Defining major trauma using the 2008 Abbreviated Injury Scale

BackgroundThe Injury Severity Score (ISS) is the most ubiquitous summary score derived from Abbreviated Injury Scale (AIS) data. It is frequently used to classify patients as ‘major trauma’ using a threshold of ISS >15. However, it is not known whether this is still appropriate, given the changes which have been made to the AIS codeset since this threshold was first used. This study aimed to identify appropriate ISS and New Injury Severity Score (NISS) thresholds for use with the 2008 AIS (AIS08) which predict mortality and in-hospital resource use comparably to ISS >15 using AIS98.MethodsData from 37,760 patients in a state trauma registry were retrieved and reviewed. AIS data coded using the 1998 AIS (AIS98) were mapped to AIS08. ISS and NISS were calculated, and their effects on patient classification compared. The ability of selected ISS and NISS thresholds to predict mortality or high-level in-hospital resource use (the need for ICU or urgent surgery) was assessed.ResultsAn ISS >12 using AIS08 was similar to an ISS >15 using AIS98 in terms of both the number of patients classified major trauma, and overall major trauma mortality. A 10% mortality level was only seen for ISS 25 or greater. A NISS >15 performed similarly to both of these ISS thresholds. However, the AIS08-based ISS >12 threshold correctly classified significantly more patients than a NISS >15 threshold for all three severity measures assessed.ConclusionsWhen coding injuries using AIS08, an ISS >12 appears to function similarly to an ISS >15 in AIS98 for the purposes of identifying a population with an elevated risk of death after injury. Where mortality is a primary outcome of trauma monitoring, an ISS >12 threshold could be adopted to identify major trauma patients.Level of evidenceLevel II evidence—diagnostic tests and criteria.     

Improving outcomes in a regional trauma system: impact of a level III trauma center

BACKGROUND: Trauma systems decrease morbidity and mortality of injured populations, and each component contributes to the final outcome. This study evaluated the association between a referring hospital's trauma designation and the survival and resource utilization of patients transferred to a level I trauma center. METHODS: Data from the Registry of the American College of Surgeons on patients transferred to a level I trauma center during a 7-year period were subdivided into 3 categories: group 1 = level III-designated trauma center; group 2 = potential level III trauma centers; and group 3 = other transferring hospitals. Trauma and Injury Severity Score methodology was used to provide a probability estimate of survival adjusted for the effect related to injury severity, physiologic host factors, and age. A W statistic was calculated for each type of referring hospital so that comparisons between observed survival and predicted survival could be measured. Differences in W, length of stay, intensive care unit days, and ventilator days were examined using general linear models. RESULTS: Patients transferred to a level I from a level III trauma center (group 1) were more seriously injured (P < .0001) and had improved survival (P < .0018) compared with those transferred from nondesignated hospitals (groups 2 and 3). Patients transferred from large nondesignated hospitals (group 2) had outcomes similar to patients transferred from all other hospitals (group 3). Level I hospital resource utilization did not show significant differences based on referring hospital type. COMMENTS: Outcomes of patients in a trauma system are associated with trauma-center designation of the referring hospitals.     

Cerebral oxygenation in major pediatric trauma: its relevance to trauma severity and outcome

Introduction

Trauma is the commonest cause of death in the pediatric population, which is prone to diffuse primary brain injury aggravated by secondary insults (eg, hypoxia, hypotension). Standard monitoring involves intracranial pressure (ICP) and cerebral perfusion pressure, which do not reflect true cerebral oxygenation (oxygen delivery [Do₂]). We explore the merits of a brain tissue oxygen-directed critical care guide.

Methods

Sixteen patients with major trauma (Injury Severity Score, >16/Pediatric Trauma Score [PTS], <7) had partial pressure of brain tissue oxygen (Pbto₂) monitor (Licox; Integra Neurosciences, Plainsboro, NJ) placed under local anesthesia using twist-drill craniostomy and definitive management of associated injuries. Pbto₂ levels directed therapy intensity level (ventilator management, inotrops, blood transfusion, and others). Patient demographics, short-term physiological parameters, Pbto₂, ICP, Glasgow Coma Score, trauma scores, and outcomes were analyzed to identify the patients at risk for low Do₂.

