Effectiveness of the APACHE II Scoring System in an Intensive Care Unit: Results of a Prospective Study

Background: The high cost of intensive care unit (ICU) services and limitations in health resources can prompt managers to use predictive scoring systems.
Objective: To evaluate the role of APACHE II as a scoring system to predict outcomes and to compare actual and expected mortality rates.
Methods: This prospective study was conducted in a10-bed, mixed ICU at Namazi University Hospital, a teaching hospital in Shiraz, Iran. All patients were included consecutively and data were collected during the first 24 h of admission. Statistical analyses were done with SPSS v.16 software. The differences were considered statistically significant at a P value of <0.05.
Results: From June to November of 2013, data were available for 110 (61.4%) ICU admission. The patients’ mean (SD) age was 55.1 (17.7) years. Mean APACHE II score was 17.85±7.4. The total standardized mortality ratio (SMR) was 0.92, and the ratio ranged from 0.48 in medical patients to 1.22 in post-elective surgery patients. With the sensitivity 18.5% and specificity 92.8%, the highest correct classification was obtained at predicted death risk 0.6 (74.5%).
Conclusion: We recommend the use of this outcome prediction score for decision-making and classifying patients based on the degree of severity of their diseases in our setting. Further work is needed with larger sample sizes to more precisely determine the generalisability of our results and evaluate validity of this outcome prediction score.