[1] Johns Hopkins Univ, Dept Comp Sci, Baltimore, MD 21218 USA
[2] Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Ctr Life Origins Dis, Dept Populat Family & Reporduct Hlth, Baltimore, MD 21218 USA
[3] Johns Hopkins Univ, Dept Appl Math & Stat, Baltimore, MD 21218 USA
[4] Bayesian Hlth, New York, NY USA