Injury Severity Score Precision for Determining Undertriage in Trauma Consultation Patients: A Retrospective Study

Objectives Because the Injury Severity Score (ISS) has not been fully endorsed for determining trauma undertriage, we investigated its precision. This study aimed to 1) compute undertriage proportions using the Peng and Cribari methods; 2) compare risk conditions and outcomes for patients with ISS ≥16 who were classified according to an activation or consultation status; 3) calculate proportions of patients with ISS ≥16, without and with qualifications (death or increased length of stay), as potential categories for assessing undertriage in trauma consultation patients; and 4) compute the undertriage proportion among trauma consultation patients by using an intracranial hemorrhage (ICH)-Glasgow Coma Scale score (GCS)-ISS categorization method and employing targeted electronic medical record audits (EMRA). Methodology Age, ISS, GCS, activation status (full, partial, or consultation), injury mechanism, death, intensive care stay, and hospital stay were obtained from the trauma registry. An adverse outcome (AO) was death, intensive care stay ≥two days, or hospital stay >five days. ICH status, clinical details, and comorbidity were obtained from EMRA. Each consultation patient was assigned to an ICH-GCS-ISS category with targeted EMRA. Results Of 2,076 consecutive trauma center admissions, 405 had full activation, 640 had partial activation, and 1,031 had consultation. Using Peng and Cribari methods, undertriage proportions were 64.2% and 21.7%, respectively. Compared with consultation patients with ISS ≥16, full or partial activation patients with ISS ≥16 had much higher proportions (p<0.0001) of non-fall mechanisms, age <70 years, GCS <15, ISS ≥25, mortality, intensive care admission, and hospital stay >five days. The proportions of consultation nonqualified ISS ≥16 undertriage and ISS ≥16-AO undertriage were 21.1% (218 ISS ≥16÷1,031) and 9.8% (101 ISS ≥16-AO÷1,031), respectively. Of the 101 ISS ≥16-AO patients, 79.2% were aged ≥70 years or had comorbidity. The consultation ISS ≥16-death undertriage proportion was 1.5% (15 ISS ≥16-deaths÷1,031). The ICH-GCS-ISS consultation categorization undertriage proportion was 11.0% (113÷1,031). ICH-GCS-ISS undertriage proportions were as follows: ICH with GCS <15, 77/77; no ICH with ISS ≥16 (EMRA for major injury), 14/60; scene ICH & GCS 15 & ISS ≥16, 0/43; transfer ICH & GCS 15 & ISS ≥16 (EMRA for intracranial mass effect), 22/69; no ICH with ISS <16, 0/629; and ICH & GCS 15 & ISS <16, 0/153. Conclusions Because ISS ≥16 consultation and activation patient risk conditions and outcomes are dissimilar, commingling these cohorts for undertriage assessment is dubious. Death and increased length of stay-qualified ISS ≥16 with EMRA can be useful to assess undertriage in trauma consultation patients. Because most ISS ≥16-AO consultations were elderly or had comorbidity, the benefit of trauma activation is uncertain. Consultation ICH-GCS-ISS categorization with EMRA was needed in only 12%, indicating a relatively facile undertriage method.