“…For parental socio-demographic factors, three studies reported maternal age [30,31,33], ve studies reported maternal educational status [15,18,53,54,18], three studies reported paternal education [16,44,59], one study reported maternal occupation [16], two studies reported mothers marital status [37,58], two studies reported area of residence [18,53], one study reported wealth index [20], three studies reported family income [16,24,59], one study reported number of siblings [56], two studies reported religion [19,40], two studies reported nomadic life style [39,53] and ethnicity was also reported by two studies [48,53]. For child socio-demographic factors, child age was reported in two studies [55,56], whilst one study reported gender [42].…”