Pubdate: Tue, 27 Aug 2002 Source: Kingsport Times-News (TN) Copyright: 2002 Kingsport Publishing Corporation Contact: http://www.timesnews.net/index.cgi Details: http://www.mapinc.org/media/1437 Note: Will not publish letters in print editions from online users who do not reside in print circulation area, unless they are former residents or have some current connection to Southwest Virginia and Northeast Tennessee. Author: David Cornell FALSE POSITIVES A recent editorial on drug testing for high school students cited the trivial rate of 3 drug users out of 797 tested, and cited the high cost paid in money and embarrassment. There is another issue, false positives. False positives conclude a child is using drugs when they are not. The food, medicine, herbal supplements or test error can cause false positives. Proper testing quizzes the student about the various foods, medicines, and herbals to eliminate improper results. False positives in the test are another matter. So how good are the tests? The literature says 3 to 40 percent false positives, particularly when the subject is not quizzed about foods and medicines. If for 797 students the false positive rate was 1 percent, then all three guilty would be found and eight innocents would be accused. Parents need to demand to know if the students are properly quizzed to eliminate the food, herbals and medicine issues and parents need to know the testing false positive rate. David Cornell Houston, Texas - --- MAP posted-by: Tom