Population study of tender point counts and pain as evidence of fibromyalgia.

OBJECTIVE: To determine the relation between tender points, complaints of pain, and symptoms of depression, fatigue, and sleep quality in the general population.
DESIGN: Two stage cross sectional study with an initial questionnaire about pain to classify those eligible for an examination of tender points.
SETTING: Two general practices in north west England.
SUBJECTS: Stratified random sample of adults from age-sex registers. Of the responders, 250 were selected for examination of tender points on the basis of their reported pain complaints; 177 subsequently participated. MAIN OUTCOME MEASURES: Tender point count (0 to 18) grouped into four categories with the highest (> or = 11) corresponding to the criteria of the American College of Rheumatology for fibromyalgia. Assessment of pain (chronic widespread, regional, none). Measures of depression, fatigue, and difficulty with sleeping.
RESULTS: Women had a higher median tender point count (six) than did men (three). Counts were higher in those with pain than in those who had no pain and in those with widespread compared with regional pain. Most subjects with chronic widespread pain, however, had fewer than 11 tender points (27/45; 60%). Two people with counts of 11 or more were in the group reporting no pain. Mean symptom scores for depression, fatigue, and sleep problems increased as the tender point count rose (P value for trend < 0.001). These trends were independent of pain complaints.
CONCLUSIONS: Tender points are a measure of general distress. They are related to pain complaints but are separately associated with fatigue and depression. Sleep problems are associated with tender points, although prospective studies are needed to determine whether they cause tenderness to develop. Fibromyalgia does not seem to be a distinct disease entity.