Look at it on the margin: A costs $250 more than B, and prevents 20 migraines. That could be a good deal.
There’s no reason to look at the ratio for each treatment. Note that doing so would recommend B over A even if A cost 35 cents and B cost 10 cents; that can’t be right.
Look at it on the margin: A costs $250 more than B, and prevents 20 migraines. That could be a good deal.
There’s no reason to look at the ratio for each treatment. Note that doing so would recommend B over A even if A cost 35 cents and B cost 10 cents; that can’t be right.