Impact of drinking water, sanitation and handwashing with soap on childhood diarrhoeal disease: updated meta‐analysis and meta‐regression

Jennyfer Wolf,Kate Medlicott,Oliver Cumming,Jamie Bartram,Thomas Clasen,Paul R Hunter,Julian P T Higgins,Sophie Boisson,Matthew C Freeman,Annette Prüss‐Ustün,Richard Johnston

doi:10.1111/tmi.13051

Abstract

Safe drinking water, sanitation and hygiene are protective against diarrhoeal disease; a leading cause of child mortality. The main objective was an updated assessment of the impact of unsafe water, sanitation and hygiene (WaSH) on childhood diarrhoeal disease. We undertook a systematic review of articles published between 1970 and February 2016. Study results were combined and analysed using meta-analysis and meta-regression. A total of 135 studies met the inclusion criteria. Several water, sanitation and hygiene interventions were associated with lower risk of diarrhoeal morbidity. Point-of-use filter interventions with safe storage reduced diarrhoea risk by 61% (RR = 0.39; 95% CI: 0.32, 0.48); piped water to premises of higher quality and continuous availability by 75% and 36% (RR = 0.25 (0.09, 0.67) and 0.64 (0.42, 0.98)), respectively compared to a baseline of unimproved drinking water; sanitation interventions by 25% (RR = 0.75 (0.63, 0.88)) with evidence for greater reductions when high sanitation coverage is reached; and interventions promoting handwashing with soap by 30% (RR = 0.70 (0.64, 0.77)) vs. no intervention. Results of the analysis of sanitation and hygiene interventions are sensitive to certain differences in study methods and conditions. Correcting for non-blinding would reduce the associations with diarrhoea to some extent. Although evidence is limited, results suggest that household connections of water supply and higher levels of community coverage for sanitation appear particularly impactful which is in line with targets of the Sustainable Development Goals.

Highlights

The Sustainable Development Goals (SDGs) adopted by 193 Member States at the UN General Assembly in 2015 aim to substantially improve water and sanitation globally and include two specific targets within Goal 6 for drinking water, sanitation and hygiene (WaSH) [1]: 6.1 By 2030, achieve universal and equitable access to safe and affordable drinking water for all. 6.2 By 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations.Progress towards the Millennium Development Goals (MDGs) which preceded the SDGs was monitored globally based on the use of improved drinking water supplies and sanitation facilities
14 new water studies, volume 00 no 00 eight new sanitation studies (Figure 3) and eight new hygiene studies (Figure 4) were included for quantitative meta-analysis alongside those studies identified in our previous water and sanitation [16] and hygiene [5] reviews
The greatest reductions are for a piped water to premises supply that has been treated to improve its quality (75% based on limited evidence) and for POU-filtered water that is safely stored in the household (61% or 48% reduction before and after adjustment for non-blinding) compared to a baseline of unimproved drinking water

Summary

Introduction

The Sustainable Development Goals (SDGs) adopted by 193 Member States at the UN General Assembly in 2015 aim to substantially improve water and sanitation globally and include two specific targets within Goal 6 for drinking water, sanitation and hygiene (WaSH) [1]: 6.1 By 2030, achieve universal and equitable access to safe and affordable drinking water for all. 6.2 By 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations.Progress towards the Millennium Development Goals (MDGs) which preceded the SDGs was monitored globally based on the use of improved drinking water supplies and sanitation facilities. The Sustainable Development Goals (SDGs) adopted by 193 Member States at the UN General Assembly in 2015 aim to substantially improve water and sanitation globally and include two specific targets within Goal 6 for drinking water, sanitation and hygiene (WaSH) [1]:. 6.1 By 2030, achieve universal and equitable access to safe and affordable drinking water for all. Progress towards the Millennium Development Goals (MDGs) which preceded the SDGs was monitored globally based on the use of improved drinking water supplies and sanitation facilities. This notice should be preserved along with the article’s URL

Methods

Results

Conclusion