[1] New York Univ, Dept Populat Hlth, Grossman Sch Med, New York, NY USA
[2] Yale Sch Med, Dept Psychiat, New Haven, CT USA
[3] Washington Baltimore High Intens Drug Trafficking, Off Natl Drug Control Policy, Baltimore, MD USA
[4] Univ Baltimore, Coll Publ Affairs, Ctr Drug Policy & Prevent, Baltimore, MD USA
[5] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY USA
[6] Univ Florida, Coll Publ Hlth & Hlth Profess, Coll Med Natl Drug Early Warning Syst, Dept Epidemiol, Gainesville, FL USA
[7] NYU, Grossman Sch Med, Dept Populat Hlth, 180 Madison Ave,Room 1752, New York, NY 10016 USA