[Diagnostic subgroups and psychosocial characteristics in chronic non-malignant pain patients referred to an out-patient pain center].

The purpose of this study is to describe an out-patient Pain Center population on the basis of IASP Classification of Chronic Pain. Furthermore, the study investigates the relationship between diagnostic subgroups of chronic non-malignant pain patients and psychosocial parameters. The average age of the patients was 42 and the mean age at the onset of pain was 34.2. In the present study about x of all the patients had severe pain with a duration of 48 months (median value), patients with dysfunctional pain, one of three diagnostic subgroups, had a significantly longer pain duration (80 months). Nearly (1/3) of all patients are not able to work regularly and 85 % felt impaired in their daily work activities. Nearly (1/3) of the patients without any somatic pathological findings had at least one invasive intervention, just like the patients in the other diagnostic subgroups, and the need-controlled pain medication reached its highest level in this group (45 %). Only 19 % of the 323 patients investigated had nociceptive-neuropathic pain complaint, whereas 53 % were suffering from dysfunctional, and 28 % had a somatoform pain disorder. So, in patients suffering from chronic pain, simultaneous somatic and psychic or psychosomatic diagnostics are indispensable due to the relevance of psychic and psychosocial factors to pain genesis, modulation and persistence. For patients in each of the described subgroups additional psychological factors such as attitudes, beliefs, self-efficacy, fear-avoidance beliefs and motivational factors always have a significant influence on the persistence of chronic pain syndromes. So, as a rule, to make a reliable diagnosis and to give a profound prognosis for the course of treatment, a close interdisciplinary cooperation is required.