title: Measuring medical complexity during inpatient rehabilitation after traumatic brain injury.
abstract: OBJECTIVE
  To compare the performance of 3 severity of illness (SOI) indices--the Comprehensive Severity Index (CSI), All Patient Refined Diagnosis Related Groups Severity of Illness, case-mix group (CMG)--and 5 well-known neurologic parameters, as measures of medical complexity.
  
  
  METHODS
  Retrospective chart review.
  
  
  METHODS
  Inpatient rehabilitation center within a level I trauma center.
  
  
  METHODS
  Consecutive traumatic brain injury (TBI) admissions (N=212).
  
  
  METHODS
  Acute inpatient TBI rehabilitation. CSI and neurologic parameters were scored by chart extraction. SOI was based on diagnosis codes by using 3M PC Grouper software, version 15.
  
  
  METHODS
  Adjusted R 2 was used to predict rehabilitation charges as a proxy of medical complexity.
  
  
  RESULTS
  The highest adjusted R 2 values for single variables predicting charges were: CMG .349, CSI .293, duration of posttraumatic amnesia .260. Adjusted R 2 values for the CMG combined with the CSI, 5 neurologic parameters, and SOI to predict charges were .446, .431, and .365, respectively.
  
  
  CONCLUSIONS
  The CMG was the best single predictor of rehabilitation charges for TBI. Predictive ability was better when the CMG was combined with the CSI or a combination of the 5 neurologic parameters. A severity index based on objective clinical findings rather than diagnostic codes may have distinct advantages for rehabilitation outcome studies and reimbursement methodology.
authors.affiliation: Division of PM&R and Statistical Data Center, LDS Hospital, 8th Avenue & C, Salt Lake City, UT 84143, USA. lddryser@ihc.com
authors.forename: David K
authors.initials: DK
authors.lastname: Ryser
authors.forename: Marlene J
authors.initials: MJ
authors.lastname: Egger
authors.forename: Susan D
authors.initials: SD
authors.lastname: Horn
authors.forename: Diana
authors.initials: D
authors.lastname: Handrahan
authors.forename: Partha
authors.initials: P
authors.lastname: Gandhi
authors.forename: Erin D
authors.initials: ED
authors.lastname: Bigler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000191:economics* / Q000534:rehabilitation*; D003953:Diagnosis-Related Groups; D017048:Health Care Costs; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014481:United States