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Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children
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Original Article
Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children Elizabeth A. Camp ∗ , Andrea T. Cruz, Rohit P. Shenoi Department of Pediatrics, Section of Emergency Medicine, Baylor College of Medicine, Houston, Texas, USA
a r t i c l e
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Article history: Received 17 October 2019 Received in revised form 31 December 2019 Accepted 17 January 2020 Keywords: Abdominal injuries Blunt injuries Diagnostic imaging Emergency medicine Obesity Pediatrics
a b s t r a c t Objectives: Children with obesity may possess unique injury characteristics that may affect their emergency care. To better understand this relationship, we investigated the association of obesity in pediatric trauma patients and intra-abdominal injuries (IAIs) and routinely utilized emergency department (ED) diagnostic procedures (computed tomography (CT) scans and ultrasound (US) examinations). Methods: This secondary data analysis utilized Pediatric Emergency Care Applied Research Network (PECARN) data from 2007 to 2010. Since height data were not available, children (2–17 years) with obesity were defined using weight-for-age percentiles. Non-parametric testing determined potential confounders. Adjusted odds ratios (aOR) were calculated using binary logistic regression for weight status and IAIs and diagnostic procedures. Results: There were 3846 patients with actual weight recorded: 3301 (85.8%) children without obesity and 545 (14.2%) with obesity. Children with obesity had decreased odds for IAI after adjusting for race, mechanical force injury (MFI) type, vomiting, and abdominal wall trauma (adjusted odds ratio (aOR) = 0.58 (95% CI 0.35–0.97); p-value = 0.04). Patients with obesity had reduced odds for a CT examination. No association was found between obesity status and US utilization. African-American patients had decreased odds for IAIs, CT scans and US examinations after adjustment which could be related to MFI type. Conclusions: Obesity appears to reduce the odds for pediatric IAIs and CT scans, but not for US examinations. Selection bias is possible due to injury severity and missing or excluded weight data. Further research is needed in other pediatric populations with obesity and blunt injuries. © 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Introduction Obesity is a major public health concern in the United States (US), with estimated prevalence rates rising to nearly 20% in children between 1999 and 2014 [1]. Concurrently, US pediatric emergency department (ED) visit rates increased beginning with 36.4 ED visits per 100 children in 2001 to 40.6 ED visits per 100 children in 2010 [2]. With obesity trends increasing in the US and a rise in ED utilization, emergency care may require a more tailored approach as obese and non-obese children may possess unique injury characteristics [3,4]. Past studies have suggested that pediatric patients may acquire specific injury patterns due to their weight [3–9]. Obese children appear to have a decreased risk for head injuries with an increased
∗ Corresponding author. E-mail addresses: [email protected] (E.A. Camp), [email protected] (A.T. Cruz), [email protected] (R.P. Shenoi).
risk of injury to the extremities [5–7,9]. The association between intra-abdominal injury (IAI) and obesity is less clear, with obesity increasing, decreasing or having no association with the injury in past studies, where the outcome was primarily defined using an anatomical injury scoring (AIS) system [3–9]. The AIS classification system codes injuries to body regions using a six point ordinal scale, with 1 coded as minor increasing to six coded as unsustainable [10]. By using AIS to define IAI severity, studies have been unable to clarify whether obesity has a beneficial or deleterious effect, possibly due to scoring variations found among certified AIS coders [10]. Inconsistent associations between IAI and obesity suggest possible uncertainty in the clinical treatment and outcomes in pediatric trauma victims. One possible biomechanical explanation for the reduced odds of IAI is that the increased subcutaneous fat found in the abdomen transfers the energy of impact to the outer regions of the body in blunt force trauma [4,5,7,8,11]. This protection was theorized to be the result of a “cushion effect” provided by the increased adipose tissue which absorbs shock to reduce damage to abdominal organs
https://doi.org/10.1016/j.orcp.2020.01.006 1871-403X/© 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
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Table 1 Comparison of demographic, clinical characteristics and organ injury in pediatric emergency department patients with and without obesity (N = 3846). Patients With Obesity N = 545 (14.2%) Median (IQR) or N (%)
P-value
12.0 (8.0, 15.0) 1982 (60.0) 44.1 (26.0, 60.0) 282 (11.1)
10.0 (7.0, 14.0) 361 (66.2) 59.3 (35.8, 87.7) 67 (16.7)
<0.001 0.01 <0.001 0.001
1731 (56.0) 1160 (37.5) 201 (6.5)
245 (48.6) 226 (44.8) 33 (6.5)
0.01
884 (26.8) 604 (18.3) 76 (2.3) 481 (14.6) 328 (10.0) 150 (4.6) 689 (20.9) 22 (0.7) 61 (1.9)
160 (29.4) 84 (15.4) 21 (3.9) 90 (16.5) 54 (9.9) 29 (5.3) 97 (17.8) 1 (0.2) 8 (1.5)
0.08
2178 (67.8) 1034 (32.2)
346 (64.7) 189 (35.3)
0.15
Patients Without Obesity N = 3301 (85.8%) Median (IQR) or N (%) Demographics/MOI Age Male Weight (kg) Hispanic Race Caucasian African-American Other races Mechanism of Injury Occupant in MVC Fall from elevation Fall downstairs Pedestrian/bike struck MV Bike riding/fall from bike MC/ATV/Scooter accident Object struck abdomen Unknown mechanism Other MOI MFI Type Impact Forcea Decelerationb
Clinical Factors ED SBP ED RR ED HR GCS Score (total) Intubated Abdominal Distention Bowel Sounds Abdominal Tender Thoracic Tender Flank Tender Pelvic Tender Abdominal Pain Abdominal Pain Severityd Mild Moderate Severe Abdominal Pain Location Diffuse Localized Vomit/Retching Distracting Pain Seat Belt Impressione Abdominal Wall Trauma
118 (109, 129) 20 (18, 24) 92 (80, 106) 15 (15, 15) 50 (1.5) 42 (1.3) 191 (6.4) 1236 (38.9) 689 (21.8) 489 (15.3) 304 (9.5) 1304 (41.3)
123 (114, 134) 20 (18, 24) 95 (84, 108) 15 (15, 15) 8 (1.5) 4 (0.8) 28 (5.6) 196 (37.7) 112 (21.4) 81 (15.5) 51 (9.8) 215 (42.0)
494 (39.9) 530 (42.8) 215 (17.4)
100 (49.0) 71 (34.8) 33 (16.2)
402 (32.4) 840 (67.6) 371 (11.4) 540 (16.8) 128 (14.8) 535 (16.3)
60 (28.8) 148 (71.2) 43 (8.1) 81 (15.3) 29 (18.1) 104 (19.1)
0.02 0.38 0.28 0.10
Liver Injured Spleen Injured Kidney Injured Pancreas Injured Gallbladder Injured GI Tract Injured Mesenteric Injured Small Bowel Injured Large Bowel Injured
61 (29.8) 78 (38.0) 48 (23.4) 10 (4.9) 2 (1.0) 30 (14.6) 10 (33.3) 24 (80.0) 6 (20.0)
5 (27.8) 7 (38.9) 2 (11.1) 2 (11.1) 0 (0.0) 1 (5.6) 0 (0.0) 1 (100.0) 1 (100.0)
0.86 0.94 0.38c 0.25c 1.00c 0.48c 1.00c 1.00c 1.00c
<0.001 0.31 <0.001 0.28 0.93 0.39c 0.49 0.60 0.81 0.91 0.88 0.78
0.04
0.31
Organ Injury
NOTE: ATV = all-terrain vehicle; ED = emergency department; GCS = Glasgow Coma Score; HR = heart rate; IQR = interquartile range; kg = kilogram; MC = motorcycle; MFI = mechanical force injury; MV = motor vehicle; MVC = motor vehicle collision; RR = respiratory rate; SBP = systolic blood pressure. a Impact force is categorized as: fall from elevation or down stairs, pedestrian/bike struck MV, bike riding or fall from bike and object struck abdomen. b Deceleration force is categorized as: occupant in MVC or motorcycle/ATV/motorized scooter collision. c P-value was calculated using the Fisher Exact Test when any cell value was less than five. d Data for abdominal pain severity was not collected using a validated tool. e Among patients who were occupants in a motor vehicle accident.
