title: The reliability and validity of the brief symptom inventory-18 in persons with traumatic brain injury.
abstract: OBJECTIVE
  To investigate the psychometric properties of the Brief Symptom Inventory-18 (BSI-18) among persons with traumatic brain injury (TBI).
  
  
  METHODS
  Inception cohort design with cross-sectional follow-up of 6 months to 15 years.
  
  
  METHODS
  Rehabilitation hospital.
  
  
  METHODS
  Adults (N=257) with moderate to severe TBI (81 inpatients and 176 follow-up participants, analyzed separately).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The BSI-18 is a brief screen of psychologic distress with a Global Severity Index (GSI), and 3 clinical subscales: somatization, anxiety, and depression.
  
  
  RESULTS
  Internal consistency of the GSI was high in both follow-up participants (alpha=.91) and inpatients (alpha=.84), whereas estimates for the somatization, anxiety, and depression subscales were more variable (alpha range, .61-.84). As would be expected for a measure of affective state, retest reliability estimates were only moderate. The BSI-18 GSI correlated with multiple measures of psychosocial adjustment. After accounting for demographics, injury severity, inpatient functional status, years since injury, and various psychosocial factors, the BSI-18 showed incremental validity in predicting concurrent functional, psychosocial, and psychologic status.
  
  
  CONCLUSIONS
  The BSI-18 GSI had excellent reliability and validity among inpatients and follow-up participants. Modest reliability estimates may place an upper bound on the validity of the BSI-18 clinical subscales in inpatient TBI populations.
authors.affiliation: Rehabilitation Institute of Michigan, Detroit, MI, USA. smeachen@wayne.edu
authors.forename: Sarah-Jane
authors.initials: SJ
authors.lastname: Meachen
authors.forename: Robin A
authors.initials: RA
authors.lastname: Hanks
authors.forename: Scott R
authors.initials: SR
authors.lastname: Millis
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Rapport
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000523:psychology* / Q000534:rehabilitation; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D011594:Psychometrics; D012044:Regression Analysis; D015203:Reproducibility of Results