In one of the widest-reaching studies on childhood diarrhea, researchers have uncovered trends in a range of individual-, community- and country-level factors that contribute to the disease, including a nearly threefold increase in prevalence for developing countries.

The study, published April 20 in Scientific Reports, found that diarrhea not only is influenced by individual demographic factors but also is associated with less-tangible factors, such as access to education and mass media. 

At more than 2,000 deaths per day, diarrhea kills more children than measles, malaria and AIDs combined. And while about 88% of diarrhea deaths are attributable to poor water access and unsanitary conditions, the factors that contribute to creating these conditions are complex and multifaceted.

"It's still a big problem. Diarrhea affects [about] 15% of children in low- and middle-income countries," said Adeniyi Francis Fagbamigbe, a researcher and lecturer of medical statistics at the University of Ibidan, in Nigeria. "We have both compositional and contextual factors that drive this likelihood of diarrhea among these under-five children."

Compositional factors are those related to individuals, such as age and sex. Contextual factors have to do with the broader availability of resources and opportunities in an area, including access to water and education. 

And while many of these factors have been linked to childhood diarrhea individually or within specific countries — for example, temperature in Peru — Fagbamigbe and his colleagues assert that the complex relationships between them have not been sufficiently explored on a wide scale.

"It's my desire [to improve] the health of children who are living today. Diarrhea is one of the top killer diseases," Fagbamigbe said. "We need both prevention and treatment to reduce the morbidity and, by extension, the mortality. I believe if we can unravel the risk factors that are associated with diarrhea, then we will be one step closer to elimination or reduction."

To begin this unraveling, Fagbamigbe and his team used the methods of medical statistics to "draw a clear line" between compositional and contextual factors impacting childhood diarrhea rates.

"My task is, majorly, to develop statistical methods or to apply them [to learning] what causes problems, how they are distributed, what is actually responsible for them," he said. 

The team analyzed diarrhea-relevant information provided by parents and guardians of 796,150 children under the age of 5 from 57 low- and middle-income countries. The data was collected as part of the Demographic and Health Survey, a global initiative to produce comprehensive and reliable data for global health research.

The researchers found that prevalence of diarrhea ranged from 3.8% in Armenia to 31.4% in Yemen, with an overall prevalence of 14.4%. Because they had such comprehensive data, they were also able to parse compositional and contextual factors contributing to this prevalence.

On an individual level, they found that males and infants were at greater risk of diarrhea. Children born at low birth weights were also at greater risk of contracting diarrhea at any age. On a country level, the odds of diarrhea nearly doubled for children living in countries with a mid-level Human Development Index, a metric developed by the United Nations to measure life expectancy, education and standard of living.

For countries with the lowest Human Development Index scores, the odds of diarrhea nearly tripled. 

Also at higher risk were children who lived in poorer households, children whose mother only had a primary education and children with poor access to mass media.

While the present study focused on morbidity, or the mere occurrence of diarrhea regardless of the outcome, the researchers are interested in next examining mortality of childhood diarrhea and seeing how the factors they have uncovered contribute to death from this disease.

This is particularly relevant because the current study suggests that there may be an "upsurge of diarrhea-associated mortality in the nearest future." 

Fagbamigbe plans to restructure his findings into a policy brief to provide recommendations to policymakers and governments. These include reinforcing diarrhea prevention and control programs at community, national and global levels. 

"It's a call to action," he said.

In the meantime, Fagbamigbe maintains that education is one of the most important strategies for preventing childhood diarrhea.

"How we will reduce the rate of the episodes of diarrhea is basically through good education, for the women in particular," he said. "We know that education opens doors of opportunities to know what is right and wrong, the type of food to eat, how to prepare their food. When I talk about education, it's not only education in the classroom."

The study, "Hierarchical disentanglement of contextual from compositional risk factors of diarrhoea among under-five children in low- and middle-income countries," published April 20 in Scientific Reports, was authored by Adeniyi Francis Fagbamigbe, University of Ibadan; A. Olalekan Uthman, University of Warwick; and Latifat Ibisomi, University of Witwatersrand.