Deaths and disability-adjusted life-years lost due to digestive diseases decreased over the last few decades, according to analyses of the Global Burden of Disease study data. However, incidence and point prevalence remained relatively steady, and there is significant variation across sociodemographic strata in all four measures.
As part of the study, a multicenter team examined data on 18 digestive diseases from over 200 countries to describe trends in age-standardized incidence, point prevalence, deaths and disability-adjusted life-years (DALYs) from 1990 to 2019 (Gastroenterology 2023;165[3]:773-785). The researchers also stratified their results by quintile of the sociodemographic index (SDI), a defined measure ranging from 0 to 1 based on three factors: the total fertility rate of women younger than 25 years of age, the average number of years of education among people aged at least 15 years and the income per capita (lag-distributed).
Highest Point Prevalence In Cirrhosis
Globally in 2019, 38.4% of prevalent diseases had digestive etiology, representing 2.9 billion cases (35,106 cases per 100,000 person-years). This overall point prevalence was similar to what it was in 1990, but the prevalence of various digestive diseases changed over the 30 years. In 2019, the subcategory of digestive diseases with the highest point prevalence was cirrhosis and other chronic liver diseases, with nearly 1.7 billion cases (20,710 cases per 100,000 person-years).
Cirrhosis trends were interesting due to the shift in the disease’s etiology, noted Eamonn Quigley, MD, the David M. Underwood Chair of Medicine in Digestive Disorders and a professor of medicine at Houston Methodist. In the past, cirrhosis was “largely attributed to the consequences of hepatitis B and hepatitis C infection,” Dr. Quigley said. “We now have a highly effective vaccine for hepatitis B, and we have highly effective treatments for hepatitis C, so at least where there’s access to the vaccine and the treatments, those diseases should virtually disappear.” However, moving forward “the big cause of cirrhosis will be nonalcoholic fatty liver disease,” he predicted. “The prevalence of obesity, metabolic syndrome and diabetes are increasing all over the world. ... So unfortunately, I think we’re going to see a continuing increase in the prevalence of cirrhosis, and we’re going to see more people getting complications of cirrhosis, including liver failure and, of course, liver cancer.”
Infection-Related Deaths Remain High
There was an annual percentage decrease of 1.89% in deaths due to digestive diseases from 1990 to 2019, but digestive disease–associated mortality remains high, with over 8 million deaths in 2019 (102 deaths per 100,000 person-years). Most digestive disease–related deaths (23.9 per 100,000 person-years) were the result of enteric infections.
That “gastroenteritis is still a major cause of death is … a shocking indictment of our lack of progress,” given the disease’s association with lack of access to clean water, sanitation and basic hygiene, Dr. Quigley said. To him, this study has illustrated that “perhaps the most important thing we could do to affect morbidity and survival from gastrointestinal diseases across the world would be give people clean water.”
DALYs were slightly lower in 2019 compared with 1990, with an annual percentage change during that time of –2.28%. Of the more than 275 million DALYs lost (3,067 per 100,000 person-years) due to digestive diseases in 2019, nearly 40% were the result of enteric infections (1,368.7 per 100,000 person-years). Enteric infections were also the leading cause of DALYs lost in 1990.
Several cancers became larger relative contributors to all digestive disease–related DALYs lost over the study period, but certain infections decreased their relative contributions over the same period (Table).
| Table. Changing Relative Contributions Of Selected Cancers and Infections To Digestive Disease–Related DALYs Lost | |
| Cancer/infection | Change from 1990 to 2019 |
|---|---|
| Colon and rectum cancer | 5th to 3rd |
| Esophageal cancer | 8th to 7th |
| Pancreatic cancer | 11th to 8th |
| Gallbladder and biliary tract cancer | 17th to 13th |
| Acute hepatitis | 7th to 11th |
| Intestinal nematode infections | 10th to 17th |
| DALYs, disability-adjusted life-years. Based on Gastroenterology 2023;165(3):773-785. | |
‘Striking’ Variation by Sociodemographic Factors
The researchers also evaluated whether disease burden measures and major causes of DALY loss varied as the SDI varied and found that lower SDIs corresponded with a higher burden of disease. Each SDI increase of 0.01 corresponded to a decrease in the incidence rate of 1,866 per 100,000 person-years, a decrease in the point prevalence of 250 per 100,000 person-years, a decrease in the mortality rate of four per 100,000 person-years and a decrease in the DALYs lost of 148 per 100,000 person-years.
The association between digestive disease burden and the SDI was both “striking” and “pretty scary” to Dr. Quigley, who perceived it as both a public health and political issue that needs to be addressed. “There are a lot of areas here that we’re never going to make progress in until we do something about poverty and access to healthcare,” he told Gastroenterology & Endoscopy News.
In the lower two SDI quintiles, enteric infections were the largest contributors to DALYs lost, both in 1990 and 2019, while in the highest two quintiles cancers of the digestive system generally contributed more to lost DALYs. However, by 2019, the contributions of cancers of the digestive system increased in lower SDI quintiles to better match what is seen in higher SDI quintiles. Cirrhosis and other chronic liver diseases were major contributors to DALYs lost across the five SDI quintiles, both in 1990 and 2019.
Applying the Data in Practice
The researchers emphasized that “the persistence of digestive disease incidence and prevalence highlights the need for ongoing efforts to address their burden globally.” The research team encouraged the use of their findings by “policymakers, public health practitioners, and researchers … to develop effective strategies to combat the global burden of digestive diseases” targeted to the countries or regions to which they are being applied.
To Dr. Quigley, these findings are also extremely relevant to practicing gastroenterologists, both to better understand how to treat a diverse patient population and to prepare for what patients may need in the future. “I think being aware of global trends is very important for every gastroenterologist because they undoubtedly will look after people who have come from different parts of the world, and whose rates of these diseases may be very different to what you’d expect in a wide, diverse population,” Dr. Quigley said. In addition, “I think this increasing rate of cirrhosis is going to be a major issue. We’re going to need more liver doctors, we’re probably going to need more liver transplant centers, and we are probably going to need to spend a lot more time and effort in preventing liver disease before it gets to an advanced stage.”
—Natasha Albaneze, MPH
This article is from the October 2023 print issue.