries. Patients with suspected physical abuse, CT imaging prior to arrival, penetrating mechanism, and instability precluding CT imaging were excluded. We compared CT scanning rates for pre-implementation (01/2016-06/2017) and post-implementation (07/2017-08/2021) time periods. Guideline compliance was evaluated by chart review and sustained through iterative process improvement cycles. RESULTS: During the pre-implementation era, 61 patients underwent 171 CT scans of which 87 (51%) scans were not indicated by guidelines. Post-implementation, 363 patients had 531 scans and only 134 (25%) CTs were not indicated. Total CTs performed declined after initiation of guidelines (2.80 vs 1.46 scans/patient, p<0.0001). Total NI CTs declined (1.41 vs 0.37 NI scans/patient, p<0.0001) reflected in significant reductions in all anatomic regions: head, cervical spine, chest, and abdomen/pelvis. Charges related to NI scans decreased from $1,490.31/patient to $408.21/patient, saving $218,000 in charges. Based on prior utilization, 146 children were spared excessive radiation with no clinically significant missed injuries since guideline implementation. CONCLUSIONS: Quality improvement and implementation science methodologies to enhance compliance with imaging guidelines for children with blunt injuries can significantly reduce unnecessary CT scanning without compromising care. This practice reduces harmful radiation exposure in a sensitive patient population and may save healthcare systems money and resources.

Centers for Mendelian Genomics: A decade of facilitating gene discovery.

PURPOSE: Mendelian disease genomic research has undergone a massive transformation over the past decade. With increasing availability of exome and genome sequencing, the role of Mendelian research has expanded beyond data collection, sequencing, and analysis to worldwide data sharing and collaboration. METHODS: Over the past 10 years, the National Institutes of Health-supported Centers for Mendelian Genomics (CMGs) have played a major role in this research and clinical evolution. RESULTS: We highlight the cumulative gene discoveries facilitated by the program, biomedical research leveraged by the approach, and the larger impact on the research community. Beyond generating a list of gene-phenotype relationships and participating in widespread data sharing, the CMGs have created resources, tools, and training for the larger community to foster understanding of genes and genome variation. The CMGs have participated in a wide range of data sharing activities, including deposition of all eligible CMG data into the Analysis, Visualization, and Informatics Lab-space (AnVIL), sharing candidate genes through the Matchmaker Exchange and the CMG website, and sharing variants in Genotypes to Mendelian Phenotypes (Geno2MP) and VariantMatcher. CONCLUSION: The work is far from complete; strengthening communication between research and clinical realms, continued development and sharing of knowledge and tools, and improving access to richly characterized data sets are all required to diagnose the remaining molecularly undiagnosed patients.

The Glucocorticoid Receptor in Osterix-Expressing Cells Regulates Bone Mass, Bone Marrow Adipose Tissue, and Systemic Metabolism in Female Mice During Aging.

Hallmarks of aging-associated osteoporosis include bone loss, bone marrow adipose tissue (BMAT) expansion, and impaired osteoblast function. Endogenous glucocorticoid levels increase with age, and elevated glucocorticoid signaling, associated with chronic stress and dysregulated metabolism, can have a deleterious effect on bone mass. Canonical glucocorticoid signaling through the glucocorticoid receptor (GR) was recently investigated as a mediator of osteoporosis during the stress of chronic caloric restriction. To address the role of the GR in an aging-associated osteoporotic phenotype, the current study utilized female GR conditional knockout (GR-CKO; GRfl/fl :Osx-Cre+) mice and control littermates on the C57BL/6 background aged to 21 months and studied in comparison to young (3- and 6-month-old) mice. GR deficiency in Osx-expressing cells led to low bone mass and BMAT accumulation that persisted with aging. Surprisingly, however, GR-CKO mice also exhibited alterations in muscle mass (reduced % lean mass and soleus fiber size), accompanied by reduced voluntary physical activity, and also exhibited higher whole-body metabolic rate and elevated blood pressure. Moreover, increased lipid storage was observed in GR-CKO osteoblastic cultures in a glucocorticoid-dependent fashion despite genetic deletion of the GR, and could be reversed via pharmacological inhibition of the mineralocorticoid receptor (MR). These findings provide evidence of a role for the GR (and possibly the MR) in facilitating healthy bone maintenance with aging in females. The effects of GR-deficient bone on whole-body physiology also demonstrate the importance of bone as an endocrine organ and suggest evidence for compensatory mechanisms that facilitate glucocorticoid signaling in the absence of osteoblastic GR function; these represent new avenues of research that may improve understanding of glucocorticoid signaling in bone toward the development of novel osteogenic agents. © 2021 American Society for Bone and Mineral Research (ASBMR).

