Heavy Rainfall Events and Diarrhea Incidence

December 26, 2013 · 0 comments

Heavy Rainfall Events and Diarrhea Incidence: The Role of Social and Environmental Factors. Am Jnl Epidem, Nov 2013.

E Carlton, et al.

The impact of heavy rainfall events on waterborne diarrheal diseases is uncertain. We conducted weekly, active surveillance for diarrhea in 19 villages in Ecuador from February 2004 to April 2007 in order to evaluate whether biophysical and social factors modify vulnerability to heavy rainfall events. A heavy rainfall event was defined as 24-hour rainfall exceeding the 90th percentile value (56 mm) in a given 7-day period within the study period. Mixed-effects Poisson regression was used to test the hypothesis that rainfall in the prior 8 weeks, water and sanitation conditions, and social cohesion modified the relationship between heavy rainfall events and diarrhea incidence.

Heavy rainfall events were associated with increased diarrhea incidence following dry periods (incidence rate ratio = 1.39, 95% confidence interval: 1.03, 1.87) and decreased diarrhea incidence following wet periods (incidence rate ratio = 0.74, 95% confidence interval: 0.59, 0.92).

Drinking water treatment reduced the deleterious impacts of heavy rainfall events following dry periods. Sanitation, hygiene, and social cohesion did not modify the relationship between heavy rainfall events and diarrhea. Heavy rainfall events appear to affect diarrhea incidence through contamination of drinking water, and they present the greatest health risks following periods of low rainfall. Interventions designed to increase drinking water treatment may reduce climate vulnerability.

GiveWell analysis of water quality interventions

December 20, 2013 · 0 comments

Water quality interventions

Summary – Water quality interventions (e.g., filtration, chlorination) aim to prevent waterborne disease, particularly diarrheal disease, a major cause of death among children in developing countries, by removing or disabling pathogens in water.

There is little debate that contaminated water causes diarrhea and that the methods used in interventions to improve water quality, chlorination for example, reduce contamination. However, in developing world settings where diarrhea is endemic, because of a lack of sanitation, hygiene, and access to safe water, the evidence for the effectiveness of these interventions is less clear.

Many randomized controlled trials in the developing world find that water quality interventions reduce diarrheal disease. But these trials are unblinded and rely on self-reported diarrhea to evaluate the interventions. None of the small number of blinded trials of water quality interventions has shown an effect. These blinded trials, like some of the unblinded studies, have various methodological weaknesses, and these weaknesses may undermine their conclusion.

Overall, we are ambivalent about the effect of water quality interventions on diarrhea. We find plausible theories grounded in the available evidence for both believing that water quality interventions reduce diarrhea and for the more pessimistic conclusion that these interventions do not have an effect. We also do not see any analysis that may lead to a more definitive answer without a significant, additional investment of time. We therefore summarize our work so far, provide feedback we’ve received from scholars and leave questions for further investigation.

From Proof to Impact

December 20, 2013 · 1 comment

From Proof to Impact |  Complete article: by Katherine Hoffmann & Lilian Lehmann,  Stanford Social Innovation Review,  Dec 5, 2013 |

Excerpts – In recent years randomized controlled trials (RCTs) have emerged as a “go-to” methodology for evaluating development interventions. Despite ongoing discussions around the ethics and epistemology of the method, we’re glad to see more evidence generated in a sector marked by so much uncertainty around which interventions work and why.

We’d like to offer four suggestions for bringing such interventions to scale. These insights are informed by our experience with the rollout of the Dispensers for Safe Water program in East Africa, though the views presented are our own. We believe that these lessons are also more broadly applicable to other projects looking to scale RCT-validated results.

1. Redefine your benchmarks.

RCTs are great at identifying effective interventions but less so at identifying cost-effective ones. Even if researchers include theoretical cost-effectiveness calculations in academic trial conclusions (and this is rare), it is difficult to project expenses at scale. Expansion makes such analysis possible.

