Reliability, Validity, and Cutoff Point of the Chinese Version of the Chelsea Critical Care Physical Assessment Tool in Critically Ill Patients

Abstract

Purpose: Translation and cross-cultural adaptation of the Chelsea Critical Care Physical Assessment Tool (CPAx) into a Chinese version of CPAx (“CPAx-Chi”), test the reliability and validity of CPAx-Chi, and verify the cutoff point for the diagnosis of intensive care unit-acquired weakness (ICU-AW) Material and methods: Translation and cross-cultural adaptation of CPAx into CPAx-Chi was based on the Brislin model. Participants were recruited from the general ICU of five third-grade class-A hospitals in western China. Adult patients (n = 200) 48 h after receiving intensive care were included (median age, 53 years; 64% males). Patients were assessed by two assessment scales: Medical Research Council Muscle Score (MRC-Score) and CPAx-Chi.Results: The item-level content validity was 0.889. The scale-level content validity was 0.955. Taking the MRC-Score scale as standard, the criterion validity of CPAx-Chi was r = 0.758 (p < 0.001) for Researcher A, and r = 0.65 (p < 0.001) for Researcher B. Cronbach’s ɑ was 0.939. The inter-rater reliability was 0.902 (p < 0.001). The AUC of CPAx-Chi for diagnosing ICU-AW based on MRC-Score ≤48 was 0.899 (95%CI 0.862–1.025) and 0.874 (0.824–0.925) for Researcher B. The maximum value of the Youden Index was 0.643, and the best cutoff point for CPAx-Chi for the diagnosis of ICU-AW was 31.5. The sensitivity was 87% and specificity was 77% for Researcher A, whereas it was 0.621, 31.5, 75%, and 87% for Researcher B, respectively. The consistency was high when taking CPAx-Chi ≤31 and MRC-Score ≤48 as the cutoff points for the diagnosis of ICU-AW. Also, kappa = 0.845 (p = 0.02) in Researcher A and 0.839 (p = 0.04) for Researcher B. Conclusions: CPAx-Chi had good content validity, criterion-related validity and reliability. CPAx-Chi showed the best accuracy in assessment of patients at risk for ICU-AW with good sensitivity and specificity at a recommended cutoff of 31.