Results

There were 10 males and 6 females (mean age, 14 years) sustaining motor vehicle accident (14), falls (1), and assault (1), with a mean Injury Severity Score of 36 (16-59); PTS, 3 (0-7); and Revised Trauma Score, 5.5 (4-11). Eleven patients (70%) had low Do₂ (Pbto₂, <20 mm Hg) on admission despite undergoing standard resuscitation affected by fraction of inspired oxygen, Pao₂, and cerebral perfusion pressure (P = .001). Eubaric hyperoxia improved cerebral oxygenation in the low-Do₂ group (P = .044). The Revised Trauma Score (r = 0.65) showed moderate correlation with Pbto₂ and was a significant predictor for low Do₂ (P = .001). In patients with Pbto₂ of less than 20 mm Hg, PTS correlated with cerebral oxygenation (r = 0.671, P = .033). The mean 2-hour Pbto₂ and the final Pbto₂ in survivors were significantly higher than deaths (21.6 vs 7.2 mm Hg [P = .009] and 25 vs 11 mm Hg [P = .01]). Although 4 of 6 deaths were from uncontrolled high ICP, PTS and 2-hour low Do₂ were significant for roots for mortality.

Conclusions

Pbto₂ monitoring allows for early recognition of low-Do₂ situations, enabling appropriate therapeutic intervention.     

Measuring trauma outcomes in India: an analysis based on TRISS methodology in a Mumbai university hospital

BACKGROUND: In this prospective study, the TRISS methodology is used to compare trauma care at a university hospital (Lokmanya Tilak Municipal General (LTMG) Hospital) in Mumbai, India, with the standards reported in the Major Trauma Outcome Study (MTOS). METHODS: Between 1 August 2001 and 31 May 2002, 1074 severely injured patients were included in the study. Survival analysis was completed for 98.3% of the patients. RESULTS: The majority of the patients were men (84%) and the average age was 31 years. 90.4% were blunt injuries, with road traffic crashes (39.2%) being the most common cause. The predicted mortality was 10.89% and the observed mortality was 21.26%. The mean Revised Trauma Score (RTS) was 6.61 +/- 1.65 and the mean Injury Severity Score (ISS) was 16.7 +/- 10.67. The average probability of survival (Ps) was 89.14. The M and Z statistics were 0.84 and -14.1593, respectively. CONCLUSION: The injured in India were found to be older, the injuries more severe and with poorer outcomes, than in the MTOS study.     

Double coding and mapping using Abbreviated Injury Scale 1998 and 2005: Identifying issues for trauma data

Introduction

The 2005 version of the Abbreviated Injury Scale (AIS05) potentially represents a significant change in injury spectrum classification, due to a substantial increase in the codeset size and alterations to the agreed severity of many injuries compared to the previous version (AIS98). Whilst many trauma registries around the world are moving to adopt AIS05 or its 2008 update (AIS08), its effect on patient classification in existing registries, and the optimum method of comparing existing data collections with new AIS05 collections are unknown. The present study aimed to assess the potential impact of adopting the AIS05 codeset in an established trauma system, and to identify issues associated with this change.

Methods

A current subset of consecutive major trauma patients admitted to two large hospitals in the Australian state of Victoria were double-coded in AIS98 and AIS05. Assigned codesets were also mapped to the other AIS version using code lists supplied in the AIS05 manual, giving up to four AIS codes per injury sustained. Resulting codesets were assessed for agreement in codes used, injury severity and calculated severity scores.

Results

602 injuries sustained by 109 patients were compared. Adopting AIS05 would lead to a decrease in the number of designated major trauma patients in Victoria, estimated at 22% (95% confidence interval, 15-31%). Differences in AIS level between versions were significantly more likely to occur amongst head and chest injuries. Data mapped to a different codeset performed better in paired comparisons than raw AIS98 and AIS05 codesets, with data mapping of AIS05 codes back to AIS98 giving significantly higher levels of agreement in AIS level, ISS and NISS than other potential comparisons, and resulting in significantly fewer conversion problems than attempting to map AIS98 codes to AIS05.

Conclusions

This study provides new insights into AIS codeset change impact. Adoption of AIS05 or AIS08 in established registries will decrease major trauma patient numbers. Code mapping between AIS versions can improve comparisons between datasets in different AIS versions, although the injury profile of a trauma population will affect the degree of comparability. At present, mapping AIS05 data back to AIS98 is recommended.     

