[1] St Pauls Hosp, Millennium Med Coll, Dept Obstet & Gynecol, Addis Ababa, Ethiopia
[2] Dartmouth Canc Ctr, Dept Radiat Oncol & Appl Sci, Lebanon, NH 03756 USA
[3] Martin Luther Univ Halle Wittenberg, Inst Med Epidemiol Biometr & Informat, Global Hlth Working Grp, D-53170 Halle, Germany
[4] Addis Ababa Univ, Sch Publ Hlth, Dept Prevent Med, Addis Ababa 9086, Ethiopia
[5] Martin Luther Univ Halle Wittenberg, Inst Med Epidemiol Biometr & Informat, D-53170 Halle, Germany
[6] Addis Ababa Univ, Sch Med, Dept Oncol, Addis Ababa 9086, Ethiopia
[7] Debre Birhan Univ, Sch Publ Hlth, Dept Epidemiol, Debre Birhan 445, Ethiopia
[8] St Peters Specialised Hosp, Dept Res, Addis Ababa 21494, Ethiopia