This post was written by Zachary Wagner (researcher at RAND and former UC Berkeley PhD student), David Levine (CEGA affiliate at UC Berkeley), and John Bosco Asiimwe (EASST fellow and lecturer at Makerere University). CEGA affiliate Will Dow is a co-author on the study, recently published in PLOS Medicine. Levine and Wagner were Asiimwe’s mentors during his visiting fellowship at UC Berkeley in 2015. Initial funding for this project was provided through the 2015 EASST Research Grant Competition.

We have long had effective treatments for many of the deadliest illnesses in low income countries. But why are effective health products underused in these contexts, and how can we increase their use? We designed an experiment in Uganda to provide insight into why cheap and effective treatment for diarrhea is underused and to test novel ways of increasing use — with promising results.

Diarrhea is a perfect example of an illness that creates a large mortality burden, even though effective technology to prevent mortality is widely available. Diarrhea kills over 500,000 children per year worldwide (mostly in sub-Saharan Africa). Nearly all deaths could be prevented with a simple and cheap “technology”: sugar, salt and water. The discovery in the 1960’s that a sugar and salt solution was absorbed by the body more rapidly than other liquids gave rise to what the Lancet referred to as “the most important medical advance of the 20th century” — oral rehydration salts (ORS). Most deaths from diarrhea are a result of dehydration, and ORS could be used to rehydrate sick children quicker and more effectively than standard fluids. And because ORS is basically just sugar and salt, it is incredibly cheap!

Our study team has long wondered why ORS use remains low, and what works to increase use. Based on research on take-up of other health products (e.g., see Dupas and Miguel for a nice review), we hypothesized price and inconvenience were key barriers to ORS take-up and that overcoming these barriers would increase ORS coverage. In collaboration with BRAC Uganda, we designed a 4-armed, cluster randomized controlled trial (RCT) that aimed to separately isolate the role of price and the role of convenience in ORS use. We enrolled community health workers (CHWs) from 118 villages, and randomly assigned them to carry out the following interventions:

1) free delivery of ORS prior to any child becoming ill (free and convenient);

2) home sales visits prior to any child becoming ill (convenient only);

3) free upon retrieval using a voucher (free only); and

4) status quo CHW distribution, where CHWs sell ORS without free delivery (control).

The free and convenient arm ensured that caretakers had ORS readily available when their child came down with diarrhea. The key here is that ORS is delivered prior to a diarrhea episode. This design allows us to answer three research questions we were interested in:

1) does delivering ORS for free before illness increase ORS coverage?

2) is price an important barrier to ORS use (free and convenient vs. convenient only)?

3) is inconvenience an important barrier to ORS use (free and convenient vs. free only)?

EASST Fellow John Bosco Asiimwe works with community health workers to help understand low use of ORS salts for diarrheal prevention

We used household surveys to measure ORS use four weeks after CHWs carried out their respective interventions. During follow-up we identified 2,363 child cases of diarrhea within four-weeks of the survey. The free and convenient arm was particularly effective, increasing ORS coverage by about 21 percentage points relative to the control group (77% vs. 56%; Figure 1). It appears that most of the increase was driven by the free distribution mechanism and not by the home delivery mechanism. In other words, ORS prices (although very low) appear to be a key barrier to take-up. The home sales arm, which had delivery without free distribution, had significantly lower ORS coverage than the free home delivery arm (64%). However, the voucher arm, which had free distribution but required retrieval, had a similar effect as the free home delivery arm. This suggests that convenience was not important in our context.

Figure 1: Treated with ORS

Several novel CHW models (include BRAC’s) are based on turning CHWs into entrepreneurs through health product sales. Our finding that prices are a key barrier to use and our recommendation that ORS instead be distributed for free runs counter to the spirit of these programs. One might expect that stripping CHWs of the financial incentive to make these home visits could dampen CHW effort. However, we find the opposite. CHWs assigned to sell ORS and keep the profits visited far fewer households during the study period than CHWs assigned to distribute products for free (35% compared to 60%). CHWs hinted that this was because free distribution was socially rewarding whereas home sales offers included a social penalty. Therefore, not only does free ORS distribution increase ORS coverage relative to an entrepreneurial model but it also increases CHW effort.


Our study suggests that price is an important barrier to ORS use. Having CHWs switch to free distribution could substantially increase ORS coverage and potentially increase CHW effort. Switching to free distribution is low-cost, easily scalable, and could substantially reduce child mortality.

This work would not have been achievable without the partnerships that were created through during Dr. Asiimwe’s time as a fellow at UC Berkeley and beyond. Dr. Asiimwe’s background in statistics and training in impact evaluation through EASST, along with his deep local knowledge and connections in Uganda, was an excellent complement to the US team’s expertise in health and experimental research. We all worked closely together throughout the project and hope to continue to do so on projects to come.


The CEGA blog is a platform for discussing key issues related to poverty alleviation and global development.

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The CEGA blog is a platform for discussing key issues related to poverty alleviation and global development.

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