Last week, Tyler Cowen published a link to a recent study of the use of ivermectin in patients who had had Covid-19 for a median of 6 days. As is his wont, he doesn’t say much about the study (other than a quizzical comment about Scott Alexander) but simply links to it. Many of the commenters on that site, though, seem very sure that ivermectin is not beneficial for those in the early stages of Covid-19. Of course, as with most comments, it’s difficult to tell what bases they have for their views.

Charley Hooper and I have written extensively about ivermectin (for example, here, here, here, and here) and have pointed out how poor some of the main studies and, in particular, the TOGETHER study, are.

This latest study appears to be no exception. Here’s an extensive critique.

The thing Charley and I noticed right way in that critique is what the evaluators label as Critical problem #13: Very late treatment.

If you go to this page and scroll down a little to the graph of efficacy versus treatment delay in days, you see that most of the treatments studied need to be administered in the first 2 to 4 days. When was the treatment in this latest study administered? The median time was 6 days.

Also, note the Critical problem #33: Extreme conflict of interest. “The ACTIV executive committee was chaired by employees of J&J and NIH, and is now chaired by employees of Pfizer and NIH. Other members of the committee are from NIAID (Dr. Fauci), FDA, and Pfizer.”

If you want to find that ivermectin is ineffective, you can surely do so.