The ICU Mobility Scale Has Construct and Predictive Validity and Is Responsive. A Multicenter Observational Study

Rationale: The ICU Mobility Scale (IMS) is a measure of mobility milestones in critically ill patients.Objectives: This study aimed to determine the validity and responsiveness of the IMS from a prospective cohort study of adults admitted to the intensive care unit (ICU).Methods: Construct and predictive validity were assessed by comparing IMS values at ICU discharge in 192 patients to other variables using Spearman rank correlation coefficient, Mann-Whitney U tests, and logistic regression. Responsiveness was assessed using change over time, effect size, floor and ceiling effects, and percentage of patients showing change.Measurements and Main Results: The IMS at ICU discharge demonstrated a moderate correlation with muscle strength (r = 0.64, P < 0.001). There was a significant difference between the IMS at ICU discharge in patients with ICU-acquired weakness (median, 4.0; interquartile range, 3.0–5.0) compared with patients without (median, 8.0; interquartile range, 5.0–8.0; P < 0.001). Increasing IMS ...