Prognostic accuracy of Acute Physiology and Chronic Health Evaluation II scores in critically ill cancer patients

Abstract

Background: The predictive accuracy of scores on the Acute Physiology and Chronic Health Evaluation II (APACHE II) for in-hospital mortality among critically ill cancer patients varies.

Objective: To evaluate the predictive accuracy of APACHE II scores for severity of illness in critically ill cancer patients and to find clinical indicators to improve the accuracy.

Methods: Actual hospital mortality rates were compared with predicted rates. Data were collected prospectively from 1263 cancer patients admitted to the intensive care unit during a 5-year period in a cancer center in Taiwan. The APACHE II score for each patient was calculated at admission. Stepwise logistic regression was used to identify clinical predictors associated with increased mortality.

Results: The scores ranged from 2 to 54. The mortality rates were 19% overall, 45% for medical patients, and 1% for surgical patients. The fit of the scores was good for the medical patients (Hosmer-Lemeshow statistic 8.2, P = .41). The estimated odds ratios for mortality of presence of metastasis and respiratory failure were 4.18 (95% CI 2.65-6.59) and 2.03 (95% CI 1.22-3.38), respectively. When metastasis and respiratory failure were incorporated into the APACHE II model, the area under the receiver operating characteristic curve for medical patients increased from 0.82 to 0.86. The fit of the modified model was excellent (Hosmer and Lemeshow statistic 6.57, P=.58).

Conclusions: APACHE II scores are predictive of hospital mortality in critically ill cancer patients. The presence of metastasis and respiratory failure at admission are also associated with outcome.