Depression: An important factor associated with disability among patients with chronic low back pain

Objective: The study aimed to compare the associations of pain indices, depression, anxiety, and somatic symptoms with disability among outpatients with chronic low back pain (CLBP). Method: Consecutive orthopedics outpatients with CLBP in a medical center were enrolled. The Oswestry Disability Index and physical functioning and role limitationsphysical of the Short-Form 36 were used as disability indices. The Hospital Anxiety and Depression Scale (HADS) and the Depression and Somatic Symptoms Scale were employed. Pain intensity was rated using a visual analogue scale. Multiple linear regressions were used to determine the impacts of these independent factors related to disability. Results: Among 225 participants (122 male, 103 female) with CLBP, patients with major depressive disorder and associated leg symptoms of CLBP had higher disability indices. A tendency was noted that depression (HADS-depression) had the highest correlation to the three disability indices, followed by pain intensity, anxiety, and somatic symptoms. After controlling for demographic variables, HADS-depression explained the highest variance of disability, followed by pain intensity. Conclusion: Depression was the most powerful factor associated with disability of CLBP among depression, anxiety, and somatic symptoms. Depression should be evaluated when investigating disability among patients with CLBP.