A Quality Improvement Approach to Decreasing Postdischarge Acute Care Reuse Among Children With Asthma.

OBJECTIVES: To reduce 7-day acute care reuse among children with asthma after discharge from an academic children's hospital by standardizing the delivery of clinical care and patient education. METHODS: A diverse group of stakeholders from our tertiary care children's hospital and local community agencies used quality improvement methods to implement a series of interventions within inpatient, emergency department (ED), and outpatient settings. These interventions were designed to improve admission, inpatient care, and discharge processes for children hospitalized because of asthma and included a focus on (1) resident education, (2) patient access to medication and asthma education, and (3) gaps in existing asthma clinical care pathways in the ED and ICU. The primary outcome was the rate of 7-day acute care reuse (combined hospital readmissions and ED revisits) after discharge from an index hospitalization for asthma, measured through a monthly review of electronic health record data and compared with a 6-month baseline period of reuse data. RESULTS: The mean 7-day reuse rate for asthma after discharge was 3.7% during the 6 months baseline period (n = 107) and 1.0% during the 15-month intervention period (n = 302). This included a shift in our median from 3.3% to 0% with an 8-month period of no 7-day reuse. CONCLUSIONS: An interprofessional quality improvement team successfully achieved and sustained a 73% reduction in mean 7-day asthma-related acute care reuse after discharge by standardizing provider training, care processes, and patient education.

Kynurenine suppresses osteoblastic cell energetics in vitro and osteoblast numbers in vivo.

Aging is a progressive process associated with declining tissue function over time. Kynurenine, an oxidized metabolite of the essential amino acid tryptophan that increases in abundance with age, drives cellular processes of aging and dysfunction in many tissues, and recent work has focused on understanding the pathways involved in the harmful effects of kynurenine on bone. In this study, we sought to investigate the effects of controlled kynurenine administration on osteoblast bioenergetics, in vivo osteoblast abundance, and marrow fat accumulation. Additionally, as an extension of earlier studies with dietary administration of kynurenine, we investigated the effects of kynurenine on Hdac3 and NCoR1 expression and enzymatic deacetylase activity as potential mechanistic contributors to the effects of kynurenine on osteoblasts. Kynurenine administration suppressed cellular metabolism in osteoblasts at least in part through impaired mitochondrial respiration, and suppressed osteoblastic numbers in vivo with no concurrent effects on marrow adiposity. Deleterious effects of kynurenine treatment on osteoblasts were more pronounced in female models as compared to males. However, kynurenine treatment did not inhibit Hdac3's enzymatic deacetylase activity nor its repression of downstream glucocorticoid signaling. As such, future work will be necessary to determine the mechanisms by which increased kynurenine contributes to aging bone bioenergetics. The current study provides novel further support for the idea that kynurenine contributes to impaired osteoblastic function, and suggests that impaired matrix production by kynurenine-affected osteoblasts is attributed in part to impaired osteoblastic bioenergetics. As circulating kynurenine levels in increase with age, and human bone density inversely correlates with the serum kynurenine to tryptophan ratio, these mechanisms may have important relevance in the etiology and pathogenesis of osteoporosis in humans.

Effect of pharmacist-led task force to reduce opioid prescribing in the emergency department.

PURPOSE: Results of a study to determine the effect of a pharmacist-led opioid task force on emergency department (ED) opioid use and discharge prescriptions are presented. METHODS: An observational evaluation was conducted at a large tertiary care center (ED volume of 115,000 visits per year) to evaluate selected opioid use outcomes before and after implementation of an ED opioid reduction program by interdisciplinary task force of pharmacists, physicians, and nurses. Volumes of ED opioid orders and discharge prescriptions were evaluated over the entire 25-month study period and during designated 1-month preimplementation and postimplementation periods (January 2017 and January 2018). Opioid order trends were evaluated using linear regression analysis and further investigated with an interrupted time series analysis to determine the immediate and sustained effects of the program. RESULTS: From January 2017 to January 2018, ED opioid orders were reduced by 63.5% and discharge prescriptions by 55.8% from preimplementation levels: from 246.8 to 90.1 orders and from 85.3 to 37.7 prescriptions per 1,000 patient visits, respectively. Over the entire study period, there were significant decreases in both opioid orders (ß, -78.4; 95% confidence interval [CI], -88.0 to -68.9; R2, 0.93; p < 0.0001) and ED discharge prescriptions (ß, -24.4; 95% CI, -27.9 to -20.9; R2, 0.90; p < 0.001). The efforts of the task force had an immediate effect on opioid prescribing practices; results for effect sustainability were mixed. CONCLUSION: A clinical pharmacist-led opioid reduction program in the ED was demonstrated to have positive results, with a more than 50% reduction in both ED opioid orders and discharge prescriptions.

