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