[4,11]. However, detecting an IAI through diagnostic tests such as computerized tomography (CT) scans and ultrasound (US) examinations and can be more challenging in the obese patient because of the increased adipose tissue [12]. By using an ED diagnosis of an IAI (determined by any diagnostic method) from a national dataset of pediatric patients, instead of utilizing the AIS scoring system (which
may be unreliable), we hope to better estimate the association between obesity status and abdominal injuries [10]. We hypothesized that patients with obesity may benefit from a theorized “cushion effect” which will reduce the odds for an IAI in patients with blunt trauma. We further aimed to assess the association of children living with obesity and common diagnostic examinations
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in the ED (US examination and CT scan) as US imaging difficulties may arise in children with obesity [12].
Table 2 Unadjusted and adjusted association between emergency department pediatric patients with obesity and intra-abdominal injuries (n = 3440). Factor
Methods Patients with obesity (yes)
Data for this secondary analysis are from a public-use dataset generated from the Pediatric Emergency Care Applied Research Network (PECARN) study (Fig. 1) [13]. Briefly, the PECARN IAI study was a national, prospective cohort study of children (<18-yearsold) presenting to 20 hospitals enrolled in PECARN from 2007 to 2010 with blunt IAI [14]. Patients were excluded in the parent study if they were pregnant, developmentally delayed, transferred after diagnostic testing, or if their injury was penetrating or occurred greater than 24 h before ED presentation [14]. In our secondary analysis, patients were further excluded if their weight was estimated by clinician, parent or Broselow Tape due to potential weight inaccuracies [15]. Patients were also excluded if they were less than 2 years old as the Center for Disease Control (CDC) 2000 growth reference nutritional anthropology tool is calculated only for children aged 2 and older [16]. This research was submitted to the institutional review board and waived due to the public access of the data and de-identification of the dataset. The exposure variable, obesity status, was determined separately by the PI (EAC). Given the constraints of a secondary data analysis, height data were not available, precluding calculating body mass index (BMI). Using available gender, weight and age data, a weight-for-age percentile and corresponding z-score were generated for each study subject aged two and older using Epi InfoTM version 7.2.2.1 (CDC; Atlanta, GA) [16,17]. Patients were coded as obese if their z-score was 2 standard deviations or greater from the mean and flagged with an “H” by the CDC as having a high weight-for-age percentile; and likely non-obese when the zscore was less than 2 and categorized as “OK” by the CDC [17]. The outcome for this study focused on blunt IAIs (determined by any diagnostic method) and documented CT and US utilization in the ED or during hospitalization. Demographic and clinical factors were compared between the obesity exposure factor (obese vs. non-obese) and study outcomes (IAI, CT scans, and US examinations) to assess statistically significant differences. To provide comparative groups among the various mechanisms of injury (MOI), a new binary variable was created that collapsed accident type by mechanical force injury (MFI). Deceleration trauma was defined by injuries sustained in motor and all-terrain vehicles (ATV) and scooter collisions; while impact force trauma was categorized by injuries occurring from falls (elevation, down stairs or bike), pedestrian or bike struck motor vehicle, bike riding and object struck abdomen [18]. A power analysis revealed the study sample had 81.5% power to detect a difference between obese and non-obese groups [19]. Categorical data were analyzed using the Pearson Chi-Square test; for any cell value less than five, the Fisher Exact test was utilized. The distribution of continuous variables were skewed, therefore nonparametric testing (Mann-Whitney test) was utilized. Any potential confounder with a p-value ≤0.20 for obesity status and demographic and clinical factors were considered for further adjustment. Binary logistic regression modeling was utilized to adjust the odds ratio association. Using a backward-step approach, the factor with the highest p-value was removed until all factors in the model had a p-value <0.05, resulting in an adjusted odds ratio (aOR) for obesity status and outcomes. To assess the reliability of the weight status coding by the PI (EAC), a 5% random sample of the data were selected using the statistical analysis software. Patients were re-coded by a co-investigator (RPS) and utilized to generate a Cohen’s kappa coefficient to determine coding reproducibility. A p-value of <0.05 was
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Patients with obesity (yes) Race White African-American Other MFI Type (deceleration) Vomit (yes) Abdominal Wall Trauma (yes)
aOR Unadjusted 0.52 Adjusted 0.58 Ref 0.51 0.59 0.66 2.49 2.38
95% CI
P-value
0.32–0.84
0.01
0.35– 0.97
0.04
– 0.36–0.72 0.29–1.18 0.47–0.93 1.74–3.55 1.73–3.28
– <0.001 0.14 0.02 <0.001 <0.001
NOTE: aOR = adjusted odds ratio; CI = confidence interval; MFI = mechanical force injury; Ref = reference.
