International Journal of Injury Control and Safety Promotion
ISSN: 1745-7300 (Print) 1745-7319 (Online) Journal homepage: http://www.tandfonline.com/loi/nics20
Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use Folafoluwa O. Odetola & Achamyeleh Gebremariam To cite this article: Folafoluwa O. Odetola & Achamyeleh Gebremariam (2015) Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use, International Journal of Injury Control and Safety Promotion, 22:3, 260-266, DOI: 10.1080/17457300.2014.925937 To link to this article: http://dx.doi.org/10.1080/17457300.2014.925937
Published online: 18 Jun 2014.
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Date: 10 November 2015, At: 18:26
International Journal of Injury Control and Safety Promotion, 2015 Vol. 22, No. 3, 260 266, http://dx.doi.org/10.1080/17457300.2014.925937
Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use Folafoluwa O. Odetolaa,b* and Achamyeleh Gebremariamb a
Department of Pediatrics and Communicable Diseases, Division of Pediatric Critical Care Medicine, University of Michigan Health System, Ann Arbor, MI, USA; bDepartment of Pediatrics and Communicable Diseases, Child Health Evaluation and Research Unit, University of Michigan Health System, Ann Arbor, MI, USA
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(Received 25 September 2013; accepted 5 May 2014) Trauma is the leading cause of mortality and morbidity among children in the USA. To examine the variation in the epidemiology and patterns of visits to emergency departments (EDs), and test the hypothesis that children evaluated at trauma centre EDs will have higher injury severity and a higher likelihood of hospitalisation versus those evaluated at nontrauma centre EDs, we analysed a national database of all injured children aged 0 20 years evaluated at US EDs in 2009. Childhood injuries are a frequent cause of visits to US EDs, with a national point prevalence of 620 cases per 10,000 children aged 0 20 years. Epidemiology of childhood injuries in the USA is significant for male gender preponderance, significant seasonal and geographical variation, and disproportionately more frequent injury to the extremities than other sites of the body. National hospital resource use was significant, with greater burden borne by trauma centres which disproportionately provided care to the most severely injured children. Keywords: injuries; emergency treatment; hospital charges
Introduction Trauma is the leading cause of mortality and morbidity among children in the USA (Schafermeyer, 1993). Substantial costs (Danseco, Miller, & Spicer, 2000; Malek, Chang, Gallagher, & Guyer, 1991) and tangible psychological and emotional burden (Aitken, et al., 2009) are borne by survivors and their caregivers. In areas without specialised paediatric emergency and trauma care services, outcomes of paediatric injury are adversely affected (Ramenofsky, Luterman, Quindlen, Riddick, L., & Curreri, 1984), and deleterious outcomes have been reported for injured children without proper triage to a paediatric trauma centre (Hartman, et al., 2008; Odetola, Mann, Hansen, Patrick, & Bratton, 2010; Potoka, et al., 2000). Given the impact of appropriate access to definitive trauma care on patient outcomes, it is important to determine recent patterns of triage of injured children to emergency departments (EDs) in the USA, and describe the recent national epidemiology of hospitalisations for paediatric injuries to highlight opportunities for injurymitigation efforts. The study was conducted to describe recent paediatric injury patterns across the USA and the national epidemiology of paediatric injuries evaluated in US EDs. Furthermore, variation in hospital resource use among children hospitalised via the EDs for the care of paediatric trauma was investigated. It was *Corresponding author. Email: [email protected] Ó 2014 Taylor & Francis
hypothesised that more injured children will be hospitalised via the ED to trauma centres and that these children will have higher injury severity and accompany higher hospital resource use compared with injured children hospitalised at non-trauma centres.
Materials and methods Study design We conducted a secondary analysis of data on injured children 0 20 years old, using the 2009 version of the Nationwide Emergency Department Sample (NEDS). Developed by the Agency for Healthcare Research and Quality, NEDS is the largest all-payer ED database in the USA, with information on ED visits that may or may not result in hospitalisation (NEDS, 2009). It includes information on patient and hospital characteristics, diagnosis and procedure codes, ED discharge status, type of payer, and ED charges. For hospitalised patients, the duration of hospitalisation and total hospital charges are also available. The 2009 NEDS includes 29 million ED visits from 964 hospital-based EDs in 29 US states, and approximates a 20% stratified sample of US hospital-based EDs. Each record in the database includes a sample weight for generation of nationally representative estimates.
