I used to have to do those too. Come to think of it, I still do! Every time I go in for med refills, I may or may not have to do a random drug screen. Hell, the first time I went to the local med clinic because I was having anxiety attacks, I had to do a urine drug screen before they would write a prescription. I take some heavy duty pills for pain control, so imagine my surprise when they told me that my test came back negative for ANYTHING. They threatened to call PD, I threatened right back to call CAP(Organization that inspects and rates medical laboratories) and JACO(Gov’t organization that inspects hospitals) to have the hospital lab inspected. After much screaming on my part, they finally got it through their thick skulls to look into why my specimen came back negative. Turns out they confused my specimen with someone else’s. I only hope that it wasn’t an expectant mother, as those “positives” would have started a call to CPS.