Modification of Glasgow Coma Scale Criteria for Injured Elders. Jeffrey M. Caterino, MD, Amy Raubenolt, MD, MPH, and Michael T.

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1 ORIGINAL RESEARCH CONTRIBUTION Modification of Glasgow Coma Scale Criteria for Injured Elders Jeffrey M. Caterino, MD, Amy Raubenolt, MD, MPH, and Michael T. Cudnik, MD, MPH Abstract Objectives: An abnormal field Glasgow Coma Scale (GCS) score of 13 has been used in our emergency medical services (EMS) system to prompt transport to a trauma center. For elders, Ohio has recently adopted a GCS of 14 to prompt EMS transport to a trauma center, as older patients respond differently to trauma and may benefit from a different GCS threshold. This study sought to determine if a field GCS of 14 is an appropriate cutoff to initiate transport to a trauma center among injured elders. Methods: This was a retrospective, observational statewide analysis of injured patients 16 years old captured by the Ohio Trauma Registry from 2002 to Outcomes studied included mortality, traumatic brain injury (TBI), neurosurgical intervention, and endotracheal intubation (ETI). Multiple imputation was performed to account for missing data. Age-stratified sensitivity and specificity for proposed GCS cutoffs of 13 and 14 were calculated. A series of multivariate logistic regression models was then constructed using each outcome as a dependent variable. Independent variables included age, GCS score, sex, blood pressure, injury type, nontrauma center, race, ethnicity, and Injury Severity Score (ISS). Two separate analyses were performed. For each age group, odds ratios (ORs) of each outcome were calculated both for the decrease in GCS from 15 to 14 and for the decrease from 14 to 13. The group of elders with GCS 14 was then compared to adults with GCS 13. Results: A total of 52,412 study patients were identified. For a GCS cutoff of 13, sensitivity among elders for each outcome was >20% less than sensitivity for adults, and specificity was 5% to 10% greater. Increasing the GCS cutoff for elders to 14 resulted in improved sensitivity for all outcomes (approximately 10%), with a decline in specificity to values near that of adults with GCS 13. In the multivariate models for elders, mortality increased with a decrease in GCS both from 15 to 14 (OR = 1.40, 95% confidence interval [CI] = 1.07 to 1.83) and from GCS 14 to 13 (OR = 2.34, 95% CI = 1.57 to 3.52). In adults, mortality did not increase with the drop from GCS 15 to 14 (OR = 1.22, 95% CI = 0.88 to 1.71) or from GCS 14 to 13 (OR = 1.45, 95% CI = 0.91 to 2.30). When comparing elders with GCS 14 to adults with GCS 13, elders had greater odds of mortality (OR = 4.68, 95% CI = 2.90 to 7.54) and TBI (OR = 1.84, 95% CI = 1.45 to 2.34). Conclusions: Changing the EMS trauma triage cutoff for elders from GCS 13 to GCS 14 results in improved sensitivity for clinically relevant outcomes. In injured elders, the decline in GCS from 15 to 14 is associated with increased mortality, a finding not observed in younger adults. Elders with GCS 14 have greater odds of mortality and TBI than adults with GCS 13. These results support recent changes in EMS trauma triage guidelines for elders adopted in Ohio. ACADEMIC EMERGENCY MEDICINE 2011; 18: ª 2011 by the Society for Academic Emergency Medicine The Glasgow Coma Scale (GCS) is commonly used to determine the severity of neurologic injury in victims of trauma. The GCS provides a score from 3 to 15 based on the patient s eye opening, speech, and movement. It is often used by prehospital providers as part of trauma triage guidelines and algorithms to deter- From the Department of Emergency Medicine, The Ohio State University (JMC, AR, MTC), Columbus, OH; and the Department of Emergency Medicine, Michigan State University, Kalamazoo (AR), Kalamazoo, MI. Received January 11, 2011; revision received April 6, 2011; accepted April 27, Address for correspondence and reprints: Jeffrey M. Caterino, MD; jeffrey.caterino@osumc.edu. Presented at the 2010 Society for Academic Emergency Medicine annual meeting, Phoenix, AZ, May This study was supported by a Trauma Grant from the Ohio Department of Public Safety. The sponsoring agency had no role in or control over the design, methods, subject recruitment, data collection, analysis, or paper preparation. The authors have no relevant financial information or potential conflicts of interest to disclose. Supervising Editor: Scott T. Wilber, MD. ISSN ª 2011 by the Society for Academic Emergency Medicine 1014 PII ISSN doi: /j x