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International Journal of Injury Control and Safety Promotion Study sample and variable identification
Statistical analysis
Children with trauma diagnoses evaluated in the EDs in 2009 were identified using International Classification of Diseases, ninth revision, clinical modification (ICD-9CM) primary or secondary diagnosis codes indicative of trauma (800 959), as previously described (Guice, Cassidy, & Oldham, 2007; Odetola, Miller, Davis, & Bratton, 2005). To ascertain injury severity, each record was coded for injury severity scores (ISSs) using ICDMAP-90 (MacKenzie & Sacco, 1997). ISS values range from 1 to 75, with higher values signifying higher severity (Baker, ONeill, Haddon, & Long, 1974). ISS was categorised into major injuries (ISS > 15) and minor injuries (ISS 15), as previously reported in the literature, to delineate levels of injury severity (Champion et al., 1990). To highlight differences in ED visits and hospitalisations according to injury severity, a further classification scheme ( 20 years, were excluded. Anatomical sites of injury were identified via the creation of a Barell Injury Diagnosis Matrix (Centers for Disease Control and Prevention, 2010), while mechanisms of injury were identified using ICD-9CM external cause of injury codes grouped using the framework recommended for presenting injury morbidity data (Centers for Disease Control and Prevention, 2011). Patient characteristics studied were age, gender, discharge quarter, payer type, mechanisms of injury, anatomical sites of injury, ISS, ED survival status, and destinations after ED discharge. Among children hospitalised from the ED, the duration of hospitalisation, use of invasive medical devices, and total hospital charges were determined. Hospital characteristics of study interest included geographical characteristics (census region, and metropolitan versus non-metropolitan location) and hospital ownership. Metropolitan status was determined using urban influence codes to signify the urban rural designation of the county where the hospital was located (Baer, Johnson-Webb, & Gesler, 1997). Trauma centre designation was based on information from the Trauma Information Exchange Program database, a national inventory of US trauma centres (HCUP NEDS Description of Data Elements, 2008). Among hospitalised patients, the use of invasive medical devices was identified using ICD-9-CM procedure codes. The devices (ICD-9-CM codes) were mechanical ventilators (96.7), arterial catheters (38.91), central venous catheters (89.62, 38.93, 38.95, 38.94), and intracranial pressure monitors (01.10). Outcomes of interest: Among hospitalised children, measures of resource use were investigated including length of hospital stay and total hospital charges.
Data were analysed in two steps:
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(1) National prevalence of paediatric trauma evaluated at US EDs was determined from the number of ED visits for paediatric trauma, expressed per 10,000 children aged 0 20 years, using 2009 US census estimates (US Census Bureau, 2012). Subsequently, patient and hospital characteristics for the visits were compared according to the trauma centre status of the hospital, using chi-square tests. (2) Among hospitalisations, patient and hospital characteristics and use of invasive medical devices were described and compared according to the trauma centre status of the hospital using chisquare tests. Use of invasive medical devices was investigated as a proxy for overall injury severity and a probable need for intensive care. The mean length of hospital stay and hospital charges were compared using the student t-test. The number of hospitalisations in the results was unweighted, while all effect estimates and the accompanying 95% confidence intervals (CIs) were calculated using sample weights to account for the complex survey design, using Stata version 10 for Windows (Stata Corporation; College Station, TX). A twosided alpha level of 0.05 was used as the threshold for statistical significance. The institutional review board at the University of Michigan, School of Medicine, granted an exempt status to the study.
Results Characteristics of paediatric trauma ED visits in the USA In 2009, of the estimated 33 million visits to US EDs by children aged 0 20 years, 5.4 million were for the evaluation of trauma, a prevalence of 620 per 10,000 children aged 0 20 years in the USA. Importantly, two-thirds of ED visits for paediatric injuries occurred at non-trauma centres. Boys comprised 62% of all visits, and 57% of visits were by children younger than six years (Table 1). Most injuries were caused, in descending frequency, by non-transport-related accidents (cuts6 pierce, strike, firearms, machinery), falls, and motor vehicle-related accidents (Figure 1). Injuries mostly involved the extremities (59%) and the head (32%) (Table 1). The mean (95% CI) ISS for children was higher at trauma centre versus non-trauma centre EDs (2.6 [2.5 2.6] vs. 2.1 [2.1 2.2]; p < .01). Also, while two-thirds of children with minor injuries were evaluated at non-trauma centre EDs, 76% of the major injuries were treated at trauma centre EDs.
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Table 1. Patient and hospital characteristics of emergency department visits by trauma centre status.
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Characteristic (%) Male gender Age in years 15 Payer type Private6 health maintenance organisation Medicaid Self6 no charge Hospital in metropolitan county Census region Northeast Midwest South West Government ownership
Overall (n D 1,215,741)
Trauma centre emergency department (n D 402,084)
Non-trauma centre emergency department (n D 813,657)
p
62
63
62
< .01
31 26 19 23 1
31 24 18 25 2
32 26 19 22 1
< .01
59 32 6 3 1
56 35 6 3 1
60 31 6 3 < 0.3
< .01
53 28 19 80
51 33 16 92
51 33 16 73
.95
20 26 35 19 73
20 32 28 20 98
20 22 39 19 59
< .01
< .01 < .01
< .01
Among children with major injuries, there was a stepwise increase in visits to trauma centres with greater injury severity (Figure 2). More children at trauma centre EDs had co-morbidities compared with those at non-trauma centre EDs (10% vs. 8%, p < .01). Hospitals in the south had the highest frequency of ED visits for childhood injuries compared to other census regions (Table 1), and most (80%) ED visits occurred in hospitals within metropolitan counties. Commercial
health care plans bore the largest burden of insurance coverage for ED visits (Table 1). A majority (94%) of ED visits for paediatric trauma culminated in discharge to home. Hospitalisation occurred in 3%, transfer to other health care facilities in 1%, while 2% of ED visits did not result in admission to the treating hospital, with unknown discharge destinations. Only 0.1% of all ED visits ended in fatality. Hospitalisation occurred more often from trauma centre (6% vs. 1%) versus nontrauma centre EDs.
