Covid-19 Living Data

Trial NCT04337541
Publication Bundgaard H
Dates: 4/3/2020 to 4/24/2020
Funding: Public (Salling Foundations)
Conflict of interest:

Methods
	RCT
	Location : Multicenter / Denmark Follow-up duration (days): 30
Inclusion criteria	Community-dwelling adults older than 18 years of age and without current or prior symptoms associated with SARS-CoV-2 (or previously tested positive for SARS-CoV-2); Working out-of-home with exposure to other people for more than 3 hours per day; Do not normally wear a face mask for daily work
Exclusion criteria	Previously tested positive for SARS-CoV-2; Wear face mask at work
Interventions
	Treatment Surgical mask (*) Duration : 30 days
	Control Standard care Definition of Standard care: * Duration : 30 days
Participants
	Randomized 6024 participants (n₁=3030 / n₂= 2994)
	Characteristics of participants N=6024 Mean age : 47.2 1746 males
Primary outcome
	In the register Difference in the number of infected individuals between the two study groups after 1 month as assessed by a combined endpoint consisting ofprimary outcome components 1, 2 and/or 3 Component 1) Positive oropharyngeal/nasal swab for SARS-CoV-2 (PCR); Component 2) Antibody test; Development of a positive SARS-CoV-2 antibody test (IgM and/or IgG) during the study period; Component 3) SARS-CoV-2 infection diagnosed in a hospital/healthcare facility.
	In the report
Documents available	Protocol Yes. In English Statistical plan NR Data-sharing stated No
Risk of bias Overall The overall risk of bias reported in the table corresponds to the highest risk of bias for the outcomes assessed for the systematic review	Some concerns
General comment	In addition to the published article and its supplementary materials, the study registry and published protocol were used in data extraction and risk of bias assessment. There were no substantive differences between the protocol, registry and report in study population, procedures, interventions or outcomes. There was substantial non-adherence in the mask group, resulting in participant crossover. There was 19% missing data (21% in mask and 18% in control groups). While the study achieved its pre-stated target sample size, the sample size calculation was powered for only a large effect size, i.e., of a 50% reduction in incidence of infections. Unblinded study.