2 ACADEMIC EMERGENCY MEDICINE October 2011, Vol. 18, No mine the most appropriate destination for injured patients. Current guidelines in the Advanced Trauma Life Support (ATLS) course recommend that patients with a GCS score of 13 should be transported by emergency medical services (EMS) providers to a trauma center. 1 There is some evidence of worsening outcomes in adult trauma patients with GCS scores at or below this level. 2 However, these guidelines are not specific to older adults, who may have a different threshold for transport to trauma centers. Almost 20% of patients in the National Trauma Data Bank (NTDB) are 65 years of age or older. 3 As the population continues to age, this number is certain to increase substantially over the next several years. Several studies have identified unique characteristics of the elder trauma patient, including increased rates of comorbidities and mortality. 3 7 Among these differences is the response to neurologic injuries, an especially important topic as there are >80,000 emergency department (ED) visits each year for traumatic brain injury (TBI) among elders. 8 Three-fourths of these patients are admitted, with resulting hospital charges of over $2 billion annually. 8 In addition, mortality from trauma rises sharply after age 70 years and is increased even for older adults with mild TBI. 8,9 Given these differences, it is possible that different GCS cutoffs should be used in the triage of elder trauma patients. Recognition of these differences and the potential for increased mortality was realized by the Ohio Department of Public Safety, which in 2008 adopted specific guidelines for use by EMS providers for the field triage of geriatric trauma patients. 10 These new guidelines recommend a GCS cutoff of 14 as an indication for transport to a trauma center in patients at least 70 years old. The primary objective of this study was to determine if a field GCS of 14 is an appropriate cutoff to initiate transport to a trauma center among injured elders. We hypothesized that injured elders with a field GCS of 14 would have worse clinical outcomes than nonelder adults with a field GCS of 13. METHODS Study Design We performed a retrospective, observational, statewide analysis of injured patients entered into the Ohio Trauma Registry. The hospital s institutional review board determined that the study did not require review, as the use of deidentified registry data did not constitute human subjects research as defined in 45 CFR 46:102(f). Additionally, the requirement for written informed consent was waived. This study was funded by an Ohio Department of Public Safety trauma grant. The authors have no conflicts of interest. The Ohio Department of Public Safety did not exercise any editorial control or review over this paper. Study Setting and Population The Ohio Trauma Registry is a statewide database maintained by the Ohio Department of Public Safety s Division of EMS through its Trauma Committee. 11 Hospital participation is required by law, and approximately 87% of Ohio hospitals, including all trauma centers, submit data to the registry. 12,13 To be eligible for the registry, patients must have an International Classification for Diseases, 9th revision, clinical modification (ICD-9-CM) code for injury (ranging from 800 to 959.9) and at least one of the following characteristics: a first or initial admission for 48 hours, transfer into or out of a hospital or ED setting regardless of length of stay, dead on arrival, or death after receipt of any evaluation or treatment. Patients with isolated hip fractures, late effects of injury, foreign bodies, or superficial abrasions are not included in the registry. 14 Data abstractors undergo online training, have access to a data dictionary, and were unaware of the hypotheses of the current study. 