Many of critically ill patients are being cared for prolonged periods in ED just because of limited number of ICU beds and utilize of ED as the entry point to the health care system. The aim of this study is evaluation efficiency of APACHE III scoring system in predicting mortality rate of the mentioned patients.

This cross-sectional, observational, analytic study was performed in one year period. A hundred patients remaining in ED and necessitating ICU hospitalizing were enrolled by the convenience type of non-probability sampling. Then, the APACHE III scores, predicted and observed mortality rates were calculated using of information obtained from patients' files, interview with the patients' family and performing required physical exams and lab tests.

In the assessment of 100 patients, men group were 56% (56) and women group 44% (44). The age of patients and the ED lengths of stay were 66.07 ± 19.92 years and 5.11 ± 3.79 days respectively. The average (± SD) of APACHE III score of the enrolled patients was 58.89 ± 18.24 and the predicted mortality rate calculated 32.73%; while, the total of observed mortality rate was 55%. The average (± SD) of APACHE III score of survivors and non-survivors were 48.63 ± 16.35 and 67.63 ± 14.84 respectively. So, there was a significant deference (p < 0.001). Also, there was a significant deference in the ED lengths of stay between survivors and non-survivors (3.20 ± 1.34 and 6.57 ± 4.40 respectively, p < 0.001).

In our study, APACHE III score and ED lengths of stay were higher versus other studies in Iran and other countries; which show more critical patients presenting to our hospital and limited ICU beds versus patients. This study results nevertheless there was significant difference between predicted and observed mortality rates, the APACHE III scoring system is applicable to evaluating care, treatment and prognosis of ED patients, as is used in ICU.