[Systematic review: does a diagnosis of fibromyalgia per se have a harmful effect on prognosis?]

The aim of the present study was to determine the extent to which a label of fibromyalgia (FM) could have a harmful effect on short- and long-term prognosis.

We performed a systematic review using a sensitive search strategy. All studies published in PubMed (since 1961), Embase (since 1991) and Cochrane Library Plus (up to 2005) were selected. The titles and abstracts of articles retrieved from the search were reviewed and clinical trials and studies on prognosis were included.

Of a total of 650 references retrieved, only 5 were analyzed in detail. Two were longitudinal studies that completely fulfilled the inclusion criteria. These studies were performed in different countries (Canada and the United Kingdom) with sufficient and representative samples. Both studies reported lower resource utilization after a diagnosis of FM. The remaining studies were analyzed in detail, although they did not fulfill the inclusion criteria: there was one longitudinal study to determine the accuracy of the diagnosis of FM, one qualitative study, and a review article. No studies against the hypothesis that a diagnosis of FM worsens prognosis were found.

There is no evidence that a diagnosis of FM per se could worsen prognosis in patients with this condition. Indeed, the available evidence, which is of moderate-good quality, suggests that, on the contrary, diagnosis reduces healthcare utilization by patients.