14 The online training includes presentations on uploading data, the data dictionary, and a self-learning packet. Data from trauma centers are extracted by dedicated trauma registrars. Various hospital personnel populate the registry in nontrauma centers, most frequently from the medical records department. All personnel undergo the online training. While the registry data set has not been externally validated, a review of documented comorbidities reveals a similar prevalence between the registry and other national estimates (personal communication November 14, 2007, with Tim Erskine, Supervisor, EMS Office of Research and Analysis). The registry was exported to the authors as Microsoft Excel files (Microsoft Corp., Redmond, WA) which were then converted into Stata format for data analysis (StataCorp, College Station, TX). Inclusion criteria for this study included all patient records in the Ohio Trauma Registry 16 years of age presenting from the scene and transported to any hospital by EMS providers. Data were abstracted for all eligible patients with entries dated between 2002 and Records without an initial EMS patient care record and a complete GCS score documented by EMS were excluded. Patients transferred between institutions (e.g., a patient transferred from a local nontrauma center ED to a trauma center) prior to their discharge from the hospital may have two records in the registry. In these cases, entries were matched to create a single entry for each traumatic event. Matching was conducted using LinkSolv version 4.1 (Strategic Matching, Inc., Morrisonville, NY). Study Protocol Data obtained from the registry for each eligible patient included demographics (age, sex, race, ethnicity), prehospital GCS, mechanism of injury (blunt vs. penetrating), Injury Severity Score (ISS), initial evaluation at a trauma center (Level I, II, or III) or nontrauma center, ICD-9 diagnoses and procedure codes, EMS systolic blood pressure (sbp), EMS and ED endotracheal intubation (ETI), and in-hospital mortality. Age, sbp, and ISS were initially coded as continuous variables; all others were coded as categorical variables. Outcome measures included in-hospital mortality, emergency intubation, clinical brain injury, and neurosurgical intervention. In-hospital mortality was defined as death in the ED or inpatient setting. Emergency intubation was defined as any EMS field or ED intubation recorded in the registry. We used definitions of clini-

3 1016 Caterino et al. GCS TRIAGE CUTOFF IN ELDER TRAUMA cally significant brain injury and neurosurgical intervention as defined in previous studies of the simplified motor score. 15 Clinical brain injury was identified by ICD-9 codes identifying skull fractures with underlying brain injury, intracranial hemorrhage, cerebral contusion, or nonspecific intracranial injury. We did not consider isolated skull fractures, concussion, or nonspecific head injury to meet this definition. Neurosurgical intervention was likewise identified by ICD-9 procedure codes that identified operations on the brain, skull, or meninges, including diagnostic and therapeutic procedures such as shunts, craniotomies, and ventriculostomies. Data were included if identified at either the initial receiving hospital or a hospital to which the patient was transferred. Data Analysis As per the Ohio Trauma Triage Criteria, patients were stratified into two groups by age: age 70 years (elders) and age <70 years (adults). Multiple imputation was used to take full advantage of the maximum numbers of subjects. Multiple imputation is a means of estimating missing data to preserve the sample size. 16,17 By doing so, one can not only maximize the number of subjects to be analyzed, but also reduce any over- or underestimations of estimates that might be found Descriptive statistics including the absolute number and proportion of subjects with each characteristic were calculated. Proportions after the imputation procedure were also calculated. Three analyses were conducted. First, we identified the effect of increasing the GCS cutoff from 13 to 14 on test characteristics for both adults and elders. Sensitivity, specificity, and likelihood ratios with 95% confidence intervals (CIs) were calculated at GCS cutoffs of both 13 and 14. Test characteristics were separately calculated for each of the outcomes in both elders and adults using all patients in the