Interviews were conducted face to face in the homes of respondents. Informed consent was obtained based on procedures approved by each institutional review board of the organizations responsible for the survey in each country. The interview schedule was translated, back-translated and harmonized using standardized WHO procedures (Harkness et al. 2008). Bilingual supervisors from each country were trained and supervised by the WMH Data Collection Coordination Center to guarantee cross-national consistency in field procedures (Pennell et al. 2008).
