[1] Boston Univ, Sch Med, Dept Dermatol, Boston, MA 02118 USA
[2] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[3] Harvard Univ, Brigham & Womens Hosp, Sch Med,Dept Med, Channing Lab, Boston, MA 02115 USA
[4] Harvard Univ, Sch Publ Hlth, Div Publ Hlth Practice, Boston, MA 02115 USA
[5] Dana Farber Canc Inst, Dept Pediat Oncol, Boston, MA 02115 USA