We've seen several times now that there are three elements necessary to realize health gains through HWTS. People have to be drinking unsafe water. They have to have access to an effective option for treatment. And they have to apply that treatment effectively and consistently. This last bit is tricky. HWTS is not like vaccination where you do something once and then you have a long term protection. It's also not like many chemicals where roughly speaking if you reduce the dose by half, you reduce the disease burden by half. Household water treatment is different, in that it has to be done consistently and correctly, over and over again, to realize the health gains. And this poses particular challenges. First, unsafe water. There's actually plenty of it out there. The Joint Monitoring Program of WHO and UNICEF reported that in 2011, 768 million people were using unimproved sources of drinking water, such as unprotected wells or springs or open surface water. But even among those using an improved source, like tap water, a bore hole, rainwater collection, improved springs and wells, drinking water is not always safe. Either the resource itself may be contaminated, or water can become contaminated thru collection, transport, and storage, as we saw in one of those animations from the first week. It's been estimated that around 1.8 billion people are actually drinking water which contains measurable E coli, or thermotolerant coliforms. So, there is plenty of unsafe water out there. And, in the discussion on targeting vulnerable groups, we talked about strategies for reaching those with particularly poor water quality. Obviously, you have to apply an effective treatment option. And, Maggie Montgomery described to us, the WHO scheme for evaluating household water treatment options. And remember, the WHO in that document has defined three classes of effectiveness based on log reduction values. Where to be highly protective, a technology must be able to reduce bacteria by at least four logs, five for viruses, and four for protozoa. The protective level is a little bit less stripped by two orders of magnitude, and the interim level applies when a technology meets the protective criterion for two of the three pathogen classes. But an option which works well in a laboratory evaluation may perform completely differently in the real world. There are differences of course in the person applying the treatment but also in the environment, the water quality, the containers used, et cetera. So it's useful to distinguish between efficacy which is how well something works under ideal controlled conditions, and effectiveness which is how well it works in the real world. The WHO scheme will measure efficacy, not effectiveness. And there's a good example of the difference between the two in Ecuador, where a long term research project has examined household water treatment with chlorine, among other things. Now, chlorine is highly effective against bacteria and particular against E. coli. And the evaluation team, led by Laura McLaughlin confirmed this with their own tests in 2009, finding LRVs of three to six, depending on the indicator organism. So the efficacy was good. But the evaluation team also found that LRVs were much lower, around one, in actual households. And that there was no significant difference in LRV between households applying chlorination and households that didn't. Even the measured chlorine residual was not significantly higher in households which reported chlorinating their water. A similar study by the same group, and this paper is by Karen Levy, found that E. coli could be detected in around half of the households reportedly protecting, practicing chlorination. And some of the factors they found that correlated with poor LRVs were high turbidity in water, higher concentrations of E. coli in the raw water. And there was also evidence of household level contamination from poor water handling and storage. Even if a treatment is effectively applied at the household level, it has to be done consistently, day in and day out. And this is a major challenge both for households to actually do this and for researchers to monitor and evaluate practices. If you ask people if they have treated their water they may respond with what they think you would like to hear, especially if you've been involved in the team promoting HWTS in the first place. So self-reported HWTS practice is subjective and probably more useful as an indicator of knowledge, or perhaps societal expectations and norms than of actual practice. In some cases, there could be more objective indicators. And chlorine is the best example because residual chlorine can be measured easily and quickly in the field. Others have attempted to observe other kinds of HWTS practice. Like seeing if a household filter is wet, or appears to be in regular use. Or if SODIS bottles are in the household, or present up on the rooftop. Another objective indicator, though, is to just measure the E. coli levels in the raw water and the stored water to see if there has been some kind of improvement in microbial water quality. So objective indicators can help to measure, effective use, but consistent use is, is harder still. Consistent use, or sometimes people say compliance or adherence means only using treated water for drinking purposes, throughout the day, the week, the month, the different seasons of the year. And it's hard to measure this. What you would really like to have would be many repeat visits what's called a longitudinal study. And this is important but very difficult and expensive to do. And where it has been done, researchers tend to find that people have very different water treatment practices, even different self-reported practices from one visit to another. A related issue is the long-term use sustainability of HWTS use. And if an evaluation is done just a few months after an intervention is complete, it probably doesn't give a very accurate picture of the long-term consistent use. HWTS is special because you have to have both effective use and high compliance, or consistent use, or adherence to get large health impacts. This is the subject of an analysis by Joe Brown and Tom Clasen, who used modeling to look at the relationship between water quality, raw water quality, consistent use of HWTS, and they use the term adherence. And health outcomes, expressed here as DALYs averted for hundred thousand persons per year. This graph shows that if the raw water is of poor quality, high risk. Let's look at classes A, B, and C. Then there are large health gains to be had. Here's