The interest in this paper is not so much the findings as the fact that it was possible at all. We famously collect a lot of routine data on what has been done to patients but never what difference that treatment actually made. This seems to be an exception.
It's interesting how the tribes have different cultures - haematologists enter everyone into trials, surgeons just get on with it, and clinical psychologists are deeply wedded to questionnaire instruments. Not sure what the tribal characteristic is for public health.