MicroRNA-183-5p Increases with Age in Bone-Derived Extracellular Vesicles, Suppresses Bone Marrow Stromal (Stem) Cell Proliferation, and Induces Stem Cell Senescence.

Microvesicle- and exosome-mediated transport of microRNAs (miRNAs) represents a novel cellular and molecular pathway for cell-cell communication. In this study, we tested the hypothesis that these extracellular vesicles (EVs) and their miRNAs might change with age, contributing to age-related stem cell dysfunction. EVs were isolated from the bone marrow interstitial fluid (supernatant) of young (3-4 months) and aged (24-28 months) mice to determine whether the size, concentration, and miRNA profile of EVs were altered with age in vivo. Results show that EVs isolated from bone marrow are CD63 and CD9 positive, and the concentration and size distribution of bone marrow EVs are similar between the young and aged mice. Bioanalyzer data indicate that EVs from both young and aged mice are highly enriched in miRNAs, and the miRNA profile of bone marrow EVs differs significantly between the young and aged mice. Specifically, the miR-183 cluster (miR-96/-182/-183) is highly expressed in aged EVs. In vitro assays demonstrate that aged EVs are endocytosed by primary bone marrow stromal cells (BMSCs), and these aged EVs inhibit the osteogenic differentiation of young BMSCs. Transfection of BMSCs with miR-183-5p mimic reduces cell proliferation and osteogenic differentiation, increases senescence, and decreases protein levels of the miR-183-5p target heme oxygenase-1 (Hmox1). In vitro assays utilizing H2O2-induced oxidative stress show that H2O2 treatment of BMSCs increases the abundance of miR-183-5p in BMSC-derived EVs, and Amplex Red assays demonstrate that H2O2 is elevated in the bone marrow microenvironment with age. Together, these data indicate that aging and oxidative stress can significantly alter the miRNA cargo of EVs in the bone marrow microenvironment, which may in turn play a role in stem cell senescence and osteogenic differentiation by reducing Hmox1 activity.

The aromatic amino acid tryptophan stimulates skeletal muscle IGF1/p70s6k/mTor signaling in vivo and the expression of myogenic genes in vitro.

OBJECTIVES: Nutrition plays a key role in the maintenance of muscle and bone mass, and dietary protein deficiency has in particular been associated with catabolism of both muscle and bone tissue. One mechanism thought to link protein deficiency with loss of muscle mass is deficiency in specific amino acids that play a role in muscle metabolism. The aim of this study was to test the hypothesis that the essential amino acid tryptophan, and its metabolite kynurenine, might directly affect muscle metabolism in the setting of protein deficiency. METHODS: Adult mice (12 mo) were fed a normal diet (18% protein), as well as diets with low protein (8%) supplemented with increasing concentrations (50, 100, and 200 uM) of kynurenine (Kyn) or with tryptophan (Trp; 1.5 mM) for 8 weeks. Myoprogenitor cells were also treated with Trp and Kyn in vitro to determine their effects on cell proliferation and expression of myogenic differentiation markers. RESULTS: All mice on the low-protein diets weighed less than the group fed normal protein (18%). Lean mass measured by dual-energy X-ray absorptiometry was lowest in mice on the high Kyn diet, whereas percent lean mass was highest in mice receiving Trp supplementation and percent body fat was lowest in mice receiving Trp. Enzyme-linked immunosorbent assays showed significant increases in skeletal muscle insulin-like growth factor-1, leptin, and the myostatin antagonist follistatin with Trp supplementation. mRNA microarray and gene pathway analysis performed on muscle samples demonstrate that mTor/eif4/p70s6k pathway molecules are significantly up-regulated in muscles from mice on Kyn and Trp supplementation. In vitro, neither amino acid affected proliferation of myoprogenitors, but Trp increased the expression of the myogenic markers MyoD, myogenin, and myosin heavy chain. CONCLUSION: These findings suggest that dietary amino acids can directly affect molecular signaling in skeletal muscle, further indicating that dietary manipulation with specific amino acids could potentially attenuate muscle loss with dietary protein deficiency.

