Discrepancy between disability and reported well-being after traumatic brain injury

Abstract

Background: Following traumatic brain injury (TBI), the clinical focus is often on disability. However, patients' perceptions of well-being can be discordant with their disability level, referred to as the 'disability paradox'. We aimed to examine the relationship between disability and health-related quality of life (HRQoL) following TBI, while taking variation in personal, injury-related and environment factors into account.

Methods: We used data from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury study. Disability was assessed 6 months post-injury by the Glasgow Outcome Scale-Extended (GOSE). HRQoL was assessed by the SF-12v2 physical and mental component summary scores and the Quality of Life after Traumatic Brain Injury overall scale. We examined mean total and domain HRQoL scores by GOSE. We quantified variance in HRQoL explained by GOSE, personal, injury-related and environment factors with multivariable regression.

Results: Six-month outcome assessments were completed in 2075 patients, of whom 78% had mild TBI (Glasgow Coma Scale 13-15). Patients with severe disability had higher HRQoL than expected on the basis of GOSE alone, particularly after mild TBI. Up to 50% of patients with severe disability reported HRQoL scores within the normative range. GOSE, personal, injury-related and environment factors explained a limited amount of variance in HRQoL (up to 29%).

Conclusion: Contrary to the idea that discrepancies are unusual, many patients with poor functional outcomes reported well-being that was at or above the boundary considered satisfactory for the normative sample. These findings challenge the idea that satisfactory HRQoL in patients with disability should be described as 'paradoxical' and question common views of what constitutes 'unfavourable' outcome.

Keywords: NEUROPSYCHOLOGY; QUALITY OF LIFE; TRAUMATIC BRAIN INJURY.

Figure 1

Plots of the SF-12v2 physical and mental health component summary scores (top) and the QOLIBRI-OS (bottom) by time point for mild (left) and moderate and severe TBI (right). The points are means and error bars are 95% CI. QOLIBRI-OS, Quality of Life after Traumatic Brain Injury overall scale; TBI, traumatic brain injury.

Figure 2

Contribution of predictors to explained variance (partial R²) of the models for SF-12 PCS (left), SF-12 MCS (middle) and QOLIBRI-OS (right). The partial R² is calculated as follows: total R² of multivariable model – R² multivariable model without individual predictor: total R² of multivariable model without individual predictor=partial R². MCS, mental component summary; PCS, physical component summary; QOLIBRI-OS, Quality of Life after Traumatic Brain Injury overall scale.

Figure 3

Adjusted association between the GOSE and the SF-12 MCS (upper) and QOLIBRI-OS (lower) for the ‘average’ patient (sex=male; age=51; marital status=married; highest level of education=second/high school, type of employment=working, preinjury mental health problems=no, preinjury substance abuse=no; preinjury health status (ASA-PS)=healthy; injury severity (GCS)=15; cause of injury=incidental fall; major extracranial injury=no; presence of intracranial traumatic abnormalities=present; satisfaction with social support=high; satisfaction with support from the hospital and health services=high; satisfaction with support from rehabilitation services=high). ASA-PS, The American Society of Anesthesiologists-physical status classification system; GOSE, Glasgow Outcome Scale-Extended; MCS, mental component summary; PCS, physical component summary; QOLIBRI-OS, Quality of Life after Traumatic Brain Injury overall scale; TBI, traumatic brain injury.