TIM HARFORD: The risk of harm and the greater good
Participants are exposed to harm in randomised trials but experiments in real-world settings are invaluable
While the world celebrated the discovery that the steroid dexamethasone was an effective treatment for Covid-19 patients on ventilators, my physician friend was unimpressed. It was obvious that dexamethasone would work, she opined; intensive care units should have been using it as a matter of course.
Perhaps. But that is what doctors thought about the use of similar steroids to treat patients with head injuries. Logically, steroids would be so effective that a clinical trial seemed unethical. Overcoming these objections, the corticosteroid randomisation after head injury trial put the steroids to the test — only to discover that, far from being lifesavers, they raised the risk of death.