Caloric restriction and the adipokine leptin alter the SDF-1 signaling axis in bone marrow and in bone marrow derived mesenchymal stem cells.

Growing evidence suggests that the chemokine stromal cell-derived factor-1 (SDF-1) is essential in regulating bone marrow (BM) derived mesenchymal stromal/stem cell (BMSC) survival, and differentiation to either a pro-osteogenic or pro-adipogenic fate. This study investigates the effects of caloric restriction (CR) and leptin on the SDF-1/CXCR4 axis in bone and BM tissues in the context of age-associated bone loss. For in vivo studies, we collected bone, BM cells and BM interstitial fluid from 12 and 20 month-old C57Bl6 mice fed ad-libitum (AL), and 20-month-old mice on long-term CR with, or without, intraperitoneal injection of leptin for 10 days (10 mg/kg). To mimic conditions of CR in vitro, 18 month murine BMSCs were treated with (1) control (Ctrl): normal proliferation medium, (2) nutrient restriction (NR): low glucose, low serum medium, or (3) NR + leptin: NR medium + 100 ng/ml leptin for 6-48 h. In BMSCs both protein and mRNA expression of SDF-1 and CXCR4 were increased by CR and CR + leptin. In contrast, the alternate SDF-1 receptor CXCR7 was decreased, suggesting a nutrient signaling mediated change in SDF-1 axis signaling in BMSCs. However, in bone SDF-1, CXCR4 and 7 gene expression increase with age and this is reversed with CR, while addition of leptin returns this to the "aged" level. Histologically bone formation was lower in the calorically restricted mice and BM adipogenesis increased, both effects were reversed with the 10 day leptin treatment. This suggests that in bone CR and leptin alter the nutrient signaling pathways in different ways to affect the local action of the osteogenic cytokine SDF-1. Studies focusing on the molecular interaction between nutrient signaling by CR, leptin and SDF-1 axis may help to address age-related musculoskeletal changes.

Selective reduction of fetuses in multiple pregnancies and the law in Australia.

This article considers whether it is lawful in Australia to terminate one or more fetuses in a multiple pregnancy selectively and, if so, under what circumstances. It begins by addressing the preliminary question whether selective reduction is covered by laws relating to abortion and provides a brief outline of the law of abortion in Australian jurisdictions. The article then considers selective reduction of high-order multiple pregnancies, before turning to selective reduction of twin pregnancies in a range of circumstances. The article demonstrates that the law of abortion, as applied to selective reduction of multiple pregnancies, is uncertain and that there are considerable variations from one State to another. It concludes that the law in this area is in need of reform to recognise that some reductions are not performed prima facie to prevent danger to the mother's health and to remove the need for doctors to assert symptomatology of mental illness in order to guard against criminal law consequences. Further, there is a need to clarify whether selective reduction/ termination is abortion for the purposes of the law, and to achieve greater consistency across jurisdictions.

The spectre of court-sanctioned sacrificial separation of teenage conjoined twins against their will.

In a recent decision of the Indian Supreme Court, judges foreshadowed authorising separation of teenage conjoined twins where both would die if not separated but where the operation could save only one. The absence of medical information advising separation precluded such a decision in the case at hand. However, the case raises a number of difficult legal and ethical questions that judges would have to consider before authorising sacrificial separation of these or other non-infant conjoined twins.

Risk of type 1 diabetes progression in islet autoantibody-positive children can be further stratified using expression patterns of multiple genes implicated in peripheral blood lymphocyte activation and function.

There is tremendous scientific and clinical value to further improving the predictive power of autoantibodies because autoantibody-positive (AbP) children have heterogeneous rates of progression to clinical diabetes. This study explored the potential of gene expression profiles as biomarkers for risk stratification among 104 AbP subjects from the Diabetes Autoimmunity Study in the Young (DAISY) using a discovery data set based on microarray and a validation data set based on real-time RT-PCR. The microarray data identified 454 candidate genes with expression levels associated with various type 1 diabetes (T1D) progression rates. RT-PCR analyses of the top-27 candidate genes confirmed 5 genes (BACH2, IGLL3, EIF3A, CDC20, and TXNDC5) associated with differential progression and implicated in lymphocyte activation and function. Multivariate analyses of these five genes in the discovery and validation data sets identified and confirmed four multigene models (BI, ICE, BICE, and BITE, with each letter representing a gene) that consistently stratify high- and low-risk subsets of AbP subjects with hazard ratios >6 (P < 0.01). The results suggest that these genes may be involved in T1D pathogenesis and potentially serve as excellent gene expression biomarkers to predict the risk of progression to clinical diabetes for AbP subjects.

