Effect of Wearing Glasses for Prevention of SARS-CoV-2 on Visits to Health Care Providers - Additional Results from a Randomized Controlled Trial

We previously published results of a pragmatic randomized trial with 3717 participants in Norway that assessed the effect of wearing glasses on the risk of being infected with SARS-CoV-2 and other respiratory infections. Here we present unpublished findings on pre-specified secondary endpoints relying on routinely collected data from Norwegian health registries: Visits to health care providers for any cause (within 21 days), for respiratory symptoms (day 3-28), and for injuries (within 21 days). 1469 participants (39.5%) visited a health care provider for any cause at least once. There was no statistically significant difference between groups, with 39.9.% of participants wearing glasses versus 39.1% in the control group received primary or specialist care (absolute risk difference 0.76%; 95% CI, -2.4% to 3.9%; relative risk 1.02; 95% CI, 0.94 to 1.10). Similarly, there was no statistically significant difference in visits due to respiratory symptoms (326 participants; 9.1% versus 8.4%; absolute risk difference 0.71%; 95% CI, -1.1% to 2.5%; relative risk 1.08; 95% CI, 0.88 to 1.33). There were 3 participants having visited primary or specialist care and having an injury registered in a registry for injuries, the difference between groups not statistically significant. The difference between participants in the proportion of visits for injury related diagnoses was nominally statistically significant (1.3% versus 0.7%; absolute risk difference 0.7%; 95% CI, 0.01% to 1.3%; relative risk 1.94; 95% CI, 1.01 to 3.89). The study underscores the potential of utilizing registry-based outcomes for randomized evaluations of public health measures for infection control.