Mapping Abbreviated Injury Scale data from 1990 to 1998 versions: A stepping-stone in the contemporary evaluation of trauma

Introduction

Many trauma registries have used the 1990 revision of the Abbreviated Injury Scale (AIS; AIS90) to code injuries sustained by trauma patients. Due to changes made to the AIS codeset since its release, AIS90-coded data lacks currency in the assessment of injury severity. The ability to map between the 1998 revision of AIS (AIS98) and the current (2008) AIS version (AIS08) already exists. The development of a map for transforming AIS90-coded data into AIS98 would therefore enable contemporary injury severity estimates to be derived from AIS90-coded data.

Methods

Differences between the AIS90 and AIS98 codesets were identified, and AIS98 maps were generated for AIS90 codes which changed or were not present in AIS98. The effectiveness of this map in describing the severity of trauma using AIS90 and AIS98 was evaluated using a large state registry dataset, which coded injury data using AIS90 over several years. Changes in Injury Severity Scores (ISS) calculated using AIS90 and mapped AIS98 codesets were assessed using three distinct methods.

Results

Forty-nine codes (out of 1312) from the AIS90 codeset changed or were not present in AIS98. Twenty-four codes required the assignment of maps to AIS98 equivalents. AIS90-coded data from 78,075 trauma cases were used to evaluate the map. Agreement in calculated ISS between coded AIS90 data and mapped AIS98 data was very high (kappa = 0.971). The ISS changed in 1902 cases (2.4%), and the mean difference in ISS across all cases was 0.006 points. The number of cases classified as major trauma using AIS98 decreased by 0.8% compared with AIS90. A total of 3102 cases (4.0%) sustained at least one AIS90 injury which required mapping to AIS98.

Conclusions

This study identified the differences between the AIS90 and AIS98 codesets, and generated maps for the conversion process. In practice, the differences between AIS90- and AIS98-coded data were very small. As a result, AIS90-coded data can be mapped to the current AIS version (AIS08) via AIS98, with little apparent impact on the functional accuracy of the mapped dataset produced.     

A Comparison Study of the Injury Score Models

Abstract Background: A central component to the statistical analysis of trauma care is the probability of survival model, which predicts outcome of the trauma event taking into account various anatomical and physiological factors. One of the key input information to the survival model is the injury score which forms the cornerstone of trauma epidemiology. There are many scoring systems currently in use, and the Injury Severity Score (ISS) as the anatomical component of the injury in the probability of survival model is a widely used one. This paper examines the possibility of representing the anatomical component of the trauma using different injury severity scoring methods described in the literature. Material and methods: The dataset used consists of 75,371 cases from the Trauma Audit and Research Network (TARN). TARN regroups 110 hospitals in the UK and it is the largest European trauma registry. Various limitations of ISS have been described in the literature and an investigation into other scoring methods, which could be calculated from the available data, was proposed. Using the available database, the alternative injury scoring methods can be calculated and their use within a Trauma score and Injury Severity Score (TRISS) probability of survival model is assessed. Results: The current score performs reasonably well, but there is some improvement in calibration associated with introducing a score, which takes into account body-region locations of all injuries.     

Predicting work-related disability and medical cost outcomes: A comparison of injury severity scoring methods

Introduction

Acute work-related trauma is a leading cause of death and disability among U.S. workers. Occupational health services researchers have described the pressing need to identify valid injury severity measures for purposes such as case-mix adjustment and the construction of appropriate comparison groups in programme evaluation, intervention, quality improvement, and outcome studies. The objective of this study was to compare the performance of several injury severity scores and scoring methods in the context of predicting work-related disability and medical cost outcomes.

Methods

Washington State Trauma Registry (WTR) records for injuries treated from 1998 to 2008 were linked with workers’ compensation claims. Several Abbreviated Injury Scale (AIS)-based injury severity measures (ISS, New ISS, maximum AIS) were estimated directly from ICD-9-CM codes using two software packages: (1) ICDMAP-90, and (2) Stata's user-written ICDPIC programme (ICDPIC). ICDMAP-90 and ICDPIC scores were compared with existing WTR scores using the Akaike Information Criterion, amount of variance explained, and estimated effects on outcomes. Competing risks survival analysis was used to evaluate work disability outcomes. Adjusted total medical costs were modelled using linear regression.

Results

The linked sample contained 6052 work-related injury events. There was substantial agreement between WTR scores and those estimated by ICDMAP-90 (kappa = 0.73), and between WTR scores and those estimated by ICDPIC (kappa = 0.68). Work disability and medical costs increased monotonically with injury severity, and injury severity was a significant predictor of work disability and medical cost outcomes in all models. WTR and ICDMAP-90 scores performed better with regard to predicting outcomes than did ICDPIC scores, but effect estimates were similar. Of the three severity measures, maxAIS was usually weakest, except when predicting total permanent disability.

