[1] Karolinska Inst, Dept Publ Hlth Sci, Stockholm, Sweden
[2] Aga Khan Univ, Dept Med, Karachi, Pakistan
[3] Aga Khan Univ, Dept Community Hlth Sci & Med, Karachi, Pakistan
[4] Norwegian Univ Sci & Technol, Dept Publ Hlth, Fac Med, N-7034 Trondheim, Norway
[5] Norwegian Univ Sci & Technol, Dept Gen Practice, Fac Med, N-7034 Trondheim, Norway