[arcticbull]

I actually disagree with your read on this.

I think a better analogy to smoking would be "30% of smokers felt that cigarettes caused them to cough chronically" in a survey of people who already had a chronic cough.

That's not the same thing as "smoking causes chronic cough in 30% of people" - rather "smoking makes coughing worse in 30% of people who already had a chronic cough." Maybe they got that from smoking, maybe they didn't, but the data doesn't show that, and it cannot be extrapolated to the general population. More data is needed.

It is in fact a subset of a subset.

[edit] btw 150 people can be enough to draw statistically significant conclusions but you need to properly design your survey and you need a suitably random sampling of your target population. Not sure this has either?

[Timshel]

And I believe your read is wrong ^^.

Looking at the data : https://about.fb.com/wp-content/uploads/2021/09/Instagram-Te...

From page 4: The research presented instagram users with a survey about a select negative experience they may have had. Only if the user reported having had such an experience did they get a random "deep dive" ...

So the "reported" here just mean answered a previous question and does not precede using Instagram or smoking.