"For 1998 to 2011 combined, 14% of middle and 28% of high school students attended schools with any SDT; rates for for-cause testing were 10% and 22%, and for any random testing were 6% and 10% (see Table 1). If any for-cause testing had occurred, the volume of students tested in the current year averaged 6 per school for middle and 17 per school for high school students. If any random testing had occurred, the average number of students tested was 80 per school for middle and 178 per school for high school students. Within schools with any random SDT, testing had been in place for more than 3 years for more than half of students (66% middle school; 58% high school), for 2–3 years for approximately one-quarter of students (25% middle school; 29% high school), and implemented in the last or current school year for 9% of middle and 14% of high school students. Few students (2%) attended schools with random drug testing among all students."
Terry-McElrath, Yvonne M., Patrick M. O’Malley, and Lloyd D. Johnston. Middle and High School Drug Testing and Student Illicit Drug Use: A National Study 1998–2011. The Journal of adolescent health: official publication of the Society for Adolescent Medicine 52.6 (2013): 707–715. PMC. Web. 23 Mar. 2017.