considered statistically significant. All analyses were conducted using the Statistical Package for the Social Sciences (SPSS), version 24 (IBM Corp., Armonk, NY). Results There are 12,044 patients in the PECARN IAI public dataset, of whom 3846 (31.9%) met the inclusion criteria of having a recorded scale weight: 3301 (85.8%) patients without obesity and 545 (14.2%) living with obesity (Fig. 1). There were 18 (3.3%) children with obesity and a blunt IAI compared to 205 children without obesity and IAIs (6.2%). Overall, children with obesity were significantly younger, male, African-American, and Hispanic (Table 1). Clinically, they had significantly higher ED systolic blood pressures (SBP) and heart rates (HR), with fewer patients experiencing vomiting (Table 1). There were no differences between obesity status and specific organ injuries (Table 1). There were several factors that could be potential confounders (p-value ≤0.20) for obesity status and outcomes: age, gender, ethnicity, race, MFI, ED SBP, ED HR, vomiting, and abdominal wall trauma (Table 1). Patients with obesity had a decreased odds for IAIs after adjusting for race, MFI, vomiting, and abdominal wall trauma (adjusted odds ratio (aOR) = 0.58 (95% Confidence Interval (CI) 0.35–0.97); p-value = 0.04) (Table 2). Within this model, African-American children had reduced odds for an IAI (aOR = 0.51 (95% CI 0.36–0.72); p-value<0.001) when compared to white children; along with MFI (deceleration) reducing IAIs (Table 2). Conversely, children experiencing vomiting, and abdominal wall trauma had approximately double the odds for an IAI (Table 2). Among diagnostic examinations, patients with obesity had a reduced odds for a CT examination after adjustment for age, ethnicity, race, ED SBP, ED HR, vomiting, and abdominal wall trauma (aOR = 0.74 (95% CI 0.58–0.96); p-value = 0.02) (Table 3). Hispanic (aOR = 0.62 (0.46–0.83); p-value = 0.002) and AfricanAmerican children (aOR = 0.46 (95% CI 0.38–0.55); p-value<0.001) had a decreased odds for a CT scan (Table 3). Patients who vomited and had abdominal wall trauma had significantly increased odds for a CT scan after adjustment (Table 3). There was no significant association between patients with obesity and US utilization after adjusting for age, ethnicity, race and ED SBP (Table 4). When comparing race and US usage, AfricanAmerican children had a decreased odds for an US examination when compared to white children (aOR = 0.54 (95% CI 0.38–0.75); pvalue<0.001) after adjusting for obesity and other factors (Table 4). As a secondary analysis, patients who had an US examination had over twice the odds of having a CT scan than patients who did not have an abdominal US examination (OR = 2.53 (95% CI 1.97–3.25); p-value<0.001) (results not shown).
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Fig. 1. Consort Diagram of PECARN Study Participants.
Table 3 Unadjusted and adjusted association between emergency department pediatric patients with obesity and computed tomography (CT) utilization (n = 2712). Factor Patients with obesity (yes) Patients with obesity (yes) Age (years) Hispanic (yes) Race White African-American Other ED SBP ED HR Vomit (yes) Abdominal Wall Trauma (yes)
aOR Unadjusted 0.80 Adjusted 0.74 1.04 0.62 Ref 0.46 0.89 1.01 1.01 1.52 2.72
95% CI
P-value
0.66–0.97
0.02
0.58–0.96 1.02–1.07 0.46–0.83
0.02 0.001 0.002
– 0.38–0.55 0.63–1.26 1.003–1.015 1.002–1.012 1.17–1.97 2.19–3.39
– <0.001 0.51 0.002 0.01 0.002 <0.001
NOTE: aOR = adjusted odds ratio; CI = confidence interval; ED = emergency department; HR = heart rate; Ref = reference; SBP = systolic blood pressure.
Five percent of the data (n = 204) was randomly selected to assess the coding reliability. The agreement between the two coders (EAC & RPS) was high with a kappa score of 0.97 (pvalue<0.001). Out of the 204 patients recoded, only one patient was misclassified as likely obese. Discussion Using data from a national, prospective, cohort study (PECARN), we determined that children with obesity had reduced odds for IAIs and CT scans, but were not associated with US examination usage. Our results are similar to other studies that found a protective effect for obesity and abdominal injuries, possibly due to a “cushion effect” [4,5,7,11]. It is also unique in that it used an ED diagnosis (determined by any diagnostic method) of an IAI as the outcome instead of utilizing the AIS scoring system, which mostly serves as a proxy measure for injury severity [3–10]. In a few studies, distinctions were made between abdominal organs, with obesity increasing the odds for kidney and hepatic
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E.A. Camp et al. / Obesity Research & Clinical Practice xxx (2020) xxx–xxx Table 4 Unadjusted and adjusted association between emergency department pediatric patients with obesity and abdominal ultrasound (US) utilization (n = 2758). Factor Patients with obesity (yes) Patients with obesity (yes) Age (years) Hispanic (yes) Race White African-American Other ED SBP
aOR Unadjusted 0.90 Adjusted 0.80 1.11 1.63 Ref 0.54 0.85 1.01
95% CI
P-value
0.63–1.30
0.58
0.50–1.30 1.06–1.15 1.05–2.53
0.37 <0.001 0.03
– 0.38–0.75 0.48–1.51 1.003–1.023
– <0.001 0.58 0.01
NOTE: aOR = adjusted odds ratio; CI = confidence interval; ED = emergency department; Ref = reference; SBP = systolic blood pressure.
injuries, and having no association in splenic injuries [3,20]. In this dataset, we were unable to distinguish a difference between any specific organ injury and obesity status. This is likely do to the small number of patients with obesity who did have a solid or hollow organ injury (n = 17). Nonetheless, the obesity prevalence rate in this study was similar to national averages during the same timeframe (14% vs. 17%) making generalizability to the national population a possibility [1]. Additionally, we discovered relevant demographic and mechanistic factors in the adjustment models. In regards to race, African-American children had a significantly reduced odds for IAIs and diagnostic tool utilization (regardless of type). Pediatric racial disparities have been identified in other diagnostic tests and health outcomes in the ED [21–23]. African-American children appear to be imaged less often when compared to white children, not only for the abdomen, but for other body regions as well (head, spine and chest) [22,23]. In this study, AfricanAmerican patients were less likely to have an IAI, CT scan, or US examination when compared to white patients after adjusting for obesity status and other factors. The association between race and IAIs could be explained by the decreased odds for a deceleration injury found in African-American children (results not shown). In this analysis, deceleration injuries and AfricanAmericans were less commonly associated with IAIs. Specifically, African-American children had a decreased odds for motorcycle, ATV and scooter collisions; motor vehicle accidents were unassociated with race (results not shown). Since African-American children are at a reduced odds for IAIs, this could also explain why they were imaged (CT scan and US examination) less often. Additionally, we looked at each MOI and its association with CT and US usage and discovered that bike riding or fall from bike and motorcycle, ATV and scooter collisions increased CT utilization; while occupant in motor vehicle collision (MVC) increased the odds for US utilization. Interestingly, African-American children had a decreased odds for bike riding or fall from bike and motorcycle, ATV and scooter collisions, suggesting that lack of imaging in African-American children could be a result of how the injury occurred instead of racial disparity in this dataset. More research is needed to better understand the relationship between MOI, race and diagnostic testing. The method by which the blunt trauma occurred may also impact the association between obesity status and IAIs. In our model, we adjusted for race, MFI, emesis and abdominal wall trauma; however, a few studies focused only on motor vehicle accidents, which may not make the effect estimates comparable [7,8,11]. Several of these studies found that obesity had a protective effect for abdominal injuries, while others did not find the same results [7,8,24,25]. This could be due to a gradient effect generated by increasing BMI [4,6,8,11]. As body mass increases, so does kinetic
