***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE Access to improved water sources is rapidly exp and ing in rural central Vietnam . We examined one NGO-led piped water supply programme to assess the drinking water quality and health impacts of piped water systems where access to ' improved ' water sources is already good . METHODS This longitudinal , prospect i ve cohort study followed 300 households in seven project areas in Da Nang province , Vietnam : 224 households who paid for an on-plot piped water connection and 76 control households from the same areas relying primarily on ' improved ' water sources outside the home . The 4-month study was intended to measure the impact of the NGO-led water programmes on households ' drinking water quality and health and to evaluate system performance . RESULTS We found that : ( i ) households connected to a piped water supply had consistently better drinking water quality than those relying on other sources , including ' improved ' sources and ( ii ) connected households experienced less diarrhoea than households without a piped water connection ( adjusted longitudinal prevalence ratio : 0.57 ( 95 % CI 0.39 - 0.86 , P = 0.006 ) and households using an ' improved ' source not piped to the plot : ( adjusted longitudinal prevalence ratio : 0.59 ( 95 % CI 0.39 - 0.91 , P = 0.018 ) . CONCLUSIONS Our results suggest that on-plot water service yields benefits over other sources that are considered ' improved ' by the WHO/UNICEF Joint Monitoring Programme BACKGROUND The promotion of household water treatment and h and washing with soap has led to large reductions in child diarrhoea in r and omized efficacy trials . Currently , we know little about the health effectiveness of behaviour-based water and hygiene interventions after the conclusion of intervention activities . METHODS We present an extension of previously published design ( propensity score matching ) and analysis ( targeted maximum likelihood estimation ) methods to evaluate the behavioural and health impacts of a pre-existing but non-r and omized intervention ( a 3-year ,  combined household water treatment and h and washing campaign in rural Guatemala ) . Six months after the intervention , we conducted a cross-sectional cohort study in 30 villages ( 15 intervention and 15 control ) that included 600 households , and 929 children < 5 years of age . RESULTS The study design created a sample of intervention and control villages that were comparable across more than 30 potentially confounding characteristics . The intervention led to modest gains in confirmed water treatment behaviour [ risk difference = 0.05 , 95 % confidence interval ( CI ) 0.02 - 0.09 ] . We found , however , no difference between the intervention and control villages in self-reported h and washing behaviour , spot-check hygiene conditions , or the prevalence of child diarrhoea , clinical acute lower respiratory infections or child growth . CONCLUSIONS To our knowledge this is the first post-intervention follow-up study of a combined household water treatment and h and washing behaviour change intervention , and the first post-intervention follow-up of either intervention type to include child health measurement . The lack of child health impacts is consistent with unsustained behaviour adoption . Our findings highlight the difficulty of implementing behaviour-based household water treatment and h and washing outside of intensive efficacy trials OBJECTIVE This study was undertaken to assess the ability of a water container with a cover and a spout to prevent household contamination of water in a Malawian refugee camp . METHODS A r and omized trial was conducted in a refugee population that had experienced repeated outbreaks of cholera and diarrhoea and where contamination of water in the home was found to be a significant cause of cholera . Four hundred Mozambican refugee households were systematic ally identified and followed over a 4-month period , one fourth of the households were r and omly assigned to exclusively use the improved container for water collection . FINDINGS Water flowing from the source wells had little or no microbial contamination although the water collectors quickly contaminated their water , primarily through contact with their h and s. Analysis of water sample s demonstrated that there was a 69 % reduction in the geometric mean of faecal coliform levels in household water and 31 % less diarrhoeal disease ( P = 0.06 ) in children under 5 years of age among the group using the improved bucket . Regression models examining diarrhoea among under 5-year-olds confirmed the protective effect of the bucket and found that visible faeces in the family latrine and the presence of animals were significantly associated with an increased diarrhoeal incidence in children . CONCLUSION Household contamination of drinking-water significantly contributed to diarrhoea in this population . Proper chlorination is a less expensive and more effective means of water quality protection in comparison with the improved bucket , but was unpopular and rarely utilized by the camp inhabitants Sophie Boisson and