VERIFICATION OF THE ACUTE PHYSIOLOGY AND CHRONIC HEALTH EVALUATION SCORING SYSTEM IN A HONG-KONG INTENSIVE-CARE UNIT

Objectives: To validate the Acute Physiology and Chronic Health Evalua tion (APACHE II) severity of illness scoring system in Chinese patient s in a multidisciplinary intensive care unit (ICU) in Hong Kong. To au dit the service and utilization of an ICU with a low ICU to hospital b ed ratio. Design: Prospective data collection and review. Setting. A 1 2-bed multidisciplinary ICU within a 1,430-bed tertiary care universit y hospital. Patients. Data from 1,573 of 1,814 consecutive patients ad mitted to the ICU from May 1988 to November 1990 were studied. The pat ients were all Chinese. Interventions: None. Measurements and Main Res ults. The patients' clinical details and APACHE II scores were recorde d on day 2 of admission and reviewed at hospital discharge or after de ath. The APACHE II scores, risk of death values, age, and length of IC U stay between survivors and nonsurvivors were compared by two-sample t-tests. Relationships between mortality and APACHE II score, risk of death, and results from previous studies were investigated using the P earson product moment coefficient and regression analysis. Predictive capacity of risk of death was assessed by receiver operating character istic curve analysis. The hospital mortality rate for study patients w as 36%. Survivors were younger, had shorter ICU stays, lower APACHE sc ores, and lower risk of death values than nonsurvivors (p < .001). The re was close correlation (r2 = .81, .77, and .76 for all patients, ope rative group, nonoperative group, respectively) between APACHE II scor es and predicted risk of death values. Risk of death was an accurate g roup predictor of death in all patients and in separate operative and nonoperative groups. Areas under the receiver operating characteristic curves were 0.89 (all patients), 0.85 (operative), and 0.88 (nonopera tive). Neither the Apache II scores nor risk of death scores were suff iciently accurate to predict outcome of individual patients. There was close concordance between observed and predicted mortality of patient groups. Mortality ratio was 0.97 (all patients), 0.89 (operative grou p), and 1.02 (nonoperative group). Chronological age, per se, was not a good predictor of mortality. The audit of the ICU service showed a s hort length (4.2 days) of ICU stay and high bed occupancy (80%). Subgr oups of low-risk, postoperative patients with good outcomes and poor-r isk patients admitted after cardiopulmonary arrest with a high mortali ty rate were identified. Conclusions: The APACHE II scoring system was an accurate predictor of group outcome in a Chinese population, makin g it suitable for comparisons between countries. Application of the AP ACHE II scoring system in a clinical audit facilitates critical apprai sal of an ICU service. Problems identified by the study were a shortag e of ICU beds and delayed referrals of patients.