It would explain at least a slight efficiency increase: presumably [some collection of factors] (SCoF) influences whether there’s a response or not. A priori you’d expect a smaller correlation of SCoF with SCoF-after-8-weeks than with SCoF-after-4-weeks.
Presumably the actual impact is larger than this would predict (at least without a better model of SCoF).
It would explain at least a slight efficiency increase: presumably [some collection of factors] (SCoF) influences whether there’s a response or not. A priori you’d expect a smaller correlation of SCoF with SCoF-after-8-weeks than with SCoF-after-4-weeks.
Presumably the actual impact is larger than this would predict (at least without a better model of SCoF).