colleagues conducted a double-blind , r and omized placebo-controlled  trial in Orissa , a state in southeast India , to evaluate the effect of  household water treatment in preventing diarrheal illnesses in children aged under five years of age . Please see later in the article for the Editors ' Daniel Maeusezahl and colleagues conducted a cluster-r and omized controlled trial in rural Bolivia of solar drinking water disinfection  , and find only moderate compliance with the intervention and no evidence of reduction in diarrhea among children INTRODUCTION Pneumonia and diarrhoea are leading causes of death in children . There is a need to develop effective interventions . OBJECTIVE We present the design and baseline findings of a community-r and omised controlled trial in rural Peru to evaluate the health impact of an Integrated Home-based Intervention Package in children aged 6 to 35 months . METHODS We r and omised 51 communities . The intervention was developed through a community-participatory approach prior to the trial . They comprised the construction of improved stoves and kitchen sinks , the promotion of h and washing , and solar drinking water disinfection ( SODIS ) . To reduce the potential impact of non-blinding bias , a psychomotor stimulation intervention was implemented in the control arm . The baseline survey included anthropometric and socio-economic characteristics . In a sub- sample we determined the level of faecal contamination of drinking water , h and s and kitchen utensils and the prevalence of diarrhoegenic Escherichia coli in stool specimen . RESULTS We enrolled 534 children . At baseline all households used open fires and 77 % had access to piped water supplies . E. coli was found in drinking water in 68 % and 64 % of the intervention and control households . Diarrhoegenic E. coli strains were isolated from 45/139 stool sample s. The proportion of stunted children was 54 % . CONCLUSIONS R and omization result ed in comparable study arms . Recently , several critical review s raised major concerns on the reliability of open health intervention trials , because of uncertain sustainability and non-blinding bias . In this regard , the presented trial featuring objective outcome measures , a simultaneous intervention in the control communities and a 12-month follow up period will provide valuable evidence Background Waterborne disease is a major risk for small water supplies in rural setting s. This study was done to assess the impact of an educational intervention design ed to improve water quality and estimate the contribution of water to the incidence of diarrhoeal disease in poor rural communities in Puerto Rico a two-part study was undertaken . Methods An educational intervention was delivered to communities relying on community water supplies . This intervention consisted of  student operators and administrators supervising and assisting community members who voluntarily " operate " these systems .  These voluntary operators had no previous training and were principally concerned with seeing that some water was delivered . The quality of that water was not something they either understood or addressed . The impact of this intervention was measured through water sampling for st and ard bacteriological indicators and a frank pathogen . In addition , face-to-face epidemiological studies design ed to determine the base-line occurrence of diarrhoeal disease in the communities were conducted . Some 15 months after the intervention a further epidemiological study was conducted in both the intervention communities and in control communities that had not received any intervention . Results Diarrhoeal illness rates over a four week period prior to the intervention were 3.5 % . Salmonella was isolated from all of 5 distributed sample s prior to intervention and from only 2 of 12 sample s after the intervention . In the 15 months follow-up study , illness rates were lower in the intervention compared to control communities ( 2.5 % vs 3.6%% ) ( RR = 0.70 , 95%CI 0.43 , 1.15 ) , though this was not statistically significant . However , in the final Poisson regression model living in an intervention system ( RR = 0.318 ; 95%CI 0.137 - 0.739 ) and owning a dog ( RR = 0.597 , 95%CI 0.145 - 0.962 ) was negatively associated with illness . Whilst size of system ( RR = 1.006 , 95%CI 1.001 - 1.010 ) and reporting problems with sewage system ( RR = 2.973 , 95%CI 1.539 - 5.744 ) were positively associated with illness . Conclusions Educational interventions directed both at identified individuals and the community in general in small communities with poor water quality is a way of giving communities the skills and knowledge to manage their own drinking water quality . This may also have important and sustainable health benefits , though further research preferably using a r and omised control trial design is needed Low-cost point-of-use ( POU ) safe water products have the potential to reduce waterborne illness , but adoption by the global poor remains low . We performed an eight-month r and omized trial of four low-cost household water treatment products in Dhaka , Bangladesh . Intervention households ( n = 600 ) received repeated educational messages about the importance of drinking safe water along with consecutive two-month free trials with each of four POU products in r and om order . Households r and omly assigned to the control group ( n = 200 ) did not receive free products or repeated educational messages .  