Variation in Testing for and Incidence of Celiac Autoimmunity in Canada: A Population-Based Study.

BACKGROUND & AIMS: The incidence of biopsy-confirmed celiac disease has increased. However, few studies have explored the incidence of celiac autoimmunity based on positive serology results. METHODS: A population-based cohort study assessed testing of tissue transglutaminase antibodies (tTG-IgA) in Alberta from 2012 to 2020. After excluding prevalent cases, incident celiac autoimmunity was defined as the first positive tTG-IgA result between 2015 and 2020. Testing and incidence rates for celiac autoimmunity were calculated per 1000 and 100,000 person-years, respectively. Incidence rate ratios (IRRs) were calculated to identify differences by demographic and regional factors. Average annual percent changes (AAPCs) assessed trends over time. RESULTS: The testing rate of tTG-IgA was 20.2 per 1000 person-years and remained stable from 2012 to 2020 (AAPC, 1.2%; 95% confidence interval [CI], -0.5 to 2.9). Testing was higher in female patients (IRR, 1.66; 95% CI, 1.65-1.66), those living in metropolitan areas (IRR, 1.39; 95% CI, 1.38-1.40), and in areas of lower socioeconomic deprivation (lowest compared to highest IRR, 1.24; 95% CI, 1.23-1.25). Incidence of celiac autoimmunity was 33.8 per 100,000 person-years and increased from 2015 to 2020 (AAPC, 6.2%; 95% CI, 3.1-9.5). Among those with tTG-IgA results ≥10 times the upper limit of normal, the incidence was 12.9 per 100,000 person-years. The incidence of celiac autoimmunity was higher in metropolitan settings (IRR, 1.28; 95% CI, 1.21-1.35) and in the least socioeconomically deprived areas compared to the highest (IRR, 1.22; 95% CI, 1.14-1.32). CONCLUSIONS: Incidence of celiac autoimmunity is high and increasing, despite stable testing rates. Variation in testing patterns may lead to underreporting the incidence of celiac autoimmunity in nonmetropolitan areas and more socioeconomically deprived neighborhoods.

Global Hospitalization Trends for Crohn's Disease and Ulcerative Colitis in the 21st Century: A Systematic Review With Temporal Analyses.

BACKGROUND & AIMS: The evolving epidemiologic patterns of inflammatory bowel disease (IBD) throughout the world, in conjunction with advances in therapeutic treatments, may influence hospitalization rates of IBD. We performed a systematic review with temporal analysis of hospitalization rates for IBD across the world in the 21st century. METHODS: We systematically reviewed Medline and Embase for population-based studies reporting hospitalization rates for IBD, Crohn's disease (CD), or ulcerative colitis (UC) in the 21st century. Log-linear models were used to calculate the average annual percentage change (AAPC) with associated 95% confidence intervals (95% CIs). Random-effects meta-analysis pooled country-level AAPCs. Data were stratified by the epidemiologic stage of a region: compounding prevalence (stage 3) in North America, Western Europe, and Oceania vs acceleration of incidence (stage 2) in Asia, Eastern Europe, and Latin America vs emergence (stage 1) in developing countries. RESULTS: Hospitalization rates for a primary diagnosis of IBD were stable in countries in stage 3 (AAPC, -0.13%; 95% CI, -0.72 to 0.97), CD (AAPC, 0.20%; 95% CI, -1.78 to 2.17), and UC (AAPC, 0.02%; 95% CI, -0.91 to 0.94). In contrast, hospitalization rates for a primary diagnosis were increasing in countries in stage 2 for IBD (AAPC, 4.44%; 95% CI, 2.75 to 6.14), CD (AAPC, 8.34%; 95% CI, 4.38 to 12.29), and UC (AAPC, 3.90; 95% CI, 1.29 to 6.52). No population-based studies were available for developing regions in stage 1 (emergence). CONCLUSIONS: Hospitalization rates for IBD are stabilizing in countries in stage 3, whereas newly industrialized countries in stage 2 have rapidly increasing hospitalization rates, contributing to an increasing burden on global health care systems.