data set. The nonimputed data set was used for this first analysis as there were no missing data in either the GCS or the outcome fields and therefore imputation would not have affected the results. For the second analysis, we used imputed data to construct a series of multivariate logistic regression models to determine if specific GCS cutoffs were independently associated with each of the four outcomes. For the first group of models, we stratified by age and compared those with GCS of 15 to those with GCS 14 in the elder and adult groups separately. We then compared those with GCS 14 to those with GCS 13 in the elder and adult groups separately. For all models, the dependent variable was one of the four outcome variable described in the previous paragraphs. The primary independent variable of interest was the GCS score, dichotomized as either 15 or 14 in the first set of models and as either 14 or 13 in the second set of models. Additional independent variables were included based on their clinical significance including sex, race, ethnicity, injury type, initial presentation to a nontrauma center, EMS sbp, and ISS. The continuous variables sbp and ISS were examined for linearity using fractional polynomial analysis. When found to be nonlinear in the logit, appropriate functional forms were selected after examining the deviances of possible transformations. Each model included only the subset of study patients with the relevant age and GCS scores. As the Hosmer-Lemeshow test may be overly sensitive to small deviations from perfect fit at large sample sizes, the fit of each model was examined using plots of observed versus expected outcomes in each decile of risk. 21 These plots were inspected visually to determine their deviation from the 45-degree line of perfect fit. Third, we used the imputed data set to identify differences in outcome between elders with GCS 14 and adults with GCS 13. We constructed multivariate logistic regression models for each outcome comparing these two groups. Methods of model construction were as described, with the exception that the primary independent variable of interest in this model was being an elder with GCS 14 compared to adults with GCS 13. These models were created using only elders with GCS 14 and adults with GCS 13. As a means of a sensitivity analysis, all multivariate analyses were repeated in the nonimputed data set with entries containing missing data dropped from the analyses. All database management and analyses were completed using STATA version 11 (StataCorp, College Station, TX). RESULTS After matching the records of patients who were transferred to another institution and eliminating patients who were not transported to a facility by EMS, a total of 92,704 records of patients 16 years of age were obtained from the Ohio Trauma Registry. Records of patients missing the initial EMS run sheet (n = 17,318), or who did not have a complete GCS recorded by EMS (n = 22,974), were excluded, leaving 52,412 records meeting entry criteria and included in the study. Among study patients, only four data elements had missing data: sex (0.04%), race (3.4%), EMS sbp (2.3%), and ISS (11.5%). Characteristics of the initial study data set, the imputed data, and the excluded records are shown in Table 1. Proportions of characteristics are generally similar between those included, the imputed data, and those excluded. When checking sample size assumptions, all multivariate models constructed (each with eight independent variables) had >80 events, except for the comparison of elders with GCS 14 to elders with GCS 13 for the neurosurgical intervention (n = 27 events) and ETI outcomes (n = 66 events). Additionally, for the comparison of elders with GCS 14 to adults with GCS 13, there were 54 events in the neurosurgical intervention model. For the first analysis, Table 2 presents test characteristics of GCS cutoffs of 13 and 14 for both elders and adults for each outcome. For mortality, increasing the GCS cutoff from 13 to 14 for elders resulted in an increase in sensitivity of 9.2% and a decrease in specificity of 8.7%. Increasing the GCS cutoff from 13 to 14 for adults resulted in a minimal increase in sensitivity (2.5%, with overlapping CIs) while still resulting in an 8.1% decrease in specificity. For TBI and ETI, increasing the cutoff in elders also provided substantial increases in sensitivity that were accompanied by

