Dr. Diaz, Mr. Rendon, and Ms. Velásquez are affiliated with the department of statistics at the Universidad Nacional in Medellin, Colombia. Ms. Susce and Dr. de Leon are affiliated with the University of Kentucky Mental Health Research Center at Eastern State Hospital in Lexington. Send correspondence to Dr. de Leon at the University of Kentucky Mental Health Research Center, 627 West Fourth Street, Lexington, Kentucky 40508 (e-mail, jdeleon@uky.edu). Harold Alan Pincus, M.D., Terri L. Tanielian, M.A., and Amy M. Kilbourne, Ph.D., M.P.H., are editors of this column.