Household wealth index
It was measured using ownership of household assets: infrastructure (e.g. homes and land ownership for agricultural activities, coffee farm, electricity), small equipment (e.g. telephone, TV, radio, ornaments, plough, sofa, mattress, stove, bicycle, motorcycle), and domestic animals (cows/oxen, mule/donkey, sheep/goat). Items were coded into a relative index of household wealth using principal component analysis following a similar procedure by others [During the analysis the following assumptions were made; the overall sampling adequacy (KMO > 0.5), Bartlett’s test of sphericity (p < 0.05), commonality > 0.5, the complex structure (correlation) not ≥ 0.40 were checked and components that collectively explain more than 60% of the variance in the set of variables were used for generation of a continuous variable by summing up the principal components into one and tertile rank was made as rich, medium and poor.