Background The prevalence of chronic non-malignant pain in developed countries is high, ranging from 14% to 50%. Patients with chronic pain are active users of health-care services and they report impaired health-related quality of life (HRQoL) when compared with the general population. Psychological distress has been identified as one of the risk factors for pain chronicity. Depression, anxiety and negative beliefs are associated with pain interference and perceived disability. Multidisciplinary pain management (MPM) aims to rehabilitating chronic pain patients by addressing both physical, psychological, social and occupational factors related to the pain problem. MPM programmes have been shown to be effective in reducing pain and improving function in patients with diverse chronic pain states. However, MPM programmes are often heterogeneous and predicting MPM treatment results in different patients groups may be difficult. Methods The present study examined changes in HRQoL after MPM in 439 patients treated at a multidisciplinary pain clinic using the 15D HRQoL questionnaire. The characteristics of the 100 patients with the greatest improvement and the 100 patients with the largest decrease in HRQoL were examined more closely (demographics, characteristics of pain, pain interference, psychiatric comorbidity, employment status, details of MPM) after answering a follow-up 15D questionnaire at three years after their MPM had ended. Result During MPM, HRQoL was significantly improved in 45.6% of the 439 patients, decreased in 30.7% of the patients and did not change in 23.7% of the patients. Patient-related factors that predicted a better HRQoL among the 100 patients with good MPM outcome compared with the 100 patients with poor MPM outcome were higher education and better employment status. Age, gender, marital status, duration of pain, number of pain sites, pain intensity or pain interference at baseline did not differ between the patient groups. Patient expectations regarding MPM were similar. A tendency towards more psychiatric comorbidity in the non-responder group was seen. The duration of MPM in the two patient groups was similar, as well as the number of medications started, the variety of specialists seen and psychiatric counselling with supportive therapy included. More non-responder than responder patients had died during the three-year follow-up period, some of the deaths were related to substance abuse. Conclusions and Implications HRQoL in chronic pain patients was significantly improved during MPM compared with the baseline. Pain duration of several years, multiple pain sites and neuropathic pain were not discerning factors between the responders and non-responders of the present study, implying that a positive change in HRQoL may be achieved by MPM even in these pain patients. In agreement with previous studies, factors predicting poor treatment outcome in the non-responder group of chronic pain patients were not treatment related. To further improve MPM outcome even in pain patients with risk factors for less benefit of treatment such as low education and poor general health, more individualized MPM approaches with emphasis on analysis and treatment of psychological symptoms and patient beliefs is essential.
Keywords: 15D questionnaire; Benefit from treatment; Chronic pain; Health-related quality of life; Multidisciplinary pain treatment.