Figure 1. Mechanisms of childhood injuries evaluated in US emergency departments in 2009.
Figure 2. Distribution of injury severity of emergency department visits by hospital type.
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International Journal of Injury Control and Safety Promotion Characteristics of national paediatric trauma hospitalisations from the ED In 2009, injuries accounted for an estimated 129,609 hospitalisations nationally. Most (71%) of the hospitalised children were boys, and two-thirds were younger than six years (Table 2). Injuries were sustained primarily from motor vehicle accidents and falls (Figure 3). Extremities were injured in 44% of hospitalisations, followed in descending order by head, torso, and spine injuries (Table 2). The mean (95% CI) ISS for hospitalised children was higher at trauma versus non-trauma centres (9.6 [9.0 10.1] vs. 5.9 [5.7 6.2]; p < .01). Furthermore, children hospitalised at trauma centres were more likely to have major injuries versus those hospitalised at non-trauma centres (22% vs. 9%; p < .01). Among hospitalisations with major injuries, 92% were at trauma centres, and more children with traumatic head injuries were hospitalised at trauma versus non-trauma centres (Table 2). There was a significant step-up in the proportion of hospitalisations to trauma centres as injury severity increased (Figure 4). Thirty-five per cent of all hospitalised children had comorbidities, occurring more frequently at trauma versus non-trauma centres (37% vs. 30%, p < .01).
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Figure 3. Mechanisms of childhood injuries among US children hospitalised for trauma care in 2009.
Paediatric trauma hospitalisations occurred more often during the warm middle half of the calendar year (April September; 56%) compared to the first (January March; 21%) or fourth quarter (October December; 22%); p 15) received ED care at trauma centres. The study findings corroborate the prior-reported epidemiology of paediatric injuries in that boys were more
often injured than girls, and injuries to the extremities and head were most prevalent (Guice, Cassidy, & Oldham, 2007). They also corroborate recent analysis of paediatric trauma centre hospitalisations which revealed motor vehicle crashes as the most frequent trigger for hospitalisations, followed distantly by falls (Haider et al., 2011). The current study observed an important difference between the predominant mechanism of injuries treated in the ED versus injuries which prompt hospitalisation. Injuries evaluated in the ED were most often triggered by nontransport-related sources (cuts, strike, firearms, and machinery), while injury hospitalisations were largely from falls and motor vehicle accidents which likely cause more extensive bodily injuries. The study findings highlight the critical need to identify injury prevention opportunities that target motor vehicle accidents and falls; however, sustenance of most injuries in the first five years of life suggests the need to start prevention efforts early in childhood. Also, given the various mechanisms of injuries that result in hospitalisations, prevention efforts will need to target multiple settings, including the home, day care and school, and during travel (Conner et al., 2010; Gardner, Smith, Chany, Fernandez, & Mckenzie, 2007; Harris, Rochette, Smith, 2011; Vollman et al., 2005; Vollman, Witsaman, Comstock, & Smith,2009). Prevention efforts will likely need to target boys disproportionately, since they appear to be more often injured than girls, and, with the preponderance of injury hospitalisations during the warm months, will also need to be seasonally adjusted. The south had the highest frequency of injuries that necessitated ED care and subsequent hospitalisation, more often at non-trauma centres than at trauma centres. It is unknown if such geographical variation reflects disparate access to trauma centres in the southern USA versus other US regions or not. Also, the pattern of visits does not account for injury severity and other potential confounders, which limits the ability to draw any inferences regarding the appropriateness, or otherwise, of the ED visits and hospitalisations. Further study should elucidate any impact of such geographical variation in health care delivery patterns on health outcomes and hospital resource use after paediatric trauma. Trauma systems are organised on the premise that timely receipt of definitive trauma care within specialised
Table 3. Invasive medical device use by trauma centre status. Characteristic (%) Mechanical ventilation Central venous catheterisation Arterial catheterisation
Overall (n D 27,802)
Trauma centre (n D 22,106)
Non-trauma centre (n D 5696)
p
7 3 1
9 3 2
2 1 0
< .01 < .01 < .01
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International Journal of Injury Control and Safety Promotion trauma centres might improve outcomes (Hulka et al., 1997; MacKenzie et al., 2006; Potoka, Schall, & Ford, 2001). Therefore, guidelines for field triage of injuries recommend triage of children to paediatric-capable trauma centres (Sasser et al., 2012; Sasser et al., 2009). We hypothesised that among children with injuries requiring ED visits, patients evaluated at trauma centres will have higher injury severity and a higher likelihood of hospitalisation versus those evaluated at non-trauma centres. The finding that over two-thirds of injured children were evaluated at non-trauma centre EDs therefore indicates persistence of the previously described discrepancy between actual clinical practice and guidelines (Densmore, Lim, Oldham, & Guice, 2006; Segui-Gomez et al., 2003). While a plausible explanation for this finding could be the paucity of specialised trauma centres nationally, it also raises the need to ascertain if these ED visits and subsequent hospitalisations reflect triage patterns based on