4 ACADEMIC EMERGENCY MEDICINE October 2011, Vol. 18, No Table 1 Characteristics of the Study Population Before and After Multiple Imputation Entire Included Study Population (n = 52,412), % (n) Imputed Study Population, % Excluded Lack of EMS Patient Care Report (n = 17,318), % Lack of EMS GCS Score (n = 22,974), % Age 70 years 30.0 (15,708) Sex Female 44.0 (23,073) Male 56.0 (29,316) Missing 0.0 (23) NA Race White 80.0 (41,881) Nonwhite 13.5 (7,076) Missing 3.4 (1,779) NA Ethnicity Hispanic 1.4 (761) Non-Hispanic 95.2 (49,872) Missing 3.4 (1,779) NA Penetrating injury 8.2 (4,296) ISS <15 (mild) 65.0 (34,077) >15 (moderate or severe) 26.6 (12,318) Missing 11.5 (6,017) NA Initial EMS sbp (mmhg) < (2,640) (48,559) Missing 2.3 (1,213) NA Location of initial presentation Level I trauma center 44.6 (23,380) 44.6 Not available Not available Level II trauma center 16.4 (8,567) 16.4 Not available Not available Level III trauma center 5.6 (2,922) 5.6 Not available Not available Nontrauma center 33.5 (17,543) 33.5 Not available Not available EMS GCS score EMS GCS (39,799) 75.9 Not available Not available EMS GCS (4,240) 8.1 Not available Not available EMS GCS (1,660) 3.2 Not available Not available EMS GCS < (6,713) 12.8 Not available Not available In-hospital mortality 5.8 (3,054) TBI 15.2 (7,963) Neurosurgical intervention 1.5 (785) 1.5 Not available Not available EMS or ED intubation 7.6 (3,991) EMS = emergency medical services; GCS = Glasgow Coma Scale; ISS = Injury Severity Score; NA = not applicable; sbp = systolic blood pressure; TBI = traumatic brain injury. decreases in specificity. For these two outcomes, there were similar changes in nonelders. Table 2 also demonstrates that the GCS 13 cutoff for elders provides much worse sensitivity and slightly better specificity than the same cutoff for younger adults. At a GCS 13 cutoff, the sensitivity for elders is over 20% less than that for adults for all outcomes. At this same GCS 13 cutoff, specificity for elders is 5% to 10% greater than that for adults for all outcomes. Increasing the GCS cutoff to 14 for elders results in improved sensitivity for all outcomes. Increasing the elder GCS cutoff to 14 also results in specificity that is equivalent to that for adults whose GCS cutoff is 13. For the second analysis, Table 3 presents the results of the multivariate regression analyses. Both sbp and ISS were found to be nonlinear in the fractional polynomial analysis. Examination of potential functions led to inclusion of the logarithm of sbp. ISS was best described as a dual function: logarithm of ISS plus one over ISS. These forms were used in all models. The first models were constructed for each age group comparing the odds of each outcome in those with GCS 15 to those with GCS 14. Elders with GCS 14 had a higher odds of mortality (odds ratio [OR] = 1.40, 95% CI = 1.07 to 1.83), TBI (OR = 2.50, 95% CI = 2.06 to 3.02), and ETI (OR = 2.22, 95% CI = 1.59 to 3.10) than those with a GCS of 15. There was no difference in the odds of mortality in those adults with a GCS 14 compared to those with GCS 15, but they were more likely to suffer from the other three outcomes. When comparing those with GCS 14 to those with GCS 13, elders had increased odds of mortality at GCS 13. For the third analysis, we compared the group of elders with GCS 14 to adults with GCS 13 (Table 4). In multivariate analysis, elders with GCS 14 had an increased odds of mortality (OR = 4.68, 95% CI = 2.90 to 7.54) and TBI (OR = 1.84, 95% CI = 1.45 to 2.34) compared to adults (nonelders) with a GCS 13. Despite this increase in mortality and TBI, these elders had lower odds of neurosurgical interventions and ETI. In the sensitivity analysis, results from the nonimputed multivariate analyses were consistent with those from

