The FDA risks being pulled into an ugly political fracas over whether to permit more patients to be treated with hydroxychloroquine.
The study that sparked the latest controversy was anything but randomized. Not only was it not randomized, outside experts noted, but patients who received hydroxychloroquine were also more likely to get steroids, which appear to help very sick patients with Covid-19. That is likely to have influenced the central finding of the Henry Ford study: that death rates were 50% lower among patients in hospitals treated with hydroxychloroquine.
How science usually works:
Nissen and Borio say observational studies simply cannot be used to determine whether a medicine is effective. Again and again they have been wrong. In one famous example, estrogen replacement therapy after menopause was thought to have benefits in preventing heart and other problems; large studies showed this was not the case. In another, a knee surgery for arthritis was shown to have no benefits over medical care.
A paper that showed that hydroxychloroquine was potentially harmful, which was published in The Lancet in May, was met with similar criticism. It was eventually withdrawn over questions about the validity of its data.
From the study itself: