REVIEW ARTICLE (META-ANALYSIS)| Volume 103, ISSUE 9, P1858-1865, September 2022

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Are There Interindividual Differences in Anxiety as a Result of Aerobic Exercise Training in Adults With Fibromyalgia? An Ancillary Meta-analysis of Randomized Controlled Trials

  • George A. Kelley
    Corresponding author George A. Kelley, DA, FACSM, Department of Epidemiology and Biostatistics, School of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9190, Morgantown, WV 26506-9190.
    Department of Epidemiology and Biostatistics, School of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV
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  • Kristi S. Kelley
    Department of Epidemiology and Biostatistics, School of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV
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  • Leigh F. Callahan
    Department of Social Medicine, University of North Carolina, Chapel Hill, NC

    Department of Orthopedics, University of North Carolina, Chapel Hill, NC

    Department of Epidemiology, University of North Carolina, Chapel Hill, NC, United States
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Published:January 16, 2022DOI:



      To determine whether true interindividual response differences (IIRD) exist with respect to changes in anxiety because of aerobic exercise training in adults with fibromyalgia (FM).

      Data Sources

      Data from a previous meta-analytical database of randomized controlled trials of exercise in adults with arthritis and other rheumatic diseases.

      Study Selection

      Randomized controlled trials limited to aerobic exercise training on anxiety in adults 18 years or older with FM were included.

      Data Extraction

      Change outcome SDs treated as point estimates for anxiety were used to calculate true IIRD from each study. In addition, treatment effect data were extracted.

      Data Synthesis

      The inverse variance heterogeneity model was used to pool all results. For the 5 studies and 321 participants in which results were pooled, statistically significant treatment effect reductions in anxiety were observed (mean, −0.77 points, 95% CI, −1.25 to −0.77). However, no significant IIRD were found (mean, 0.6 points, 95% CI, −1.2 to 1.5). The 95% prediction interval for true IIRD in a future study was −1.7 to 0.8. The percent chance, ie, probability, of a clinically meaningful difference in variability, was 61.5% (only possibly clinically important).


      The results of the current study suggest that aerobic exercise is associated with reductions in anxiety among adults with fibromyalgia. However, there is currently a lack of convincing evidence to support the notion that true IIRD exist. Therefore, a search for potential mediators and moderators associated with aerobic exercise and changes in anxiety among adults with FM may not be warranted. However, additional research is needed before any true level of certainty can be established. This includes (1) the assessment of IIRD in future randomized controlled trials, (2) randomized controlled trials of longer duration, and (3) an increase in the proportion of men included in randomized controlled trials.


      List of abbreviations:

      FM (fibromyalgia), GRADE (Grading of Recommendations Assessment, Development, and Evaluation), IIRD (interindividual response difference), MCID (minimal clinically important difference), NNT (number needed to treat), PI (prediction interval)
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      Linked Article

      • Correction
        Archives of Physical Medicine and RehabilitationVol. 104Issue 1
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          In the article, “Are There Interindividual Differences in Anxiety as a Result of Aerobic Exercise Training in Adults With Fibromyalgia? An Ancillary Meta-analysis of Randomized Controlled Trials” ( ), the 95% confidence interval in the second sentence of the Data Synthesis section of the abstract should be “−1.25 to −0.29”. Also, in the first row of Table 1, the 95% confidence interval likewise should be “−1.25 to −0.29”.
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