Another thought
I know insurance companies nor any employer will change their drug policies over my post but I would like to relate my first hand experience with drugs in the workplace.
Cocaine users always come to work.... they have to, they need the money, coke is expensive. Same goes for pot users, it can be expensive, so they need a full paycheck. Now for the legal drugs, alcohol users have a problem showing up for work, when they do show, they are in a nasty mood, hug over from the night before. Tobacco users show up, take more breaks than most until they die which is usually pretty soon. Also drug testing will usually show pot use within 2 to 4 weeks, but cocaine, herion and etc. don't show up if not used for a few days to a week before the test. If you look at the statistics, alcohol and tobacco take a much larger toll and expense on society but hey they are taxable so they must be OK