Pain epidemiology and health related quality of life in chronic non-malignant pain patients referred to a Danish multidisciplinary pain center

This paper presents the results of a detailed study of the pain epidemiology and health related quality of life (HRQL) in 150 chronic non-malignant pain patients consecutively referred to a Danish multidisciplinary pain center. Mean pain severity was 71.6 (SD = 18.5) on the VAS scale. Forty-two percent reported poor quality of sleep. HRQL was evaluated with the Medical Outcome Study-Short Form (SF-36), the Hospital Anxiety and Depression scale (HAD) and the Psychological General Well-Being Scale (PGWB). Compared with the normal population (NP) both SF-36 scores and PGWB scores were significantly reduced (P < 0.001) indicating that physical, psychological and social well-being were severely reduced. On the HAD scale 58% were found to have a depressive or anxiety disorder. Statistically significant but modest correlations were found between pain severity and HRQL. Psychological and social well-being was closely correlated. Sixty-three percent of the referred patients had neurogenic pain conditions. Of these, only 25% were treated with antidepressants or anticonvulsants at referral. Seventy-three percent were treated with opioids at referral. Mean opioid consumption was 64 mg of morphine per day (range 1-280 mg). Compared with the NP the chronic pain patients had used the health care system five times more often in the years prior to referral (P < 0.001). The study confirms the severe multidimensional impact of chronic pain and demonstrates that HRQL of chronic non-malignant pain patients is among the lowest observed for any medical condition.