Longitudinal Internal Validity of the Quality of Life after Brain Injury: Response Shift and Responsiveness

The Quality of Life after Brain Injury (QoLIBRI) questionnaire was developed and validated to assess disease-specific health-related quality of life (HRQoL) in individuals after TBI. The present study aims to determine its longitudinal validity by assessing its responsiveness and response shift from 3 to 6 months post-injury. Analyses were based on data from the European longitudinal observational cohort Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury study. A total of 1659 individuals recovering from TBI were included in the analyses. Response shift was assessed using longitudinal measurement invariance testing within the confirmatory factor analyses framework. Responsiveness was analyzed using linear regression models that compared changes in functional recovery as measured by the Glasgow Outcome Scale-Extended (GOSE) with changes in the QoLIBRI scales from 3 to 6 months post-injury. Longitudinal tests of measurement invariance and analyses of discrepancies in practical significance indicated the absence of response shift. Changes in functional recovery status from three to six months were significantly associated with the responsiveness of the QoLIBRI scales over the same time period. The QoLIBRI can be used in longitudinal studies and is responsive to changes in an individual's functional recovery during the first 6 months after TBI.

Quality of Life After Brain Injury: Psychometric Properties of the Spanish Translation of the QoLIBRI

Traumatic brain injury (TBI) is frequently followed by a variety of physical, emotional, and cognitive symptoms, which affect the patient's daily life, their social relations, and their work/educational status. In addition to function measures, health-related quality of life (HRQoL) has received increasing attention as an important outcome after TBI, as it may guide rehabilitation and evaluate treatment success. Here, we report on psychometric properties of a Spanish translation of the quality of life after brain injury (QoLIBRI) questionnaire, a disease-specific instrument to assess HRQoL in patients after TBI. Classical test theory, item response theory, and structural equation modeling were used to evaluate psychometric properties of the Spanish QoLIBRI translation in a convenience sample of N = 155 patients with TBI. A subset of n = 23 patients were tested twice with a test-retest interval of ≤2 weeks. Internal consistency and test-retest reliabilities were high (Cronbach's α: 0.78-0.96; ICCs: 0.81-0.96). Rasch analysis infit (range 0.52-1.20) and outfit indices (range 0.50-1.17) supported unidimensionality of subscales, whereas SEM analysis tended to support a correlated six-factor model (CFI = .88, RMSEA = .068, 95% confidence interval [.061, .075]). Results show favorable psychometric properties of the Spanish translation of the QoLIBRI, comparable to the international version. It is, thus, a useful instrument for clinicians and researchers assessing the impact of TBI on quality of life, the outcomes of rehabilitation, and may be included in epidemiological surveys.