Stanley Pillimer, MD

Fibromyalgia is one of a constellation of painful musculoskeletal disorders that have been delineated since rheumatism was mentioned in the Hippocratic writings. With the publication of the American College of Rheumatology 1990 classification criteria for fibromyalgia, a simple, uniform case definition became available for clinical investigation of the disorder. Case definition is pivotal in epidemiologic studies and the ACR 1990 criteria have the advantage of simplicity. Prior to this, various criteria were used by a number of investigators and included other features such as morning stiffness, non-restorative sleep and aggravating features (e.g. cold weather), in addition to pain and tenderness. Criteria that may be sensible in clinical practice may not be as useful for evaluation of a large population. The ACR criteria require the examination of 18 tender points and this may discourage incorporating fibromyalgia into large surveys with a physical examination component. However, modification of the ACR criteria by increasing the number of criteria to incorporate associated features, such as irritable bowel or bladder, sleep disorder, cognitive difficulties, psychological distress, or chronic fatigue, into the definition of fibromyalgia will tend to increase the heterogeneity of the populations studied. Changing the ACR by requiring more extensive physical examination or laboratory testing or diagnostic imaging would tend to hamper the conduct or feasibility of epidemiologic and clinical projects.

Presented at the National Fibromyalgia Research Association's New Dimensions in Fibromyalgia Symposium, September 14-15, 1997, in Portland, Oregon.