Alexithymia and 7.5-year incidence of compensated low back pain in 1207 urban public transit operators

ObjectiveAlexithymia, a lack of emotional awareness, was positively associated with self-reported low back pain (LBP) in cross-sectional studies. We assessed the association of alexithymia with 7.5-year incidence of LBP prospectively in a cohort study of 1207 San Francisco transit operators.MethodsAlexithymia was measured by the 20-item Toronto Alexithymia Scale (TAS-20). LBP was assessed by physician-confirmed diagnoses from administrative workers' compensation data. Cox proportional hazards analyses controlled for demographic, behavioral, and physical and psychosocial job factors measured by questionnaire and interview.ResultsOf all drivers, 27.7% (n=334) filed compensated claims for LBP injuries with workers' compensation insurance during the 7.5-year observation time. The hazard ratios from the fully adjusted model were 0.73 (0.56-0.96) for the TAS-20 scale and 0.82 (0.69-0.98) for the subscale “difficulty describing feelings.” Alexithymia scores did not predict the duration of compensated work disability.ConclusionIn contrast to previous cross-sectional positive associations between alexithymia and LBP, alexithymia is negatively associated with compensated LBP claims. We hypothesize that shame and reporting behavior may explain these inconsistent results.