patient injury severity. It was therefore instructive to observe that, although two-thirds of all ED visits for childhood injuries occurred at non-trauma centre EDs, approximately four of every five major injuries were evaluated within trauma centre EDs, highlighting preferential triage of the most severely injured children to trauma centres. Children with head injuries and hence higher injury severity were hospitalised more often within trauma versus non-trauma centres, with the converse being true for extremity injuries which accrue lower overall injury severity. Evaluation of resource use among hospitalised injured children revealed a higher use of invasive medical devices, marginally longer stay, and higher hospital charges for children who received care at trauma versus nontrauma centres. A higher use of invasive medical devices and longer hospitalisation within trauma centres likely reflects preponderance of children with more severe injuries at trauma versus non-trauma centres. Higher hospital charges for care within trauma centres, however, corroborates prior studies which reported similar higher costs of care in trauma versus non-trauma centres (Goldfarb, Bazzoli, & Coffey, 1996; MacKenzie et al., 2010). While it might be surmised that higher charges for hospitalisations at trauma versus non-trauma centres could be attributed to higher injury severity and extensive medical rehabilitation for these patients, future studies should address the cost-effectiveness of paediatric trauma care accounting for variation in injury severity by type of hospital. The study findings should be interpreted in light of certain limitations. The study was limited by inability to accurately separate paediatric trauma centres from adult trauma centres. It was therefore not possible to ascertain any impact of specific paediatric trauma centre care on resource use and outcomes, compared with non-trauma centres. Also, inter-hospital transfer between EDs and its
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potential impact on patterns of hospital resource use could not be ascertained. The strengths of the study include a large sample size, a population-based study design that addressed trauma care within a broad spectrum of EDs nationally, and indepth analysis of the national prevalence and patterns of paediatric injuries, all lending credence to the generalisability of the study findings. In conclusion, childhood injuries are a frequent cause of ED visits and are associated with significant demographic, geographical, and seasonal variation in their occurrence. Childhood injuries accrue substantial hospital resource use, borne largely by trauma centres where the most severely injured children receive care. The study findings are important for future research geared towards injury mitigation and an improved understanding of factors that influence hospital resource use and clinical outcomes after paediatric trauma.
Competing interests The authors have no financial relationships relevant to this article to disclose. The authors have no conflicts of interest relevant to this article to disclose. Both authors had full access to all the data and take full responsibility for the integrity of the data and accuracy of data analysis.
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Odetola, F.O., Mann, N.C., Hansen, K.W., Patrick, S., & Bratton, S.L. (2010). Source of admission and outcomes for critically injured children in the mountain states. Archives of Pediatrics & Adolescent Medicine, 164, 277 282. Odetola, F.O., Miller, W.C., Davis, M.M., & Bratton, S.L. (2005). The relationship between the location of pediatric intensive care unit facilities and child death from trauma: A countylevel ecologic study. Journal of Pediatrics, 147, 74 77. Potoka, D.A., Schall, L.C., & Ford, H.R. (2001). Improved functional outcome for severely injured children treated at pediatric trauma centers. Journal of Trauma, 51, 824 832. Potoka, D.A., Schall, L.C., Gardner, M.J., Stafford, P.W., Peitzman, A.B., & Ford, H.R. (2000). Impact of pediatric trauma centers on mortality in a statewide system. Journal of Trauma, 49, 237 245. Ramenofsky, M.L., Luterman, A., Quindlen, E., Riddick, L., & Curreri, P.W. (1984). Maximum survival in pediatric trauma: The ideal system. Journal of Trauma, 24, 818 822. Sasser, S.M., Hunt, R.C., Faul, M., Sugerman, D., Pearson, W.S., Dulski, T., . . . Lerner, E.B.; Centers for Disease Control and Prevention (CDC). (2012). Guidelines for field triage of injured patients: Recommendations of the National Expert Panel on Field Triage, 2011. MMWR Recommendations and Reports, 61(RR01), 1 20. Sasser, S.M., Hunt, R.C., Sullivent, E.E., Wald, M.M., Mitchko, J., Jurkovich, G.J., . . . Sattin, R.W.; National Expert Panel on Field Triage, Centers for Disease Control and Prevention (CDC). (2009). Guidelines for field triage of injured patients: Recommendations of the National Expert Panel on Field Triage. MMWR Recommendations and Reports, 58, 1 35. Erratum in: MMWR Recommendations and Reports, 58, 172 (2009). Schafermeyer, R. (1993). Pediatric trauma. Emergency Medicine Clinics of North America, 11, 187 205. Segui-Gomez, M., Chang, D.C., Paidas, C.N., Jurkovich, G.J., Mackenzie, E.J., & Rivara, F.P. (2003). Pediatric trauma care: An overview of pediatric trauma systems and their practices in 18 US states. Journal of Pediatric Surgery, 38, 1162 1169. US Census Bureau. (2012). Statistical abstract of the United States (131st ed.). Washington, DC; https://www.census. gov/compendia/statab Vollman, D., Khosla, K., Shields, B.J., Beeghly, B.C., Bonsu, B., & Smith, G.A. (2005). Lawn mower-related injuries to children. Journal of Trauma, 59, 724 428. Vollman, D., Witsaman, R., Comstock, R.D., & Smith, G.A. (2009). Epidemiology of playground equipment-related injuries to children in the United States, 1996 2005. Clinical Pediatrics (Philadelphia), 48, 66 71.