The Global Incidence of Peptic Ulcer Disease Is Decreasing Since the Turn of the 21st Century: A Study of the Organisation for Economic Co-Operation and Development (OECD).

INTRODUCTION: Peptic ulcer disease (PUD) is a common cause of hospitalization worldwide. We assessed temporal trends in hospitalization for PUD in 36 Organisation for Economic Co-operation and Development (OECD) countries since the turn of the 21st century. METHODS: The OECD database contains data on PUD-related hospital discharges and mortality for 36 countries between 2000 and 2019. Hospitalization rates for PUD were expressed as annual rates per 100,000 persons. Joinpoint regression models were used to calculate the average annual percent change (AAPC) with 95% confidence intervals (CIs) for each country, which were pooled using meta-analyses. The incidence of PUD was forecasted to 2021 using autoregressive integrated moving average and Poisson regression models. RESULTS: The overall median hospitalization rate was 42.4 with an interquartile range of 29.7-60.6 per 100,000 person-years. On average, hospitalization rates (AAPC = -3.9%; 95% CI: -4.4, -3.3) and morality rates (AAPC = -4.7%; 95% CI: -5.6, -3.8) for PUD have decreased from 2000 to 2019 globally. The forecasted incidence of PUD hospitalizations in 2021 ranged from 3.5 per 100,000 in Mexico to 92.1 per 100,000 in Lithuania. Across 36 countries in the OECD, 329,000 people are estimated to be hospitalized for PUD in 2021. DISCUSSION: PUD remains an important cause of hospitalization worldwide. Reassuringly, hospitalizations and mortality for PUD have consistently been falling in OECD countries in North America, Latin America, Europe, Asia, and Oceania. Identifying underlying factors driving these trends is essential to sustaining this downward momentum.

The prevalence and incidence of NAFLD worldwide: a systematic review and meta-analysis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide and the leading cause of liver-related morbidity and mortality. We aimed to predict the burden of NAFLD by examining and estimating the temporal trends of its worldwide prevalence and incidence. METHODS: In this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, and Web of Science without language restrictions for reports published between date of database inception and May 25, 2021. We included observational cross-sectional or longitudinal studies done in study populations representative of the general adult population, in whom NAFLD was diagnosed using an imaging method in the absence of excessive alcohol consumption and viral hepatitis. Studies were excluded if conducted in paediatric populations (aged <18 years) or subgroups of the general population. Summary estimates were extracted from included reports by KR and independently verified by HA using the population, intervention, comparison, and outcomes framework. Primary outcomes were the prevalence and incidence of NAFLD. A random-effects meta-analysis was used to calculate overall and sex-specific pooled effect estimates and 95% CIs. FINDINGS: The search identified 28 557 records, of which 13 577 records were screened; 299 records were also identified via other methods. In total, 72 publications with a sample population of 1 030 160 individuals from 17 countries were included in the prevalence analysis, and 16 publications with a sample population of 381 765 individuals from five countries were included in the incidence analysis. The overall prevalence of NAFLD worldwide was estimated to be 32·4% (95% CI 29·9-34·9). Prevalence increased significantly over time, from 25·5% (20·1-31·0) in or before 2005 to 37·8% (32·4-43·3) in 2016 or later (p=0·013). Overall prevalence of NAFLD was significantly higher in men than in women (39·7% [36·6-42·8] vs 25·6% [22·3-28·8]; p<0·0001). The overall incidence of NAFLD was estimated to be 46·9 cases per 1000 person-years (36·4-57·5); 70·8 cases per 1000 person-years (48·7-92·8) in men and 29·6 cases per 1000 person-years (20·2-38·9) in women (p<0·0001). There was considerable heterogeneity between studies of both NAFLD prevalence (I2=99·9%) and NAFLD incidence (I2=99·9%). INTERPRETATION: Worldwide prevalence of NAFLD is considerably higher than previously estimated and is continuing to increase at an alarming rate. Incidence and prevalence of NAFLD are significantly higher among men than among women. Greater awareness of NAFLD and the development of cost-effective risk stratification strategies are warranted to address the growing burden of NAFLD. FUNDING: Canadian Institutes of Health.

The Multiple Waves of COVID-19 in Patients With Inflammatory Bowel Disease: A Temporal Trend Analysis.

