The main question this raises for me is whether David is daft or whether he's lying. It's at least one or the other. Let's go through what David's said and why he's completely wrong and how, as a result, he's spreading misinformation. In the Rogan clip, David said "Sudden blindness. It's called NAION, which is now twice as more prevalent because of the GLP-1 drugs.... Sudden blindness has doubled seemingly because these meds [referring to GLP-1RAs]." To support this claim, David must provide data showing that the population rate of "sudden blindness" (and perhaps just NAION) has doubled. Does he? No. What he links, instead, is a study that compares small groups of people at one particular ophthalmology clinic who were taking GLP-1RAs to those taking either other diabetes medications or other obesity medications. He also linked a press release on a conference presentation to a similarly-weak analysis. Can you grasp the difference between what he should've linked and what he did link? He linked non-causal comparisons of groups that are very different from the general population, but he should've linked EHR or alternative monitoring-based prevalence estimates, like what I pulled. Now, if we take David's linked studies seriously, then the actual rate of NAION in society should be well beyond the actually diagnosed rate. The actual rate is 2-10 per 100,000. In one of the studies he linked, it's almost 2% of the diabetics on non-GLP-1RA medication and almost 9% on GLP-1RAs. Given the number of Americans who have used GLP-1RAs by now, you should know many people who went blind. But you do not, because these studies don't apply to the general population. I pointed this out before in a post linked in the thread that David is replying to, meaning that in addition to being daft, a liar, or both, he's also not circumspected, because his specific links were already shown to lead to absurd conclusions. In fact, the result was also shown to not hold up when the analysis is done in large, population-representative samples with better controls: My conclusions subsequently replicated again: And again: David's only holds up in weak studies with small samples, poor controls, and results that imply that HUGE portions of the population should've already gone blind -- and they have not, so they are obviously wrong. This is part of what I was getting at in the thread: we can sanity check these studies. If they imply that there should be an epidemic of blindness, we can look to see in descriptive data if there is such an epidemic. Since there is not, we know the studies are flawed in one or more ways that prevent generalizing from them. Get it? David didn't. Instead, he decided to go on one of the most popular podcasts and fail to even describe his referenced studies correctly. David's "sudden blindness" remark was actually fortuitous for me, because using all forms of acute blindness, we have enough power to detect a trend lately, if there's been one. There hasn't, as I noted. Looking at NAION specifically, we're left with a different conclusion: there's not enough power to detect a doubling (there is more than enough to detect what David's cited studies imply though!). The numbers have not drifted at all with age controlled (they're nonsignificantly down), which means that there's not even a reason to suspect the incidence is up. That also means there's not a reason for David to have said what he did. He just yapped without underlying data to support what he said, and data actually contradicting it. David's comment started ironically, by accusing me of having a financial conflict of interest. Ironically, he has a financial conflict of interest, in that he is developing a therapy that he believes will help with this issue that isn't actually an issue. So, he's financially incentivized to play it up, even though doing so is lying and is harmful because it gets patients to avoid good drugs on the basis of alleged side effects that would, at most, be extremely rare, and are more likely not present at all. So, is David dumb? Is he lying? Or is he a bad actor? Of course, he can be all of the above.