Actually, that was my study. I was the fourth author (always the most important!)
There was no control group, this was an observational study. Needless to say, there was no money to fund a controlled study.
That said, this merely documented whether a person took an analgesic, but not why. So my conclusion is that the most likely reason for them taking it, was that they were having pain, and in this setting, most likely a headache.
Measured that way, it would be fairly amazing if the people with AMS did not have a higher rate of analgesics.