BACKGROUND: Cases of coronavirus disease 2019 (COVID-19) have emerged in discrete waves. We explored temporal trends in the reporting of COVID-19 in inflammatory bowel disease (IBD) patients. METHODS: The Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) is an international registry of IBD patients diagnosed with COVID-19. The average percent changes (APCs) were calculated in weekly reported cases of COVID-19 during the periods of March 22 to September 12, September 13 to December 12, 2020, and December 13 to July 31, 2021. RESULTS: Across 73 countries, 6404 cases of COVID-19 were reported in IBD patients. COVID-19 reporting decreased globally by 4.2% per week (95% CI, -5.3% to -3.0%) from March 22 to September 12, 2020, then climbed by 10.2% per week (95% CI, 8.1%-12.3%) from September 13 to December 12, 2020, and then declined by 6.3% per week (95% CI, -7.8% to -4.7%). In the fall of 2020, weekly reporting climbed in North America (APC, 11.3%; 95% CI, 8.8-13.8) and Europe (APC, 17.7%; 95% CI, 12.1%-23.5%), whereas reporting was stable in Asia (APC, -8.1%; 95% CI, -15.6-0.1). From December 13, 2020, to July 31, 2021, reporting of COVID-19 in those with IBD declined in North America (APC, -8.5%; 95% CI, -10.2 to -6.7) and Europe (APC, -5.4%; 95% CI, -7.2 to -3.6) and was stable in Latin America (APC, -1.5%; 95% CI, -3.5% to 0.6%). CONCLUSIONS: Temporal trends in reporting of COVID-19 in those with IBD are consistent with the epidemiological patterns COVID-19 globally.

Global Incidence of Acute Pancreatitis Is Increasing Over Time: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Acute pancreatitis is a common disease with significant associated morbidity and mortality. We performed a systematic review and meta-analysis of population-based studies to explore the changing temporal trends of acute pancreatitis incidence globally. METHODS: We performed a systematic literature search to identify population-based studies reporting the annual incidence of acute pancreatitis. Abstracts were assessed independently to identify applicable articles for full-text review and data extraction. Joinpoint temporal trend analyses were performed to calculate the average annual percent change (AAPC) with 95% confidence intervals (CIs). The AAPCs were pooled in a meta-analysis to capture the overall and regional trends in acute pancreatitis incidence over time. Temporal data were summarized in a static map and an interactive, web-based map. RESULTS: Forty-four studies reported the temporal incidence of acute pancreatitis (online interactive map: https://kaplan-acute-pancreatitis-ucalgary.hub.arcgis.com/). The incidence of acute pancreatitis has increased from 1961 to 2016 (AAPC, 3.07%; 95% CI, 2.30% to 3.84%; n = 34). Increasing incidence was observed in North America (AAPC, 3.67%; 95% CI, 2.76% to 4.57%; n = 4) and Europe (AAPC, 2.77%; 95% CI, 1.91% to 3.63%; n = 23). The incidence of acute pancreatitis was stable in Asia (AAPC, -0.28%; 95% CI, -5.03% to 4.47%; n = 4). CONCLUSIONS: This meta-analysis provides a comprehensive overview of the global incidence of acute pancreatitis over the last 56 years and demonstrates a steadily rising incidence over time in most countries of the Western world. More studies are needed to better define the changing incidence of acute pancreatitis in Asia, Africa, and Latin America.

An International Reporting Registry of Patients With Celiac Disease and COVID-19: Initial Results From SECURE-CELIAC.

Surveillance Epidemiology Under Research Exclusion for Celiac Disease (SECURE-CELIAC) is an international, de-identified adult and pediatric database created to monitor and report on the severity of coronavirus disease 2019 (COVID-19) outcomes in patients with celiac disease (CD).

Association Between Celiac Disease and Autism Spectrum Disorder: A Systematic Review.