ISSN: 1745-7300 (Print) 1745-7319 (Online) Journal homepage: http://www.tandfonline.com/loi/nics20
Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use Folafoluwa O. Odetola & Achamyeleh Gebremariam To cite this article: Folafoluwa O. Odetola & Achamyeleh Gebremariam (2015) Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use, International Journal of Injury Control and Safety Promotion, 22:3, 260-266, DOI: 10.1080/17457300.2014.925937 To link to this article: http://dx.doi.org/10.1080/17457300.2014.925937
Published online: 18 Jun 2014.
Submit your article to this journal
Article views: 55
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=nics20 Download by: [Deakin University Library]
Date: 10 November 2015, At: 18:26
International Journal of Injury Control and Safety Promotion, 2015 Vol. 22, No. 3, 260 266, http://dx.doi.org/10.1080/17457300.2014.925937
Paediatric trauma in the USA: patterns of emergency department visits and associated hospital resource use Folafoluwa O. Odetolaa,b* and Achamyeleh Gebremariamb a
Department of Pediatrics and Communicable Diseases, Division of Pediatric Critical Care Medicine, University of Michigan Health System, Ann Arbor, MI, USA; bDepartment of Pediatrics and Communicable Diseases, Child Health Evaluation and Research Unit, University of Michigan Health System, Ann Arbor, MI, USA
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(Received 25 September 2013; accepted 5 May 2014) Trauma is the leading cause of mortality and morbidity among children in the USA. To examine the variation in the epidemiology and patterns of visits to emergency departments (EDs), and test the hypothesis that children evaluated at trauma centre EDs will have higher injury severity and a higher likelihood of hospitalisation versus those evaluated at nontrauma centre EDs, we analysed a national database of all injured children aged 0 20 years evaluated at US EDs in 2009. Childhood injuries are a frequent cause of visits to US EDs, with a national point prevalence of 620 cases per 10,000 children aged 0 20 years. Epidemiology of childhood injuries in the USA is significant for male gender preponderance, significant seasonal and geographical variation, and disproportionately more frequent injury to the extremities than other sites of the body. National hospital resource use was significant, with greater burden borne by trauma centres which disproportionately provided care to the most severely injured children. Keywords: injuries; emergency treatment; hospital charges
Introduction Trauma is the leading cause of mortality and morbidity among children in the USA (Schafermeyer, 1993). Substantial costs (Danseco, Miller, & Spicer, 2000; Malek, Chang, Gallagher, & Guyer, 1991) and tangible psychological and emotional burden (Aitken, et al., 2009) are borne by survivors and their caregivers. In areas without specialised paediatric emergency and trauma care services, outcomes of paediatric injury are adversely affected (Ramenofsky, Luterman, Quindlen, Riddick, L., & Curreri, 1984), and deleterious outcomes have been reported for injured children without proper triage to a paediatric trauma centre (Hartman, et al., 2008; Odetola, Mann, Hansen, Patrick, & Bratton, 2010; Potoka, et al., 2000). Given the impact of appropriate access to definitive trauma care on patient outcomes, it is important to determine recent patterns of triage of injured children to emergency departments (EDs) in the USA, and describe the recent national epidemiology of hospitalisations for paediatric injuries to highlight opportunities for injurymitigation efforts. The study was conducted to describe recent paediatric injury patterns across the USA and the national epidemiology of paediatric injuries evaluated in US EDs. Furthermore, variation in hospital resource use among children hospitalised via the EDs for the care of paediatric trauma was investigated. It was *Corresponding author. Email: [email protected] Ó 2014 Taylor & Francis
hypothesised that more injured children will be hospitalised via the ED to trauma centres and that these children will have higher injury severity and accompany higher hospital resource use compared with injured children hospitalised at non-trauma centres.