For example, Innovations for Poverty Action (IPA) did an initial test of a chlorine dispenser system aimed at encouraging rural Kenyans to treat their drinking water. The original study focused on identifying optimal strategies for promoting community behavior change, but at scale, service delivery costs to remote rural areas grew increasingly salient. We at Dispensers for Safe Water had a theory about which delivery model was best—a cheap hub-and-spoke distribution system using schools or clinics as delivery points—and we tested it. While delivery costs were low under this model, adoption and the quality of service delivery also suffered. Surprisingly, a much pricier strategy—direct delivery to water points—was equally cost-effective because of increased impact through higher adoption.

2. Source ideas creatively.

As field staff gain experience with an intervention, encourage them to contribute to program research and development. In Uganda, we invited staff members to compete to see who could most effectively increase chlorine adoption at randomly selected water points within a fixed budget. While these ideas are “team-sourced,” we will rigorously evaluate them and the outcomes will be actionable. The jury’s still out, but we’re excited about the proposals generated and even more excited to see the results.

3. Learn from and test past experiences.

Natural variation in implementation contexts can lead to unpredictable results. Prepare projects so that there is room to reflect regularly (to determine what worked well) and test proactively (to determine whether it will work well in the future).

When we first expanded into Uganda, we had an extremely successful pilot that topped average adoption by about 30 percentage points, so we went back and talked to the initial pilot’s implementing staff to figure out why (we believe it was a combination of time spent with local leaders and frequent follow-up with communities). Dispensers for Safe Water is now trying to replicate the strategies used in that early pilot on a larger scale, testing the result with a randomized, controlled evaluation, of course.

4. Iterate, evaluate, and course-correct continuously.

Scale-up offers an incredible opportunity for learning through increased sample size, but it’s important to recall that the ultimate aim of scale is to improve people’s lives. The benefit of moving beyond the confines of an RCT is that once you’ve gathered convincing evidence that a new idea works, you can change course mid-way without worrying about preserving the integrity of the “treatment” and “control” groups for the duration of a formal trial. This rapidly reduces the time horizon on learning and iteration.

In Kenya, we piloted the use of megaphones to publicize community education meetings at the village level in the hope of increasing meeting attendance (a strong correlate of adoption). When a preliminary analysis showed that these were associated with higher attendance over a sample of about 200 dispensers, we adopted them across the dispensers remaining in that installation round, iterating in real time.

 

The Hyper-Efficient, Highly Scientific Scheme to Help the World’s Poor

December 20, 2013 · 0 comments

The Hyper-Efficient, Highly Scientific Scheme to Help the World’s Poor | Complete article: by J. Benko, Wired.com, Dec 11, 2013 |

Excerpts - The first thing you need to know about randomized controlled trials, especially those pertaining to economics and human behavior, is that they’re hard—very hard.

A 2004 experiment to promote water treatment wound up suggesting a solution that the researchers hadn’t imagined. In this case, the larger goal was to combat diarrheal diseases, which kill millions of people every year, especially children under 5. Chlorine treatments can render water safe; but despite years of education efforts in Kenya, few people purchased and used the chlorine solution, even though it was widely available.

To test remedies, the researchers identified 88 springs that supplied nearly 2,000 households in western Kenya. Surveys of local women, who usually collect the water for the family and monitor children’s health, found that 70 to 90 percent knew about the chlorine product but only 5 percent used it, and IPA’s in-home tests detected chlorine in the water of just 2 percent of households. These women knew how to make their water safe, but they weren’t doing it.

After that, the researchers spent four years testing different interventions. Giving away the chlorine solution helped in the near term, but when the free supply ran out, usage fell off. Half-off coupons for chlorine were a bust; out of 2,724 coupons handed out, just 10 percent were ever redeemed. The study also tested whether local “promoters,” sent door to door with one free voucher per family, might succeed in evangelizing the use of chlorine among their neighbors. Promoters did make a difference in the short term; in this cohort, 40 percent of household water samples showed evidence of chlorine. But that number fell significantly when the vouchers ran out.

