[1] Harvard TH Chan Sch Publ Hlth, Dept Biostat, Boston, MA USA
[2] Stanford Univ, Quantitat Sci Unit, Palo Alto, CA 94304 USA
[3] Univ Calif Berkeley, Dept Stat, Berkeley, CA 94720 USA
[4] McGill Univ, Dept Epidemiol Biostat & Occupat Hlth, Montreal, PQ, Canada
[5] Harvard TH Chan Sch Publ Hlth, Dept Epidemiol, Boston, MA USA