Criterion validity of a single-item measure of fear avoidance behavior following mild traumatic brain injury

Maladaptive coping such as fear avoidance behavior can prolong recovery from mild traumatic brain injury (mTBI). Routine assessment of fear avoidance may improve management of mTBI. This study aimed to validate a single-item measure of fear avoidance to make its assessment more pragmatic. The present study is a secondary analysis of a clinical trial that involved adults with persistent post-concussion symptoms (N = 90, 63% female). Participants completed the single-item fear avoidance rating, a validated legacy measure of fear avoidance (Fear Avoidance Behavior after Traumatic Brain Injury; FAB-TBI), and measures of anxiety (General Anxiety Disorder-7), depression (Patient Health Questionnaire-9), post-concussion symptoms (Rivermead Postconcussion Symptoms Questionnaire), and disability (World Health Organization Disability Assessment Schedule 12.0). Questionnaires were completed twice, at baseline (mean 18.1 weeks post injury) and again 12-16 weeks later following study-delivered rehabilitation in addition to usual care. We analyzed the associations (Spearman's correlations) and agreement (weighted Kappa) between the single-item and FAB-TBI at baseline, posttreatment, individual FAB-TBI item scores, and the change in scores between baseline and posttreatment. In addition, we examined correlations between the single-item fear avoidance measure and related constructs, including anxiety, depression, post-concussion symptoms, and disability. The single-item fear avoidance measure correlated strongly with the FAB-TBI both at baseline and following treatment (ρ = 0.63 - 0.67, p < .001), and moderately with FAB-TBI item scores (ρ = 0.4 - 0.6). The correlation between the change in these scores from baseline to posttreatment was moderate (ρ = 0.45, p < .001). Agreement between the single-item fear avoidance measure and discretized FAB-TBI scores was moderate (κ = 0.45 - 0.51). Before and after treatment, the single-item fear avoidance measure correlated moderately with anxiety (ρ = 0.34), depression (ρ = 0.43), post-concussion symptoms (ρ = 0.50), and disability (ρ = 0.43). The FAB-TBI was more strongly correlated with these measures (ρ = 0.53 - 0.73). In summary, the present study supports the criterion validity of the single-item fear avoidance measure. This measure may be a useful screening and monitoring tool for patients with mTBI but is not a substitute for the FAB-TBI questionnaire.