title: Functional Status Score for the ICU: An International Clinimetric Analysis of Validity, Responsiveness, and Minimal Important Difference.
abstract: OBJECTIVE
  To evaluate the internal consistency, validity, responsiveness, and minimal important difference of the Functional Status Score for the ICU, a physical function measure designed for the ICU.
  
  
  METHODS
  Clinimetric analysis.
  
  
  METHODS
  Five international datasets from the United States, Australia, and Brazil.
  
  
  METHODS
  Eight hundred nineteen ICU patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  Clinimetric analyses were initially conducted separately for each data source and time point to examine generalizability of findings, with pooled analyses performed thereafter to increase power of analyses. The Functional Status Score for the ICU demonstrated good to excellent internal consistency. There was good convergent and discriminant validity, with significant and positive correlations (r = 0.30-0.95) between Functional Status Score for the ICU and other physical function measures, and generally weaker correlations with nonphysical measures (|r| = 0.01-0.70). Known group validity was demonstrated by significantly higher Functional Status Score for the ICU scores among patients without ICU-acquired weakness (Medical Research Council sum score, ≥ 48 vs < 48) and with hospital discharge to home (vs healthcare facility). Functional Status Score for the ICU at ICU discharge predicted post-ICU hospital length of stay and discharge location. Responsiveness was supported via increased Functional Status Score for the ICU scores with improvements in muscle strength. Distribution-based methods indicated a minimal important difference of 2.0-5.0.
  
  
  CONCLUSIONS
  The Functional Status Score for the ICU has good internal consistency and is a valid and responsive measure of physical function for ICU patients. The estimated minimal important difference can be used in sample size calculations and in interpreting studies comparing the physical function of groups of ICU patients.
authors.affiliation: 1Outcome After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, MD.2Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.3Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.4Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD.5Department of Physiotherapy, School of Health Sciences, University of Melbourne, Melbourne, VIC, Australia.6Department of Physical Therapy, Universidade Catolica de Brasilia, Brasilia, Brazil.7Department of Physical Therapy, Hospital Santa Luzia, Brasilia, Brazil.8Department of Research and Education, D'OR Institute, Brasilia, Brazil.9Health Sciences Program, Escola Superior de Ciencias da Saude, Brasilia, Brazil.10Department of Physical Therapy, Hospital de Base do Distrito Federal, Brasilia, Brazil.11School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada.
authors.forename: Minxuan
authors.initials: M
authors.lastname: Huang
authors.forename: Kitty S
authors.initials: KS
authors.lastname: Chan
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Zanni
authors.forename: Selina M
authors.initials: SM
authors.lastname: Parry
authors.forename: Saint-Clair G B
authors.initials: SG
authors.lastname: Neto
authors.forename: Jose A A
authors.initials: JA
authors.lastname: Neto
authors.forename: Vinicius Z M
authors.initials: VZ
authors.lastname: da Silva
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Kho
authors.forename: Dale M
authors.initials: DM
authors.lastname: Needham
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008875:Middle Aged; D010351:Patient Discharge; D015203:Reproducibility of Results; D012720:Severity of Illness Index