OBJECTIVE: The aim of the study was to perform a systematic review assessing the research investigating the association between celiac disease (CD) and autism spectrum disorder (ASD). METHODS: A literature search of MEDLINE and EMBASE was performed without limits placed on year or language. Observational studies reporting on the occurrence of CD among patients with ASD and/or the occurrence of ASD among patients with CD were included. Study design, characteristics, diagnostic criteria for ASD and CD, and the frequency of positive cases in the studied sample were recorded. Study quality was assessed using an adapted Newcastle-Ottawa Quality Assessment Scale. Due to substantial heterogeneity between studies, a meta-analysis was not performed. RESULTS: Of the 298 unique citations identified within our search strategy, 17 articles evaluating the association between CD and ASD were included. Of those articles, 13 observed samples of patients with ASD, and 6 observed samples of patients with CD. Overall, most studies had small sample sizes and reported no evidence for an association between the 2 conditions. However, a limited number of population-based studies of higher quality suggested a potential association between CD and ASD. CONCLUSIONS: Most studies assessing an association between CD and ASD are at risk for systematic and/or random error. A potential link has, however, been shown in a handful of high-quality studies, and, therefore, this comorbidity cannot be ruled out. Future studies should recruit larger sample sizes, include precise definitions of CD and ASD, and exclude patients with ASD on a gluten-free diet.

Effect of IBD medications on COVID-19 outcomes: results from an international registry.

OBJECTIVE: We sought to evaluate COVID-19 clinical course in patients with IBD treated with different medication classes and combinations. DESIGN: Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) is a large, international registry created to monitor outcomes of IBD patients with confirmed COVID-19. We used multivariable regression with a generalised estimating equation accounting for country as a random effect to analyse the association of different medication classes with severe COVID-19, defined as intensive care unit admission, ventilator use and/or death. RESULTS: 1439 cases from 47 countries were included (mean age 44.1 years, 51.4% men) of whom 112 patients (7.8%) had severe COVID-19. Compared with tumour necrosis factor (TNF) antagonist monotherapy, thiopurine monotherapy (adjusted OR (aOR) 4.08, 95% CI 1.73 to 9.61) and combination therapy with TNF antagonist and thiopurine (aOR 4.01, 95% CI 1.65 to 9.78) were associated with an increased risk of severe COVID-19. Any mesalamine/sulfasalazine compared with no mesalamine/sulfasalazine use was associated with an increased risk (aOR 1.70, 95% CI 1.26 to 2.29). This risk estimate increased when using TNF antagonist monotherapy as a reference group (aOR 3.52, 95% CI 1.93 to 6.45). Interleukin-12/23 and integrin antagonists were not associated with significantly different risk than TNF antagonist monotherapy (aOR 0.98, 95% CI 0.12 to 8.06 and aOR 2.42, 95% CI 0.59 to 9.96, respectively). CONCLUSION: Combination therapy and thiopurines may be associated with an increased risk of severe COVID-19. No significant differences were observed when comparing classes of biologicals. These findings warrant confirmation in large population-based cohorts.MKH should be changed to MDK for co-last author line.

Physician Practice Patterns in Holding Inflammatory Bowel Disease Medications due to COVID-19, in the SECURE-IBD Registry.

BACKGROUND: We aimed to describe physician practice patterns in holding or continuing IBD therapy in the setting of COVID-19 infection, using the Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease [SECURE-IBD] registry. METHODS: IBD medications that were stopped due to COVID-19 were recorded in the SECURE-IBD registry in addition to demographic and clinical data. We conducted descriptive analyses to understand characteristics associated with stopping IBD medications in response to active COVID-19 infection. RESULTS: Of 1499 patients, IBD medications were stopped in 518 [34.6%] patients. On bivariate and multivariable analyses, a diagnosis of ulcerative colitis or IBD-unspecified was associated with a lower odds of stopping medication compared with Crohn's disease (adjusted odds ratio [aOR] 0.6, 95% confidence interval [CI] 0.48, 0.75). When evaluating specific medications, 5-aminosalicylic acid was more likely to be continued [p <0.001] whereas anti-tumour necrosis factor therapy and immunomodulator therapy were more likely to be stopped [global p <0.001]. Other demographic and clinical characteristics did not affect prescription patterns. CONCLUSIONS: IBD medications other than immunomodulators were continued in the majority of IBD patients with COVID-19, in the international SECURE-IBD registry. Future studies are needed to understand the impact of stopping or continuing IBD medications on IBD- and COVID-19 related outcomes.

