A New Scale Based on CT Classification and the Glasgow Coma Scale to Extract Non-preventable Trauma Death in TRISS Methodology

Abstract

To improve the quality of trauma care, we adopted the TRISS methodology in Japan from 1995, but have faced difficulties judging the preventability with reliability and objectivity by peer review. In this study, the authors designed and verified a new objective scale based on CT classification and the Glasgow Coma Scale to extract non-preventable death. All trauma patients admitted to 10 designated trauma and emergency medical centers around the Tokyo metropolitan area from April 1, 1994, until March 31, 1996, were reviewed. During the period, 3, 476 trauma patients were admitted, and 351 out-of-hospital cardiac arrests were excluded. Of the remaining 3125 patients, 747 patients were dead, and 189 (25.3%) of them had a Ps value of more than 0.5 and were defined as unexpected death. By peer review, we judged 84 cases as preventable trauma death (PTD) and the other 105 (55.6%) as non-preventable trauma death. There were 346 severe head injury patients without other severe fatal traumas. The mean GCS was compared to mortality for each CT classification. They are statistically significant difference for GCS and mortality. Patients whose mortality exceeds 50% significantly might be decided as non-preventable trauma death without further discussion by peer review. These subgroups include GCS 3 to 5 of D₃, GCS 3 to 5 of D₄, and GCS 3 of SDH. Patients whose mortality exceeds 50%, but not significantly because of a small number might be considered as candidates of non-preventable trauma death at the peer review discussion. These subgroups include GCS 6 to 8 of D₃, GCS 4 to 5 of SDH and GCS 3 to 5 of MIX. This new objective scale will contribute to future trauma analysis and improvement of trauma care quality.