Classification of Chronic Pain at a Multidisciplinary Pain Rehabilitation Clinic

Abstract

OBJECTIVE: To make a detailed diagnostic analysis of patients with chronic pain syndromes, including classification according to the International Association for the Study of Pain (IASP).DESIGN: Descriptive study of consecutive referrals during a two‐year period.SETTING: A multidisciplinary out‐patient pain clinic focused on occupational rehabilitation.SUBJECTS: A total of 309 chronic pain patients.METHODS: After a standardized multimodal physical and psychological examination, the chronic pain syndrome of each patient was assigned one or more clinical diagnoses; assigned to an etiological pain category (nociceptive pain, non‐nociceptive including idiopathic pain, and psychological pain); and coded diagnostically according to IASP taxonomy.RESULTS: In all, 397 clinical diagnoses were made (ie, a mean of 1.3 diagnoses per patient). A large majority (87%) received a diagnosis of myalgia. Myofascial pain (trigger point syndrome) was diagnosed in two‐thirds of the patients and was the most frequent clinical pain syndrome. A total of 51.8% of the pain syndromes were categorized as nociceptive, 43.0% as idiopathic and less than 1% as pain of psychological origin. Classification using the IASP system yielded a very high proportion of nociceptive, musculoskeletal pain syndromes of high intensity, with widespread pain and/or pain located in the neck/shoulder/arm region, and of dysfunctional etiology.CONCLUSIONS: Musculoskeletal pain was very common in this series, and myofascial pain syndromes were the most frequent specific pain disorders. However, myofascial pain had generally gone unrecognized by the referring physician. In contrast to findings of other studies, the incidence of low back pain and of primary psychological pain was low. Comparison of the results with those of Swedish epidemiological surveys showed the frequencies of the diagnoses in this series to be representative of chronic pain syndromes in the Swedish general population.