It is that marijuana-users do not go to the ER more frequently than non-marijuana users, i.e. users are no more likely to go the ER than non-users.
In any case, evidence that ‘medical marijuana users are no healthier than the rest of us’ would not be evidence that ‘marijuana is medically ineffective’. Medical marijuana is not supposed to make its users healthier than your average non-user. That doesn’t make sense. Are you familiar with the medical uses of marijuana? This is like finding evidence that ‘ibuprofen users are no healthier than the rest of us’ and concluding that ‘ibuprofen is medically ineffective’.
