[stareatgoats]

> "cases were no less healthy than controls presurgery in the first 9 years of life"

Looks like they addressed that (heading: Testing for Biases in General Health Before Surgery)

[vanderZwan]

And elsewhere, a bit more explicitly:

> Participants in the case and control groups were selected such that their health did not differ significantly prior to surgery.

[laretluval]

> Participants in the case and control groups were selected such that their health did not differ significantly prior to surgery.

And yet some of them got the surgeries and some didn’t, so it’s unclear if the control was adequate.

[tankerslay]

>And yet some of them got the surgeries and some didn’t, so it’s unclear if the control was adequate.

It is what it is. The documented evidence suggests that the medical histories of the two groups diverged strongly at the moment of surgery.

It is possible that the decision to have surgery depended primarily upon an arbitrary judgment of the surgeon, in which case the randomization is adequate.

It is also possible that the pre-surgery health of the two groups diverged in a way that was not well-documented in the medical record, in which case the control is inadequate.

However, this latter possibility is still not flattering to the medical community. If the conclusion of the study is even possibly correct, it raises a serious question of why such a flimsy paper trail accompanied such a momentous cost-benefit decision in the lives of these children.