Accuracy and reliability of APACHE II scoring in two intensive care units - Problems and pitfalls in the use of APACHE II and suggestions for improvement

Acute Physiology and Chronic Health Evaluation (APACHE) II scoring is widel y used as an index of illness severity, for outcome prediction, in research protocols and to assess intensive care unit performance and quality of car e. Despite its widespread use, little is known about the reliability and va lidity of APACHE II scores generated ill everyday clinical practice. We ret rospectively re-assessed APACHE II scores from the charts of 186 randomly s elected patients admitted to our medical and surgical intensive care units. These 'new' scores were compared with the original scores calculated by th e attending physician. We found that most scores calculated retrospectively were lower than the original scores; 51% of our patients would have receiv ed a lower score, 26% a higher score and only 23% would have remained uncha nged. Overall, the original scores changed by an average of 6.4 points. We identified various sources of error and concluded that wide variability exi sts in APACHE II scoring in everyday clinical practice, with the score bein g generally overestimated. Accurate use of the APACHE II scoring system req uires adherence to strict guidelines and regular training of medical staff using the system.