[1] Dartmouth Med Sch, Dept Community & Family Med, Lebanon, NH USA
[2] Dartmouth Med Sch, Norris Cotton Canc Ctr, Lebanon, NH USA
[3] Inst Clin Evaluat Sci, Toronto, ON, Canada
[4] Univ Chicago, Dermatol Sect, Chicago, IL 60637 USA
[5] Aarhus Univ Hosp, Dept Clin Epidemiol, DK-8000 Aarhus C, Denmark
[6] Aarhus Univ Hosp, Dept Dermatol, DK-8000 Aarhus C, Denmark
[7] Harvard Univ, Sch Publ Hlth, Dept Environm Hlth, Boston, MA 02115 USA
[8] Dartmouth Hitchcock Med Ctr, Dept Med, Dermatol Sect, Lebanon, NH 03766 USA
[9] Dartmouth Hitchcock Med Ctr, Dept Pathol, Lebanon, NH 03766 USA
[10] Harvard Univ, Beth Israel Deaconess Med Ctr, Sch Med, Dept Dermatol, Boston, MA 02215 USA