“…The sample sizes of the studies varied greatly, from 300 to 3,070 individuals. Seven studies were conducted in rural settings [12,13,19,21,22,29,30], four studies on rural and urban residents [11,16,17,28], one study on urban residents [32], three studies on urban informal sector employees [27,33,34] and one study on the urban poor [18]. Most of the studies involved face-to-face interviews with the respondents.…”