“…Nine studies were based in Bangladesh, 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 5 in India, 28 , 29 , 30 , 31 , 32 5 in Nepal, 33 , 34 , 35 , 36 , 37 1 in Pakistan, 38 and 1 in Afghanistan. 39 Fifteen of 20 studies were cross-sectional, 19 , 20 , 23 , 24 , 25 , 26 , 27 , 28 , 30 , 32 , 33 , 34 , 35 , 37 , 38 , 39 with data for both exposure and outcome obtained from household questionnaires as part of national demographic and health surveys. Three studies were case–control, 21 , 31 , 36 2 were prospective cohort studies, 22 , 29 and 1 was a retrospective cohort study.…”