Positive drug tests among U.S. workers hit the highest level since 2001 last year, according to an analysis released Wednesday by Quest Diagnostics, one of the largest drug-testing laboratories in the country.
Why it matters: The increase in the rate of positive results from an all-time low between 2010 and 2012 was partially driven by an increase in positive marijuana tests, likely reflecting the fact that the number of states that have legalized it for both medical and recreational use has grown since then.