A, B and C, if HWTS is always applied. But if you take even 10% of your water without treatment or have 90% adherence, then in classes A and B, you have very little health impact. That's because even a little bit of highly contaminated water, consumed once in a while, can give you diarrheal disease. For class C water at moderate risk health gains are less sensitive to compliance. But there is still a big drop off and so that if you drink water with about, treated water about 75% of the time, you're getting about half of the possible reduction in disease. Now moderate and low risk waters are relatively clean to begin with, so there are not large reductions in disease to be had at all. Even if compliance is, is 100%. Now this analysis assumed two log reduction for all pathogens. A similar study by Kyle Enger looked at how compliance and efficacy of treatment interact, again but, to yield reductions in diarrheal disease. This graph on the left shows that in order to reduce diarrheal disease by 90%. You could use a treatment that achieves two log reductions either 100% or 99% of the time or a treatment with three log reductions that you use 95% of the time. If you use the treatment much less than that, you might achieve around 50% reduction in disease and the efficacy of the treatment becomes less important. Why use a treatment that reduces nine LRV if you drink untreated water half the time. And the second graph shows the same point, but taking a more contaminated raw water as the starting point. Here, you need a three log reductions to get even 90% reduction in disease. Over the past few weeks we've seen some really stunning examples of how HWTS has been taken up consistently in certain cases. There were the biosand filters in Cambodia, where nearly 90% of people were using filters which had been distributed from six months to eight years previously. And here, use was defined by self-report but confirmed with inspection of the biosand filter to see if it looked like, if it was in use, if it was functional, if it was wet, et cetera. Then there was the LifeStraw Family, filter in Zambia, part of the HIV/AIDS intervention, where 96% of the women in the study were still using the filter. 95% of them reported having drunk no unfiltered water or given any to their children on the previous day. And here compliance could have been even higher if rats hadn't eaten two of the filters. There is another LifeStraw evaluation in Congo which showed more modest compliance with about 2 3rds of people classified as consistent users after eight months. But nearly all of them reported having drunk some untreated water on the previous day. So this is maybe a medium compliance example. A study of SODIS in Zimbabwe looked at three different indicators of SODIS. Self-reported practice are calculated through a detailed interview and drink diary, and then observation by looking for bottles on the rooftop. Now, these three measures agreed fairly well with each other and for any of the indicators. More than 2 3rds of the households which had received household visits were confirmed users more than two years after the interventions. Finally, chlorine treatment offers the most objective indicator of actual use by measuring residual chlorination. And the evaluation by Harshfield in Haiti found 56% of people practicing adequate chlorination up to eight years after the intervention. Of course, it's not always such good news. And there are plenty of examples of low uptake as well. It's actually just as important to report and study these to learn about what didn't work. One example is the ceramic pot filters in Cambodia where only 31% of people were still using filters as reported in an interview and confirmed by visual inspection. But here the usage was highly dependent on the amount of time that had passed since receiving the filter, and usage was very high in the initial months. It was breakage that was a problem. Before the LifeStraw Family filter, there was the LifeStraw personal. We didn't look at that one in the membrane module, but its another membrane treatment in which you suck water directly through a filter into your mouth like a straw. And in this evaluation in Ethiopia, only about a third of people reported using the filter in the previous week. And about one in eight people describe themselves as consistent users. This study is actually a classic example of respondent bias for diarrheal disease. Because, these same households reported a 25% reduction in diarrhea, which just isn't plausible with such low levels of compliance. Finally, a large evaluation of SODIS in Bolivia found that about a third of people were actually practicing treatment. Here defined by self-report and confirmed by observation. And in one of the earlier evaluations of HWTS a study of Pure in Guatemala, while Proctor and Gamble was still considering a commercial strategy. This involved a long pilot and heavy promotion of Pure. But, six months after that intervention, only 5% of the target households had actually purchased sachets. Then these last two examples are of technical innovations that were being piloted in the field. So, it's perhaps not fair to judge them as mature products. Both for the Mesita Azul in Mexico, the ultraviolet system, and the chulli pasteurization system in Bangladesh. These both worked well technically, but had fairly low uptake. In fact, in Bangladesh only 21 out of 101 households reported using their chullis. But on a repeat visit it was found that 17 of these households were either not actually using them at all or were using them incorrectly by passing the water through them without a fire burning. So here, only four households were actually applying the technology consistently and correctly. Now, how can we explain this huge range in compliance, sometimes for the very same product in different settings? Well, household water treatment is a very personal behavior. So behavior change and theories of behavior change are certainly important. But there are also external factors outside the personal domain, such as availability of supply chains, the presence of a supporting policy environment, et cetera, that are also important in determining use. And these factors will be highly contextual in different settings and different sub-populations within a given setting. Let's take a look now at some of the theoretical frameworks that have been used to explain adoption and uptake of HWTS. A classic text in behavioral change is Rogers' Diffusion of Innovations Theory, first published in 1962 and now on its fifth edition. Rogers analyzed how