@MintyFreshOne RCTs are not necessary in the context of masks, we already have empirical evidence from aerosol science, physics, and other industries besides healthcare that require masking, that they offer effective protection. The issue at hand is also too complex and settings too diverse and changing with many confounding factors, to definitely confirm via RCT that masks work.
"But what constitutes evidence in this context [mask wearing]? There has been an almost exclusive focus on evidence from experimental studies, specifically the randomized controlled trial(RCT), which is characterized as the "gold standard" of research, as it allows for the determination of causality. However, the reason such evidence is still lacking, should be obvious – the RCT is neither feasible nor appropriate for determining the effectiveness of mask-wearing in the community in protecting against COVID-19, and moreover, its use will be considered unethical in the context of a deadly pandemic. At the minimum, an RCT would require manipulation of the intervention, by way of the researcher randomly assigning some members of the community to wear a face mask and others not to, and ensuring that both community groups are similar, based on key background characteristics, in other words, controlling for potential confounding factors." www.medpagetoday.com/infectiousdisease/covid19/87870
One supposed RCT (Loeb et al 2022) gained a lot of media interest last year focusing on healthcare workers assigned a surgical mask but with the option to wear N95s, but it had many flaws: no control of masking outside the workplace, no requirement to mask when at work but not with COVID patients, only 80% of the N95 group wore their mask 'always', the surgical group sometimes wore N95, the different country sites all had very different sample sizes and characteristics, and staff had different responsibilities, to list a few. In any case, it showed a 15% increase in infections with surgical masks. Here's one takedown but there are others out there: first10em.com/the-now-infamous-but-not-very-helpful-n95-trial-loeb-2022/
There was also the DANMASK study last year but similarly flawed - small sample size, during a period of low COVID incidence, it used antibody tests that are on the US FDA's removed list, it was only a 30 day study so missed infections/recorded infections preceding the study, it had no ethical approval.
I shared a school masking study precisely because it shows that even with imperfect mask wearing (e.g. taking them off for lunch, kids in surgicals) it's still better than nothing. There's a natural experiment that happened in Alberta, Canada where schools that removed their mask mandates had 3 times more outbreaks than those that kept masks (source is official government statistics cited in this news article: www.cbc.ca/news/canada/calgary/alberta-government-mask-mandates-1.647720)
And more studies that show masks work in school and other indoor settings:
Comparison in US counties with/without school mask mandates: www.cdc.gov/mmwr/volumes/70/wr/mm7039e3.htm?s_cid=mm7039e3_w
Study in Arizona schools: www.cdc.gov/mmwr/volumes/70/wr/mm7039e1.htm?s_cid=mm7039e1_w
California indoor spaces: www.cdc.gov/mmwr/volumes/71/wr/mm7106e1.htm?s_cid=mm7106e1_w
At the end of the day, we can pick and choose our papers, but physics dictates that you will be protected more with a mask than without. Even if it's not fit tested.