Background In recent years, several trauma scoring systems have been developed and validated for use in prediction of outcome. TRISS combines physiologic and anatomic components of injury with age to characterise the severity of injury. The APACHE II score consists of 12 physiologic variables ,pre morbid health ,and patient age . To investigate the association between APACHE II score, TRISS score and the outcome of care among trauma patients.

Methods The retrospective descriptive study was undertaken during 2012–2014. Medical records of 209 patients admitted to the Trauma ICU were reviewed for age, sex, admitting APACHE II and TRISS scores, length of ICU stay and outcome of care. Outcome of care referred to whether the patients died or survived at discharge. Multiple logistic regression was used to construct the prediction model.

Results Factors significantly and independently associated with the outcome of Trauma ICU care were APACHE II score, TRISS score, and length of ICU stay. For each point increased of APACHE II score, patient survival rate decreased 1.12 times (Adjusted odds ratio: AOR = 1.12, 95% CI: = 1.04–1.22). However, when ICU length of stay increased 1 day survival rate increased 1.26 times (AOD = 1.26, 95% CI: = 1.12–1.41). Similarly, when TRISS score increased 0.1 point, survival rate increased 5.42 times (AOD = 5.52–532.67).

Conclusions Less severe illness (lower APACHE II score), higher probability of survival (higher TRISS score) and longer ICU length of stay significantly predicted patient survival in the Trauma ICU.