|
Well AFAIK the BMI was always supposed to be a screen - that is, a tool that could identify people who may be at risk of weight problems that could then be given follow-up tests etc. that would further clarify if they are overweight or underweight. In that sense it's an excellent test because it fulfills all the criteria of a good screen - it is very simple, quick, and cheap to administer, and would have a very low rate of false negatives, (i.e. people who are identified as in the normal range who are actually over or underweight; I can't think of many reasons that this would occur as I think the cut offs are fairly conservative), even though it has a relatively high rate of false positives. But it should never ever be used as a single diagnostic indicator.
__________________
|