Corticosteroids, But Not TNF Antagonists, Are Associated With Adverse COVID-19 Outcomes in Patients With Inflammatory Bowel Diseases: Results From an International Registry.

BACKGROUND AND AIMS: The impact of Coronavirus disease 2019 (COVID-19) on patients with inflammatory bowel disease (IBD) is unknown. We sought to characterize the clinical course of COVID-19 among patients with IBD and evaluate the association among demographics, clinical characteristics, and immunosuppressant treatments on COVID-19 outcomes. METHODS: Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) is a large, international registry created to monitor outcomes of patients with IBD with confirmed COVID-19. We calculated age-standardized mortality ratios and used multivariable logistic regression to identify factors associated with severe COVID-19, defined as intensive care unit admission, ventilator use, and/or death. RESULTS: 525 cases from 33 countries were reported (median age 43 years, 53% men). Thirty-seven patients (7%) had severe COVID-19, 161 (31%) were hospitalized, and 16 patients died (3% case fatality rate). Standardized mortality ratios for patients with IBD were 1.8 (95% confidence interval [CI], 0.9-2.6), 1.5 (95% CI, 0.7-2.2), and 1.7 (95% CI, 0.9-2.5) relative to data from China, Italy, and the United States, respectively. Risk factors for severe COVID-19 among patients with IBD included increasing age (adjusted odds ratio [aOR], 1.04; 95% CI, 1.01-1.02), ≥2 comorbidities (aOR, 2.9; 95% CI, 1.1-7.8), systemic corticosteroids (aOR, 6.9; 95% CI, 2.3-20.5), and sulfasalazine or 5-aminosalicylate use (aOR, 3.1; 95% CI, 1.3-7.7). Tumor necrosis factor antagonist treatment was not associated with severe COVID-19 (aOR, 0.9; 95% CI, 0.4-2.2). CONCLUSIONS: Increasing age, comorbidities, and corticosteroids are associated with severe COVID-19 among patients with IBD, although a causal relationship cannot be definitively established. Notably, tumor necrosis factor antagonists do not appear to be associated with severe COVID-19.

Incidence of Celiac Disease Is Increasing Over Time: A Systematic Review and Meta-analysis.

OBJECTIVES: To conduct a systematic review and meta-analysis that defines the worldwide incidence of celiac disease (CD) and examines temporal trends. METHODS: MEDLINE and EMBASE were searched for population-based studies reporting the incidence of CD in the overall population, children, or adults. No limits were placed on year or language of publication. Studies solely examining at-risk populations (e.g., patients with type 1 diabetes) were excluded. Random-effects models were performed to meta-analyze sex- and age-specific incidence in the 21st century. Temporal trend analyses assessed the average annual percent change in CD incidence over time. RESULTS: Of 11,189 citations, 86 eligible studies were identified for inclusion, of which 50 were deemed suitable for analyses. In the 21st century, the pooled female incidence of CD was 17.4 (95% confidence interval [CI]: 13.7, 21.1) (I = 99.5%) per 100,000 person-years, compared with 7.8 (95% CI: 6.3, 9.2) (I = 98.6%) in males. Child-specific incidence was 21.3 per 100,000 person-years (95% CI: 15.9, 26.7) (I = 99.7%) compared with 12.9 (95% CI: 7.6, 18.2) (I = 99.9%) in adults. Pooling average annual percent changes showed the incidence of CD to be increasing by 7.5% (95% CI: 5.8, 9.3) (I = 79.6%) per year over the past several decades. DISCUSSION: Incidence of CD is highest in females and children. Overall, the incidence has been significantly rising in the latter half of the 20th century and into the 21st century throughout the Western world. Population-based studies in Africa, Asia, and Latin America are needed to provide a comprehensive picture of the global incidence of CD.

Progression of Inflammatory Bowel Diseases Throughout Latin America and the Caribbean: A Systematic Review.

