The doctors claiming that it works also claim that they ran a controlled study.
It’s not that complicated for a drug that everything is already known about.
Let people try it.
I seem to recall that those who ran the study explained that they were not able to randomize the groups in the study. Also, they lost six from the treatment group, three of whom were very seriously ill. The group which experienced 100% success consisted of only six people.
Finally, the group of six who were successfully "cured" were treated with both hydroxychloroquine AND azithromycin. The group that was treated with only hydroxychloroquine experienced, if I recall correctly, only 57% success.
Given the lack of properly randomized treatment and control groups, I don't understand how those who did the study came up with the probability calculations they published. I see the study as having many of the shortcomings of anecdotal evidence.