Households ' willingness to pay for these products was quite low on average ( as measured by bids in an incentive-compatible real-money auction ) , although a modest share was willing to pay the actual or expected retail price for low-cost chlorine-based products . Furthermore , contrary to our hypotheses that both one 's own personal experience and the influence of one 's peers would increase consumers ' willingness to pay , direct experience significantly decreased mean bids by 18 - 55 % for three of the four products and had no discernible effect on the fourth . Neighbor experience also did not increase bids . Widespread dissemination of safe water products is unlikely until we better underst and the preferences and aspirations of these at-risk population We conducted a r and omized , placebo-controlled , triple-blinded trial to determine the health impact of daily use of sodium dichloroisocyanurate ( NaDCC ) tablets for household drinking water treatment in periurban Ghana . We r and omized 240 households ( 3,240 individuals ) to receive either NaDCC or placebo tablets .  All households received a 20-liter safe water storage vvessel . Over 12 weeks , 446 diarrhea episodes ( 2.2 % ) occurred in intervention and 404 ( 2.0 % ) in control households ( P = 0.38 ) . Residual free chlorine levels indicated appropriate tablet use . Escherichia coli was found in stored water at baseline in 96 % of intervention and 88 % of control households and at final evaluation in 8 % of intervention and 54 % of control households ( P = 0.002 ) . NaDCC use did not prevent diarrhea but improved water quality . Diarrhea rates were low and water quality improved in both groups . Safe water storage vessels may have been protective . A follow-up health impact study of NaDCC tablets is warranted BACKGROUND This project directly and empirically measured the level of  gastrointestinal ( GI ) illness  related to the consumption of tapwater prepared from sewage-contaminated surface waters and meeting current water quality criteria . METHODS A r and omized intervention trial was carried out ; 299 eligible households were supplied with domestic water filters ( reverse-osmosis ) that eliminate microbial and chemical contaminants from their water , and 307 households were left with their usual tapwater without a filter . The GI symptomatology was evaluated by means of a family health diary maintained prospect ively by all study families over a 15-month period . RESULTS The estimated annual incidence of GI illness was 0.76 among tapwater drinkers compared with 0.50 among filtered water drinkers ( p less than 0.01 ) . These findings were consistently observed in all population subgroups . CONCLUSION It is estimated that 35 % of the reported GI illnesses among the tapwater drinkers were water-related and preventable . Our results raise questions about the adequacy of current st and ards of drinking water quality to prevent water-borne endemic gastrointestinal illness Background The evaluation of more than one intervention in the same r and omised controlled trial can be achieved using a parallel group design . However this requires increased sample size and can be inefficient , especially if there is also interest in considering combinations of the interventions . An alternative may be a factorial trial , where for two interventions participants are allocated to receive neither intervention , one or the other , or both . Factorial trials require special considerations , however , particularly at the design and analysis stages . Discussion Using a 2 × 2 factorial trial as an example , we present a number of issues that should be considered when planning a factorial trial . The main design issue is that of sample size . Factorial trials are most often powered to detect the main effects of interventions , since adequate power to detect plausible interactions requires greatly increased sample sizes . The main analytical issues relate to the investigation of main effects and the interaction between the interventions in appropriate regression models . Presentation of results should reflect the analytical strategy with an emphasis on the principal research questions . We also give an example of how baseline and 
    Output:
    
Overall , improvements in drinking water and sanitation were associated with decreased risks of diarrhoea .
Specific improvements , such as the use of water filters , provision of high- quality piped water and sewer connections , were associated with greater reductions in diarrhoea compared with other interventions .
The results show that inadequate water and sanitation are associated with considerable risks of diarrhoeal disease and that there are notable differences in illness reduction according to the type of improved water and sanitation implemented