Construction and validation of a risk assessment scale for multidrug-resistant bacteria infections in critically ill patients

Background To develop a risk assessment scale for infections caused by multidrug-resistant organisms (MDROs) in patients with critical illness and to evaluate its reliability and validity. Methods An initial risk assessment scale for MDRO infections in patients with critical illness was developed by using a systematic literature review, the Delphi method, and the analytic hierarchy process. Data from 750 critically ill patients admitted to the intensive care unit (ICU) of a Grade A tertiary hospital in China between January 2019 and June 2025 were analyzed. The scale’s reliability and validity were assessed through exploratory factor analysis ( n = 450) and confirmatory factor analysis ( n = 300). Results The risk assessment scale for MDRO infection in patients with critical illness comprised five dimensions and 20 items. The Cronbach’s alpha for the total scale was 0.873. The scale-level content validity index was 0.925, with the content validity indices for individual scale items ranging 0.875–1.000. Exploratory factor analysis enabled the extraction of five common factors, which accounted for 67.861% of the cumulative variance. Confirmatory factor analysis yielded χ 2 /DF = 1.912, RMSEA = 0.055, CFI = 0.945, TLI = 0.935, and GFI = 0.906. The predictive efficacy of the scale for MDRO infections was validated via ROC curve analysis, yielding an area under the curve (AUC) of 0.788, sensitivity of 0.741, and specificity of 0.707, indicating a robust overall discriminative capability. Conclusion The risk assessment scale for MDRO infection in patients with critical illness demonstrated good reliability and validity, enabling the scientific and reliable assessment of patient infection risk.