Dichotomization

Beautifully stated. This motivates me to add that an RCT estimates patient tendencies , and unless it’s a 6-period randomized crossover (or similar) design, it cannot estimate effects of treatments on individual patients. The best we can do is to covariate adjust down to a level of detail that current measurements allow, so that we can best predict what the treatment effect will be in certain types of patients in total (group-level estimates for very small groups, e.g., 73 year old males with stage 2 disease at baseline).