Conclusions

Injury severity was significantly associated with work disability and medical cost outcomes for work-related injuries. Injury severity can be estimated using either ICDMAP-90 or ICDPIC when ICD-9-CM codes are available. We observed little practical difference between severity measures or scoring methods. This study demonstrated that using existing software to estimate injury severity may be useful to enhance occupational injury surveillance and research.     

The modified rapid emergency medicine score: A novel trauma triage tool to predict in-hospital mortality

BackgroundTrauma systems currently rely on imperfect and subjective tools to prioritize responses and resources, thus there is a critical need to develop a more accurate trauma severity score. Our objective was to modify the Rapid Emergency Medicine (REMS) Score for the trauma population and test its accuracy as a predictor of in-hospital mortality when compared to other currently used scores, including the Revised Trauma Score (RTS), the Injury Severity Score (ISS), the “Mechanism, Glasgow Coma Scale, Age and Arterial Pressure” (MGAP) score, and the Shock Index (SI) score.MethodsThe two-part study design involved both a modification step and a validation step. The first step incorporated a retrospective analysis of a local trauma database (3680 patients) where three components of REMS were modified to more accurately represent the trauma population. Using clinical judgment and goodness-of-fit tests, systolic blood pressure was substituted for mean arterial pressure, the weighting of age was reduced, and the weighting of Glasgow Coma Scale was increased. The second part comprised validating the new modified REMS (mREMS) score retrospectively on a U.S. National Trauma Databank (NTDB) that included 429,711 patients admitted with trauma in 2012. The discriminate power of mREMS was compared to other trauma scores using the area under the receiver operating characteristic (AUC) curve.ResultsOverall the mREMS score with an AUC of 0.967 (95% CI: 0.963–0.971) was demonstrated to be higher than RTS (AUC 0.959 [95% CI: 0.955–0.964]), ISS (AUC 0.780 [95% CI 0.770–0.791]), MGAP (AUC 0.964 [95% CI: 0.959–0.968]), and SI (AUC 0.670 [95% CI: 0.650–0.690]) in predicting in-hospital mortality on the NTDB.ConclusionIn the trauma population, mREMS is an accurate predictor of in-hospital mortality, outperforming other used scores. Simple and objective, mREMS may hold value in the pre-hospital and emergency department setting in order to guide trauma team responses.     

Impact of joint theater trauma system initiatives on battlefield injury outcomes

Introduction

The US military forces developed and implemented the Joint Theater Trauma System (JTTS) and Joint Theater Trauma Registry (JTTR) using US civilian trauma system models with the intent of improving outcomes after battlefield injury.

Methods

The purpose of this analysis was to elaborate the impact of the JTTS. To quantify these achievements, the JTTR captured mechanism, acute physiology, diagnostic, therapeutic, and outcome data on 23,250 injured patients admitted to deployed US military treatment facilities from July 2003 through July 2008 for analysis. Comparative analysis to civilian trauma systems was done using the National Trauma Data Bank (NTDB).

Results

In contrast to civilian trauma systems with an 11.1% rate of penetrating injury, 68.3% of battlefield wounds were by penetrating mechanism. In the analyzed cohort, 23.3% of all patients had an Injury Severe Score (ISS) ≥16, which is similar to the civilian rate of 22.4%. In the military injury population, 66% of injuries were combat-related. In addition, in the military injury group, 21.8% had metabolic evidence of shock with a base deficit ≥5, 29.8% of patients required blood transfusion, and 6.4% of the total population of combat casualties required massive transfusion (>10 U red blood cells/24 hours). With this complex and severely injured population of battlefield injuries, the JTTS elements were used to recognize and remedy more than 60 trauma system issues requiring leadership and advocacy, education, research, and alterations in clinical care. Of particular importance to the trauma system was the implementation and tracking of performance improvement indicators and the dissemination of 27 evidence-based clinical practice guidelines (CPGs). In particular, the damage control resuscitation guideline was associated with a decrease in mortality in the massively transfused from 32% pre-CPG to 21% post-CPG. As evidence of the effectiveness of the JTTS, a mortality rate of 5.2% after battlefield hospital admission is comparable to a case fatality rate of 4.3% reported in an age-matched cohort from the NTDB.

Conclusions

JTTS initiatives contributed to improved survival after battlefield injury. The JTTS has set the standard of trauma care for the modern battlefield using contemporary systems-based methodologies.     