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energy which can reverse the protective effect of increased adipose tissue in MVCs [4,11]. In a subgroup analysis, we found that obesity was associated with decreased odds for IAIs among impact force injuries, but was not associated in reducing IAIs in deceleration injuries (results not shown). In addition, deceleration injuries were associated with reduced odds for an IAI, but only in patients without obesity (results not shown). A possible explanation is that physical characteristics derived from obesity can introduce slack into the seat belt mechanism, preventing ideal restraint and increasing injury risk in MVCs [26]. Previous research spanning decades has shown a correlation between seat belt impressions and abdominal, chest, skeletal and neck injuries known collectively as the “seat belt syndrome”; so named because of the injury pattern sustained in MVCs when restrained [27]. We found a similar increased risk between the presence of seat belt impressions and an IAI in children without obesity, but did not find a significant difference among children living with obesity (results not shown). This could also be due to the improper fit of seat belts found in passengers with obesity [26]. In this dataset, the statistical difference between patients with obesity and those without, may stem from a small sample size, with only one patient defined as obese having a seat belt impression and IAI. In addition, there was no significant difference between obesity status and having a seat belt impression. In this study, it is unclear what role obesity plays in car restraints and subsequent abdominal injuries. However, our finding of a lack of association between noted seat belt impressions and IAIs in children with obesity does adds to the growing literature reporting no association between seat belt impressions and IAI in stable patients [28,29]. This reverse finding could be due in part to improvements made in occupant restraint technology; specifically in the areas of smart restraint systems that can adjust for occupant size, position and impact force [30,31]. There were several study limitations. Although the reliability of coding for weight status was high, defining “obese” using only gender, weight and age (weight-for-age) may misclassify borderline patients who may or may not be obese [32,33]. BMI is the most common anthropometric measurement used to define obesity; however, height data were not included the PECARN dataset [32]. It’s also debatable whether BMI is the most appropriate approach to define obesity as it does not quantify visceral fat tissue and does not distinguish between muscle and adipose tissue [32]. We used CDC definitions of obesity, which may underestimate obesity in non-white children, in whom World Health Organization growth curves may be more accurate [16]. Additionally, PECARN centers are predominantly located in large children’s hospitals in urban regions, potentially decreasing generalizability to other settings. Practice guidelines for treatment of acute trauma may also not be comparable across study sites, which directly effects imagery outcomes (CT and US). Also the prevalence of IAIs in this dataset was low (likely obese = 3%; not likely obese = 6%) which effects study power; however, the overall rates were comparable to another study (obese = 6%; non-obese = 11%) where statistical significance was achieved [5]. Another limitation was self-reported or staff documented ethnicity and race. Previous studies have shown that self-reported race or perception of race does not correlate well with federal coding when the patient is a minority, which could possibly misclassify patients in this study [34,35]. Lastly, actual weight was only recorded in approximately 40% of the cases. When comparisons were made between outcomes and recorded weight status, patients with a measured weight were significantly less likely to have an IAI, CT scan and US examination than patients without a recorded or estimated weight. This could possibly be due to the severity of the injury, with less injured children physically able to get on a scale and have their actual weight
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recorded. If this population is less injured, it could create a selection bias resulting in an inaccurate association. Therefore, more research is needed in patients with measured weight and height data and definitive clinical outcomes. Conclusion In this study, children with obesity had a reduced odds for a blunt IAIs and CT scans in the ED. Further research is needed to explain the association of IAIs and childhood obesity, especially in motor vehicle accidents, where improved seat belt technology could reduce injuries. Additional research is also needed to determine if the reduced odds for diagnostic imagery are found in other African-American populations and if any relationship exists between race and MOI, which could potentially impact pediatric ED treatment. Conflict of interest None. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.orcp.2020.01. 006. References [1] Ogden CL, Carroll MD, Fryar CD, Flegal KM. Prevalence of obesity among adults and youth: United States, 2011-2014. NCHS Data Brief 2015;219(1):8. [2] Rasooly IR, Mullins PM, Alpern ER, Pines JM. US emergency department use by children, 2001-2010. Pediatr Emerg Care 2014;30:602–7, http://dx.doi.org/10. 1097/PEC.0000000000000204. [3] Vaughan N, Tweed J, Greenwell C, Notrica DM, Langlais CS, Peter SD, et al. The impact of morbid obesity on solid organ injury in children using the ATOMAC protocol at a pediatric level I trauma center. J Pediatr Surg 2017;52:345–8, http://dx.doi.org/10.1016/j.jpedsurg.2016.09.002. [4] Meroz Y, Gozal Y. Management of the obese trauma patient. Anesthesiol Clin 2007;25:91–8. [5] Rana AR, Michalsky MP, Teich S, Groner JI, Caniano DA, Schuster DP. Childhood obesity: a risk factor for injuries observed at a level-1 trauma center. J Pediatr Surg 2009;44:1601–5, http://dx.doi.org/10.1016/j.jpedsurg.2008.11.060. [6] Brown CV, Neville AL, Salim A, Rhee P, Cologne K, Demetriades D. The impact of obesity on severely injured children and adolescents. J Pediatr Surg 2006;41:88–91. [7] Haricharan RN, Griffin RL, Barnhart DC, Harmon CM, McGwin G. Injury patterns among obese children involved in motor vehicle collisions. J Pediatr Surg 2009;44, http://dx.doi.org/10.1016/j.jpedsurg.2009.02.029, 1218-22. [8] Pollack KM, Xie D, Arbogast KB, Durbin DR. Body mass index and injury risk among US children 9-15 years old in motor vehicle crashes. Inj Prev 2008;14:366–71, http://dx.doi.org/10.1136/ip.2008.019208. [9] Pomerantz WJ, Timm NL, Gittelman MA. Injury patterns in obese versus nonobese children presenting to a pediatric emergency department. Pediatrics 2010;125:681–5, http://dx.doi.org/10.1542/peds.2009-2367. [10] Ringdal KG, Skaga NO, Hestnes M, Steen PA, Roislien J, Rehn M, et al. Abbreviated injury scale: not a reliable basis for summation of injury severity in trauma facilities? Injury 2013;44:691–9, http://dx.doi.org/10.1016/j.injury.2012.06.032. [11] Arbabi S, Wahl WL, Hemmila MR, Kohoyda-Inglis C, Taheri PA, Wang SC. The cushion effect. J Trauma 2003;54:1090–3.
