July 26, 2004 -- Use of methamphetamine, a synthetic stimulant drug, surged among workers in 2003, according to a study by Quest Diagnostics Inc. The company predicts that the number of "meth" users will continue to grow as the drug gains popularity in eastern U.S. states.

Of the more than 7 million drug tests analyzed by Quest last year, 4.5 percent returned positive results, up slightly from 4.4 percent in 2002. The study didn't break use out by occupation or industry, but concluded that meth use jumped 68 percent among the general workforce, which represented employees across a wide spectrum of occupations.

Use of amphetamines, the drug group that includes meth, rose by more than 44 percent in 2003, showing up in 0.49 percent of all drug tests among the general workforce. Positive returns for the drug group were 0.34 percent in 2002. This type of jump was unprecedented in the study's 16-year history, Quest noted. Prior year-over-year increases of amphetamine use were between 14 and 17 percent.

Opiate use also saw a large jump in 2003, increasing more than 25 percent from 2002, which marked the single largest year-over-year change in opiate use among workers since 1999.

Nearly 3 percent of all workers tested positive for marijuana use, making it by far the most used drug. Cocaine was second, with 0.74 percent of workers testing positive.

Positive results have fluctuated in the range of 4 and 6 percent since 1996, down from the highs of the late 1980s, when positive returns fell in the 11 to 14 percent range. Quest, however, sampled a much smaller group at that time.