Comparison of severity and pattern of injuries between motorcycle riders and their pillions: A matched study

Introduction

Motorcyclists and their pillion riders are the most vulnerable group of road users in Singapore, accounting for 50% of all road traffic accident fatalities in 2011. This study aims to compare the severity and pattern of injuries between matched pairs of riders and pillions.

Methods

Thirty-two matched pairs who presented to the A&E of an urban hospital from 1 August 2011 to 20 March 2012 were enrolled. Data were obtained from the hospital's trauma registry records, clinical records and accident victims were interviewed individually. Analysis was done using Stata 10 and considered rider-pillion pairs.

Results

Thirty-one pairs agreed to participate. There was no statistically significant difference in the ISS between riders and pillions (p = 0.25). There was no significant difference in the probability of survival, Revised Trauma Score, distribution of injuries, total duration of admission and ICU stay between riders and pillions. When one party of the matched pair sustained a head, face, thoracic, abdominal/pelvic, extremity or external injury, the likelihood that the other party had an injury in the same region was 31%, 14%, 10%, 14%, 56% and 68% respectively. Cohen's kappa values were 0.28, 0.15, 0.05, 0.17, 0.24 and −0.16 for the respective regions.

Discussion

By comparing the severity and pattern of injuries between naturally matched pairs on the same motorcycle, one can account for potential confounding by the type and impact of collision, rider experience, amount of time to availability of medical aid, and other factors that may influence the outcome. Our study shows no statistically significant difference in the ISS and distribution of injuries between riders and pillions of matched pairs. Therefore, future health and insurance policies should provide equal coverage for both riders and pillions. Medical practitioners should approach riders and pillions similarly as there is no significant difference in their injury distribution. When one party of a matched pair presents with a head, extremity or external injury, care should be taken to look for an injury in the same region in the other party.

Conclusion

Our study shows that there is no statistically significant difference in the ISS of riders and pillions. The pattern of injury is also similar. This study provides us useful information in the clinical management of motorcyclists and their pillions.     

Factors affecting anatomical region of injury, severity, and mortality for road trauma in a high-income developing country: Lessons for prevention

Objectives

To study the factors affecting anatomical region of injury, severity, and mortality among road users in United Arab Emirates so as to improve preventive measures.

Methods

Data of the Trauma Registry of Al Ain city were collected prospectively over 3 years (2003-2006) at the main trauma hospital. For traffic injuries, the following were assessed: gender, nationality, road user type, anatomical region(s) of injury, systolic blood pressure on admission, Glasgow Coma Scale (GCS), Injury Severity Score (ISS), and mortality. Analysis included frequencies, cross-tabulations, and logistic regression.

Results

There were 1070 patients, 89% male, 25% UAE nationals, and with a mean age of 31 years. Expatriates, mainly from non-Arabic speaking, low-income countries, accounted for 88% of injured pedestrians, whilst nationals were overrepresented among vehicle occupants (29%), and motorcyclists 37%. Injuries of the extremities and head were frequent among pedestrians, motorcyclists, and bicyclists, whilst head and spine injuries were most common among front and rear vehicle occupants and drivers. The median ISS was five for pedestrians and four for all other road user types, including rear vehicle occupants. The mean hospitalisation was 9.7 days; 13% of patients were admitted to ICU with mean stay of 6.5 days. Overall mortality was 4%; pedestrians accounted for 61% of deaths. Predictors of mortality were GCS (p < 0.001), ISS (p < 0.01) and systolic blood pressure on admission (p < 0.03).

Conclusions

Head injury was a major factor affecting mortality, followed by injury severity and hypotension. To reduce injury incidence and severity, legislation and education are needed to ensure use of seat belts by all vehicle occupants including rear passengers, high-visibility devices by other road users, helmets by motorcyclists and bicyclists, protective clothing and boots for motorcyclists, and traffic engineering for pedestrians.     

Trauma and Injury Severity Score (TRISS): Is it time for variable re-categorisations and re-characterisations?

Background

Despite its limitations, the Trauma and Injury Severity Score (TRISS) continues to be the most commonly used tool for benchmarking trauma outcome. Since its inception, considerable energy has been devoted to improving TRISS. However, there has been no investigation into the classification or characterisation of the TRISS variables. Using a major nationally representative database, this study aims to explore the adequacy of the existing TRISS model by investigating variable re-categorisations and alternative characterisations in a logistic model used to predict survival in adults after traumatic injury.