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Original Article
Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children Elizabeth A. Camp ∗ , Andrea T. Cruz, Rohit P. Shenoi Department of Pediatrics, Section of Emergency Medicine, Baylor College of Medicine, Houston, Texas, USA
a r t i c l e
i n f o
Article history: Received 17 October 2019 Received in revised form 31 December 2019 Accepted 17 January 2020 Keywords: Abdominal injuries Blunt injuries Diagnostic imaging Emergency medicine Obesity Pediatrics
a b s t r a c t Objectives: Children with obesity may possess unique injury characteristics that may affect their emergency care. To better understand this relationship, we investigated the association of obesity in pediatric trauma patients and intra-abdominal injuries (IAIs) and routinely utilized emergency department (ED) diagnostic procedures (computed tomography (CT) scans and ultrasound (US) examinations). Methods: This secondary data analysis utilized Pediatric Emergency Care Applied Research Network (PECARN) data from 2007 to 2010. Since height data were not available, children (2–17 years) with obesity were defined using weight-for-age percentiles. Non-parametric testing determined potential confounders. Adjusted odds ratios (aOR) were calculated using binary logistic regression for weight status and IAIs and diagnostic procedures. Results: There were 3846 patients with actual weight recorded: 3301 (85.8%) children without obesity and 545 (14.2%) with obesity. Children with obesity had decreased odds for IAI after adjusting for race, mechanical force injury (MFI) type, vomiting, and abdominal wall trauma (adjusted odds ratio (aOR) = 0.58 (95% CI 0.35–0.97); p-value = 0.04). Patients with obesity had reduced odds for a CT examination. No association was found between obesity status and US utilization. African-American patients had decreased odds for IAIs, CT scans and US examinations after adjustment which could be related to MFI type. Conclusions: Obesity appears to reduce the odds for pediatric IAIs and CT scans, but not for US examinations. Selection bias is possible due to injury severity and missing or excluded weight data. Further research is needed in other pediatric populations with obesity and blunt injuries. © 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Introduction Obesity is a major public health concern in the United States (US), with estimated prevalence rates rising to nearly 20% in children between 1999 and 2014 [1]. Concurrently, US pediatric emergency department (ED) visit rates increased beginning with 36.4 ED visits per 100 children in 2001 to 40.6 ED visits per 100 children in 2010 [2]. With obesity trends increasing in the US and a rise in ED utilization, emergency care may require a more tailored approach as obese and non-obese children may possess unique injury characteristics [3,4]. Past studies have suggested that pediatric patients may acquire specific injury patterns due to their weight [3–9]. Obese children appear to have a decreased risk for head injuries with an increased
∗ Corresponding author. E-mail addresses: [email protected] (E.A. Camp), [email protected] (A.T. Cruz), [email protected] (R.P. Shenoi).
risk of injury to the extremities [5–7,9]. The association between intra-abdominal injury (IAI) and obesity is less clear, with obesity increasing, decreasing or having no association with the injury in past studies, where the outcome was primarily defined using an anatomical injury scoring (AIS) system [3–9]. The AIS classification system codes injuries to body regions using a six point ordinal scale, with 1 coded as minor increasing to six coded as unsustainable [10]. By using AIS to define IAI severity, studies have been unable to clarify whether obesity has a beneficial or deleterious effect, possibly due to scoring variations found among certified AIS coders [10]. Inconsistent associations between IAI and obesity suggest possible uncertainty in the clinical treatment and outcomes in pediatric trauma victims. One possible biomechanical explanation for the reduced odds of IAI is that the increased subcutaneous fat found in the abdomen transfers the energy of impact to the outer regions of the body in blunt force trauma [4,5,7,8,11]. This protection was theorized to be the result of a “cushion effect” provided by the increased adipose tissue which absorbs shock to reduce damage to abdominal organs
https://doi.org/10.1016/j.orcp.2020.01.006 1871-403X/© 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
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Table 1 Comparison of demographic, clinical characteristics and organ injury in pediatric emergency department patients with and without obesity (N = 3846). Patients With Obesity N = 545 (14.2%) Median (IQR) or N (%)
P-value
12.0 (8.0, 15.0) 1982 (60.0) 44.1 (26.0, 60.0) 282 (11.1)
10.0 (7.0, 14.0) 361 (66.2) 59.3 (35.8, 87.7) 67 (16.7)
<0.001 0.01 <0.001 0.001
1731 (56.0) 1160 (37.5) 201 (6.5)
245 (48.6) 226 (44.8) 33 (6.5)
0.01
884 (26.8) 604 (18.3) 76 (2.3) 481 (14.6) 328 (10.0) 150 (4.6) 689 (20.9) 22 (0.7) 61 (1.9)
160 (29.4) 84 (15.4) 21 (3.9) 90 (16.5) 54 (9.9) 29 (5.3) 97 (17.8) 1 (0.2) 8 (1.5)
0.08
2178 (67.8) 1034 (32.2)
346 (64.7) 189 (35.3)
0.15
Patients Without Obesity N = 3301 (85.8%) Median (IQR) or N (%) Demographics/MOI Age Male Weight (kg) Hispanic Race Caucasian African-American Other races Mechanism of Injury Occupant in MVC Fall from elevation Fall downstairs Pedestrian/bike struck MV Bike riding/fall from bike MC/ATV/Scooter accident Object struck abdomen Unknown mechanism Other MOI MFI Type Impact Forcea Decelerationb
Clinical Factors ED SBP ED RR ED HR GCS Score (total) Intubated Abdominal Distention Bowel Sounds Abdominal Tender Thoracic Tender Flank Tender Pelvic Tender Abdominal Pain Abdominal Pain Severityd Mild Moderate Severe Abdominal Pain Location Diffuse Localized Vomit/Retching Distracting Pain Seat Belt Impressione Abdominal Wall Trauma
118 (109, 129) 20 (18, 24) 92 (80, 106) 15 (15, 15) 50 (1.5) 42 (1.3) 191 (6.4) 1236 (38.9) 689 (21.8) 489 (15.3) 304 (9.5) 1304 (41.3)
123 (114, 134) 20 (18, 24) 95 (84, 108) 15 (15, 15) 8 (1.5) 4 (0.8) 28 (5.6) 196 (37.7) 112 (21.4) 81 (15.5) 51 (9.8) 215 (42.0)
494 (39.9) 530 (42.8) 215 (17.4)
100 (49.0) 71 (34.8) 33 (16.2)
402 (32.4) 840 (67.6) 371 (11.4) 540 (16.8) 128 (14.8) 535 (16.3)
60 (28.8) 148 (71.2) 43 (8.1) 81 (15.3) 29 (18.1) 104 (19.1)
0.02 0.38 0.28 0.10
Liver Injured Spleen Injured Kidney Injured Pancreas Injured Gallbladder Injured GI Tract Injured Mesenteric Injured Small Bowel Injured Large Bowel Injured
61 (29.8) 78 (38.0) 48 (23.4) 10 (4.9) 2 (1.0) 30 (14.6) 10 (33.3) 24 (80.0) 6 (20.0)
5 (27.8) 7 (38.9) 2 (11.1) 2 (11.1) 0 (0.0) 1 (5.6) 0 (0.0) 1 (100.0) 1 (100.0)
0.86 0.94 0.38c 0.25c 1.00c 0.48c 1.00c 1.00c 1.00c
<0.001 0.31 <0.001 0.28 0.93 0.39c 0.49 0.60 0.81 0.91 0.88 0.78
0.04
0.31
Organ Injury
NOTE: ATV = all-terrain vehicle; ED = emergency department; GCS = Glasgow Coma Score; HR = heart rate; IQR = interquartile range; kg = kilogram; MC = motorcycle; MFI = mechanical force injury; MV = motor vehicle; MVC = motor vehicle collision; RR = respiratory rate; SBP = systolic blood pressure. a Impact force is categorized as: fall from elevation or down stairs, pedestrian/bike struck MV, bike riding or fall from bike and object struck abdomen. b Deceleration force is categorized as: occupant in MVC or motorcycle/ATV/motorized scooter collision. c P-value was calculated using the Fisher Exact Test when any cell value was less than five. d Data for abdominal pain severity was not collected using a validated tool. e Among patients who were occupants in a motor vehicle accident.
