Retractions7 July 2020

Notice of Retraction: Effectiveness of Surgical and Cotton Masks in Blocking SARS-CoV-2

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Author, Article and Disclosure Information

According to recommendations by the editors of Annals of Internal Medicine, we are retracting our article, “Effectiveness of Surgical and Cotton Masks in Blocking SARS-CoV-2. A Controlled Comparison in 4 Patients,” which was published at Annals.org on 6 April 2020 (1).

We had not fully recognized the concept of limit of detection (LOD) of the in-house reverse transcriptase polymerase chain reaction used in the study (2.63 log copies/mL), and we regret our failure to express the values below LOD as “<LOD (value).” The LOD is a statistical measure of the lowest quantity of the analyte that can be distinguished from the absence of that analyte. Therefore, values below the LOD are unreliable and our findings are uninterpretable. Reader comments raised this issue after publication. We proposed correcting the reported data with new experimental data from additional patients, but the editors requested retraction.

Reference

  • 1. Bae S Kim MC Kim JY et alEffectiveness of surgical and cotton masks in blocking SARS-CoV-2: a controlled comparison in 4 patients. Ann Intern MedEpub 6 April 2020. [PMID: 32251511]. doi:10.7326/M20-1342 MedlineGoogle Scholar

Comments

Ian Goddard8 July 2020
The author's interpretation of their results was misleading

A big problem with this study was the peculiar interpretation of the results by the authors. Their results, given in log copies per mL, show that surgical masks reduced median viral emission by 27.5% and cotton masks reduced median viral emission by 80.4%. Just the fact that a reusable cotton mask was more effective than a manufactured surgical mask was news worthy by itself. Instead, the public was misled to believe the masks were totally ineffective.

It is hard to understand how the authors deemed that an 80% reduction of viral emission constitutes an “ineffective” intervention. With 80% reduction of viral emissions writ large, tens of thousands who have died of Covid-19 might be alive today. Cotton masks have never been promoted as 100% effective, not even N95 masks are. So setting that up as a rigid pass-fail metric was misleading and has endangered public health by obfuscating important degrees of efficacy.  

The Editors of Annals of Internal Medicine30 June 2020
Response from Editors

Bae and colleagues proposed to provide additional data from new experiments done on additional patients. Such information would not correct the problems with the published study and should be evaluated as a new study. The editors continue to believe that the appropriate action was to retract the article. We would welcome the opportunity to review a new study with appropriately presented, interpretable data.

Ben J27 June 2020
Concerned that the editors wouldn't allow you to update your study
In your retraction statement, you said, "We proposed correcting the reported data with new experimental data from additional patients, but the editors requested retraction." This is concerning. The scientific and medical community should welcome corrected reporting and new data. That's how we learn and grow and come closer to the truth. There is no down side to allowing you to public an updated/corrected study. This makes no sense and raises concerns about the motivations of the editors.