Table 1

Study methods

Bangladesh-1 (icddr,b)Bangladesh-2 (IRC-BRAC)Cameroon (ICED, LSHTM)India (ICED, LSHTM)Malawi (collaboration*)
Geographical location177 subdistricts (upazillas) across Bangladesh (estimated population size 750 000)Rangpur and Rajshahi Districts, Bangladesh (estimated population size 34 149 858)Fundong Health District, North-West Region (estimated population size 125 604)Mahbubnager District, Telegana State (estimated population size 4 053 028)Rumphi District, Northern Region (estimated population size 203 054)
Year of data collection20142015201320142014
Sample size (response rate %)1248 households (90%)20 000 households (98%)4080 individuals (87%)4080 individuals (88%)1800 households (100%)
Sampling strategyTwo-stage cluster randomised sampling with probability proportionate to size, stratified by household wealth categoryPopulation censusTwo-stage cluster randomised sampling with probability proportionate to size, stratified by urban and ruralTwo-stage cluster randomised sampling with probability proportionate to size, stratified by urban and ruralTwo-stage cluster randomised sampling across four purposively selected administration units†
Study definition of disability statusYes/no reported by household head followed by list of conditionsWashington Group Short Set reported by individual if present, or household head if notWashington Group Short Set+2 (self-report unless<8) or clinical impairmentWashington Group Short Set+2 (self-report unless<8) or clinical impairmentWashington Group extended set (report by household head or primary caregiver)
Population-level WASH data Yes—sanitation only Yes No—data for case and control households only No—data for case and control households only Yes
Household-level WASH data Yes—sanitation only Yes Yes—data for case and control households only Yes—data for case and control households only Yes
Individual-level WASH data Yes—people with disabilities only Yes—sanitation only Yes—people with disabilities only Yes—people with disabilities only Yes—people with disabilities only
  • *Environmental Health Group at the London School of Hygiene and Tropical Medicine (LSHTM), the Water Engineering and Development Centre at Loughborough University, Mzuzu University and the Centre for Social Research at the University of Malawi.

  • †Purposive selection criteria: limited exposure to sanitation promotion and relative ease of access.

  • WASH, water, sanitation and hygiene.

  • ICED, International Centre for Evidence in Disability