Association of pain score documentation and analgesic use in a pediatric emergency department.

OBJECTIVES: This study characterizes the association between pain score documentation and analgesic administration among pediatric emergency department patients. METHODS: This is a secondary analysis of a prospectively collected research database from an academic emergency department. Records of randomly sampled pediatric patients seen between August 2005 and October 2006 were reviewed. Pain scores from age-appropriate 0 to 10 numeric pain rating scales were abstracted (≥ 7 considered severe). Descriptive statistics and 95% confidence intervals (CIs) were calculated. RESULTS: An initial pain score was documented in 87.4% of 4514 patients enrolled, 797 (17.7%) with severe pain. Of these, 63.1% (95% CI, 59.7%-66.5%) received an analgesic, and 16.7% (95% CI, 14.2%-19.5%) received it parenterally. Initial pain score documentation was similar across age groups. Patients younger than 2 years with severe pain were less likely to receive analgesics compared with teenaged patients with severe pain (32.1%; 95% CI, 15.9%-52.3%) versus 67.6% (95% CI, 63.2%-71.7%). Of 502 patients with documented severe pain who received analgesic, 23.3% (95% CI, 19.7%-27.3%) had a second pain score documented within 2 hours of the first. Documentation of a second pain score was associated with the use of parenteral analgesic and a second dose of analgesic. CONCLUSIONS: In this population, initial pain score documentation was common, but severe pain was frequently untreated, most often in the youngest patients. Documentation of a second pain score was not common but was associated with more aggressive pain management when it occurred. Further study is needed to investigate causation and to explore interventions that increase the likelihood of severe pain being treated.

Pharmacokinetics of intravenous lorazepam in pediatric patients with and without status epilepticus.

OBJECTIVE: To evaluate the single dose pharmacokinetics of an intravenous dose of lorazepam in pediatric patients treated for status epilepticus (SE) or with a history of SE. STUDY DESIGN: Ten hospitals in the Pediatric Emergency Care Applied Research Network enlisted patients 3 months to 17 years with convulsive SE (status cohort) or for a traditional pharmacokinetics study (elective cohort). Sparse sampling was used for the status cohort, and intensive sampling was used for the elective cohort. Non-compartmental analyses were performed on the elective cohort, and served to nest compartmental population pharmacokinetics analysis for both cohorts. RESULTS: A total of 48 patients in the status cohort and 15 patients in the elective cohort were enrolled. Median age was 7 years, 2 months. The population pharmacokinetics parameters were: clearance, 1.2 mL/min/kg; half-life, 16.8 hours; and volume of distribution, 1.5 L/kg. On the basis of the pharmacokinetics model, a 0.1 mg/kg dose is expected to achieve concentrations of approximately 100 ng/mL and maintain concentrations >30 to 50 ng/mL for 6 to 12 hours. A second dose of 0.05 mg/kg would achieve desired therapeutic serum levels for approximately 12 hours without excessive sedation. Age-dependent dosing is not necessary beyond using a maximum initial dose of 4 mg. CONCLUSIONS: Lorazepam pharmacokinetics in convulsive SE is similar to earlier pharmacokinetics measured in pediatric patients with cancer, except for longer half-life, and similar to adult pharmacokinetics parameters except for increased clearance.

Separating conjoined twins: a medical and criminal law dilemma.

Surgical separation of conjoined twins that results in the death of one of the twins raises complex moral, ethical and legal issues. Of particular concern is the potential for homicide charges against doctors. In two recent cases, one in England and one in Queensland, judges declared the surgery to be lawful but the legal reasoning employed is problematical and may be difficult to apply to future conjoined twins cases, such as infant twins where one is not fully developed, or where it is proposed to separate adult twins. A determination of the threshold issue of whether there are two individual persons capable of being killed may require a reconsideration of existing legal definitions and statutory provisions. Similarly, the excuses and justifications for homicide may need to be clarified or reviewed in the context of separation of conjoined twins.

Perceived challenges to obtaining informed consent for a time-sensitive emergency department study of pediatric status epilepticus: results of two focus groups.

