Runar Barstad Solberg

Dear Editor We appreciate the constructive feedback and would like to address some of the key critical points that have been raised. Fujito and Donzeilli express concerns about our reliance on self-reports of a subjective outcome given that the participants were aware that they used a mask or not, which we acknowledge represents a risk of bias.

Opinion BMJ 2024; 386 doi: https://doi.org/10.1136/bmj.q1661 Cite this as: BMJ 2024;386:q1661 Atle Fretheim, research director1, Runar Barstad Solberg, scientist1, Lars G Hemkens, senior scientist2 1Centre for Epidemic Interventions Research, Norwegian Institute of Public Health, Oslo, Norway 2Pragmatic Evidence Lab, Research Centre for Clinical Neuroimmunology and Neuroscience Basel (RC2NB), Basel, Switzerland We need open and nuanced discussions about research findings on public health and...

Methods We conducted a pragmatic parallel two arm individually 1:1 randomised superiority trial. Details on the rationale, design, and statistical analysis plan can be found elsewhere.89 The trial was performed according to a published protocol, with exceptions (see Protocol Amendments section), and the principles outlined in the Declaration of Helsinki. We followed the Consolidated Standards of Reporting Trials (CONSORT) guidelines (see supplementary material, table 1).