10-year follow-up of chronic non-malignant pain patients: opioid use, health related quality of life and health care utilization.

BACKGROUND: In Denmark, opioids have been used liberally for many years in the treatment of non-malignant pain, but long-term consequences as tolerance and influence on health related quality of life remain unknown. AIM: Adherence to medical treatment, opioid dose escalation, health related quality of life, anxiety, depression, coping strategies and health care utilization were evaluated in chronic pain patients 10 years after treatment in a multidisciplinary pain centre. METHODS: Information was gathered from medical records, postal questionnaires and a central hospital register. RESULTS: Opioid dose escalation occurred in only a few patients. Increase and decrease in opioid dose were almost equally frequent. Sixty percent of those discharged on long acting opioids were still on that treatment at follow-up. Twenty-eight percent of the patients initiated opioid treatment after discharge from the pain centre. Occupational status was identified as a determining factor for future opioid use. Opioid users had a lower health related quality of life, higher occurrence of depression and more frequent use of coping strategies like 'Catastrophizing' and 'Hoping and Praying'. Adjuvant analgesics were highly discontinued. Multidisciplinary pain treatment reduced the number of hospital admissions and in-hospital days. CONCLUSION: We recommend that future research on opioid treatment does not only focus on biological issues. The effect of opioids needs to be viewed in a much more complex context where consequences like health related quality of life, depression and the role of various coping strategies are included.