5 1018 Caterino et al. GCS TRIAGE CUTOFF IN ELDER TRAUMA Table 2 Sensitivity and Specificity of Proposed GCS Cutoffs Stratified by Age for the Population of 52,412 Subjects GCS Cutoff Sensitivity, % (95% CI) Specificity,% (95% CI) Positive LR (95% CI) Negative LR (95% CI) Mortality Elders GCS ( ) 93.8 ( ) 8.20 ( ) 0.52 ( ) GCS ( ) 85.1 ( ) 3.99 ( ) 0.48 ( ) Adults GCS ( ) 85.0 ( ) 5.72 ( ) 0.17 ( ) GCS ( ) 76.9 ( ) 3.81 ( ) 0.15 ( ) TBI Elders GCS ( ) 94.3 ( ) 4.85 ( ) 0.77 ( ) GCS ( ) 86.8 ( ) 3.24 ( ) 0.66 ( ) Adults GCS ( ) 87.1 ( ) 4.12 ( ) 0.54 ( ) GCS ( ) 80.0 ( ) 3.26 ( ) 0.44 ( ) Neurosurgical intervention Elders GCS ( ) 91.5 ( ) 5.02 ( ) 0.63 ( ) GCS ( ) 82.8 ( ) 2.89 ( ) 0.61 ( ) Adults GCS ( ) 81.8 ( ) 3.61 ( ) 0.42 ( ) GCS ( ) 73.9 ( ) 2.88 ( ) 0.34 ( ) ETI Elders GCS ( ) 92.9 ( ) 8.07 ( ) 0.46 ( ) GCS ( ) 84.2 ( ) 4.20 ( ) 0.40 ( ) Adults GCS ( ) 87.1 ( ) 6.10 ( ) 0.25 ( ) GCS ( ) 79.0 ( ) 4.01 ( ) 0.20 ( ) Elders are 70 years; adults < 70 years. ETI = endotracheal intubation to the note; GCS = Glasgow Coma Scale; LR = likelihood ratio; TBI = traumatic brain injury. the imputed set in duration, magnitude, and significance of ORs except in two cases. Adults with GCS 13 had greater mortality than those with GCS 14 (OR = 1.67, 95% CI = 1.03 to 2.71). Also, there was no difference in the odds of neurosurgical interventions among adults with GCS 13 (OR = 1.51, 95% CI = 0.99 to 2.33) compared to adults with GCS 14. All models in the sensitivity analysis demonstrated adequate fit by the Hosmer-Lemeshow test. DISCUSSION When evaluating the injured patient, EMS providers must quickly determine the need for transport to a trauma center, as trauma center care improves mortality for moderate to severely injured patients, including elders Identification of patients at risk for adverse outcomes is the primary reason for use of field trauma triage criteria such as the GCS. 27,28 Although widely adopted, such criteria have rarely been validated in older populations. In fact, several studies have demonstrated particularly poor sensitivity of widely used criteria for predicting moderate to severe injury in elders when compared to younger adults In response, Ohio has recently instituted specific geriatric trauma triage criteria for EMS providers that include use of GCS 14 as the cutoff for transport to a trauma center. 10 In this study, we observed that elders with a GCS of 14 have greater mortality than both elders with GCS 15 and adults with GCS 13. Increasing the GCS cutoff to 14 for elders improves sensitivity for detection of clinically important outcomes. These results support the recent changes in trauma triage guidelines for elders adopted in Ohio. This study has three primary findings that support this conclusion. First, increasing the GCS cutoff from 13 to 14 for elders improves sensitivity. At a GCS cutoff of 13, there was much worse sensitivity for each outcome in elders than in adults, a result consistent with prior studies For example, a GCS 13 cutoff was only 50.7% sensitive in detecting mortality in elders, but was 85.7% sensitive in adults. In tandem with this lower sensitivity, a GCS cutoff of 13 demonstrated higher specificity for elders than adults. For all four outcomes, increasing the cutoff for elders to a GCS 14 improved sensitivity while resulting in no worse specificity than younger adults at a GCS cutoff of 13. Second, for elders the decline in GCS from 15 to 14 was an independent marker of increased mortality, TBI, and ETI. This same decline in GCS from 15 to 14 among adults was not associated with increased mortality, although it was associated with the other three study outcomes. Adjusted mortality, then, appears to increase for elders at GCS 14, but not until GCS 13 for younger adults. This is likely secondary to differences in elderly patient physiology, as well as the increased risk of serious brain injury in elderly patients compared to younger patients, offering further justification for the use of any change of the GCS score in elderly patients to be an indication for direct transport to a trauma center. Finally, elders with a GCS of 14 have higher odds of mortality (OR = 4.68) and of TBI (OR = 1.84) than adults with GCS 13, suggesting that the transport of this population of elders directly to trauma centers may be advantageous. Despite greater odds of mortality and TBI, these elders were less likely to undergo neurosurgical intervention or ETI. As both of these outcomes are dependent on provider treatment decisions, further study of choices made in providing advanced interventions to injured elders is warranted. 32 Our findings are consistent with previous work on injured elders. It has been shown that elders with severe head injury have worse outcomes than younger patients

