title: The Norwegian version of the QOLIBRI - a study of metric properties based on a 12 month follow-up of persons with traumatic brain injury.
abstract: BACKGROUND
  Consequences after Traumatic brain injury (TBI) affect the injured person's self-image and quality of life. The purpose was to assess the health related quality of life (HRQoL) at 12 months after a TBI in patients admitted to regional trauma centres, and to evaluate the metric properties of the Norwegian version of the Quality of Life After Brain Injury (QOLIBRI) questionnaire.
  
  
  METHODS
  Two hundred four patients with TBI of all severities were included. HRQoL at 12 months post-injury was measured by the QOLIBRI. It has a total scale and 6 subscales (satisfied with Cognition, Self, Daily Life and Autonomy and Social Relationships, and bothered by Emotions and Physical Problems). Demographic and injury related data were registered. Disability was registered by Glasgow Outcome Scale Extended (GOSE) and Rivermead Post-Concussion Questionnaire, and mental health by Hospital Anxiety and Depression Scale. Descriptive statistics, internal consistency by Cronbach's alpha and Corrected Item-Total Correlations were calculated. Rasch analysis, Principal Component Analysis (PCA) and Structural Equation Modelling (SEM) were applied.
  
  
  RESULTS
  Mean age was 37.6 (SD 15.4) years; 72% were men, and 41% had higher education. Over 60% were severely injured. Mean Glasgow Coma Scale score was 9.3 (SD 4.5). According to the GOSE 5.9% had severe disability, 45.5% had moderate disability, and 48.5% had good recovery at 12 months post-injury. The QOLIBRI scales had a high internal consistency (α = 0.75-0.96), and only Physical Problems had an α < 0.85. In the Rasch analysis all subscales and their items fit the Rasch model, except for the depression item in the Emotion subscale. PCA and SEM analyses supported a six-factor structure in a second-order latent model. The QOLIBRI supports an underlying unidimensional HRQoL model. The SEM model fit statistics of the second-order model indicated a moderate fit to the observed data (CFI = 0.86, TLI = 0.85, RMSEA = 0.076, SRMR = 0.061, χ2= 1315.76, df = 623, p-value < 0.001).
  
  
  CONCLUSIONS
  The Norwegian QOLIBRI has favourable psychometric properties, but there were some weaknesses related to its measurement properties of the total score when tested on a TBI population where many had severe TBI, and many had good recovery.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Postbox 4950, Nydalen, 0424, Oslo, Norway. h.l.soberg@medisin.uio.no.
authors.forename: Helene Lundgaard
authors.initials: HL
authors.lastname: Soberg
authors.affiliation: Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Postbox 4950, Nydalen, 0424, Oslo, Norway.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Roe
authors.affiliation: Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Brunborg
authors.affiliation: Institute of Medical Psychology and Medical Sociology, University Medical Centre Göttingen, Göttingen, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: von Steinbüchel
authors.affiliation: Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Postbox 4950, Nydalen, 0424, Oslo, Norway.
authors.forename: Nada
authors.initials: N
authors.lastname: Andelic
mesh_terms: D000293:Adolescent; D000328:Adult; D000070642:Brain Injuries, Traumatic / Q000523:psychology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006233:Persons with Disabilities / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D023261:Glasgow Outcome Scale; D006801:Humans; D008297:Male; D009664:Norway; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012649:Self Concept; D011795:Surveys and Questionnaires; D014177:Translations; D055815:Young Adult
keywords: Disability; GOSE; Metric properties; Outcome measure; QOLIBRI; Quality of life; Traumatic brain injury