APACHE II, data accuracy and outcome prediction.

From review of 122 intensive care charts, Acute Physiology and Chronic Health Evaluation (APACHE) II points were determined for eight physiological values. Using a strict interpretation of APACHE II criteria, an average of 20.6% of these points were higher and 6.7% lower than the points entered originally into an intensive care database. The resulting 1.73 points mean increase in APACHE II score increased predicted mortality from 24.8% to 27.8% and decreased the mortality ratio (observed hospital deaths devided by predicted deaths) from 1.52 (95% confidence interval: 1.11-2.03) to 1.35 (95% confidence interval: 0.99-1.81). There were few errors entering the data recorded on the audit form into the intensive care unit database with an optical mark reader and keyboard. Inaccuracy and inconsistency in data collection must be excluded before differences in mortality ratios are ascribed to intensive care unit performance.