Data from a literature review demonstrate that despite the numerous studies performed worldwide to ascertain irritable bowel syndrome prevalence among adults, study methodologies are not uniform, leaving clinicians with a lack of reliable global prevalence data.
William E. Whitehead, PhD, from the Center for Functional GI & Motility Disorders, University of North Carolina at Chapel Hill, and colleagues conducted a multinational literature review to assess the global prevalence of IBS, and evaluate the diversity in study methodologies. A working team whose members represented different geographical areas were responsible for finding relevant studies in an assigned region using Medline, Embase, Web of Science, Cochrane, Latindex, Bireme, SciELO and other databases. After exclusions, 83 studies from 41 different countries were included.
William E. Whitehead
“The assessment of prevalence rates is important for understanding the distribution and burden of disease, for the evaluation of treatment modalities, to provide incentive for the development of new drugs and for the allocation of health care resources and research funding,” the researchers wrote.
They examined the heterogeneity of the studies and assessed mean prevalence and pooled prevalence rates. By individual country, the mean prevalence was highest in Mexico at 35.5% and lowest in France and Iran at 1.1%.
Pooled regional prevalence rates varied significantly. The prevalence rate in Latin America was 17.5% (95% CI, 16.9% to 18.2%); 9.6% (9.5% to 9.8%) in Asia; and 7.1% (8.0% to 8.3%) in North America/ Europe/Australia/New Zealand. The rate was also calculated to be 5.8% (5.6% to 6.0%) in the Middle East and Africa; however, there was a comparable lack of data from Africa, Eastern Europe and Arab countries.
“We believe that the most significant finding of the present study is the extent of methodological variance in the included studies and the statistically significant degree of heterogeneity among them, not the calculated pooled global IBS prevalence or even the prevalence by geographical region,” the researchers wrote. “ … Given current methodological limitations, the goal of ascertaining a globally representative prevalence rate for IBS is likely to elude researchers for some time. However, this might actually be less important than determining reliable regional estimates of IBS prevalence and comparing these differences among regions in terms of variables such as diet, exposure to pathogens, health care practices, psychological variables, and prevailing cultural and religious beliefs. Studies with this more limited goal may advance our understanding of the pathophysiology of IBS and improve its medical management more effectively than a global estimate of IBS prevalence.”
Disclosures: The researchers report no relevant financial disclosures.