No effects were found in favor of Hatha or Iyengar yoga exercises for improving cancer-related fatigue, depression symptoms, or quality of life: a systematic review with meta-analysis and metaregression

Objective To summarize the evidence on the effectiveness of Hatha or Iyengar yoga exercises on cancer-related fatigue, depression symptoms, and the overall quality of life in adults with cancer. Methods A systematic review with meta-analysis was conducted. The CINAHL (via EBSCOhost), Embase, PubMed, and SPORTDiscus (via EBSCOhost) databases were searched from inception to 7th November 2022. Clinical trials evaluating cancer-related fatigue, depression symptoms, and the overall quality of life were included. The risk of bias was assessed using the Cochrane Risk of Bias tool 2. The Template for Intervention Description and Replication (TIDieR) checklist was used to check if the interventions reviewed were described in detail to be implemented in the clinical setting. The Grading of Recommendations, Assessment, Development, and Evaluations approach was used to rate the certainty of evidence. Meta-regressions, sensitivity analyses, and subgroup meta-analyses were conducted to explore sources of heterogeneity. Results Eleven studies were included ( N = 777 participants). Overall, Hatha, Iyengar, and the combination of both yoga styles did not improve any of the outcomes of interest. In addition, five studies had a high risk of bias, and six studies had some concerns about biases. Weaknesses in reporting modifications during the development of the study were observed (TIDieR item 10). The certainty of evidence ranged from low to very low across the outcomes. Conclusions We could not make sound clinical recommendations with the current quality of the findings.