Materials and methods Study design We conducted a secondary analysis of data on injured children 0 20 years old, using the 2009 version of the Nationwide Emergency Department Sample (NEDS). Developed by the Agency for Healthcare Research and Quality, NEDS is the largest all-payer ED database in the USA, with information on ED visits that may or may not result in hospitalisation (NEDS, 2009). It includes information on patient and hospital characteristics, diagnosis and procedure codes, ED discharge status, type of payer, and ED charges. For hospitalised patients, the duration of hospitalisation and total hospital charges are also available. The 2009 NEDS includes 29 million ED visits from 964 hospital-based EDs in 29 US states, and approximates a 20% stratified sample of US hospital-based EDs. Each record in the database includes a sample weight for generation of nationally representative estimates.
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International Journal of Injury Control and Safety Promotion Study sample and variable identification
Statistical analysis
Children with trauma diagnoses evaluated in the EDs in 2009 were identified using International Classification of Diseases, ninth revision, clinical modification (ICD-9CM) primary or secondary diagnosis codes indicative of trauma (800 959), as previously described (Guice, Cassidy, & Oldham, 2007; Odetola, Miller, Davis, & Bratton, 2005). To ascertain injury severity, each record was coded for injury severity scores (ISSs) using ICDMAP-90 (MacKenzie & Sacco, 1997). ISS values range from 1 to 75, with higher values signifying higher severity (Baker, ONeill, Haddon, & Long, 1974). ISS was categorised into major injuries (ISS > 15) and minor injuries (ISS 15), as previously reported in the literature, to delineate levels of injury severity (Champion et al., 1990). To highlight differences in ED visits and hospitalisations according to injury severity, a further classification scheme ( 20 years, were excluded. Anatomical sites of injury were identified via the creation of a Barell Injury Diagnosis Matrix (Centers for Disease Control and Prevention, 2010), while mechanisms of injury were identified using ICD-9CM external cause of injury codes grouped using the framework recommended for presenting injury morbidity data (Centers for Disease Control and Prevention, 2011). Patient characteristics studied were age, gender, discharge quarter, payer type, mechanisms of injury, anatomical sites of injury, ISS, ED survival status, and destinations after ED discharge. Among children hospitalised from the ED, the duration of hospitalisation, use of invasive medical devices, and total hospital charges were determined. Hospital characteristics of study interest included geographical characteristics (census region, and metropolitan versus non-metropolitan location) and hospital ownership. Metropolitan status was determined using urban influence codes to signify the urban rural designation of the county where the hospital was located (Baer, Johnson-Webb, & Gesler, 1997). Trauma centre designation was based on information from the Trauma Information Exchange Program database, a national inventory of US trauma centres (HCUP NEDS Description of Data Elements, 2008). Among hospitalised patients, the use of invasive medical devices was identified using ICD-9-CM procedure codes. The devices (ICD-9-CM codes) were mechanical ventilators (96.7), arterial catheters (38.91), central venous catheters (89.62, 38.93, 38.95, 38.94), and intracranial pressure monitors (01.10). Outcomes of interest: Among hospitalised children, measures of resource use were investigated including length of hospital stay and total hospital charges.
Data were analysed in two steps:
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(1) National prevalence of paediatric trauma evaluated at US EDs was determined from the number of ED visits for paediatric trauma, expressed per 10,000 children aged 0 20 years, using 2009 US census estimates (US Census Bureau, 2012). Subsequently, patient and hospital characteristics for the visits were compared according to the trauma centre status of the hospital, using chi-square tests. (2) Among hospitalisations, patient and hospital characteristics and use of invasive medical devices were described and compared according to the trauma centre status of the hospital using chisquare tests. Use of invasive medical devices was investigated as a proxy for overall injury severity and a probable need for intensive care. The mean length of hospital stay and hospital charges were compared using the student t-test. The number of hospitalisations in the results was unweighted, while all effect estimates and the accompanying 95% confidence intervals (CIs) were calculated using sample weights to account for the complex survey design, using Stata version 10 for Windows (Stata Corporation; College Station, TX). A twosided alpha level of 0.05 was used as the threshold for statistical significance. The institutional review board at the University of Michigan, School of Medicine, granted an exempt status to the study.
