Functional disability in patients with low back pain: the mediator role of suffering and beliefs about pain control in patients receiving physical and chiropractic treatment

BACKGROUND Low back pain is the leading cause of disability worldwide. There is evidence that depression, anxiety, and external locus of control are negative predictors of functional disability in low back patients. METHODS This study focused on the mediator role of suffering and beliefs about pain control in the relationship between psychological morbidity and functional disability in patients receiving physical therapy and chiropractic treatment for chronic low back pain. The sample included 213 patients receiving chiropractic treatment and 125 receiving physical therapy, who answered the following instruments: Beliefs about Pain Control Questionnaire; Inventory of Subjective Experiences of Suffering in Illness; Oswestry Low Back Pain Disability Questionnaire; and the Hospital Anxiety and Depression Scales. RESULTS Suffering was a mediator in the relationship between depression and functional disability in both treatment groups. Only beliefs related to external chance events mediated the relationship between depression and functional disability in the physical therapy group, but not in the chiropratic teratment group. CONCLUSION Intervention should focus on suffering regardless of the type of treatment and target beliefs about pain control, in patients receiving physical therapy treatment since they seem to play a key role in functional disability in patients with low back pain.