HighlightsSubjective suffering mediated the relationship between depression and functional disability regardless of the type of treatment.Beliefs about chance events mediated the relationship between depression and functional disability only in the physical therapy treatment.Intervention should target cognitive and psychological factors in LBP patients.

This study focused on cognitive representations of low back pain patients receiving chiropractic ( n = 213) versus physiotherapy treatment ( n = 125). Variables assessed included satisfaction with care, illness perceptions, beliefs about pain and medicines, attitudes towards doctors and medicine, suffering, adherence and functional incapacity. In the chiropractic treatment, functional incapacity was predicted by painful symptoms, suffering and personal control, and in the physiotherapy treatment by age, pain intensity, positive suffering, care satisfaction, illness identity and medication adherence. The groups differed on all cognitive variables assessed. Interventions should take into consideration cognitive dimensions, across treatment modalities.

Low back pain (LBP) induces significant burden on individuals and healthcare systems, with societal costs. 1 There are two types of LBP: (a) mechanical pain (associated with disc, joint, ligament, and muscle problems or injuries) and (b) non-mechanical or referred pain (associated with tumor, infection, disorders of other internal organs, and neuropathic pain). 2 LBP is the most prevalent rheumatic and musculoskeletal disease (RMD) 3 and patients often experience physical discomfort and functional limitations that lasts for at least 1 day, affecting their daily activities, social and working lives. 4 The symptoms may result in disability, with implications on quality of life. 4 It is estimated that 5%-10% of individuals live with LBP and about 10% to 40% of all patients with LBP develop chronic symptoms with disability. 5 According to the EpiReumaPt study, in Portugal, 26.4% (95% CI 23.3%-29.5%) of individuals are diagnosed with LBP. 6 Recent studies have shown the substantial role of psychosocial factors in the LBP disability process and outcomes, in primary care and after surgery. 7 LBP becomes persistent and 3 months after the initial consultation, a large proportion of patients, in primary healthcare settings, continue to have pain complaints and report disability. 8 Pain is a subjective experience 9 and because it is influenced by