title: Weighted index explained more variance in physical function than an additively scored functional comorbidity scale.
abstract: OBJECTIVE
  1) examine association between the Functional Comorbidity Index (FCI) and discharge functional status (FS); 2) examine impact of FCI on FS when added to comprehensive models; and 3) compare additive FCI with weighted FCI and list of condition variables (list).
  
  
  METHODS
  Patients were drawn from Focus On Therapeutic Outcomes, Inc. (FOTO) database (1/1/06-12/31/07). FS collected using computer adaptive tests. Linear regression examined association between FCI and FS. Three methods of including functional comorbidities (FC) were compared.
  
  
  RESULTS
  Relationship between FCI and FS varied by group (range, 0.02-0.9). Models with weighted index or list had similar R². Weighted FCI or list increased R² of crude models by <0.01 for cervical, shoulder, and lumbar; by 0.01 for wrist/hand, knee, and foot/ankle; by 0.02 for hip; by 0.03 for elbow; and by 0.08 for neurological. Addition of FCI to comprehensive models added <0.01 to R² (all groups). Weighted FCI increased R² by <0.01 for cervical, lumbar, and shoulder; by 0.01 for wrist/hand, hip, knee, and foot/ankle; by 0.02 for elbow; and by 0.04 for neurological; whereas list increased R² by <0.01 for cervical, shoulder, and lumbar; by 0.01 for knee and foot/ankle; by 0.02 for elbow, wrist/hand, and hip; and by 0.05 for neurological.
  
  
  CONCLUSIONS
  List of comorbidities or weighted FCI is preferable to using additive FCI.
authors: Providence VA Medical Center, Department of Community Health, Box G-S121(6), Brown University, Providence, RI 02908, USA. linda_resnik@brown.edu
authors: Linda
authors: L
authors: Resnik
authors: Pedro
authors: P
authors: Gozalo
authors: Dennis L
authors: DL
authors: Hart
mesh_terms: D000553:Ambulatory Care; D015897:Comorbidity; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000453:epidemiology / Q000534:rehabilitation*; D017063:Outcome Assessment, Health Care; D010351:Patient Discharge; D026741:Physical Therapy Modalities; D020127:Recovery of Function; D016896:Treatment Outcome