Table of Contents  
Year : 2022  |  Volume : 54  |  Issue : 2  |  Page : 147-149

Common errors while working on yoga intervention randomized controlled trials

Inter-University Center for Yogic Sciences, Delhi, India

Date of Submission30-Sep-2022
Date of Decision22-Nov-2022
Date of Acceptance23-Nov-2022
Date of Web Publication15-Dec-2022

Correspondence Address:
Dr. Mohit Nirwan
Inter-University Center for Yogic Sciences, Vasant Kunj, Delhi
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ym.ym_134_22

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There is a steady rise in interest among researchers in exploring the effect of yoga on various disease conditions, improving holistic health in a healthy population. Innumerous studies have already highlighted the benefits, but integrating yoga into mainstream modern medicine remains a distant goal. The prominent reason is because of poor-quality trials in yoga research. Therefore, the significant vital issues which should be addressed to improve randomized controlled trials in yoga research are discussed.

Keywords: Alternative therapies, CheckList stAndardising the Reporting of Interventions For Yoga, complementary therapies, CONsolidated Standards Of Reporting Trials, risk of bias, trial quality

How to cite this article:
Nirwan M. Common errors while working on yoga intervention randomized controlled trials. Yoga Mimamsa 2022;54:147-9

How to cite this URL:
Nirwan M. Common errors while working on yoga intervention randomized controlled trials. Yoga Mimamsa [serial online] 2022 [cited 2023 Jun 6];54:147-9. Available from:

  Introduction Top

Every researcher working on yoga would agree that it benefits a diseased or healthy population. However, various systematic reviewers have pointed out that although yoga was beneficial, the studies either failed to reach a statistical significance or were biased.[1],[2],[3],[4],[5] Only a handful of systematic reviews and meta-analyses concluded the other way around.[6],[7] Therefore, even with enough studies/data on the positive impact of yoga on human health, we failed to integrate yoga into therapeutics/prescriptions in modern medicine. So what went wrong? To answer the question, I would like to pinpoint the following mistakes.

  Yoga Intervention and Delivery Top

Yoga is a vast subject; a philosophy has many branches; hence, mention of yoga intervention is insufficient. Details of the yoga intervention should be available to increase transparency and reproducibility. Furthermore, the common problem is that anyone with a yoga certificate is regarded as competent enough to deliver the intervention. A careful decision should be taken in considering the yoga instructor because the person is delivering the “dose” of the intervention. A yoga instructor may bring certain variations in the yoga protocol without communicating. They may introduce asana variations which they have learned from their yoga schools. Their credentials and experience should be assessed first-hand before giving them the responsibility of yoga delivery.

  Trial Registration Top

Trial researchers generally register grant-approved proposals and subsequent experiment protocols involving patients. However, a common misconception is that it is a requirement for only the patient group and not the healthy population with yoga intervention. Researchers getting institutional ethics clearance should always register their study protocol on a national trial registry. Registering trials will help them be peer reviewed even before starting the experiment, and they have the opportunity to “correct” their protocols and prevent duplication. Randomized controlled trials should follow CONsolidated Standards Of Reporting Trials (CONSORT) guidelines.[8]

  Risk of BIAS Top

Systematic reviewers know the importance of assessing a study's bias risk. Principal investigators unknowingly introduce several risks of bias in their protocols, for instance, not to mention the randomization method in detail and not blinding the study participants and assessors for allocation sequence, outcomes, etc. Although it is almost impossible to “blind” participants in yoga trials, a study has addressed the issue by not fully informing the participant of the exact intervention.[9] It is highly desirable to prevent bias and decrease the influence of the knowledge of yoga intervention on self-reported outcomes and qualitative data to increase trustworthiness.

Researchers often neglect the importance of separate personals for data collection, yoga instructors, and data analysts. Commonly, the person collecting data will also analyze it later. He/she may know the participants' group, so being unintentional can contribute to bias. Sometimes, due to remote conditions where a team of researchers cannot go, a researcher is “mandatory” to conduct a yoga trial in which the data collector, yoga instructor, and data analyst are the same.[10]

  Statistics Top

Using statistics before starting a trial, especially for sample size calculation and final data treatment, is essential. The uncertainties in data's final form after the trial cannot be ignored; hence, sound knowledge of basic statistics must properly “handle” the data. Overinflating the results of the yoga intervention group due to inappropriate statistical analysis is scientific misconduct. Data manipulation/fabrication cannot be ignored. The use of the last observation carried forward approach for adjusting the missing outcomes without proper justification results in high bias. Selective reporting only statistically significant results accounts for bias.

