title: Latent Class Factor Analysis of the Functional Independence Measure confirmed four distinct dimensions in patients undergoing neurological rehabilitation.
abstract: OBJECTIVE
  The FIM instrument is broadly applied in varying rehabilitation services for outcome assessment. Thus, it is important to examine its applicability for services which may differ from the situations and patients for which it was originally developed. The aims of the present study were to examine 1) whether the four FIM dimensions "activities of daily living", "sphincter management", "mobility", and "executive function" can be retrieved by Latent Class Factor Analysis (LCFA); and 2) whether the four dimensions show floor effects in patients with acquired brain injuries undergoing intensive post-acute rehabilitation.
  
  
  METHODS
  We analyzed the FIM data of 269 patients with acquired brain injuries undergoing intensive post-acute rehabilitation. To examine the dimensional structure of the FIM instrument we carried out LCFA. Cronbach's alpha was used to measure the internal consistency. We examined the distribution of the dimension scores to identify floor effects.
  
  
  RESULTS
  LCFA confirmed the postulated four dimensions. The explained variance of items assigned to the four dimensions ranged from 46% to 89%. Cronbach's alpha coefficients of the four subscales ranged from 0.94 to 0.96. The percentage of patients scoring the minimum possible score in each of the retrieved dimensions ranged from 22.3% to 47.9%.
  
  
  CONCLUSIONS
  When applying the FIM instrument to patients undergoing intensive neurological rehabilitation its dimensionality should be kept in mind. For some patients this outcome measure might not be discriminative enough due to floor effects.
authors.affiliation: Outcomes Research, MSD Sharp & Dohme GmbH, Haar, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Scheuringer
authors.forename: E
authors.initials: E
authors.lastname: Grill
authors.forename: C
authors.initials: C
authors.lastname: Boldt
authors.forename: G
authors.initials: G
authors.lastname: Stucki
mesh_terms: D000203:Activities of Daily Living / Q000145:classification*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000534:rehabilitation*; D003430:Cross-Sectional Studies; D056344:Executive Function / Q000502:physiology; D005163:Factor Analysis, Statistical; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D017063:Outcome Assessment, Health Care / Q000145:classification*; D020127:Recovery of Function; D055815:Young Adult