BACKGROUND & AIMS: The incidence of inflammatory bowel diseases (IBD) is increasing in Latin America. We performed a systematic review to identify clinical and epidemiologic features of IBD in Latin America (including Mexico, Central America, and South America) and the Caribbean. METHODS: We searched MEDLINE, EMBASE, and SciELO databases for clinical or epidemiologic studies of Crohn's disease (CD) or ulcerative colitis (UC) from Latin American and Caribbean countries and territories that reported incidence, prevalence, ratio of UC:CD, IBD phenotype, and treatment, through September 12, 2018. Data were extracted from 61 articles for analysis. RESULTS: The incidence and prevalence of IBD have been steadily increasing in Latin America and the Caribbean. The incidence of CD in Brazil increased from 0.08 per 100,000 person-years in 1988 to 0.68 per 100,000 person-years in 1991-1995 to 5.5 per 100,000 person-years in 2015. The highest reported prevalence of IBD was in Argentina, in 2007, at 15 and 82 per 100,000 person-years for CD and UC, respectively. The ratio of UC:CD exceeded 1 in all regions throughout Latin America and the Caribbean with the exception of Brazil. Treatment with tumor necrosis factor antagonists increased steadily for patients with CD (43.4% of all patients in Brazil were treated in 2014) but less so for patients with UC (4.5% of all patients were treated in 2014). Surgery for IBD decreased with time. In Chile, surgeries were performed on 57.0% of patients with CD and 18.0% of patients with UC during the period of 1990-2002; these values decreased to 38.0% and 5.0%, respectively, during the period of 2012-2015. In Peru, 6.9% of patients with UC received colectomies in the period of 2001-2003 and 6.2% in 2004-2014. CONCLUSIONS: In a systematic review, we found the incidence of IBD to be increasing throughout Latin America and the Caribbean. Population-based epidemiology studies are needed to evaluate the increase in IBD in these regions, which differ from other global regions in climate, culture, demographics, diet, healthcare delivery and infrastructure, and socioeconomic status.

Trends in hospitalisation rates for inflammatory bowel disease in western versus newly industrialised countries: a population-based study of countries in the Organisation for Economic Co-operation and Development.

BACKGROUND: Hospitalisation rates for inflammatory bowel disease (IBD) vary across the world. We aimed to investigate temporal patterns of hospitalisation for IBD in member countries of the Organisation for Economic Co-operation and Development (OECD). METHODS: From the OECD database, we assessed IBD-related hospitalisation rates (expressed as annual rates per 100 000 inhabitants) for 34 countries from 1990 to 2016. We calculated mean hospitalisation rates for the period 2010-15 and used joinpoint regression models to calculate average annual percentage changes with 95% CIs. FINDINGS: Mean hospitalisation rates for IBD from 2010 to 2015 were highest in North America (eg, 33·9 per 100 000 in the USA), Europe (eg, 72·9 per 100 000 in Austria), and Oceania (eg, 31·5 per 100 000 in Australia). Hospitalisation rates for IBD were stabilising or decreasing over time in many countries in these regions but increasing in others. Countries in Asia and Latin America and the Caribbean had the lowest IBD-related hospitalisation rates but the greatest increases in rates over time. For example, Turkey had an annual hospitalisation rate of 10·8 per 100 000 inhabitants and an average annual percentage change of 10·4% (95% CI 5·2-15·9). Similarly, Chile had an annual hospitalisation rate of 9·0 per 100 000 inhabitants and an average annual percentage change of 5·9% (4·9-7·0). INTERPRETATION: Hospitalisation rates for IBD are high in western countries but are typically stabilising or decreasing, whereas rates in many newly industrialised countries are rapidly increasing, which reflects the known increase in IBD prevalence in these countries. Potential explanations for these trends include changes in the epidemiology of IBD, health-care delivery, and infrastructure in these countries, as well as overall country-specific patterns in hospitalisations and differences between countries in data collection methods. FUNDING: None.

Population Density and Risk of Inflammatory Bowel Disease: A Prospective Population-Based Study in 13 Countries or Regions in Asia-Pacific.