OBJECTIVES: The objective was to describe the perspective of research personnel on issues of informed consent in a time-sensitive clinical study under emergency circumstances. METHODS: The authors convened concurrent focus groups of research staff and investigators involved in a pharmacokinetic study of lorazepam for status epilepticus (SE). Moderators led discussion with open-ended questions on selected issues of parental consent, communication and understanding, patient assent, and comparison to other types of studies. Focus group transcripts were analyzed to identify themes and subthemes from the discussions. RESULTS: Most themes and subthemes were identified in both research staff and investigator focus groups. Focus group discussion points were categorized into three main themes: barriers to and enablers of informed consent, barriers to and enablers of actual enrollment, and overall ethical concerns about the research. Many of the issues identified were unique to emergency research. CONCLUSIONS: From the perspectives of research staff and investigators enrolling patients in a time-sensitive emergency department study, the authors identified several areas of concern that should be addressed when planning future emergency studies.

Widespread genomic signatures of natural selection in hominid evolution.

Selection acting on genomic functional elements can be detected by its indirect effects on population diversity at linked neutral sites. To illuminate the selective forces that shaped hominid evolution, we analyzed the genomic distributions of human polymorphisms and sequence differences among five primate species relative to the locations of conserved sequence features. Neutral sequence diversity in human and ancestral hominid populations is substantially reduced near such features, resulting in a surprisingly large genome average diversity reduction due to selection of 19-26% on the autosomes and 12-40% on the X chromosome. The overall trends are broadly consistent with "background selection" or hitchhiking in ancestral populations acting to remove deleterious variants. Average selection is much stronger on exonic (both protein-coding and untranslated) conserved features than non-exonic features. Long term selection, rather than complex speciation scenarios, explains the large intragenomic variation in human/chimpanzee divergence. Our analyses reveal a dominant role for selection in shaping genomic diversity and divergence patterns, clarify hominid evolution, and provide a baseline for investigating specific selective events.

Use of shotgun proteomics for the identification, confirmation, and correction of C. elegans gene annotations.

We describe a general mass spectrometry-based approach for gene annotation of any organism and demonstrate its effectiveness using the nematode Caenorhabditis elegans. We detected 6779 C. elegans proteins (67,047 peptides), including 384 that, although annotated in WormBase WS150, lacked cDNA or other prior experimental support. We also identified 429 new coding sequences that were unannotated in WS150. Nearly half (192/429) of the new coding sequences were confirmed with RT-PCR data. Thirty-three (approximately 8%) of the new coding sequences had been predicted to be pseudogenes, 151 (approximately 35%) reveal apparent errors in gene models, and 245 (57%) appear to be novel genes. In addition, we verified 6010 exon-exon splice junctions within existing WormBase gene models. Our work confirms that mass spectrometry is a powerful experimental tool for annotating sequenced genomes. In addition, the collection of identified peptides should facilitate future proteomics experiments targeted at specific proteins of interest.

The epidemiology of emergency medical services use by children: an analysis of the National Hospital Ambulatory Medical Care Survey.

OBJECTIVE: There is an absence of nationally representative data describing pediatric patients who use emergency medical services (EMS) and the factors associated with EMS use by children. This study characterizes pediatric emergency department (ED) visits for which the patient arrived by EMS and identifies factors associated with those visits using a nationally representative database. METHODS: A secondary analysis of the ED component of the 1997-2000 National Hospital Ambulatory Medical Care Survey was performed. The dependent variable was the mode of arrival to the ED (EMS vs. not EMS), and independent variables were grouped into four domains: demographic, clinical, system, and service characteristics. Bivariate analyses and multivariate logistic regression analyses were conducted. RESULTS: There were 110.9 million ED visits by children aged<19 years between 1997 and 2000. Pediatric patients constituted 27.3% of all ED visits during this time, and 7.9 million (7.1%) of these patients arrived via EMS. Pediatric patients represented 13% of all EMS transports. The annual EMS utilization rate by children was 26 per 1,000, compared with 66 per 1,000 in the adult population (p<0.001). Sixteen percent of children transported by EMS were admitted to the hospital. Sixty-two percent of pediatric patients arriving at the ED by EMS were transported as a result of injury or poisoning. Characteristics significantly associated with arrival by EMS in the final multivariate model included demographic (age, African American race, urban residence), clinical (need for greater immediacy of care, illnesses associated with certain diagnoses), and service (greater number of diagnostic services) variables. CONCLUSIONS: Pediatric patients transported by EMS are more likely to have injuries and poisoning, and have higher-acuity illness than those arriving at the ED by other means. The epidemiology of pediatric EMS use may have important operational, training, and public health implications and requires further study.