Objective: To determine if assigning the label of fibromyalgia (FM) to individuals with chronic widespread pain has a significant effect on long-term health status, function, and health service utilization.
Methods: In the London Fibromyalgia Epidemiology Study, 100 individuals with FM were identified by screening 3,395 non-institutionalized adults. Only 28 of the 100 had been previously diagnosed with FM; for 72, the diagnostic label was new. All 28 with prediagnosed FM were female compared with 58 of the 72 newly diagnosed cases. In a prospective, within-group comparison, we compared previously non-labeled FM cases at study entry (prelabeling) and at 18 and 36 months followup (postlabeling) with respect to general health status, fibromyalgia-related symptoms, and all items from the Fibromyalgia Impact Questionnaire (FIQ) (including total FIQ score, and several measures of health service utilization) to see if health status, function, and health services utilization had changed, using paired t-tests. We also compared percentage reporting work disability at baseline and 18 months using Pearson's chi(2).
Results: Fifty-six (78%) of the original 72 newly diagnosed FM cases were available for reassessment at 18 months, and 43 (60%) at 36 months. Although physical functioning decreased slightly over time, there also was a statistically significant improvement in satisfaction with health, and newly diagnosed FM cases reported fewer symptoms and major symptoms over the long term. No other differences in clinical status or health service use occurred over time.
Conclusion: The FM label does not have a meaningful adverse affect on clinical outcome over the long term. Further research is necessary to document the short- and long-term effect of labeling in the chronic pain patient.