INTRODUCTION: Living in an urban environment may increase the risk of developing inflammatory bowel disease (IBD). It is unclear if this observation is seen globally. We conducted a population-based study to assess the relationship between urbanization and incidence of IBD in the Asia-Pacific region. METHODS: Newly diagnosed IBD cases between 2011 and 2013 from 13 countries or regions in Asia-Pacific were included. Incidence was calculated with 95% confidence interval (CI) and pooled using random-effects model. Meta-regression analysis was used to assess incidence rates and their association with population density, latitude, and longitude. RESULTS: We identified 1175 ulcerative colitis (UC), 656 Crohn's disease (CD), and 37 IBD undetermined (IBD-U). Mean annual IBD incidence per 100 000 was 1.50 (95% CI: 1.43-1.57). India (9.31; 95% CI: 8.38-10.31) and China (3.64; 95% CI, 2.97-4.42) had the highest IBD incidence in Asia. Incidence of overall IBD (incidence rate ratio [IRR]: 2.19; 95% CI: 1.01-4.76]) and CD (IRR: 3.28; 95% CI: 1.83-9.12) was higher across 19 areas of Asia with a higher population density. In China, incidence of IBD (IRR: 2.37; 95% CI: 1.10-5.16) and UC (IRR: 2.63; 95% CI: 1.2-5.8) was positively associated with gross domestic product. A south-to-north disease gradient (IRR: 0.94; 95% CI: 0.91-0.98) was observed for IBD incidence and a west-to-east gradient (IRR: 1.14; 95% CI: 1.05-1.24) was observed for CD incidence in China. This study received IRB approval. CONCLUSIONS: Regions in Asia with a high population density had a higher CD and UC incidence. Coastal areas within China had higher IBD incidence. With increasing urbanization and a shift from rural areas to cities, disease incidence may continue to climb in Asia.

Rural and urban disparities in the care of Canadian patients with inflammatory bowel disease: a population-based study.

BACKGROUND AND AIMS: Canada's large geographic area and low population density pose challenges in access to specialized health care for remote and rural residents. We compared health services use, surgical rate, and specialist gastroenterologist care in rural and urban inflammatory bowel disease (IBD) patients in Canada. METHODS: We used validated algorithms that were applied to population-based health administrative data to identify all people living with the following three Canadian provinces: Alberta, Manitoba, and Ontario (ON). We compared rural residents with urban residents for time to diagnosis, hospitalizations, outpatient visits, emergency department (ED) use, surgical rate, and gastroenterologist care. Multivariable regression compared the outcomes in rural/urban patients, controlling for confounders. Provincial results were meta-analyzed using random-effects models to produce overall estimates. RESULTS: A total of 36,656 urban and 5,223 rural residents with incident IBD were included. Outpatient physician visit rate was similar in rural and urban patients. IBD-specific and IBD-related hospitalization rates were higher in rural patients (incidence rate ratio [IRR] 1.17, 95% CI 1.02-1.34, and IRR 1.27, 95% CI 1.04-1.56, respectively). The rate of ED visits in ON were similarly elevated for rural patients (IRR 1.53, 95% CI 1.42-1.65, and IRR 1.33, 95% CI 1.25-1.40). There were no differences in surgical rates or prediagnosis lag time between rural and urban patients. Rural patients had fewer IBD-specific gastroenterologist visits (IRR 0.79, 95% CI 0.73-0.84) and a smaller proportion of their IBD-specific care was provided by gastroenterologists (28.3% vs 55.2%, P<0.0001). This was less pronounced in children <10 years at diagnosis (59.3% vs 65.0%, P<0.0001), and the gap was widest in patients >65 years (33.0% vs 59.2%, P<0.0001). CONCLUSION: There were lower rates of gastroenterologist physician visits, more hospitalizations, and greater rates of ED visits in rural IBD patients. These disparities in health services use result in costlier care for rural patients. Innovative methods of delivering gastroenterology care to rural IBD patients (such as telehealth, online support, and remote clinics) should be explored, especially for communities lacking easy access to gastroenterologists.

Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies.

