Are difficulties perceiving and expressing emotions associated with low-back pain? The relationship between lack of emotional awareness (alexithymia) and 12-month prevalence of low-back pain in 1180 urban public transit operators.

OBJECTIVE To assess the association of alexithymia (deficit in emotional awareness) with 12-month prevalence of low back pain (LBP) cross-sectionally in a cohort study of 1180 San Francisco transit operators. METHODS Alexithymia was measured by the Toronto Alexithymia Scale (TAS-20). LBP was assessed in medical histories during drivers relicensing exams. Multivariate logistic regression analyses controlled for demographic, behavioral (smoking, alcohol, coping style), and physical and psychosocial job factors measured by questionnaire and interview. RESULTS Of all the drivers, 31.4% suffered from LBP. Scoring in the upper quartile of alexithymia summary scores was associated with twofold higher odds of LBP (adjusted odds ratio=2.00, 95% confidence interval: 1.31-3.00). The association was stronger in women (adj. OR=4.35) than in men (adj. OR=1.83). The factor "difficulty identifying feelings" showed the strongest association with LBP (adj. OR=2.23). CONCLUSION The results support an association between alexithymia and LBP.