[4,11]. However, detecting an IAI through diagnostic tests such as computerized tomography (CT) scans and ultrasound (US) examinations and can be more challenging in the obese patient because of the increased adipose tissue [12]. By using an ED diagnosis of an IAI (determined by any diagnostic method) from a national dataset of pediatric patients, instead of utilizing the AIS scoring system (which
may be unreliable), we hope to better estimate the association between obesity status and abdominal injuries [10]. We hypothesized that patients with obesity may benefit from a theorized “cushion effect” which will reduce the odds for an IAI in patients with blunt trauma. We further aimed to assess the association of children living with obesity and common diagnostic examinations
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in the ED (US examination and CT scan) as US imaging difficulties may arise in children with obesity [12].
Table 2 Unadjusted and adjusted association between emergency department pediatric patients with obesity and intra-abdominal injuries (n = 3440). Factor
Methods Patients with obesity (yes)
Data for this secondary analysis are from a public-use dataset generated from the Pediatric Emergency Care Applied Research Network (PECARN) study (Fig. 1) [13]. Briefly, the PECARN IAI study was a national, prospective cohort study of children (<18-yearsold) presenting to 20 hospitals enrolled in PECARN from 2007 to 2010 with blunt IAI [14]. Patients were excluded in the parent study if they were pregnant, developmentally delayed, transferred after diagnostic testing, or if their injury was penetrating or occurred greater than 24 h before ED presentation [14]. In our secondary analysis, patients were further excluded if their weight was estimated by clinician, parent or Broselow Tape due to potential weight inaccuracies [15]. Patients were also excluded if they were less than 2 years old as the Center for Disease Control (CDC) 2000 growth reference nutritional anthropology tool is calculated only for children aged 2 and older [16]. This research was submitted to the institutional review board and waived due to the public access of the data and de-identification of the dataset. The exposure variable, obesity status, was determined separately by the PI (EAC). Given the constraints of a secondary data analysis, height data were not available, precluding calculating body mass index (BMI). Using available gender, weight and age data, a weight-for-age percentile and corresponding z-score were generated for each study subject aged two and older using Epi InfoTM version 7.2.2.1 (CDC; Atlanta, GA) [16,17]. Patients were coded as obese if their z-score was 2 standard deviations or greater from the mean and flagged with an “H” by the CDC as having a high weight-for-age percentile; and likely non-obese when the zscore was less than 2 and categorized as “OK” by the CDC [17]. The outcome for this study focused on blunt IAIs (determined by any diagnostic method) and documented CT and US utilization in the ED or during hospitalization. Demographic and clinical factors were compared between the obesity exposure factor (obese vs. non-obese) and study outcomes (IAI, CT scans, and US examinations) to assess statistically significant differences. To provide comparative groups among the various mechanisms of injury (MOI), a new binary variable was created that collapsed accident type by mechanical force injury (MFI). Deceleration trauma was defined by injuries sustained in motor and all-terrain vehicles (ATV) and scooter collisions; while impact force trauma was categorized by injuries occurring from falls (elevation, down stairs or bike), pedestrian or bike struck motor vehicle, bike riding and object struck abdomen [18]. A power analysis revealed the study sample had 81.5% power to detect a difference between obese and non-obese groups [19]. Categorical data were analyzed using the Pearson Chi-Square test; for any cell value less than five, the Fisher Exact test was utilized. The distribution of continuous variables were skewed, therefore nonparametric testing (Mann-Whitney test) was utilized. Any potential confounder with a p-value ≤0.20 for obesity status and demographic and clinical factors were considered for further adjustment. Binary logistic regression modeling was utilized to adjust the odds ratio association. Using a backward-step approach, the factor with the highest p-value was removed until all factors in the model had a p-value <0.05, resulting in an adjusted odds ratio (aOR) for obesity status and outcomes. To assess the reliability of the weight status coding by the PI (EAC), a 5% random sample of the data were selected using the statistical analysis software. Patients were re-coded by a co-investigator (RPS) and utilized to generate a Cohen’s kappa coefficient to determine coding reproducibility. A p-value of <0.05 was
3
Patients with obesity (yes) Race White African-American Other MFI Type (deceleration) Vomit (yes) Abdominal Wall Trauma (yes)
aOR Unadjusted 0.52 Adjusted 0.58 Ref 0.51 0.59 0.66 2.49 2.38
95% CI
P-value
0.32–0.84
0.01
0.35– 0.97
0.04
– 0.36–0.72 0.29–1.18 0.47–0.93 1.74–3.55 1.73–3.28
– <0.001 0.14 0.02 <0.001 <0.001
NOTE: aOR = adjusted odds ratio; CI = confidence interval; MFI = mechanical force injury; Ref = reference.