Materials and methods

Data were obtained from the National Trauma Data Bank National Sample Project (NSP). Each variable in the TRISS model was related to discharge status and various categorisations considered using weighted logistic regression. Categorisations were treated nominally, using a series of indicator variables. For each variable and classification level, the best category combination was ascertained using the Bayesian Information Criterion (BIC). All best 5-category classified TRISS variables were combined, as were all best 10-category classified TRISS variables, and their predictive performance assessed against two conventionally defined TRISS models on the unweighted NSP sample using area under the Receiver Operating Characteristic curve (AUC) and BIC statistics.

Results

Overall, the weighted sample included 1,124,001 adults with injury events and known discharge status, of whom 1,061,709 (94.5%) were alive at discharge. When separately related to discharge status, each re-classified TRISS variable yielded a superior BIC statistic to its original specification. When investigating predictive performance, complete information was available for 167,239 (79.9%) adults with blunt and 20,643 (82.3%) adults with penetrating injury mechanisms. AUC and BIC estimates for the re-classified TRISS models were superior to the conventionally defined TRISS models. While having better predictive precision, the complexity associated with the best 10-category model resulted in the best 5-category model being preferred for penetrating mechanism injuries and being negligibly inferior for blunt mechanism injuries.

Discussion

Substantial improvements in the predictive power of TRISS were demonstrated by re-classifying the component variables and treating the variable categories nominally. However, before a new TRISS model with updated coefficients can be published, variable interactions and the effect of missing data needs thorough statistical evaluation.     

The Trauma and Injury Severity Score (TRISS) revised

Background

The Trauma and Injury Severity Score (TRISS) remains the most commonly used tool for benchmarking trauma fatality outcome. Recently, it was demonstrated that the predictive power of TRISS could be substantially improved by re-classifying the component variables and treating the variable categories nominally. This study aims to develop revised TRISS models using re-classified variables, to assess these models’ predictive performances against existing TRISS models, and to identify and recommend a preferred TRISS model.

Materials and methods

Revised TRISS models for blunt and penetrating injury mechanism were developed on an adult (aged ≥15 years) sample from the National Trauma Data Bank National Sample Project (NSP), using 5-category variable classifications and weighted logistic regression. Their predictive performances were then assessed against existing TRISS models on the unweighted NSP, National Trauma Data Bank (NTDB), and New Zealand Database (NZDB) samples using area under the Receiver Operating Characteristic curve (AUC) and Bayesian Information Criterion (BIC) statistics.

Results

The weighted NSP sample included 1,124,001 adults with blunt or penetrating injury mechanism events and known discharge status, of whom 1,061,709 (94.5%) survived to discharge. Complete information for all TRISS variables was available for 896,212 (79.7%). Revised TRISS models that included main-effects and two-factor interaction terms had superior AUC and BIC statistics to main-effects models and existing TRISS models for patients with complete data in NSP, NTDB and NZDB samples. Predictive performance decreased as the number of variables with missing values included within revised TRISS models increased, but model performances generally remained superior to existing TRISS models.

Discussion

Revised TRISS models had importantly improved predictive capacities over existing TRISS models. Additionally, they were easily computed, utilised only those variables already collected for existing TRISS models, and could be applied and produce meaningful survival probabilities when one or more of the predictor variables contained missing values. The preferred revised TRISS model included main-effects and two-factor interaction terms and allowed for missing values in all predictor variables. A strong case exists for replacing existing TRISS models in trauma scoring systems benchmarking software with this preferred revised TRISS model.     

Assessment of the severity of injuries to hands by powered wood splitters

Abstract

Our aim was to rate the severity of injuries to hands by powered wood splitters. The patients were identified from a computerised registry, and the cause of injury was confirmed by written questionnaire and structured telephone interview. Information about the anatomy of the injury was gathered from patients' records and radiographs. Severity of injury was rated according to the Hand Injury Severity Scoring System (HISS system) and the Injury Severity Score (ISS). The reliability of HISS rating was tested. The mean Hand Injury Severity Score (HISS) was 63 and the mean ISS was 3.7. Twenty-five (19%) of patients had minor, 41 (31%) had moderate, 30 (23%) had severe, and 35 (27 %) had major injuries when scored by the HISS system. Children's injuries were more severe than those of adults. There was no difference in severity between injuries made by wedge and screw splitters. It is not possible to avoid serious hand injuries from powered wood splitters completely by prohibiting one of the two main types of splitter.