6 ACADEMIC EMERGENCY MEDICINE October 2011, Vol. 18, No Table 3 Results of Multivariate Logistic Regression Models for Each Level of GCS Score* GCS 14 Compared to GCS 15 GCS 13 Compared to GCS 14 OR SE (95% CI) OR SE (95% CI) Mortality Elders ( ) ( ) Adults ( ) ( ) TBI Elders ( ) ( ) Adults ( ) ( ) Neurosurgical intervention Elders ( ) 2.41à 1.02 ( ) Adults ( ) ( ) ETI Elders ( ) 1.16à 0.36 ( ) Adults ( ) ( ) Elders 70 years; adults < 70 years. ETI = endotracheal intubation; GCS = Glasgow Coma Scale; ISS = Injury Severity Score; sbp = systolic blood pressure; SE = standard error. *Controlling for sex, sbp (log form), injury type, nontrauma center, race, ethnicity, and ISS (log form plus one over ISS) Model is based on dichotomous versions of systolic BP and ISS as models with transformed continuous forms lacked convergence àregression results based on <80 outcomes which may result in unstable estimates. Table 4 Results of Multivariate Logistic Regression Models for Comparing Adults With GCS 13 to Elders with GCS 14* Elders Outcomes OR SE (95% CI) Mortality ( ) TBI ( ) Neurosurgical intervention 0.39à 0.14 ( ) ETI ( )à ETI = endotracheal intubation; GCS = Glasgow Coma Scale; ISS = Injury Severity Score; SE = standard error. *Controlling for elder age, sex, systolic BP (log form), injury type, non-trauma center, race, ethnicity, and ISS (log form plus one over ISS) Model is based on dichotomous versions of systolic BP and ISS as models with transformed continuous forms lacked convergence. àregression results based on <80 outcomes which may result in unstable estimates. with the same level of injury This finding extends even to elders with minor head injury. 9,32,33 Susman et al. 9 found that among those with GCS 13 to 15, the mortality rate for elders was significantly greater compared to that of younger patients. Bouras et al. 32 found that in patients with GCS 14, mortality rates remained near 0% in adults under 65 years of age, but increased to 10% to 15% in patients 65 years and over. These studies demonstrate similar mortality rates in their elder patients to the 10% mortality rate found in our elders with GCS 14 and the 5.5% rate found in our elders with GCS 15. Their mortality rates for younger adults are also within the range we found for younger adults with GCS 13 (4.5%). In these studies, mortality in elders increased with each individual decline in GCS level from 15 to 14 to 13. This increase was not observed in younger adults. We provide additional discrete information regarding the relationship between GCS and outcomes in elders that further clarifies the results of these prior studies, as we have analyzed data both by age group and by specific GCS score, comparing between and among these groups. Across our statewide registry, we have described the changes in outcome (morbidity and mortality) at each step of GCS from 15 to 14 to 13 for both elders and adults. With mortality beginning to rise for elders at GCS 14, this may be a more attractive cutoff for transport to a trauma center in older adults. The additional reporting of sensitivity and specificity at each cutoff provides greater clarity on the effect of selecting such a cutoff. In elders, a GCS 14 is associated with increasing mortality, even when controlling for multiple confounding factors. Using this as a cutoff for transport to a trauma center would improve the sensitivity of the triage process with only minor losses in specificity. The additional analysis of adults less than 70 years of age seems to indicate that there would be no advantage either in predicting outcome or in improving sensitivity specificity for increasing the GCS cutoff in younger adults. These findings, if validated in other studies and states, would not only potentially improve the outcomes of injured elders by transporting them to a higher level of care directly, but might also aid in simplifying the transport of elders in the prehospital setting. Namely, any change in an elderly patient s GCS would be used to determine the need for transport to a trauma center, rather than calculating the exact GCS score. This would decrease the potential confusion of calculating a GCS for elderly patients, as prior work has demonstrated the challenges of calculating field GCS in injured patients. This would also potentially decrease the time EMS personnel have to spend on the scene, which would result in faster transport to a