considered statistically significant. All analyses were conducted using the Statistical Package for the Social Sciences (SPSS), version 24 (IBM Corp., Armonk, NY). Results There are 12,044 patients in the PECARN IAI public dataset, of whom 3846 (31.9%) met the inclusion criteria of having a recorded scale weight: 3301 (85.8%) patients without obesity and 545 (14.2%) living with obesity (Fig. 1). There were 18 (3.3%) children with obesity and a blunt IAI compared to 205 children without obesity and IAIs (6.2%). Overall, children with obesity were significantly younger, male, African-American, and Hispanic (Table 1). Clinically, they had significantly higher ED systolic blood pressures (SBP) and heart rates (HR), with fewer patients experiencing vomiting (Table 1). There were no differences between obesity status and specific organ injuries (Table 1). There were several factors that could be potential confounders (p-value ≤0.20) for obesity status and outcomes: age, gender, ethnicity, race, MFI, ED SBP, ED HR, vomiting, and abdominal wall trauma (Table 1). Patients with obesity had a decreased odds for IAIs after adjusting for race, MFI, vomiting, and abdominal wall trauma (adjusted odds ratio (aOR) = 0.58 (95% Confidence Interval (CI) 0.35–0.97); p-value = 0.04) (Table 2). Within this model, African-American children had reduced odds for an IAI (aOR = 0.51 (95% CI 0.36–0.72); p-value<0.001) when compared to white children; along with MFI (deceleration) reducing IAIs (Table 2). Conversely, children experiencing vomiting, and abdominal wall trauma had approximately double the odds for an IAI (Table 2). Among diagnostic examinations, patients with obesity had a reduced odds for a CT examination after adjustment for age, ethnicity, race, ED SBP, ED HR, vomiting, and abdominal wall trauma (aOR = 0.74 (95% CI 0.58–0.96); p-value = 0.02) (Table 3). Hispanic (aOR = 0.62 (0.46–0.83); p-value = 0.002) and AfricanAmerican children (aOR = 0.46 (95% CI 0.38–0.55); p-value<0.001) had a decreased odds for a CT scan (Table 3). Patients who vomited and had abdominal wall trauma had significantly increased odds for a CT scan after adjustment (Table 3). There was no significant association between patients with obesity and US utilization after adjusting for age, ethnicity, race and ED SBP (Table 4). When comparing race and US usage, AfricanAmerican children had a decreased odds for an US examination when compared to white children (aOR = 0.54 (95% CI 0.38–0.75); pvalue<0.001) after adjusting for obesity and other factors (Table 4). As a secondary analysis, patients who had an US examination had over twice the odds of having a CT scan than patients who did not have an abdominal US examination (OR = 2.53 (95% CI 1.97–3.25); p-value<0.001) (results not shown).
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Fig. 1. Consort Diagram of PECARN Study Participants.
Table 3 Unadjusted and adjusted association between emergency department pediatric patients with obesity and computed tomography (CT) utilization (n = 2712). Factor Patients with obesity (yes) Patients with obesity (yes) Age (years) Hispanic (yes) Race White African-American Other ED SBP ED HR Vomit (yes) Abdominal Wall Trauma (yes)
aOR Unadjusted 0.80 Adjusted 0.74 1.04 0.62 Ref 0.46 0.89 1.01 1.01 1.52 2.72
95% CI
P-value
0.66–0.97
0.02
0.58–0.96 1.02–1.07 0.46–0.83
0.02 0.001 0.002
– 0.38–0.55 0.63–1.26 1.003–1.015 1.002–1.012 1.17–1.97 2.19–3.39
– <0.001 0.51 0.002 0.01 0.002 <0.001
NOTE: aOR = adjusted odds ratio; CI = confidence interval; ED = emergency department; HR = heart rate; Ref = reference; SBP = systolic blood pressure.
Five percent of the data (n = 204) was randomly selected to assess the coding reliability. The agreement between the two coders (EAC & RPS) was high with a kappa score of 0.97 (pvalue<0.001). Out of the 204 patients recoded, only one patient was misclassified as likely obese. Discussion Using data from a national, prospective, cohort study (PECARN), we determined that children with obesity had reduced odds for IAIs and CT scans, but were not associated with US examination usage. Our results are similar to other studies that found a protective effect for obesity and abdominal injuries, possibly due to a “cushion effect” [4,5,7,11]. It is also unique in that it used an ED diagnosis (determined by any diagnostic method) of an IAI as the outcome instead of utilizing the AIS scoring system, which mostly serves as a proxy measure for injury severity [3–10]. In a few studies, distinctions were made between abdominal organs, with obesity increasing the odds for kidney and hepatic
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E.A. Camp et al. / Obesity Research & Clinical Practice xxx (2020) xxx–xxx Table 4 Unadjusted and adjusted association between emergency department pediatric patients with obesity and abdominal ultrasound (US) utilization (n = 2758). Factor Patients with obesity (yes) Patients with obesity (yes) Age (years) Hispanic (yes) Race White African-American Other ED SBP
aOR Unadjusted 0.90 Adjusted 0.80 1.11 1.63 Ref 0.54 0.85 1.01
95% CI
P-value
0.63–1.30
0.58
0.50–1.30 1.06–1.15 1.05–2.53
0.37 <0.001 0.03
– 0.38–0.75 0.48–1.51 1.003–1.023
– <0.001 0.58 0.01
NOTE: aOR = adjusted odds ratio; CI = confidence interval; ED = emergency department; Ref = reference; SBP = systolic blood pressure.
injuries, and having no association in splenic injuries [3,20]. In this dataset, we were unable to distinguish a difference between any specific organ injury and obesity status. This is likely do to the small number of patients with obesity who did have a solid or hollow organ injury (n = 17). Nonetheless, the obesity prevalence rate in this study was similar to national averages during the same timeframe (14% vs. 17%) making generalizability to the national population a possibility [1]. Additionally, we discovered relevant demographic and mechanistic factors in the adjustment models. In regards to race, African-American children had a significantly reduced odds for IAIs and diagnostic tool utilization (regardless of type). Pediatric racial disparities have been identified in other diagnostic tests and health outcomes in the ED [21–23]. African-American children appear to be imaged less often when compared to white children, not only for the abdomen, but for other body regions as well (head, spine and chest) [22,23]. In this study, AfricanAmerican patients were less likely to have an IAI, CT scan, or US examination when compared to white patients after adjusting for obesity status and other factors. The association between race and IAIs could be explained by the decreased odds for a deceleration injury found in African-American children (results not shown). In this analysis, deceleration injuries and AfricanAmericans were less commonly associated with IAIs. Specifically, African-American children had a decreased odds for motorcycle, ATV and scooter collisions; motor vehicle accidents were unassociated with race (results not shown). Since African-American children are at a reduced odds for IAIs, this could also explain why they were imaged (CT scan and US examination) less often. Additionally, we looked at each MOI and its association with CT and US usage and discovered that bike riding or fall from bike and motorcycle, ATV and scooter collisions increased CT utilization; while occupant in motor vehicle collision (MVC) increased the odds for US utilization. Interestingly, African-American children had a decreased odds for bike riding or fall from bike and motorcycle, ATV and scooter collisions, suggesting that lack of imaging in African-American children could be a result of how the injury occurred instead of racial disparity in this dataset. More research is needed to better understand the relationship between MOI, race and diagnostic testing. The method by which the blunt trauma occurred may also impact the association between obesity status and IAIs. In our model, we adjusted for race, MFI, emesis and abdominal wall trauma; however, a few studies focused only on motor vehicle accidents, which may not make the effect estimates comparable [7,8,11]. Several of these studies found that obesity had a protective effect for abdominal injuries, while others did not find the same results [7,8,24,25]. This could be due to a gradient effect generated by increasing BMI [4,6,8,11]. As body mass increases, so does kinetic