Results Characteristics of paediatric trauma ED visits in the USA In 2009, of the estimated 33 million visits to US EDs by children aged 0 20 years, 5.4 million were for the evaluation of trauma, a prevalence of 620 per 10,000 children aged 0 20 years in the USA. Importantly, two-thirds of ED visits for paediatric injuries occurred at non-trauma centres. Boys comprised 62% of all visits, and 57% of visits were by children younger than six years (Table 1). Most injuries were caused, in descending frequency, by non-transport-related accidents (cuts6 pierce, strike, firearms, machinery), falls, and motor vehicle-related accidents (Figure 1). Injuries mostly involved the extremities (59%) and the head (32%) (Table 1). The mean (95% CI) ISS for children was higher at trauma centre versus non-trauma centre EDs (2.6 [2.5 2.6] vs. 2.1 [2.1 2.2]; p < .01). Also, while two-thirds of children with minor injuries were evaluated at non-trauma centre EDs, 76% of the major injuries were treated at trauma centre EDs.
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Table 1. Patient and hospital characteristics of emergency department visits by trauma centre status.
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Characteristic (%) Male gender Age in years 15 Payer type Private6 health maintenance organisation Medicaid Self6 no charge Hospital in metropolitan county Census region Northeast Midwest South West Government ownership
Overall (n D 1,215,741)
Trauma centre emergency department (n D 402,084)
Non-trauma centre emergency department (n D 813,657)
p
62
63
62
< .01
31 26 19 23 1
31 24 18 25 2
32 26 19 22 1
< .01
59 32 6 3 1
56 35 6 3 1
60 31 6 3 < 0.3
< .01
53 28 19 80
51 33 16 92
51 33 16 73
.95
20 26 35 19 73
20 32 28 20 98
20 22 39 19 59
< .01
< .01 < .01
< .01
Among children with major injuries, there was a stepwise increase in visits to trauma centres with greater injury severity (Figure 2). More children at trauma centre EDs had co-morbidities compared with those at non-trauma centre EDs (10% vs. 8%, p < .01). Hospitals in the south had the highest frequency of ED visits for childhood injuries compared to other census regions (Table 1), and most (80%) ED visits occurred in hospitals within metropolitan counties. Commercial
health care plans bore the largest burden of insurance coverage for ED visits (Table 1). A majority (94%) of ED visits for paediatric trauma culminated in discharge to home. Hospitalisation occurred in 3%, transfer to other health care facilities in 1%, while 2% of ED visits did not result in admission to the treating hospital, with unknown discharge destinations. Only 0.1% of all ED visits ended in fatality. Hospitalisation occurred more often from trauma centre (6% vs. 1%) versus nontrauma centre EDs.
Figure 1. Mechanisms of childhood injuries evaluated in US emergency departments in 2009.
Figure 2. Distribution of injury severity of emergency department visits by hospital type.
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International Journal of Injury Control and Safety Promotion Characteristics of national paediatric trauma hospitalisations from the ED In 2009, injuries accounted for an estimated 129,609 hospitalisations nationally. Most (71%) of the hospitalised children were boys, and two-thirds were younger than six years (Table 2). Injuries were sustained primarily from motor vehicle accidents and falls (Figure 3). Extremities were injured in 44% of hospitalisations, followed in descending order by head, torso, and spine injuries (Table 2). The mean (95% CI) ISS for hospitalised children was higher at trauma versus non-trauma centres (9.6 [9.0 10.1] vs. 5.9 [5.7 6.2]; p < .01). Furthermore, children hospitalised at trauma centres were more likely to have major injuries versus those hospitalised at non-trauma centres (22% vs. 9%; p < .01). Among hospitalisations with major injuries, 92% were at trauma centres, and more children with traumatic head injuries were hospitalised at trauma versus non-trauma centres (Table 2). There was a significant step-up in the proportion of hospitalisations to trauma centres as injury severity increased (Figure 4). Thirty-five per cent of all hospitalised children had comorbidities, occurring more frequently at trauma versus non-trauma centres (37% vs. 30%, p < .01).
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Figure 3. Mechanisms of childhood injuries among US children hospitalised for trauma care in 2009.
