Comparison groups in yoga research: A systematic review and critical evaluation of the literature

Abstract

Objectives Comparison groups are essential for accurate testing and interpretation of yoga intervention trials. However, selecting proper comparison groups is difficult because yoga comprises a very heterogeneous set of practices and its mechanisms of effect have not been conclusively established. Methods We conducted a systematic review of the control and comparison groups used in published randomized controlled trials (RCTs) of yoga. Results We located 128 RCTs that met our inclusion criteria; of these, 65 included only a passive control and 63 included at least one active comparison group. Primary comparison groups were physical exercise (43%), relaxation/meditation (20%), and education (16%). Studies rarely provided a strong rationale for choice of comparison. Considering year of publication, the use of active controls in yoga research appears to be slowly increasing over time. Conclusions Given that yoga has been established as a potentially powerful intervention, future research should use active control groups. Further, care is needed to select comparison conditions that help to isolate the specific mechanisms of yoga’s effects.

Yoga research review

“…The question of comparison groups was addressed by a systematic review of the literature [9]. This research group identified 125 randomized controlled trials that met their criteria, and of these, 65 used an active comparison group.…”

Evaluation of a Specialized Yoga Program for Persons Admitted to a Complex Continuing Care Hospital: A Pilot Study

“…Future research trials should use a randomized, controlled trial study design with appropriate control conditions (e.g., wait-list, exercise, walking, or education) and a longitudinal design with follow-up intervals to determine lasting effects of a yoga practice [118]. Targeting self-compassion in the content and philosophy portions of the yoga interventions may enable researchers to further explore its mediating role of this construct on other psychological or physical experiences prevalent in this population.…”

Effects of yoga, strength training and advice on back pain: a randomized controlled trial

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