The GLasses Against transmission of SARS-CoV-2 in the communitY (GLASSY) trial: A pragmatic randomized trial (study protocol)

Abstract

Background: A systematic review of observational studies indicated that eye protection may be an effective measure to prevent SARS-CoV-2 infections. Randomized trials are needed to assess whether the observed associations are caused by protection of the eye or confounding factors such as other systematic differences between users and non-users of eye protection, co-interventions, or changes in COVID-19 incidence when comparisons were done over time. Methods: Pragmatic, virtual, parallel group, 1:1 randomized, superiority trial. We will recruit and randomize participants via an online portal. The trial will be fully remote and virtual without any personal interaction between investigators and participants. All members of the public are eligible who confirm that they are at least 18 years of age, do not regularly wear glasses, have not contracted COVID-19 since December 15th 2021, and are willing to be randomized to wear, or not wear glasses in public when close to other people, for a 2-week period. Persons who are dependent on visual aids but typically use contact lenses are eligible. The participants will be randomized (1:1) to wear glasses (sunglasses or other types of glasses) in public spaces when close to others (public transport, shopping centers etc.), or to the control group. The control group will be asked not to wear glasses in public spaces when close to others. The primary outcome is positive test for COVID-19. We aim to include about 25,000 participants to have a statistical power of 80% to detect a relative risk reduction of 25% for the primary outcome. Discussion: Many have easy access to sunglasses or other glasses. Wearing glasses may provide eye protection and repurposing sunglasses for infection control could be a simple, readily available, environmentally friendly, safe, and sustainable infection prevention measure.

Glasses Against transmission of SARS-CoV-2 in the community (GLASSY): a pragmatic randomized trial

“…The result for our primary endpoint is very uncertain, with a wide confidence interval compatible with both important benefit and harm. If we only emphasize this outcome, our trial can be interpreted as largely “negative” although the confidence interval around the estimate includes a 25% relative reduction, which is what we had deemed a reasonable minimal important difference in our sample size estimation [7]. We had probably achieved a more precise estimate had we been more successful with our recruitment of participants.…”

“…The study protocol was published prior to the start of the study [7]. There were no major deviations from the protocol.…”

“…This was based on an expected event rate of 2% in the control group and 1.5% in the intervention group. The underlying assumptions are provided in the study protocol [7].…”

Clinical trial research agenda on COVID-19 – the first two years in Germany and beyond

“…Another example is the “GLasses Against transmission of SARS-CoV-2 in the community” (GLASSY) trial that was initiated in Norway; a pragmatic, randomized, and fully remote and virtual trial without any personal interaction between investigators and participants. It evaluates whether SARS-CoV-2 infections can be reduced when participants are asked to wear glasses (sunglasses or other glasses) when they are outside of their home and close to others (e.g., on public transport, in shopping centres) compared to participants that are asked to wear no glasses in public spaces [33] .…”