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 limitations-physical 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.