International Journal of Yoga

LETTER TO EDITOR
Year
: 2018  |  Volume : 11  |  Issue : 1  |  Page : 83--84

The Conclusions Are Unsupported by the Data, Are Based on Invalid Analyses, Are Incorrect, and Should be Corrected: Letter Regarding “Sleep Quality and Body Composition Variations in Obese Male Adults after 14 weeks of Yoga Intervention: A Randomized Controlled Trial”


David B Allison 
 Department of Epidemiology and Biostatistics, School of Public Health, Indiana University Bloomington, Bloomington, IN, USA

Correspondence Address:
David B Allison
Department of Epidemiology and Biostatistics, School of Public Health, Indiana University Bloomington, 1025 E 7th Street, PH 111, Bloomington, IN 47405
USA




How to cite this article:
Allison DB. The Conclusions Are Unsupported by the Data, Are Based on Invalid Analyses, Are Incorrect, and Should be Corrected: Letter Regarding “Sleep Quality and Body Composition Variations in Obese Male Adults after 14 weeks of Yoga Intervention: A Randomized Controlled Trial”.Int J Yoga 2018;11:83-84


How to cite this URL:
Allison DB. The Conclusions Are Unsupported by the Data, Are Based on Invalid Analyses, Are Incorrect, and Should be Corrected: Letter Regarding “Sleep Quality and Body Composition Variations in Obese Male Adults after 14 weeks of Yoga Intervention: A Randomized Controlled Trial”. Int J Yoga [serial online] 2018 [cited 2022 Dec 6 ];11:83-84
Available from: https://www.ijoy.org.in/text.asp?2018/11/1/83/222100


Full Text

Dear Sir,

Rshikesan et al. conducted a parallel randomized controlled trial (RCT) in which participants were assigned to either a yoga or a control condition and effects on sleep and body composition variables were observed.[1] In parallel RCTs, the correct analyses for inferences about treatment effects entail comparing outcomes between the treatment and control groups.[2],[3],[4],[5] Rshikesan et al. conducted the correct analyses and found no statistically significant effects. Therefore, the correct conclusions of the study would have been that the data did not show that the treatment was effective.

Surprisingly, those were not the conclusions reported by Rshikesan et al. Rshikesan et al. incorrectly concluded that “The results indicate the beneficial effects of integrated approach of yoga therapy on body composition and sleep quality in obese males.” They drew these conclusions by mistakenly relying on the fact that some of the within-group changes in outcome variables were statistically significant for the yoga group but not for the control group. Unfortunately, such an analytic strategy is invalid. The invalidity of this approach has been noted repeatedly in the literature.[3],[4],[5],[6],[7] The use of this inappropriate analytic approach, referred to as the difference in nominal significance (DINS) error, can result in an inflated Type I (false-positive) error rate as high as 50% (i.e., 0.50 instead of the usual 0.05) when sample sizes are equal across groups.[3],[4],[5]

Other papers have had to be corrected[8],[9],[10] or retracted[11],[12] because of making the DINS error. Ironically, in this very journal, this same error occurred in a different paper and was noted last year.[13]

Given that the primary conclusions offered in the paper by Rshikesan et al. are incorrect, an erratum or retraction should be issued.[14]

Acknowledgment

Supported in part by NIH grants R25DK099080 and R25HL124208. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or any other organization.

Financial support and sponsorship

This study was financially supported in part by NIH grants R25DK099080 and R25HL124208.

Conflicts of interest

There are no conflicts of interest.

References

1Rshikesan PB, Subramanya P, Singh D. Sleep quality and body composition variations in obese male adults after 14 weeks of yoga intervention: A randomized controlled trial. Int J Yoga 2017;10:128-37.
2Moher D, Hopewell S, Schulz KF, Montori V, Gøtzsche PC, Devereaux PJ, et al. CONSORT 2010 explanation and elaboration: Updated guidelines for reporting parallel group randomised trials. Br Med J 2010;340:c869.
3Bland JM, Altman DG. Comparisons against baseline within randomised groups are often used and can be highly misleading. Trials 2011;12:264.
4Bland JM, Altman DG. Best (but oft forgotten) practices: Testing for treatment effects in randomized trials by separate analyses of changes from baseline in each group is a misleading approach. Am J Clin Nutr 2015;102:991-4.
5George BJ, Beasley TM, Brown AW, Dawson J, Dimova R, Divers J, et al. Common scientific and statistical errors in obesity research. Obesity (Silver Spring) 2016;24:781-90.
6Allison DB, Brown AW, George BJ, Kaiser KA. Reproducibility: A tragedy of errors. Nature 2016;530:27-9.
7Gelman A, Stern H. The difference between “significant” and “not significant” is not itself statistically significant. Am Stat 2006;60:328-31.
8Allison DB, Antoine LH, George BJ. Incorrect statistical method in parallel-groups RCT led to unsubstantiated conclusions. Lipids Health Dis 2016;15:77.
9Allison DB. RE: Statistical Interpretation Error in Metformin Trail Paper; Published online June 25, 2017. Available from: http://www.pediatrics.aappublications.org/content/early/2017/06/08/peds. 2016-4285.comments#re-statistical-interpretation-error-in-metformin-trail-paper. [Last accessed on 2017 Dec 01].
10Allison DB, Williams MS, Hand GA, Jakicic JM, Fontaine KR. Conclusion of “Nordic walking for geriatric rehabilitation: A randomized pilot trial” is based on faulty statistical analysis and is inaccurate. Disabil Rehabil 2015;37:1692-3.
11Dimova RB, Allison DB. Inappropriate statistical method in a parallel-group randomized controlled trial results in unsubstantiated conclusions. Nutr J 2016;15:58.
12Cassani RS, Fassini PG, Silvah JH, Lima CMM Marchini JS. Retraction note: Impact of weight loss diet associated with flaxseed on inflammatory markers in men with cardiovascular risk factors: A clinical study. Nutr J 2016;15:59.
13George BJ, Goldsby TU, Brown AW, Li P, Allison DB. Unsubstantiated conclusions from improper statistical design and analysis of a randomized controlled trial. Int J Yoga 2016;9:87-8.
14Committee on Publication Ethics. Guidelines for Retracting Articles. Available from: http://www.publicationethics.org/files/retraction%20guidelines.pdf. [Last accessed on 2017 Sep 06].