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energy which can reverse the protective effect of increased adipose tissue in MVCs [4,11]. In a subgroup analysis, we found that obesity was associated with decreased odds for IAIs among impact force injuries, but was not associated in reducing IAIs in deceleration injuries (results not shown). In addition, deceleration injuries were associated with reduced odds for an IAI, but only in patients without obesity (results not shown). A possible explanation is that physical characteristics derived from obesity can introduce slack into the seat belt mechanism, preventing ideal restraint and increasing injury risk in MVCs [26]. Previous research spanning decades has shown a correlation between seat belt impressions and abdominal, chest, skeletal and neck injuries known collectively as the “seat belt syndrome”; so named because of the injury pattern sustained in MVCs when restrained [27]. We found a similar increased risk between the presence of seat belt impressions and an IAI in children without obesity, but did not find a significant difference among children living with obesity (results not shown). This could also be due to the improper fit of seat belts found in passengers with obesity [26]. In this dataset, the statistical difference between patients with obesity and those without, may stem from a small sample size, with only one patient defined as obese having a seat belt impression and IAI. In addition, there was no significant difference between obesity status and having a seat belt impression. In this study, it is unclear what role obesity plays in car restraints and subsequent abdominal injuries. However, our finding of a lack of association between noted seat belt impressions and IAIs in children with obesity does adds to the growing literature reporting no association between seat belt impressions and IAI in stable patients [28,29]. This reverse finding could be due in part to improvements made in occupant restraint technology; specifically in the areas of smart restraint systems that can adjust for occupant size, position and impact force [30,31]. There were several study limitations. Although the reliability of coding for weight status was high, defining “obese” using only gender, weight and age (weight-for-age) may misclassify borderline patients who may or may not be obese [32,33]. BMI is the most common anthropometric measurement used to define obesity; however, height data were not included the PECARN dataset [32]. It’s also debatable whether BMI is the most appropriate approach to define obesity as it does not quantify visceral fat tissue and does not distinguish between muscle and adipose tissue [32]. We used CDC definitions of obesity, which may underestimate obesity in non-white children, in whom World Health Organization growth curves may be more accurate [16]. Additionally, PECARN centers are predominantly located in large children’s hospitals in urban regions, potentially decreasing generalizability to other settings. Practice guidelines for treatment of acute trauma may also not be comparable across study sites, which directly effects imagery outcomes (CT and US). Also the prevalence of IAIs in this dataset was low (likely obese = 3%; not likely obese = 6%) which effects study power; however, the overall rates were comparable to another study (obese = 6%; non-obese = 11%) where statistical significance was achieved [5]. Another limitation was self-reported or staff documented ethnicity and race. Previous studies have shown that self-reported race or perception of race does not correlate well with federal coding when the patient is a minority, which could possibly misclassify patients in this study [34,35]. Lastly, actual weight was only recorded in approximately 40% of the cases. When comparisons were made between outcomes and recorded weight status, patients with a measured weight were significantly less likely to have an IAI, CT scan and US examination than patients without a recorded or estimated weight. This could possibly be due to the severity of the injury, with less injured children physically able to get on a scale and have their actual weight
Please cite this article in press as: Camp EA, et al. Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children. Obes Res Clin Pract (2020), https://doi.org/10.1016/j.orcp.2020.01.006
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recorded. If this population is less injured, it could create a selection bias resulting in an inaccurate association. Therefore, more research is needed in patients with measured weight and height data and definitive clinical outcomes. Conclusion In this study, children with obesity had a reduced odds for a blunt IAIs and CT scans in the ED. Further research is needed to explain the association of IAIs and childhood obesity, especially in motor vehicle accidents, where improved seat belt technology could reduce injuries. Additional research is also needed to determine if the reduced odds for diagnostic imagery are found in other African-American populations and if any relationship exists between race and MOI, which could potentially impact pediatric ED treatment. Conflict of interest None. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.orcp.2020.01. 006. References [1] Ogden CL, Carroll MD, Fryar CD, Flegal KM. Prevalence of obesity among adults and youth: United States, 2011-2014. NCHS Data Brief 2015;219(1):8. [2] Rasooly IR, Mullins PM, Alpern ER, Pines JM. US emergency department use by children, 2001-2010. Pediatr Emerg Care 2014;30:602–7, http://dx.doi.org/10. 1097/PEC.0000000000000204. [3] Vaughan N, Tweed J, Greenwell C, Notrica DM, Langlais CS, Peter SD, et al. The impact of morbid obesity on solid organ injury in children using the ATOMAC protocol at a pediatric level I trauma center. J Pediatr Surg 2017;52:345–8, http://dx.doi.org/10.1016/j.jpedsurg.2016.09.002. [4] Meroz Y, Gozal Y. Management of the obese trauma patient. Anesthesiol Clin 2007;25:91–8. [5] Rana AR, Michalsky MP, Teich S, Groner JI, Caniano DA, Schuster DP. Childhood obesity: a risk factor for injuries observed at a level-1 trauma center. J Pediatr Surg 2009;44:1601–5, http://dx.doi.org/10.1016/j.jpedsurg.2008.11.060. [6] Brown CV, Neville AL, Salim A, Rhee P, Cologne K, Demetriades D. The impact of obesity on severely injured children and adolescents. J Pediatr Surg 2006;41:88–91. [7] Haricharan RN, Griffin RL, Barnhart DC, Harmon CM, McGwin G. Injury patterns among obese children involved in motor vehicle collisions. J Pediatr Surg 2009;44, http://dx.doi.org/10.1016/j.jpedsurg.2009.02.029, 1218-22. [8] Pollack KM, Xie D, Arbogast KB, Durbin DR. Body mass index and injury risk among US children 9-15 years old in motor vehicle crashes. Inj Prev 2008;14:366–71, http://dx.doi.org/10.1136/ip.2008.019208. [9] Pomerantz WJ, Timm NL, Gittelman MA. Injury patterns in obese versus nonobese children presenting to a pediatric emergency department. Pediatrics 2010;125:681–5, http://dx.doi.org/10.1542/peds.2009-2367. [10] Ringdal KG, Skaga NO, Hestnes M, Steen PA, Roislien J, Rehn M, et al. Abbreviated injury scale: not a reliable basis for summation of injury severity in trauma facilities? Injury 2013;44:691–9, http://dx.doi.org/10.1016/j.injury.2012.06.032. [11] Arbabi S, Wahl WL, Hemmila MR, Kohoyda-Inglis C, Taheri PA, Wang SC. The cushion effect. J Trauma 2003;54:1090–3.
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Please cite this article in press as: Camp EA, et al. Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children. Obes Res Clin Pract (2020), https://doi.org/10.1016/j.orcp.2020.01.006