Finally, the researchers tried a new strategy, one that they had come to late in their design. Collaborating with engineers at MIT and Tufts and local artisans in Kenya, they developed chlorine dispensers that could be installed at the spring. Each tank was large enough for a whole community; two turns of a knob would release the right amount of chlorine to treat the standard 20-liter jerrican that women typically carry water in. In communities with these dispensers, the percentage of households with detectable chlorine in their water jumped to 60 percent, versus 58 percent in a group where seven free bottles were actually delivered to their homes. And the dispensers cost less than a third as much.

 

 

Water source and diarrhoeal disease risk in children under 5 years old in Cambodia

December 17, 2013 · 1 comment

Water source and diarrhoeal disease risk in children under 5 years old in Cambodia: a prospective diary based study. BMC Public Health, Dec 2013.

Paul R Hunter, et al.

Background – Despite claims that the Millennium Development Goals (MDG) targets on access to safe drinking water have been met, many 100 s of millions of people still have no access. The challenge remains how to provide these people and especially young children with safe drinking water.

Method - We report a longitudinal study designed to assess the effectiveness of an intervention based on provided treated drinking water in containers on self-reported diarrhoea in children. The intervention was “1001 fontaines pour demain” (1001 F) is a non-governmental not for profit organization (created in 2004 and based in Caluire, France) that helps local entrepreneurs treat package, and sell safe drinking water. Cases and controls were chosen at village and household level by propensity score matching Participants were visited twice a month over six months and asked to complete a diarrhoea health diary.

Results - In total 4275 follow-up visits were completed on 376 participants from 309 homes. Diarrhoea was reported in 20.4% of children on each visit, equating to an incidence rate estimate of 5.32 episodes per child per year (95% confidence interval = 4.97 to 5.69). Compared to those drinking 1001 F water, children drinking surface water were 33% (95% CI -1 to 17%), those drinking protected ground water were 62% (95% CI 19 to 120%) and those drinking other bottled water 57% (95% CI 15 to 114%) more likely to report diarrhoea. Children drinking harvested rainwater had similar rates of diarrhoea to Children drinking 1001 F water.

Conclusion - Our study suggests that 1001 F water provides a safer alternative to groundwater or surface water. Furthermore, our study raises serious concerns about the validity of assuming protected groundwater to be safe water for the purposes of assessing the MDG targets. By contrast our study provides addition evidence of the relative safety of rainwater harvesting.

(Im)Proving global impact: the integration of remotely reporting sensors in water projects

December 10, 2013 · 0 comments

(Im)Proving global impact: How the integration of remotely reporting sensors in water projects may demonstrate and enhance positive change, 2013. GWF Discussion Paper 1349, Global Water Forum, Canberra, Australia.

Evan Thomas.

This article argues that improved feedback on the actual impact of development programs may ensure the success of poverty reduction interventions such as water filters, water pumps, latrines, and cookstoves. Rather than infrequent data collection, more continuous feedback may improve community partnerships through continuous engagement and improved responsiveness. We hope to enable greater cooperation in these programs by separating evidence from advocacy.

 

Counting heads: case study

December 10, 2013 · 0 comments

Counting heads: case study. DEMAND: ASME Global Development Review, 2013.

Evan Thomas; Kay Mattson.

The objectives of this Case Study were to:

  • Compare and contrast the findings from two complementary approaches to field evaluations of a water, sanitation and hygiene program in greater Jakarta.
  • Highlight the complementary nature of monitoring instrumentation and traditional survey methods.
  • Assess how instrumentation might provide important program feedback not normally available with traditional survey tools.
  • Assess the potential impact of sensor acquired data on traditional survey tools.

Use of Remotely Reporting Electronic Sensors for Assessing Use of Water Filters and Cookstoves in Rwanda

December 10, 2013 · 1 comment

Use of Remotely Reporting Electronic Sensors for Assessing Use of Water Filters and Cookstoves in Rwanda. Env Sci Technol, Nov 2013.

Evan Thomas, et al.

Remotely reporting electronic sensors offer the potential to reduce bias in monitoring use of environmental health interventions. In the context of a five-month randomized controlled trial of household water filters and improved cookstoves in rural Rwanda, we collected data from intervention households on product compliance using (i) monthly surveys and direct observations by community health workers and environmental health officers, and (ii) sensor-equipped filters and cookstoves deployed for about two weeks in each household.

