[1] Univ Malaya, Fac Med, Dept Nursing Sci, Kuala Lumpur, Malaysia
[2] Univ Peradeniya, Fac Allied Hlth Sci, Dept Nursing, Peradeniya, Sri Lanka
[3] Univ Malaya, Julius Ctr, Fac Med, Dept Social & Prevent Med, Kuala Lumpur, Malaysia
[4] Univ Peradeniya, Fac Med, Dept Community Med, Peradeniya, Sri Lanka
[5] Univ Kentucky, Coll Med, Dept Family & Community Med, Lexington, KY 40506 USA
[6] Univ Washington, Sch Med, Dept Hlth Metr Sci, Seattle, WA 98195 USA