An antibiotic decision-making tool for patients with pneumonia admitted to a medical intensive care unit

•A simple scoring tool composed of five predictors was developed.•This tool predicted multidrug resistance risk for patients admitted to medical intensive care units (MICUs) with pneumonia.•The scoring tool could help timely and appropriate antibiotic decision-making in the MICU.

Pneumonia is a leading cause of death in medical intensive care units (MICUs). Delayed or inappropriate antibiotic therapy largely increases morbidity and mortality. Multidrug-resistant (MDR) micro-organisms are major reasons for inappropriate antibiotic use. Currently there is no good antibiotic decision-making tool designed for critically ill patients. The objective of this study was to develop a convenient MDR prediction scoring system for patients admitted to MICUs with pneumonia. A retrospective cohort study was conducted using databases and chart reviews of pneumonia patients admitted to a 30-bed MICU from 2012 to 2013. Forward logistic regression was applied to identify independent MDR risk factors for prediction tool development. A total of 283 pneumonia episodes from 263 patients with positive cultures from blood or respiratory secretions were recruited, of which 154 (54.4%) were MDR episodes. Long-term ventilation (OR = 11.09; P = 0.026), residence in a long-term care facility (OR = 2.50; P = 0.005), MDR infection/colonisation during the preceding 90 days (OR = 2.08; P = 0.041), current hospitalisation ≥2 days (OR = 1.98; P = 0.019) and stroke (OR = 1.81; P = 0.035) were identified as independent predictors for MDR pneumonia. The area under the ROC curve of this prediction tool was much higher than that of ATS/IDSA classification (0.69 vs. 0.54; P < 0.001). The prediction accuracy of this tool with risk score ≥1 for MDR infections was 63.7%. This simple five-item, one-step scoring tool for critically ill patients admitted to the MICU could help physicians provide timely appropriate empirical antibiotics.