  Self-Reported Outcomes and Interviews Top

Data is in the form of questionnaires, the participant is the outcome assessor, and the interviewer is the facilitator. The participant knows that he/she has been doing yoga in the study. The reported data, whether in the form of pencil paper or interviews, is likely to be “influenced” because of the knowledge of the yoga intervention. Since it is very difficult to “blind” the experimental group participant for yoga intervention, researchers' primary outcomes should not be questionnaires and interviews, in my view. Often, the interviewer knows the participants' group allocation and introduces bias. Additional bias may be introduced if the interviewer analyses the qualitative data.

Sometimes we are “greed” for data and bombard a participant with lengthy questionnaires. In this scenario, a participant may get fatigued and face a response burden. Therefore, the data collected would be highly biased even though it “looks” promising.

  Other Issues Top

Another problem with randomized yoga trials is that the researchers often focus only on the yoga group. They do not intend to give “matched attention” to the control group. They are introducing bias and may result in dropouts in the nonyoga group. Therefore, equal attention should be paid to the control group to minimize bias and provide matched attention.

“Per-protocol” and “intention-to-treat” data analysis is another neglected challenge. Researchers randomize the participants but report the data who are adhering to the intervention and not according to their assigned intervention. This introduces bias because the power of randomization is lost. However, a per-protocol analysis may be done because of dropouts and missing outcomes. It is suggested to conduct a “modified intention-to-treat” analysis to accommodate missing outcomes problems in the analysis, and simultaneously, prevent bias.

  Discussion Top

While designing a trial, a biostatistician should be a team member or at least be consulted for appropriate data treatment and reporting. Although many points discussed are general for any randomized trial, an emphasis on yoga intervention trials was made to improve quality. Fortunately, we now have CheckLlist stAndardising the Reporting of Interventions For Yoga (CLARIFY) guidelines[11] to improve the transparency of reporting yoga interventions. Every yoga randomized controlled trial should follow and report according to the CLARIFY and CONSORT guidelines. This will help prevent bias in the studies, and the quality of studies involving yoga intervention will improve significantly, and integration with modern medicine will become possible.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Cramer H, Lauche R, Klose P, Langhorst J, Dobos G. Yoga for schizophrenia: A systematic review and meta-analysis. BMC Psychiatry 2013;13:32.  Back to cited text no. 1
Patel NK, Newstead AH, Ferrer RL. The effects of yoga on physical functioning and health related quality of life in older adults: A systematic review and meta-analysis. J Altern Complement Med 2012;18:902-17.  Back to cited text no. 2
Zhu F, Zhang M, Wang D, Hong Q, Zeng C, Chen W. Yoga compared to non-exercise or physical therapy exercise on pain, disability, and quality of life for patients with chronic low back pain: A systematic review and meta-analysis of randomized controlled trials. PLoS One 2020;15:e0238544.  Back to cited text no. 3
Cramer H, Lange S, Klose P, Paul A, Dobos G. Yoga for breast cancer patients and survivors: A systematic review and meta-analysis. BMC Cancer 2012;12:412.  Back to cited text no. 4
Sieczkowska SM, Casagrande PO, Coimbra DR, Vilarino GT, Andreato LV, Andrade A. Effect of yoga on the quality of life of patients with rheumatic diseases: Systematic review with meta-analysis. Complement Ther Med 2019;46:9-18.  Back to cited text no. 5
Pan Y, Yang K, Wang Y, Zhang L, Liang H. Could yoga practice improve treatment-related side effects and quality of life for women with breast cancer? A systematic review and meta-analysis. Asia Pac J Clin Oncol 2017;13:e79-95.  Back to cited text no. 6
Sivaramakrishnan D, Fitzsimons C, Kelly P, Ludwig K, Mutrie N, Saunders DH, et al. The effects of yoga compared to active and inactive controls on physical function and health related quality of life in older adults – Systematic review and meta-analysis of randomised controlled trials. Int J Behav Nutr Phys Act 2019;16:33.  Back to cited text no. 7
Schulz KF, Altman DG, Moher D, CONSORT Group. CONSORT 2010 statement: Updated guidelines for reporting parallel group randomized trials. Ann Intern Med 2010;152:726-32.  Back to cited text no. 8
Kaminsky DA, Guntupalli KK, Lippmann J, Burns SM, Brock MA, Skelly J, et al. Effect of yoga breathing (pranayama) on exercise tolerance in patients with chronic obstructive pulmonary disease: A randomized, controlled trial. J Altern Complement Med 2017;23:696-704.  Back to cited text no. 9
Nirwan M, Jyothish K, Halder K, Chakraborty S, Saha M, Pathak A, et al. Yoga intervention as a potential countermeasure for polar T3 syndrome. Def Life Sci J 2019;4:163-9.  Back to cited text no. 10
Moonaz S, Nault D, Cramer H, Ward L. CLARIFY 2021: Explanation and elaboration of the delphi-based guidelines for the reporting of yoga research. BMJ Open 2021;11:e045812.  Back to cited text no. 11


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