We thank Dr. Richard Cash and Prof. Kathryn Maitland for their helpful comments.
An incredibly successful intervention has been the use of oral rehydration therapy (ORT): a simple salt and sugar solution. In our related post on the topic we look in more detail about what ORT is, how it was developed and estimates of how many lives it has saved across the world.
In this post we focus on the future potential of ORT; what are the barriers to it saving more lives, and how many could it save?
We are not benefiting from the full potential of ORT. The main reason for this is that it is not as widely used as it could be. As the map below shows, the coverage of ORT is still low.
According to data from UNICEF, on average only 44% of children with diarrhea receive ORT (you can view this data on the Chart tab in the interactive visualization below).2 In some countries the coverage is very low, at less than 1-in-5.
Of course, one has to ask: does every child with diarrhea need ORT? According to the current WHO guidelines, the need for ORT should be determined based on the degree of child’s dehydration.3 If a child has diarrhea but is not dehydrated, home treatment with fluids that contain salt, such as rice water or chicken stock, is sufficient. If a packet of ORT salts is available it can be used but is not a necessary treatment. If a child has moderate or severe dehydration, ORT should be given. According to a study conducted in 2012, 35.2% of all diarrheal cases in children were classified as moderate or severe, suggesting that at least a third of diarrheal instances should have been treated with ORT: in 2012 that accounted for 588 million diarrheal episodes.4
Greater promotion and education about the use of ORT in healthcare facilities and community centers could potentially increase ORT coverage. In addition to increasing coverage, more lives could also potentially be saved by switching to a more effective ‘low osmolarity’ ORT formulation, that is currently recommended by the WHO.5
An analysis from 2010 by Munos et al. in the International Journal of Epidemiology is the most widely cited study that provides estimates for the number of potential lives a wider use of ORT could save. The study looked at all the available literature on ORT at the time and suggested that, if every child who needs ORT would receive it, 93% of child deaths caused by diarrhea could be prevented.6 This implies a huge potential for ORT.
We should be somewhat cautious, however. The study is the only currently available published research review that measures the effectiveness of ORT. And because there are only a few studies that have looked at how providing ORT directly affects child mortality, the 93% figure was determined based on a very small sample. Furthermore, it should be noted that children with diarrhea often have associated comorbidities, such as malnutrition and viral or bacterial infections. These comorbidities may require treatments in addition to ORT, which was not assessed in the Munos et al. study.7,8,9 Organizations including WHO, UNICEF and GiveWell cite the 93% figure, but also note its limitations.10
Another notable study published in The Lancet in 2003 estimated the potential of ORT and other treatments to prevent all-cause child mortality.11 This study concluded that, in the year 2000, 88% of deaths from diarrheal diseases could have been prevented if available treatments and interventions were used to their full extent. Full coverage of ORT, specifically, could have saved the lives of around 68% of children who died from diarrhea in that year.
More studies are clearly needed. But even if we are cautious and consider these figures overestimates, the evidence still suggests that ORT could be saving hundreds of thousands of more lives if its coverage was increased.
It is worth noting that the potential of ORT does not stop at saving the lives of children. ORT can be used to effectively treat adults as well.12 People aged 70 and older are the largest demographic dying from diarrhoeal diseases. With increasing numbers of people reaching older age today, the number of older people suffering from diarrhoeal diseases can be expected to grow.
The fact that we are not using ORT to its full potential becomes clear when we look at the distribution of deaths from diarrheal disease among children in different regions: the vast majority of cases occur in South Asia and Sub-Saharan Africa where, as the map above shows, ORT coverage is very low at just 37 and 39 percent, respectively.13
What is so amazing about ORT is not only that it is simple, practical and effective, but, like so many scientific discoveries, once it has been discovered, everyone can benefit from this knowledge. It is what economists call a nonrival good. In fact, Paul Romer, the winner of the 2018 Nobel Memorial Prize in Economic Sciences, often uses ORT as his favourite example of a nonrival good – an idea which does not diminish in its value the more people adopt it and use it.14
Ideas that save millions are far and few between, and ORT is perhaps one of the simplest. We can use simple ideas to solve complex problems, such as how to save the lives of as many children as possible.
ORT is a great success story in public health. However, it is important to remember that diarrhea itself is not a disease per se but a symptom of many other causes, such as microbial infections and food poisoning. By improving basic standards of living, such as access to clean water, sanitation and access to vaccines, we can prevent the development of diarrhea in the first place and eliminate the causes upfront before the symptoms take over.
One of the leading causes of diarrhea in children is rotavirus infection, for which childhood wasting and the lack of sanitation and clean water are the major risk factors.15 In addition to limiting these risk factors, we should also try to increase the efficacy and coverage of the rotavirus vaccine. We discuss rotavirus vaccine in another post, but as a vaccine that was introduced relatively recently, it still has a lot of potential for saving the lives of many more children.