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Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH Benefits study design and rationale
  1. Benjamin F Arnold1,
  2. Clair Null2,3,
  3. Stephen P Luby4,5,
  4. Leanne Unicomb4,
  5. Christine P Stewart6,
  6. Kathryn G Dewey6,
  7. Tahmeed Ahmed7,8,
  8. Sania Ashraf4,
  9. Garret Christensen3,9,
  10. Thomas Clasen2,
  11. Holly N Dentz2,3,
  12. Lia C H Fernald1,
  13. Rashidul Haque4,10,
  14. Alan E Hubbard1,
  15. Patricia Kariger1,
  16. Elli Leontsini11,
  17. Audrie Lin1,
  18. Sammy M Njenga12,
  19. Amy J Pickering13,
  20. Pavani K Ram14,
  21. Fahmida Tofail7,
  22. Peter J Winch11,
  23. John M Colford Jr1
  1. 1School of Public Health, University of California, Berkeley, California, USA
  2. 2Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
  3. 3Innovations for Poverty Action, New Haven, Connecticut, USA
  4. 4Centre for Communicable Diseases, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
  5. 5Stanford University, Stanford, California, USA
  6. 6Program in International and Community Nutrition, University of California, Davis, California, USA
  7. 7Centre for Nutrition & Food Security, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
  8. 8BRAC University, James P Grant School of Public Health, Dhaka, Bangladesh
  9. 9Department of Economics, Swarthmore College, Swarthmore, Pennsylvania, USA
  10. 10Centre for Communicable Diseases and Centre for Vaccine Sciences, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
  11. 11Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
  12. 12Eastern & Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
  13. 13Civil and Environmental Engineering, Stanford University, Stanford, California, USA
  14. 14School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, New York, USA
  1. Correspondence to Benjamin F Arnold; benarnold{at}


Introduction Enteric infections are common during the first years of life in low-income countries and contribute to growth faltering with long-term impairment of health and development. Water quality, sanitation, handwashing and nutritional interventions can independently reduce enteric infections and growth faltering. There is little evidence that directly compares the effects of these individual and combined interventions on diarrhoea and growth when delivered to infants and young children. The objective of the WASH Benefits study is to help fill this knowledge gap.

Methods and analysis WASH Benefits includes two cluster-randomised trials to assess improvements in water quality, sanitation, handwashing and child nutrition—alone and in combination—to rural households with pregnant women in Kenya and Bangladesh. Geographically matched clusters (groups of household compounds in Bangladesh and villages in Kenya) will be randomised to one of six intervention arms or control. Intervention arms include water quality, sanitation, handwashing, nutrition, combined water+sanitation+handwashing (WSH) and WSH+nutrition. The studies will enrol newborn children (N=5760 in Bangladesh and N=8000 in Kenya) and measure outcomes at 12 and 24 months after intervention delivery. Primary outcomes include child length-for-age Z-scores and caregiver-reported diarrhoea. Secondary outcomes include stunting prevalence, markers of environmental enteropathy and child development scores (verbal, motor and personal/social). We will estimate unadjusted and adjusted intention-to-treat effects using semiparametric estimators and permutation tests.

Ethics and dissemination Study protocols have been reviewed and approved by human subjects review boards at the University of California, Berkeley, Stanford University, the International Centre for Diarrheal Disease Research, Bangladesh, the Kenya Medical Research Institute, and Innovations for Poverty Action. Independent data safety monitoring boards in each country oversee the trials. This study is funded by a grant from the Bill & Melinda Gates Foundation to the University of California, Berkeley.

Registration Trial registration identifiers ( NCT01590095 (Bangladesh), NCT01704105 (Kenya).

  • Drinking Water
  • Sanitation
  • Handwashing

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