Page 96 - Journal of Special Operations Medicine - Summer 2015

Interobserver Variability in
Injury Severity Scoring After Combat Trauma:
Different Perspectives, Different Values?

Iain M. Smith, MB BChir, MSc, MRCSEd;
David N. Naumann, MB BChir, MRCS; Paul Guyver, MBBS, FRCS;
Jonathan Bishop, PhD; Simon Davies, BN(Hons), DipIMC RCSEd, RGN;
Jonathan B. Lundy, MD; Douglas M. Bowley, MBBS, FRCS

ABSTRACT
Background: Anatomic measures of injury burden pro- Introduction
vide key information for studies of prehospital and Coding is a key process in trauma systems, providing
in-hospital trauma care. The military version of the Ab- a standardized record of individual injuries and a ba-
breviated Injury Scale [AIS(M)] is used to score injuries sis for calculation of estimates of overall injury burden.
in deployed military hospitals. Estimates of total trauma Such scores are commonly reported as demographic pa-
burden are derived from this. These scores are used for rameters in the trauma literature and are used to assess
categorization of patients, assessment of care quality, the performance and governance of care within and be-
and research studies. Scoring is normally performed ret- tween trauma systems. Accuracy and reproducibility
1,2
rospectively from chart review. We compared data re- in scoring, therefore, are essential.
corded in the UK Joint Theatre Trauma Registry (JTTR)
and scores calculated independently at the time of sur- There are four widely used scoring systems of importance
gery by the operating surgeons to assess the concordance in the assessment of the burden of traumatic injuries: (1)
between surgeons and trauma nurse coordinators in as- the Abbreviated Injury Scale (AIS) ; (2) a military ad-
3,4
signing injury severity scores. Methods: Trauma casual- aptation of the AIS [AIS(M)], which has been reported
5
ties treated at a deployed Role 3 hospital were assigned to predict mortality for casualties injured on military
AIS(M) scores by surgeons between 24 September 2012 operations more accurately than the civilian version ;
6
and 16 October 2012. JTTR records from the same pe- (3) the Injury Severity Score (ISS) ; and (4) the New In-
7
riod were retrieved. The AIS(M), Injury Severity Score jury Severity Score (NISS). These scores are calculated
8
(ISS), and New Injury Severity Score (NISS) were com- using objective and consistent measures. The first two
pared between datasets. Results: Among 32 matched systems are based on the assignment of injury severity
casualties, 214 injuries were recorded in the JTTR, to individual injuries within defined anatomic regions
whereas surgeons noted 212. Percentage agreement for by matching the injury against detailed descriptions
number of injuries was 19%. Surgeons scored 75 injuries within the relevant dictionary; the remaining systems are
as “serious” or greater compared with 68 in the JTTR. derivatives of these. Illustrative injuries for the various
Percentage agreement for the maximum AIS(M), ISS, AIS(M) grades are shown in Table 1, and Figure 1 shows
and NISS assigned to cases was 66%, 34%, and 28%,
respectively, although the distributions of scores were
not statistically different (median ISS: surgeons: 20 [in- Table 1 Examples of Injuries Assigned Various Abbreviated
terquartile range (IQR), 9–28] versus JTTR: 17.5 [IQR, Injury Scale (Military Version) Scores
9–31.5], p = .7; median NISS: surgeons: 27 [IQR, 12– Score Severity Example
42] versus JTTR: 25.5 [IQR, 11.5–41], p = .7). Conclu- 1 Minor Isolated rib fracture
sion: There are discrepancies in the recording of AIS(M)
between surgeons directly involved in the care of trauma 2 Moderate Testicular avulsion
casualties and trauma nurse coordinators working by 3 Serious Simple hemothorax
retrospective chart review. Increased accuracy might be
achieved by actively collaborating in this process. 4 Severe Below-knee traumatic
amputation
Keywords: Injury Severity Score; Abbreviated Injury Scale; 5 Critical Femoral artery injury with
trauma; surgeon; trauma nurse coordinator >20% blood loss
6 Maximum Torso transsection

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