The Accuracy of a Fibromyalgia Diagnosis in General Practice

To compare the characteristics of people with fibromyalgia (FM) with those with other forms of nonmalignant chronic pain.

A prospective cohort study conducted in a chronic pain management clinic within an academic medical center.

Many symptoms of the chronic pain syndrome FM are common to other pain or musculoskeletal syndromes. FM may be misdiagnosed by clinicians.

Thirty-three patients with a working diagnosis of FM were identified: 26 (78.8%) participated in the study. They were matched by age (mean = 53.0 years) and gender (80.8% female) to a control group with other forms of chronic nonmalignant pain.

Standardized physical examinations for FM were undertaken using the 1990 and revised 2010 American College of Rheumatology (ACR) guidelines. The groups were compared using diagnoses of psychiatric disorders and responses to the Pain Disability Index, Personal Health Questionnaire, Revised Fibromyalgia Impact Questionnaire, and Rapid Estimate Adult Literacy in Medicine.

The most common psychiatric disorders were depression (44.4%) and anxiety (27.3%). Incidence of at least one psychiatric condition was 80.8%, and the only difference (P = 0.002) between the two populations was the mean number of tender points: 5.6 (±4.2) vs controls 3.2 (±2.2). Only three (11.5%) participants with a prior diagnosis of FM fulfilled the 1990 ACR diagnostic criteria, increasing to 38.5% when the 2010 criteria were applied; however, 46.1% of controls also met the revised diagnostic criteria.

FM is commonly misdiagnosed: all patients with a working diagnosis should be reassessed and reviewed to ensure that the most appropriate treatment is provided.