innovations spread through various communication channels and came up with a list of five stages that people progress through as they decide to adopt a new behavior. These are awareness or knowledge, here that they could treat their drinking water with some technology. People should then be persuaded that this would be a good thing to do before they will take a decision to try it out. But even then it has to implemented regularly and people have to, in the end, confirm that this is that they want to do for the behavior to be adopted sustainability. Rogers also identifies five attributes of innovations which help them to be adopted. I think he liked the number five because he also talked about five different types of adopters. But the five attributes then are that the innovation should have an advantage over the current practice. It should be compatible with existing values and needs. It shouldn't be too complex either. It's useful if an innovation can be experimented with, trialed on a limited basis. People like to try things out. And ideally they, and other people as well, should be able to observe the results of an innovation. And these factors together contribute to a greater likelihood of uptake. So that's one framework. Here at Eawag, Professor Hans-Joachim Mosler has developed a theory of behavior change based on psychological theory that's called RANAS. And that stands for risks, attitudes, norms, abilities, and self-regulation. Professor Mosler defines factors which fit into these five blocks, which together can determine how likely people are to adopt and sustain a new behavior. In his studies, in his research, his team first measures which of these factors are most important in a given context. And then designs custom interventions to influence the critical factors, and so achieve better uptake and sustained use. Let's look at one more conceptual framework that was developed recently by Robert Dreibelbis and his colleagues, who published a systematic review of theories of behavior change in wash. And also developed a conceptual framework taking elements from the different contributions reviewed. It's called IBM-WASH and it's not sponsored by a major computer company. It stands for the Integrated Behavioral Model for Water, Sanitation and Hygiene. The authors consider three classes of factors, or dimensions. Where the contextual factor, represents background factors like access to markets, the policy environment, characteristics of the household, and the environment, and so on. And these factors are largely outside of the control of interventions, but have important influences on HWTS, uptake, and use. The psychosocial dimension considers factors like those described in the RANAS model. Which, in principle, could be targeted and influenced by interventions. Finally the technical dimension includes the specific characteristics of the HWTS technology to be applied, and how these are preferred or not preferred by potential users. Each of these three classes of factors, these three dimensions is considered to apply at different scales, five different levels, ranging from the individual up to larger groups and, eventually, the entire society. Here are a few reviews of behavior change that are all available on the Internet. The first comes from the Johns Hopkins Center for Communication programs. Here's the systematic review that led to the IBM-WASH framework. And here is a tool kit from Eawag, from Professor Mosler and his group. WHO and UNICEF have published a really useful tool kit on monitoring and evaluation of HWTS programs. You can download it by clicking on the icon or it's in the supplementary reading list as well. This tool kit is meant to provide an overall framework for planning, conducting, and utilizing monitoring and evaluation data to improve HWTS programming. And the tool kit provides a set of 20 core indicators that are recommended for monitoring correct and consistent use of HWTS. These core indicators are grouped into five classes. Reported and observed use, correct, consistent use and storage, knowledge and behavior, other environmental health interventions, and water quality. I encourage you to look at the full list in the report. But for today's module about effective and consistent use, the most relevant groups are the ones for correct consistent use and water quality. In the correct and consistent use group, there are six different indicators. A mixture of self-reports and observations, demonstrations. And again these indicators are somewhat prone to bias. But they can provide an upper limit for actual practice. The water quality indicators are more objective. These involve actual measurements of water quality either for E. coli or other indicator bacteria, or for residual chlorine in the case of chlorination. The raw water may also be tested. So that for E. coli or thermotolerant coliforms, an LRV could be calculated. And some people include a certain level of removal as part of a definition for confirmed use of HWTS. This module has drawn heavily on a number of publications, some of which you have seen in previous lectures, and many of these are freely available on the internet. On the PDF version, you can just click on the hyperlink and get to the actual report or paper. These references are mostly about compliance, either studies that have measured actual use or models linking compliance with health outcomes. And these references, are more about behavior change. That could be a nice subject for an entire MOOC or maybe several MOOCs. So in conclusion, we saw two models that predict that for HWTS to lead to health gains, the technology has to be applied effectively and consistently. Of course, the drinking water should be unsafe as well. And in order to get behavior change, it may also be necessary that people perceive the water as unsafe, which is a very different thing. Well, effective use can be measured and should be measured when monitoring HWTS. Consistent use is harder to monitor. It typically requires multiple visits, and it's probably most appropriate at a research level. There are a range of different frameworks for thinking about and achieving and monitoring effective and consistent use of HWTS. Including the behavioral change elements, but also other dimensions such as the contextual or technical dimensions in the IBM-WASH framework. The important question though isn't which framework is more accurate or comprehensive. But to recognize that consistent and effective use is critical to realizing health gains through HWTS, and to take steps to both promote and monitor actual use.
