... study report revisiting households to confirm findings?An important strategy to reduce bias is to revisit a sampleof households to ensure that the findings are replicable. As exemplified in the ... 3St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada, 4Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada, 5Harvard Humanitarian ... selection bias, by asking neighbours to assist intracing the occupants of empty households. If they couldnot find occupants or if occupants refused to participate,or if no household member older...