The adoption rate interpreted by the sensors varied from the household reporting: 90.5% of households reported primarily using the intervention stove, while the sensors interpreted 73.2% use, and 96.5% of households reported using the intervention filter regularly, while the sensors interpreted no more than 90.2%. The sensor-collected data estimated use to be lower than conventionally collected data both for water filters (approximately 36% less water volume per day) and cookstoves (approximately 40% fewer uses per week).

An evaluation of intrahousehold consistency in use suggests that households are not using their filters or stoves on an exclusive basis, and may be both drinking untreated water at times and using other stoves (“stove-stacking”). These results provide additional evidence that surveys and direct observation may exaggerate compliance with household-based environmental interventions.

The Impact of School WASH Interventions on the Health of Younger Siblings of Pupils

December 2, 2013 · 0 comments

The Impact of School Water, Sanitation, and Hygiene Interventions on the Health of Younger Siblings of Pupils: a Cluster-Randomized Trial in Kenya. Am J Public Health. 2013 Nov 14.

Dreibelbis R, Freeman MC, Greene LE, Saboori S, Rheingans R.

Objectives. We examined the impact of school water, sanitation, and hygiene (WASH) interventions on diarrhea-related outcomes among younger siblings of school-going children.

Methods. We conducted a cluster-randomized trial among 185 schools in Kenya from 2007 to 2009. We assigned schools to 1 of 2 study groups according to water availability. Multilevel logistic regression models, adjusted for baseline measures, assessed differences between intervention and control arms in 1-week period prevalence of diarrhea and 2-week period prevalence of clinic visits among children younger than 5 years with at least 1 sibling attending a program school.

Results. Among water-scarce schools, comprehensive WASH improvements were associated with decreased odds of diarrhea (odds ratio [OR] = 0.44; 95% confidence interval [CI] = 0.27, 0.73) and visiting a clinic (OR = 0.36; 95% CI = 0.19, 0.68), relative to control schools. In our separate study group of schools with greater water availability, school hygiene promotion and water treatment interventions and school sanitation improvements were not associated with differences in diarrhea prevalence between intervention and control schools.

Conclusions. In water-scarce areas, school WASH interventions that include robust water supply improvements can reduce diarrheal diseases among young children.

Heavy Rainfall Events and Diarrhea Incidence: The Role of Social and Environmental Factors

December 2, 2013 · 0 comments

Heavy Rainfall Events and Diarrhea Incidence: The Role of Social and Environmental Factors. Am J Epidemiol. 2013 Nov 19.

Carlton EJ, Eisenberg JN, Goldstick J, Cevallos W, Trostle J, Levy K.

The impact of heavy rainfall events on waterborne diarrheal diseases is uncertain. We conducted weekly, active surveillance for diarrhea in 19 villages in Ecuador from February 2004 to April 2007 in order to evaluate whether biophysical and social factors modify vulnerability to heavy rainfall events. A heavy rainfall event was defined as 24-hour rainfall exceeding the 90th percentile value (56 mm) in a given 7-day period within the study period. Mixed-effects Poisson regression was used to test the hypothesis that rainfall in the prior 8 weeks, water and sanitation conditions, and social cohesion modified the relationship between heavy rainfall events and diarrhea incidence. Heavy rainfall events were associated with increased diarrhea incidence following dry periods (incidence rate ratio = 1.39, 95% confidence interval: 1.03, 1.87) and decreased diarrhea incidence following wet periods (incidence rate ratio = 0.74, 95% confidence interval: 0.59, 0.92).

Drinking water treatment reduced the deleterious impacts of heavy rainfall events following dry periods. Sanitation, hygiene, and social cohesion did not modify the relationship between heavy rainfall events and diarrhea. Heavy rainfall events appear to affect diarrhea incidence through contamination of drinking water, and they present the greatest health risks following periods of low rainfall. Interventions designed to increase drinking water treatment may reduce climate vulnerability.

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