Road traffic trauma outcome at Kenyatta National Hospital: comparison of the Trauma and Injury Severity Score (TRISS) and the Trauma Mortality Prediction Model (TMPM)

Abstract

Background: Road traffic trauma is an increasing problem whose managem~t in Kenya has been suboptimal. The goal of improving health care quality and trauma care in particular, rely on the ability to accurately measure health care outcomes. Achieving this goal requires the use of validated risk adjustment models for benchmarking of hospital performance.

Objectives: Comparison of the trauma and injury severity score (TruSS) methodology and the trauma mortality prediction model (TMPM) in evaluation of the road traffic trauma outcomes at Kenyatta national hospital.

Design: Prospective descriptive study Material and methods: Patients presenting at the accident and emergency of Kenyatta national hospital after road traffic trauma were prospectively studied. Data was collected on demographic factors, respiratory rate, blood pressure and Glasgow coma scale, injuries sustained and emergency disposition.

Data management/Analysis: Mortality was the dependent variable. The independent variables (TruSS AND TMPM models) were assessed by measures of discrimination (using the area under ROC) and calibration (using the Hosmer-Lemeshow [H-L] statistic). STATA 12 was used for analysis. In all analyses, confidence interval and significance level of P value were 95% and 0.05 respectively.

Results: A total of 210 patients with road traffic injuries were recruited into the study. Male comprised 78.6% of the study cohort. The mean age was 33.1 yrs (range 15-63). The means systolic blood pressure was 115.5 (61-210), respiratory rate 20.9 (8-34) and Glasgow coma scale 13.7 (3-15). The mean injury severity score was 10.37 (2-34). Most patients (71.9%) were directly admitted in the orthopedic wards from the accident and emer~ency unit. TruSS exhibited significantly better discrimination (TruSS ROC= 0.786 (0.610 - 0.961); TMPM-ICD 9= 0.641 (0.479 - 0.802)) and calibration (TruSS H-L = 0.38; TMPM-ICD 9 H-L =16.9) compared to TMPM-ICD 9.

Conclusion: TruSS outperformed TMPM-ICD 9 for evaluation of road traffic casualties at KNH and should be used for benchmarking road traffic trauma outcomes at Kenyatta National hospital.