title: The ICU Mobility Scale Has Construct and Predictive Validity and Is Responsive. A Multicenter Observational Study.
abstract: The ICU Mobility Scale (IMS) is a measure of mobility milestones in critically ill patients.
  
  
  
  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).
  
  
  
  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.
  
  
  
  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 values at ICU discharge were associated with survival to 90 days (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.14-1.66) and discharge home (OR, 1.16; 95% CI, 1.02-1.32) but not with return to work at 6 months (OR, 1.09; 95% CI, 0.92-1.28). The IMS was responsive with a significant change from study enrollment to ICU discharge (d = 0.8, P < 0.001), with IMS values increasing in 86% of survivors during ICU admission. No substantial floor (14% scored 0) or ceiling (4% scored 10) effects were present at ICU discharge.
  
  
  
  Our findings support the validity and responsiveness of the IMS as a measure of mobility in the ICU.
authors.affiliation: 1 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine.|2 Department of Physiotherapy, The Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Claire J
authors.initials: CJ
authors.lastname: Tipping
authors.affiliation: 1 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bailey
authors.affiliation: 1 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine.|3 The University of Melbourne, Melbourne, Victoria, Australia.|4 Austin Health, Heidelberg, Victoria, Australia.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.affiliation: 4 Austin Health, Heidelberg, Victoria, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Berney
authors.affiliation: 5 The Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
authors.forename: Heidi
authors.initials: H
authors.lastname: Buhr
authors.affiliation: 3 The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Denehy
authors.affiliation: 6 Curtin University, Perth, Western Australia, Australia.|7 Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Meg
authors.initials: M
authors.lastname: Harrold
authors.affiliation: 2 Department of Physiotherapy, The Alfred Hospital, Melbourne, Victoria, Australia.|8 Latrobe University, Melbourne, Victoria, Australia.
authors.forename: Anne
authors.initials: A
authors.lastname: Holland
authors.affiliation: 1 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine.
authors.forename: Alisa M
authors.initials: AM
authors.lastname: Higgins
authors.affiliation: 9 Australian and New University, Melbourne, Victoria, Australia.|10 Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.|11 Center for Clinical Management Research, Veterans Affairs Ann Arbor Health System, Ann Arbor, Michigan.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
authors.affiliation: 12 Johns Hopkins University, Baltimore, Maryland.
authors.forename: Dale
authors.initials: D
authors.lastname: Needham
authors.affiliation: 13 The Mater Hospital, Brisbane, Queensland, Australia.
authors.forename: Jeff
authors.initials: J
authors.lastname: Presneill
authors.affiliation: 14 The St George Hospital, Kogarah, New South Wales, Australia.|15 The University of New South Wales, Sydney, New South Wales, Australia.|16 The George Institute For Global Health, Sydney, New South Wales, Australia.
authors.forename: Manoj
authors.initials: M
authors.lastname: Saxena
authors.affiliation: 18 Monash University, Melbourne, Victoria, Australia.|3 The University of Melbourne, Melbourne, Victoria, Australia.|17 Western Health, Melbourne, Victoria, Australia.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Skinner
authors.affiliation: 7 Royal Perth Hospital, Perth, Western Australia, Australia.|19 University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Steve
authors.initials: S
authors.lastname: Webb
authors.affiliation: 20 Wellington Hospital, Wellington, New Zealand; and.|21 Medical Research Institute of New Zealand, Wellington, New Zealand.
authors.forename: Paul
authors.initials: P
authors.lastname: Young
authors.affiliation: 12 Johns Hopkins University, Baltimore, Maryland.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Zanni
authors.affiliation: 1 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine.|2 Department of Physiotherapy, The Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Carol L
authors.identifier: 0000-0001-9002-2075
authors.initials: CL
authors.lastname: Hodgson
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia; D016638:Critical Illness / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D053580:Muscle Strength / Q000502:physiology*; D009520:New Zealand; D010351:Patient Discharge / Q000706:statistics & numerical data*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D017741:Survivors / Q000706:statistics & numerical data*
keywords: cohort studies; critical illness; intensive care units; outcome assessment; rehabilitation