Validating the APACHE IV score in predicting length of stay in the intensive care unit among patients with sepsis

The Acute Physiology and Chronic Health Evaluation (APACHE) IV model can predict the intensive care unit (ICU) length of stay (LOS) in critically ill patients. Thus, this study aimed to validate the performance of the APACHE IV score in predicting ICU LOS among patients with sepsis. This retrospective study was conducted in the medical ICU of a tertiary university between 2017 and 2020. A total of 1,039 sepsis patients were enrolled. Patients with an ICU stay of 1 and > 3 days accounted for 20.1% and 43.9%. The overall observed and APACHE IV predicted ICU LOS were 6.3 ± 6.5 and 6.8 ± 6.5, respectively. The APACHE IV slightly over-predicted ICU LOS with standardized length of stay ratio 0.95 (95% CI 0.89-1.02). The predicted ICU LOS based on the APACHE IV score was statistically longer than the observed ICU LOS (p < 0.001) and were poorly correlated (R² = 0.02, p < 0.001), especially in patients with a lower severity of illness. In conclusions the APACHE IV model poorly predicted ICU LOS in patients with sepsis. The APACHE IV score needs to be modified or we need to make a new specific model to predict ICU stays in patients with sepsis.