Raina MacIntyre

And by intention to treat analysis, which is just analysing it according to the arms to which it was randomised without looking at whether they actually complied or not, there was no effectiveness.

However, we found that a lot of parents didn't comply with using the masks.

They were meant to wear it every time they were in the same room as the child that was sick, but a lot of parents just didn't do it.

They felt uncomfortable doing it.

But if you just took the ones who did wear it, it was efficacious, highly efficacious.

So if you do wear it, then it will protect you from getting infected from another family member.

Yeah, they're actually really difficult trials to do.

And the other point is we, in medicine in general, we focus very heavily on drugs and vaccines, on products, on pharmaceutical products.

And there's been much less research in general across the board on non-pharmaceutical interventions.

We started the very first face mask trial in 2006.

Another group in Hong Kong started one soon after.

At that time, it was the peak of pandemic planning around the fears of H5N1 turning into a pandemic.

And so a lot of people were interested in knowing the actual efficacy of masks.

But until that point, there'd never been a randomized controlled clinical trial.

They are really difficult trials to conduct because, you know, unlike doing a trial to see if your blood pressure is low, gets lower on the drugs, you have to actually measure infection outcomes

And the intervention itself can affect other people because of contagion.

So in a closed setting like a household or a hospital ward, putting a mask on a few people can actually prevent infection in more than just the person who's using the intervention.

So the design of such studies is really difficult.

The measuring the outcomes is difficult.

They're complex studies to do, which is probably another reason why nobody had done them.