Correction: The Effect of Protandim® Supplementation on Athletic Performance and Oxidative Blood Markers in Runners
Year: 2020
Type: erratum
Abstract: The authors are correcting this article [1] to address queries and errors that were noted following its publication.Updated versions of Table 2 (S1 File) and Table 4 (S2 File) are included here, as errors in the corresponding tables in [1] were identified following publication.In the published article [1], when discussing adverse event outcomes (i.e.side effects), the Fisher's exact test was used to assess the significance of the difference between the number of subjects that experienced at least one event of a given sign or symptom between groups.All pvalues were found to be non-significant.When a comparison of proportions between groups was performed (Chi-square, N-1) [2], the authors found no significant differences between groups in the proportion of subjects experiencing at least one event from any sign or symptom (all p > 0.05) (S2 File).However, due to the limited sample sizes only substantial differences in proportions would be expected to be statistically significant in the analyses of adverse event outcomes; the trial was not designed with enough power to determine whether the proportions of adverse events in the two groups were statistically significant.The analysis of adverse events between groups was not a primary or secondary objective of the study.The adverse events were provided as preliminary data for future studies and for added interest to the reader.The authors direct readers to S2 File (which includes 3 Tabs) to review the primary data regarding adverse events (side effects) over the 88-day supplementation period.Summary (Tabs 1 and 2) and individual data (Tab 3) are provided here.Of note, one participant in the placebo group accounted for 118 episodes of gas (flatulence), which accounts for a significant amount of the 127 episodes of gas for the Placebo group; 9 different subjects (47%) in the placebo group experienced at least 1 event from any sign/symptom list; and 11 different subjects (56%) in the Protandim 1 group experienced at least 1 event from any sign/symptom list.Questions were raised about the selective inclusion of participants aged 35-46 for the analyses in Fig 7 of the original article.As noted in The Funding statement and in the 5 th paragraph of the Discussion section, a post-hoc analysis was conducted by LifeVantage Inc.However, these analyses were not included in the original study protocol, and the study did not include enough participants to enable a full assessment of age effects.The authors discussed the issue of p-hacking and concerns about unplanned statistical tests in the Discussion (5 th paragraph).As noted in the original article, one of the authors who participated in the randomization of subjects also served as a participant in this study.Here, the authors clarify that this author was blinded to allocation group: GSZ randomized subjects, including himself, to group 1 versus group 2 but did not know which group was experimental versus control.This assignment was determined by the company, which directly allocated the placebo and Protandim supplements coded by numbers and letters.The author was not informed as to the meaning of the codes
Source: PLoS ONE
Language: English
Subfield: Rehabilitation
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,695
OpenAlex ID: W4247597641