Thomas Clasen|Kelly Alexander|David Sinclair|Sophie Boisson|Rachel Peletz|Howard H. Chang|Fiona Majorin|Sandy Cairncross
Interventions to improve water quality for preventing diarrhoea
Emory University|Emory University|Liverpool School of Tropical Medicine|London School of Hygiene & Tropical Medicine|Emory University|London School of Hygiene & Tropical Medicine|University of London|London School of Hygiene & Tropical Medicine
background diarrhoea major cause death disease especially among young children lowincome countries settings many infectious agents associated diarrhoea spread water contaminated faeces remote lowincome settings sourcebased water quality improvement includes providing protected groundwater springs wells bore holes harvested rainwater alternative surface sources rivers lakes pointofuse water quality improvement interventions include boiling chlorination flocculation filtration solar disinfection mainly conducted home objectives assess effectiveness interventions improve water quality preventing diarrhoea search methods searched cochrane infectious diseases group specialized register 11 november 2014 central cochrane library 7 november 2014 medline 1966 10 november 2014 embase 1974 10 november 2014 lilacs 1982 7 november 2014 also handsearched relevant conference proceedings contacted researchers organizations working field checked references identified studies 11 november 2014 selection criteria randomized controlled trials rcts quasircts controlled beforeandafter studies cba comparing interventions aimed improving microbiological quality drinking water intervention children adults data collection analysis two review authors independently assessed trial quality extracted data used metaanalyses estimate pooled measures effect appropriate investigated potential sources heterogeneity using subgroup analyses assessed quality evidence using grade approach main results fortyfive clusterrcts two quasircts eight cba studies including 84000 participants met inclusion criteria included studies conducted low middleincome countries lmics 50 studies unimproved water sources 30 studies unimproved unclear sanitation 34 studies primary outcome studies selfreported diarrhoea high risk bias due lack blinding 80 included studies sourcebased water quality improvements currently insufficient evidence know sourcebased improvements protected wells communal tap stands chlorinationfiltration community sources consistently reduce diarrhoea one clusterrct five cba studies low quality evidence found studies evaluating reliable pipedin water supplies delivered households pointofuse water quality interventions average distributing water disinfection products use household level may reduce diarrhoea around one quarter home chlorination products rr 077 95 ci 065 091 14 trials 30746 participants low quality evidence flocculation disinfection sachets rr 069 95 ci 058 082 four trials 11788 participants moderate quality evidence however substantial heterogeneity size effect estimates individual studies pointofuse filtration systems probably reduce diarrhoea around half rr 048 95 ci 038 059 18 trials 15582 participants moderate quality evidence important reductions diarrhoea episodes shown ceramic filters biosand systems lifestraw filters ceramic rr 039 95 ci 028 053 eight trials 5763 participants moderate quality evidence biosand rr 047 95 ci 039 057 four trials 5504 participants moderate quality evidence lifestraw rr 069 95 ci 051 093 three trials 3259 participants low quality evidence plumbed filters evaluated highincome settings rr 081 95 ci 071 094 three trials 1056 participants fixed effects model lowincome settings solar water disinfection sodis distribution plastic bottles instructions leave filled bottles direct sunlight least six hours drinking probably reduces diarrhoea around third rr 062 95 ci 042 094 four trials 3460 participants moderate quality evidence subgroup analyses larger effects seen trials higher adherence trials provided safe storage container cases reduction diarrhoea shown studies evident settings improved unimproved water sources sanitation authors conclusions interventions address microbial contamination water pointofuse may important interim measures improve drinking water quality homes reached safe reliable pipedin water connections average estimates effect individual pointofuse intervention generally show important effects comparisons estimates provide evidence superiority one intervention another comparisons confounded study setting design population studies assessing effects household connections chlorination point delivery help improve knowledge base evidence suggests effectiveness improves adherence studies assessing programmatic approaches optimising coverage longterm utilization interventions among vulnerable populations could also help strategies improve health outcomes