even though this comes at an epistemic cost as the resulting data is poorer than that which could have been gathered if the trial continued to completion.
There are ways of handling that epistemically, although they’re more complicated—if enough evidence is acquired quickly, the harmful part of the trial is stopped—whichever that is.
Sure—there’s a fair bit of literature on ‘optimal stopping’ rules for interim results in clinical trials to try and strike the right balance.
It probably wouldn’t have helped much for Salk’s dilemma: Polio is seasonal and the outcome of interest is substantially lagged from the intervention—which has to precede the exposure, and so the ‘window of opportunity’ is quickly lost; I doubt the statistical methods for conducting this were well-developed in the 50s; and the polio studies were already some of the largest trials ever conducted, so even if available these methods may have imposed even more formidable logistical challenges. So there probably wasn’t a neat pareto-improvement of “Let’s run an RCT with optimal statistical control governing whether we switch to universal administration” Salk and his interlocutors could have agreed to pursue.
There are ways of handling that epistemically, although they’re more complicated—if enough evidence is acquired quickly, the harmful part of the trial is stopped—whichever that is.
Sure—there’s a fair bit of literature on ‘optimal stopping’ rules for interim results in clinical trials to try and strike the right balance.
It probably wouldn’t have helped much for Salk’s dilemma: Polio is seasonal and the outcome of interest is substantially lagged from the intervention—which has to precede the exposure, and so the ‘window of opportunity’ is quickly lost; I doubt the statistical methods for conducting this were well-developed in the 50s; and the polio studies were already some of the largest trials ever conducted, so even if available these methods may have imposed even more formidable logistical challenges. So there probably wasn’t a neat pareto-improvement of “Let’s run an RCT with optimal statistical control governing whether we switch to universal administration” Salk and his interlocutors could have agreed to pursue.