Q&A: Fatal and non-fatal burden of disease associated with child growth failure

Child growth failure (CGF), which includes underweight, wasting, and stunting, is among the factors most strongly associated with mortality and morbidity in children younger than 5 years worldwide. 

Dr. Bobby Reiner (Professor of Health Metrics Sciences at IHME within the School of Medicine at the University of Washington) discusses the findings from a new study that used data from the Global Burden of Disease (GBD) 2023 study to estimate CGF prevalence, the risk of infectious diseases associated with CGF, and the disease mortality, morbidity, and overall burden associated with CGF.

Read the study, published in The Lancet Child & Adolescent Health.

Video transcript

This transcript has been lightly edited for clarity

What is child growth failure, and what elements does it include?

There’s an expectation that as a child grows, they’re going to be taller and get heavier. And child growth failure is basically a measure, or a quantification, of children who haven’t hit the right heights or the expected weights. 

Stunting means a child is shorter than one would expect. Wasting means, given how tall a child is, they weigh less than you expect. And underweight means, given their age, they weigh less than you would expect.

What causes child growth failure, and how does this study add to our understanding of the condition?

So there are a whole bunch of different causes of child growth failure. A lot of it actually has to do with what happens in the womb, with the mother’s health, with the child’s health right at birth.

Certainly a child that’s born prematurely we’ll expect to be underweight. But as a child ages, if they’re unable to access appropriate nutrition, they’re likely to develop some level of child growth failure. Also, certain infectious diseases can also contribute to child growth failure by making the body unable to absorb nutrients.

How does child growth failure interact with diseases such as diarrhea, measles, malaria, etc.?

Child growth failure is both a risk factor for those infectious diseases, where a child who is severely stunted or severely wasted is more likely to have a negative outcome or severely negative outcome when they’re infected by those diseases. But also, things like diarrhea themselves can cause severe child growth failure due to the enteric diseases in the stomach, making it unlikely for a child to be able to absorb nutrients.

So it’s kind of this vicious cycle where child growth failure can make an infectious disease worse. But then the presence of that infectious disease can make child growth failure worse.

What are the key findings of the study?

In this work, what we’ve done is we’ve tried to re-quantify and re-estimate the risk factors of stunting, wasting, and underweight. And then how do we think they’re related to malaria, diarrhea, lower respiratory infections, and measles? This work has fundamentally changed both our estimation of who is experiencing child growth failure, and how bad it is to get child growth failure, relative to those infectious diseases, compared to previous work.

Here we’re looking at a global trend of the fraction of all under-5 disease burden that’s attributable to child growth failure. We can see a pretty substantial decline from around 30% in 2000 to, currently, a little bit lower than 20% for the overall burden. But that’s still a large fraction of the overall burden attributable to child growth failure.

We can see those estimates of the fraction of burden associated with child growth failure translates into roughly 2.7 million deaths in the year 2000. And now right around 1 million deaths in the year 2023.

Again, we can then parse the relative importance of underweight, wasting, and stunting to see again that each one of them is still associated with, or contributing to, around 500,000 deaths and, in some circumstances, closer to a million deaths, even today.

Finally, one of the issues with looking at something like mortality is that it tells you the number of deaths. But if the population is shrinking or growing, you don’t necessarily know as much about the overall trend of the relative risk

Here, when we convert mortality directly into mortality rate, by dividing by the growing world’s population, we see a slightly different picture in terms of the fast reduction from 2000 to 2015, but then a little bit of a stabilization from 2020 onward.

You can see, for example, in the US or in Canada, or Australia or much of Europe, child growth failure–attributable death rate is less than 1 or, at the very least, less than 3 per 100,000. On the other hand, for parts of the sub-Saharan regions, in Central Africa, some Western African regions, we can see that the attributable death rate exceeds 250 per 100,000.

We also look at how child growth failure burden varies within children under the age of 5. In terms of the fraction through time, we see that the worst, the largest fraction of disease burden associated with child growth failure, is found in 12–24-month-old children, in terms of death and then, kind of across the board, we have relatively lower disability-adjusted life years associated with child growth failure.

While we found that child growth failure in general is going down, which is good, there’s still substantial burden in a number of different countries where we have more child growth failure, more stunting, wasting, and underweight than we would want.

Also, with our new re-estimation of how bad different levels of child growth failure are, we have a new understanding of, well, actually, stunting is still a substantial global problem – as opposed to previously, we might have thought that really only wasting is the large problem.

How do you hope the findings of this study will be used?

So again, what we’re trying to do is estimate where there still is a problem, what type of problem it is, how things have progressed to this date. Hopefully, people can use this information to make new decisions about new interventions and understand how to re-prioritize child growth failure relative to other diseases.