Drug use among U.S. workers declined to a 17-year low last year a report released Monday by a New York drug-testing company says.

Quest Diagnostics said of tests for all drugs performed by the company for the combined U.S. workforce, 4.1 percent had positive results in 2005 compared to 13.6 percent in 1988.

In addition to the drop for overall workplace drug use, Quest said a preliminary review of amphetamine test results for the first five months of this year showed a sharp drop of 10 percent in positive results. Among federal safety workers, the rate of decline was 20 percent for the same period.

Since 2004, the incidence of amphetamines drug-test positives has dropped 45 percent, Quest reported.

Copyright 2006 by United Press International