7 1020 Caterino et al. GCS TRIAGE CUTOFF IN ELDER TRAUMA trauma center and less time that an ambulance is out of service for other potential patients. With further validation, consideration should be given by others to modifying current trauma triage guidelines to use any change in GCS as a criterion for transport of an elder patient to a trauma center. LIMITATIONS Limitations of this study include those inherent in the examination of large, preexisting databases. Actual data abstraction is by local hospitals and thus subject to variability. In particular, trauma centers use trauma registrars, who may be more accurate than medical records personnel at nontrauma centers. We also had a large number of patients excluded due to absence of EMS patient care reports or GCS scores. Although their characteristics were very similar to the study population, we cannot exclude the possibility of unexamined confounders resulting in an inclusion bias. This may have resulted in underestimation of the CIs. The registry does not identify deaths after hospital discharge, which may represent a significant component of mortality due to trauma. 36 Such deaths are particularly increased in elders, so we would expect the spread between younger and older patients regarding mortality to be even greater than that observed in this study. 36 A wide range of ages has been used in the trauma literature to define elders, ranging from 50 through 80 years. 4,5,26,30,31,37,38 We chose age 70 as the cutoff for elders based on its use by the Ohio geriatric criteria, as well as previous analysis of mortality trends in the Ohio Trauma Registry. 39 Even though there has been some controversy concerning the inter-rater reliability and reproducibility of some field GCS scores, 40,41 these issues arise primarily for the most severe injuries, and such agreement has been excellent for GCS scores of 13 to We did not consider the presence of medical comorbidities, such as anticoagulation use, in our models. Specifically, documentation of anticoagulation use is not reliably available in the trauma registry. These additional factors may influence the results of the multivariate models. Finally, we did not examine hospital resource use for these patients, such as length of intensive care unit stay or the use of blood products, which might offer additional information with regards to the necessity of transport directly to a trauma center. Future studies should investigate whether elders with a GCS of 14 utilize greater hospital resources or not. CONCLUSIONS Changing the EMS trauma triage cutoff for elders from GCS 13 to GCS 14 results in improved sensitivity for four clinically relevant outcomes. In injured elders, the decline in GCS from 15 to 14 is associated with increased mortality, a finding not observed in younger adults. Additionally, elders with GCS 14 have greater odds of mortality and TBI than younger adults with GCS 13. These results support recent changes in trauma triage guidelines for elders adopted in Ohio. The authors would like to acknowledge Tim Erskine, EMT-P, Supervisor and Acting State Trauma Coordinator, and Sue Morris, EMT-P, Data Analyst from the Ohio EMS Division s Office of Research and Analysis for their aid in obtaining the data set. References 1. American College of Surgeons. ATLS: Advanced Trauma Life Support Program for Doctors. Chicago, IL: American College of Surgeons, Ross SE, Leipold C, Terregino C, O Malley KF. Efficacy of the motor component of the Glasgow Coma Scale in trauma triage. J Trauma. 1998; 45: Clark DE, Fantus R (eds). National Trauma Data Bank 2007 Annual Report, Version 7.0. Available at: pdf. Accessed Jul 13, Richmond TS, Kauder D, Strumpf N, Meredith T. Characteristics and outcomes of serious traumatic injury in older adults. J Am Geriatr Soc. 2002; 50: Morris JA Jr, MacKenzie EJ, Damiano AM, Bass SM. 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