Importance: Fibromyalgia is a chronic condition that results in a significant burden to individuals and society.
Objective: To investigate the effectiveness of therapies for reducing pain and improving quality of life (QOL) in people with fibromyalgia.
Data sources: Searches were performed in the MEDLINE, Cochrane, Embase, AMED, PsycInfo, and PEDro databases without language or date restrictions on December 11, 2018, and updated on July 15, 2020.
Study selection: All published randomized or quasi-randomized clinical trials that investigated therapies for individuals with fibromyalgia were screened for inclusion.
Data extraction and synthesis: Two reviewers independently extracted data and assessed risk of bias using the 0 to 10 PEDro scale. Effect sizes for specific therapies were pooled using random-effects models. The quality of evidence was assessed using the Grading of Recommendations Assessment (GRADE) approach.
Main outcomes and measures: Pain intensity measured by the visual analog scale, numerical rating scales, and other valid instruments and QOL measured by the Fibromyalgia Impact Questionnaire.
Results: A total of 224 trials including 29 962 participants were included. High-quality evidence was found in favor of cognitive behavioral therapy (weighted mean difference [WMD], -0.9; 95% CI, -1.4 to -0.3) for pain in the short term and was found in favor of central nervous system depressants (WMD, -1.2 [95% CI, -1.6 to -0.8]) and antidepressants (WMD, -0.5 [95% CI, -0.7 to -0.4]) for pain in the medium term. There was also high-quality evidence in favor of antidepressants (WMD, -6.8 [95% CI, -8.5 to -5.2]) for QOL in the short term and in favor of central nervous system depressants (WMD, -8.7 [95% CI, -11.3 to -6.0]) and antidepressants (WMD, -3.5 [95% CI, -4.5 to -2.5]) in the medium term. However, these associations were small and did not exceed the minimum clinically important change (2 points on an 11-point scale for pain and 14 points on a 101-point scale for QOL). Evidence for long-term outcomes of interventions was lacking.
Conclusions and relevance: This systematic review and meta-analysis suggests that most of the currently available therapies for the management of fibromyalgia are not supported by high-quality evidence. Some therapies may reduce pain and improve QOL in the short to medium term, although the effect size of the associations might not be clinically important to patients.