Paediatric trauma hospitalisations occurred more often during the warm middle half of the calendar year (April September; 56%) compared to the first (January March; 21%) or fourth quarter (October December; 22%); p 15) received ED care at trauma centres. The study findings corroborate the prior-reported epidemiology of paediatric injuries in that boys were more
often injured than girls, and injuries to the extremities and head were most prevalent (Guice, Cassidy, & Oldham, 2007). They also corroborate recent analysis of paediatric trauma centre hospitalisations which revealed motor vehicle crashes as the most frequent trigger for hospitalisations, followed distantly by falls (Haider et al., 2011). The current study observed an important difference between the predominant mechanism of injuries treated in the ED versus injuries which prompt hospitalisation. Injuries evaluated in the ED were most often triggered by nontransport-related sources (cuts, strike, firearms, and machinery), while injury hospitalisations were largely from falls and motor vehicle accidents which likely cause more extensive bodily injuries. The study findings highlight the critical need to identify injury prevention opportunities that target motor vehicle accidents and falls; however, sustenance of most injuries in the first five years of life suggests the need to start prevention efforts early in childhood. Also, given the various mechanisms of injuries that result in hospitalisations, prevention efforts will need to target multiple settings, including the home, day care and school, and during travel (Conner et al., 2010; Gardner, Smith, Chany, Fernandez, & Mckenzie, 2007; Harris, Rochette, Smith, 2011; Vollman et al., 2005; Vollman, Witsaman, Comstock, & Smith,2009). Prevention efforts will likely need to target boys disproportionately, since they appear to be more often injured than girls, and, with the preponderance of injury hospitalisations during the warm months, will also need to be seasonally adjusted. The south had the highest frequency of injuries that necessitated ED care and subsequent hospitalisation, more often at non-trauma centres than at trauma centres. It is unknown if such geographical variation reflects disparate access to trauma centres in the southern USA versus other US regions or not. Also, the pattern of visits does not account for injury severity and other potential confounders, which limits the ability to draw any inferences regarding the appropriateness, or otherwise, of the ED visits and hospitalisations. Further study should elucidate any impact of such geographical variation in health care delivery patterns on health outcomes and hospital resource use after paediatric trauma. Trauma systems are organised on the premise that timely receipt of definitive trauma care within specialised
Table 3. Invasive medical device use by trauma centre status. Characteristic (%) Mechanical ventilation Central venous catheterisation Arterial catheterisation
Overall (n D 27,802)
Trauma centre (n D 22,106)
Non-trauma centre (n D 5696)
p
7 3 1
9 3 2
2 1 0
< .01 < .01 < .01
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International Journal of Injury Control and Safety Promotion trauma centres might improve outcomes (Hulka et al., 1997; MacKenzie et al., 2006; Potoka, Schall, & Ford, 2001). Therefore, guidelines for field triage of injuries recommend triage of children to paediatric-capable trauma centres (Sasser et al., 2012; Sasser et al., 2009). We hypothesised that among children with injuries requiring ED visits, patients evaluated at trauma centres will have higher injury severity and a higher likelihood of hospitalisation versus those evaluated at non-trauma centres. The finding that over two-thirds of injured children were evaluated at non-trauma centre EDs therefore indicates persistence of the previously described discrepancy between actual clinical practice and guidelines (Densmore, Lim, Oldham, & Guice, 2006; Segui-Gomez et al., 2003). While a plausible explanation for this finding could be the paucity of specialised trauma centres nationally, it also raises the need to ascertain if these ED visits and subsequent hospitalisations reflect triage patterns based on patient injury severity. It was therefore instructive to observe that, although two-thirds of all ED visits for childhood injuries occurred at non-trauma centre EDs, approximately four of every five major injuries were evaluated within trauma centre EDs, highlighting preferential triage of the most severely injured children to trauma centres. Children with head injuries and hence higher injury severity were hospitalised more often within trauma versus non-trauma centres, with the converse being true for extremity injuries which accrue lower overall injury severity. Evaluation of resource use among hospitalised injured children revealed a higher use of invasive medical devices, marginally longer stay, and higher hospital charges for children who received care at trauma versus nontrauma centres. A higher use of invasive medical devices and longer hospitalisation within trauma centres likely reflects preponderance of children with more severe injuries at trauma versus non-trauma centres. Higher hospital charges for care within trauma centres, however, corroborates prior studies which reported similar higher costs of care in trauma versus non-trauma centres (Goldfarb, Bazzoli, & Coffey, 1996; MacKenzie et al., 2010). While it might be surmised that higher charges for hospitalisations at trauma versus non-trauma centres could be attributed to higher injury severity and extensive medical rehabilitation for these patients, future studies should address the cost-effectiveness of paediatric trauma care accounting for variation in injury severity by type of hospital. The study findings should be interpreted in light of certain limitations. The study was limited by inability to accurately separate paediatric trauma centres from adult trauma centres. It was therefore not possible to ascertain any impact of specific paediatric trauma centre care on resource use and outcomes, compared with non-trauma centres. Also, inter-hospital transfer between EDs and its
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potential impact on patterns of hospital resource use could not be ascertained. The strengths of the study include a large sample size, a population-based study design that addressed trauma care within a broad spectrum of EDs nationally, and indepth analysis of the national prevalence and patterns of paediatric injuries, all lending credence to the generalisability of the study findings. In conclusion, childhood injuries are a frequent cause of ED visits and are associated with significant demographic, geographical, and seasonal variation in their occurrence. Childhood injuries accrue substantial hospital resource use, borne largely by trauma centres where the most severely injured children receive care. The study findings are important for future research geared towards injury mitigation and an improved understanding of factors that influence hospital resource use and clinical outcomes after paediatric trauma.
Competing interests The authors have no financial relationships relevant to this article to disclose. The authors have no conflicts of interest relevant to this article to disclose. Both authors had full access to all the data and take full responsibility for the integrity of the data and accuracy of data analysis.
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