[1] McMaster Univ, Populat Hlth Res Inst, Hamilton, ON, Canada
[2] Hamilton Hlth Sci, Hamilton, ON, Canada
[3] Univ Oxford, Clin Trial Serv Unit, Oxford OX1 2JD, England
[4] Duke Univ, Duke Clin Res Inst, Durham, NC USA
[5] Food & Drug Regulat Agcy, Rockville, MD USA