Using blood or urine samples has been the standard for workplace drug testing for years. One of the country’s biggest laboratories says we may be looking at a better, more convenient testing method for some types of drug use.

Quest Diagnostics has released the details of a testing study that shows for the first half of 2009:

• Three of every 1,000 urine tests performed on job applicants and employees showed up positive for cocaine, while hair testing showed cocaine use  in 32 of 1,000 samples.
• For every methamphetamine, 1,000 urine sample resulted in one positive test, while the same number of hair samples resulted in nine positives.

Quest’s reason for the higher number of hair-tests positives: Hair samples tend to show drug use going back further than urine samples — typically 90 days vs. one to three days.

The study also calls into question the size of the reported drop in drug use the last several years. For instance, urine tests show cocaine use is down 57% since 2005, but hair tests show only a 36% drop. For methamphetamines, urine tests show a decline of 64% for that same period, but hair tests show only a 55% drop.

Hair tests cost about twice as much as typical urine tests, Quest, notes.