BACKGROUND: Inflammatory bowel disease is a global disease in the 21st century. We aimed to assess the changing incidence and prevalence of inflammatory bowel disease around the world. METHODS: We searched MEDLINE and Embase up to and including Dec 31, 2016, to identify observational, population-based studies reporting the incidence or prevalence of Crohn's disease or ulcerative colitis from 1990 or later. A study was regarded as population-based if it involved all residents within a specific area and the patients were representative of that area. To be included in the systematic review, ulcerative colitis and Crohn's disease needed to be reported separately. Studies that did not report original data and studies that reported only the incidence or prevalence of paediatric-onset inflammatory bowel disease (diagnosis at age <16 years) were excluded. We created choropleth maps for the incidence (119 studies) and prevalence (69 studies) of Crohn's disease and ulcerative colitis. We used temporal trend analyses to report changes as an annual percentage change (APC) with 95% CI. FINDINGS: We identified 147 studies that were eligible for final inclusion in the systematic review, including 119 studies of incidence and 69 studies of prevalence. The highest reported prevalence values were in Europe (ulcerative colitis 505 per 100 000 in Norway; Crohn's disease 322 per 100 000 in Germany) and North America (ulcerative colitis 286 per 100 000 in the USA; Crohn's disease 319 per 100 000 in Canada). The prevalence of inflammatory bowel disease exceeded 0·3% in North America, Oceania, and many countries in Europe. Overall, 16 (72·7%) of 22 studies on Crohn's disease and 15 (83·3%) of 18 studies on ulcerative colitis reported stable or decreasing incidence of inflammatory bowel disease in North America and Europe. Since 1990, incidence has been rising in newly industrialised countries in Africa, Asia, and South America, including Brazil (APC for Crohn's disease +11·1% [95% CI 4·8-17·8] and APC for ulcerative colitis +14·9% [10·4-19·6]) and Taiwan (APC for Crohn's disease +4·0% [1·0-7·1] and APC for ulcerative colitis +4·8% [1·8-8·0]). INTERPRETATION: At the turn of the 21st century, inflammatory bowel disease has become a global disease with accelerating incidence in newly industrialised countries whose societies have become more westernised. Although incidence is stabilising in western countries, burden remains high as prevalence surpasses 0·3%. These data highlight the need for research into prevention of inflammatory bowel disease and innovations in health-care systems to manage this complex and costly disease. FUNDING: None.

Corrigendum: Rural and Urban Residence During Early Life Is Associated with a Lower Risk of Inflammatory Bowel Disease: A Population-Based Inception and Birth Cohort Study.

This corrects the article DOI: 10.1038/ajg.2017.208.

Rural and Urban Residence During Early Life is Associated with Risk of Inflammatory Bowel Disease: A Population-Based Inception and Birth Cohort Study

OBJECTIVES: To determine the association between inflammatory bowel disease (IBD) and rural/urban household at the time of diagnosis, or within the first 5 years (y) of life. METHODS: Population-based cohorts of residents of four Canadian provinces were created using health administrative data. Rural/urban status was derived from postal codes based on population density and distance to metropolitan areas. Validated algorithms identified all incident IBD cases from administrative data (Alberta: 1999-2008, Manitoba and Ontario: 1999-2010, and Nova Scotia: 2000-2008). We determined sex-standardized incidence (per 100,000 patient-years) and incident rate ratios (IRR) using Poisson regression. A birth cohort was created of children in whom full administrative data were available from birth (Alberta 1996-2010, Manitoba 1988-2010, and Ontario 1991-2010). IRR was calculated for residents who lived continuously in rural/urban households during each of the first 5 years of life. RESULTS: There were 6,662 rural residents and 38,905 urban residents with IBD. Incidence of IBD per 100,000 was 33.16 (95% CI 27.24-39.08) in urban residents, and 30.72 (95% CI 23.81-37.64) in rural residents (IRR 0.90, 95% CI 0.81-0.99). The protective association was strongest in children <10 years (IRR 0.58, 95% CI 0.43-0.73) and 10-17.9 years (IRR 0.72, 95% CI 0.64-0.81). In the birth cohort, comprising 331 rural and 2,302 urban residents, rurality in the first 1-5 years of life was associated with lower risk of IBD (IRR 0.75-0.78). CONCLUSIONS: People living in rural households had lower risk of developing IBD. This association is strongest in young children and adolescents, and in children exposed to the rural environment early in life.