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Randomized Controlled Trial
. 2022 Aug 20;23(1):698.
doi: 10.1186/s13063-022-06606-0.

Effectiveness and adherence to closed face shields in the prevention of COVID-19 transmission: a non-inferiority randomized controlled trial in a middle-income setting (COVPROSHIELD)

Andrea Ramirez Varela  1 , Alejandro Pacheco Gurruchaga  2 , Silvia Restrepo Restrepo  3 , Juan David Martin  2 , Yessica Daniela Campaz Landazabal  4 , Guillermo Tamayo-Cabeza  4 , Sandra Contreras-Arrieta  4 , Yuldor Caballero-Díaz  4 , Luis Jorge Hernandez Florez  4 , John Mario González  4   5 , Juan Carlos Santos-Barbosa  4   5 , José David Pinzón  6 , Juan José Yepes-Nuñez  4 , Rachid Laajaj  7 , Giancarlo Buitrago Gutierrez  8 , Martha Vives Florez  9 , Janner Fuentes Castillo  4 , Gianni Quinche Vargas  4 , Andres Casas  10 , Antonio Medina  11 , Eduardo Behrentz  12 ; CoVIDA Working Group
Collaborators, Affiliations
Randomized Controlled Trial

Effectiveness and adherence to closed face shields in the prevention of COVID-19 transmission: a non-inferiority randomized controlled trial in a middle-income setting (COVPROSHIELD)

Andrea Ramirez Varela et al. Trials. .

Abstract

Background: The use of respiratory devices can mitigate the spread of diseases such as COVID-19 in community settings. We aimed to determine the effectiveness of closed face shields with surgical face masks to prevent SARS-CoV-2 transmission in working adults during the COVID-19 pandemic in Bogotá, Colombia.

Methods: An open-label non-inferiority randomized controlled trial that randomly assigned participants to one of two groups: the intervention group was instructed to wear closed face shields with surgical face masks, and the active control group was instructed to wear only surgical face masks. The primary outcome was a positive reverse transcription polymerase chain reaction test, IgG/IgM antibody test for SARS-CoV-2 detection, or both during and at the end of the follow-up period of 21 days. The non-inferiority limit was established at - 5%.

Results: A total of 316 participants were randomized, 160 participants were assigned to the intervention group and 156 to the active control group. In total, 141 (88.1%) participants in the intervention group and 142 (91.0%) in the active control group completed the follow-up.

Primary outcome: a positive SARS-CoV-2 test result was identified in one (0.71%) participant in the intervention group and three (2.1%) in the active control group. In the intention-to-treat analysis, the absolute risk difference was - 1.40% (95% CI [- 4.14%, 1.33%]), and in the per-protocol analysis, the risk difference was - 1.40% (95% CI [- 4.20, 1.40]), indicating non-inferiority of the closed face shield plus face mask (did not cross the non-inferiority limit).

Conclusions: The use of closed face shields and surgical face masks was non-inferior to the surgical face mask alone in the prevention of SARS-CoV-2 infection in highly exposed groups. Settings with highly active viral transmission and conditions such as poor ventilation, crowding, and high mobility due to occupation may benefit from the combined use of masks and closed face shields to mitigate SARS-CoV-2 transmission.

Trial registration: ClinicalTrials.gov NCT04647305 . Registered on November 30, 2020.

Keywords: COVID-19; Clinical trial; Closed face shield; Face mask; SARS-CoV-2.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Study flowchart
Fig. 2
Fig. 2
Distribution of study participants according to socioeconomic stratum, vulnerability index, and residence localities. a Vulnerability index. b Socioeconomic stratum. c Residence localities
Fig. 3
Fig. 3
Comparison of the results of the intention-to-treat and per-protocol analyses
Fig. 4
Fig. 4
Post hoc analysis
See this image and copyright information in PMC

References

    1. Dong E, Du H, Gardner L. An interactive web-based dashboard to track COVID-19 in real time. Lancet Infect Dis. 2020;20(5):533–534. doi: 10.1016/S1473-3099(20)30120-1. - DOI - PMC - PubMed
    1. Institute for Health Metrics and Evaluation (IHME). Global total deaths - COVID-19 projections. Seattle: IHME, University of Washington; 2021.
    1. Institute for Health Metrics and Evaluation (IHME) Total deaths in Latin America and Caribbean. Seattle: IHME, University of Washington; 2021.
    1. Institute for Health Metrics and Evaluation (IHME) Daily deaths in Latin America and Caribbean. Seattle: IHME, University of Washington; 2021.
    1. Institute for Health Metrics and Evaluation (IHME). Total deaths in Colombia. Seattle: IHME, University of Washington; 2021.

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