MR Enterography Scores Correlate with Degree of Mucosal Healing in Pediatric Crohn's Disease: A Pilot Study.

Objectives: MR enterography (MRE) Index of Activity (MaRIA) and Clermont are validated scores that correlate with Crohn's disease (CD) activity; however, the Clermont score has not been validated to correlate with the degree of change in mucosal inflammation post induction treatment in children. This pilot study evaluated if MaRIA and Clermont scores can serve as surrogates to ileocolonoscopy for assessing interval change in mucosal inflammation in pediatric CD post-induction treatment. Methods: Children with known or newly diagnosed ileocolonic CD starting or changing therapy underwent ileocolonoscopy, scored with simple endoscopic score for Crohn's disease (SES-CD), and MRE on the same day at two time points (Week 0 and 12). Accuracy of global MaRIA and Clermont indices relative to ileocolonoscopy in detecting degree of post-treatment interval change in mucosal inflammation was assessed through correlational coefficients (r). Inter-reader agreement was calculated for imaging scores through intraclass correlation (ICC). Results: Sixteen children (mean age 11.5 ± 2.8) were evaluated. Global MaRIA/Clermont correlated with SES-CD in detecting the degree of change in mucosal inflammation (r = 0.676 and r = 0.677, P < 0.005, respectively). Correlation for pooled timepoint assessments between SES-CD and global MaRIA/Clermont was moderate (r = 0.546, P < 0.001 and r = 0.582, P < 0.001, respectively). Inter-rater reliability for global MaRIA and Clermont was good (ICC = 0.809 and ICC = 0.768, respectively, P < 0.001). Conclusions: MRE-based global scores correlate with endoscopic indices and may be used to monitor disease changes in children with CD undergoing induction treatment, which can advise the physician if treatment changes should be made.

Increasing Complexity of New Nursing Home Residents in Ontario, Canada: A Serial Cross-Sectional Study.

OBJECTIVES: The main objective of the study was to investigate annual changes in the sociodemographic characteristics, morbidity, and functional status of new nursing home residents in Ontario, Canada, between 2000 and 2015. A secondary objective was to develop and assess the quality of an algorithm for ascertaining admissions into publicly funded nursing homes in Ontario using a combination of health administrative data sources that indirectly identifies the residential status of new nursing home residents. DESIGN: Population-based serial cross-sectional study with an accompanying quality assessment study of algorithms. SETTING: Publicly funded nursing care homes in Ontario, Canada. PARTICIPANTS: The reference standard for the assessment of algorithm performance was 21 544 newly admitted nursing home residents identified from the Resident Assessment Instrument-Minimum Data Set in 2012. The selected algorithm was then used to identify serial cross-sectional cohorts of newly admitted residents between 2000 and 2015 that ranged in size between 14 651 and 23 630 residents. MEASUREMENTS: Sociodemographic characteristics, morbidity, and functional status of new residents were determined upon admission to examine patterns in the cohorts' profiles. RESULTS: The proportion of residents aged 85 years and older increased from 45.1% to 53.8% over 16 years. The proportions of individuals with seven or more chronic conditions (from 14.1% to 22.1%) and with nine or more prescription medications (from 44.9% to 64.2%) have also increased in parallel over time. Hypertension, osteoarthritis, and dementia were the most prevalent conditions captured, with the proportion of incoming residents with dementia increasing from 42.3% to 54.1% between 2000 and 2015. Newly admitted residents were more likely to have extensive physical and cognitive impairments upon admission. CONCLUSION: Admission trends show that new residents were older and had greater multimorbidity and limitations in physical functioning over time. J Am Geriatr Soc 68:1293-1300, 2020.

Generational Patterns of Asthma Incidence among Immigrants to Canada over Two Decades. A Population-based Cohort Study.

RATIONALE: Canada, an industrialized country with high endemic asthma rates, is characterized by a large immigrant population. OBJECTIVES: We sought to provide insight into the relative contribution of environmental exposure to asthma risk by comparing asthma rates among recent immigrants relative to long-term residents of Canada. METHODS: This was a population-based, retrospective cohort study performed using provincial health administrative data for all residents of Ontario, Canada. Residents with and without a diagnosis of asthma from fiscal years 1996-2012 were included. Individuals were categorized as being immigrants (landed in Canada after 1985) or long-term residents of Ontario by linkage with the Immigration, Refugees, and Citizenship Canada's Permanent Resident Database. We calculated the age- and sex-standardized incidence of asthma among residents of Ontario, and compared the incidence of asthma among immigrants and long-term residents using incidence rate ratios (IRRs). RESULTS: Analysis of approximately 11.7 million records showed that 2.2 immigrants arrived in Canada during the study period, with over 50% from East and South Asia and the Pacific. We found that asthma incidence was lower among immigrants compared with long-term residents (IRR = 0.30; 95% confidence interval = 0.30-0.30; P < 0.001). However, Ontario-born children of immigrants from most world regions had significantly higher asthma incidence compared with children of long-term residents (IRR = 1.44; 95% confidence interval = 1.43-1.45; P < 0.001). The overall incidence of asthma in Ontario decreased between 1996 and 2012 (Ptrend < 0.001). Immigrants contributed to only a small proportion of the asthma incidence in Ontario, and changes within this group did not significantly affect trends in the overall Ontario population asthma incidence. CONCLUSIONS: The higher asthma incidence seen among children of immigrants, but not in their parents, suggests that being born in Canada was critical for determining asthma risk. These findings support the importance of in utero and/or early life exposures on asthma development.

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.

Health Services Use during Transition from Pediatric to Adult Care for Inflammatory Bowel Disease: A Population-Based Study Using Health Administrative Data.

OBJECTIVES: To evaluate the impact of the transfer from pediatric to adult care on health services use for adolescents with inflammatory bowel disease (IBD). STUDY DESIGN: A population-based retrospective cohort study identified all children diagnosed with IBD from 1994 to 2008 and treated by pediatric gastroenterologists in Ontario, Canada, using health administrative data. Self-controlled case series analyses compared health service use in the 2 years before and 2 years after transfer with adult gastroenterologists, with a 6-month washout period at transfer. Outcomes evaluated included IBD-specific and IBD-related hospitalizations, emergency department use, outpatient visits, and laboratory use. The relative incidence (RI) in the post-transfer period was compared with pretransfer periods using Poisson regression analysis controlling for transfer starting age. Analyses were stratified by IBD type: Crohn's disease (CD) and ulcerative colitis (UC). RESULTS: There were 536 patients included in the study (388 CD, 148 UC). Emergency department use rate was higher after transfer for both CD (RI, 2.12; 95% CI, 1.53-2.93) and UC (RI, 2.34; 95% CI, 1.09-5.03), as were outpatient visits (CD: RI, 1.56; 95% CI, 1.42-1.72; UC: RI, 1.48; 95% CI, 1.24-1.76), and laboratory investigations (CD: RI, 1.43; 95% CI, 1.26-1.63; UC: 1.38; 95% CI, 1.13-1.68). There was no change in the hospitalization rate (CD: RI, 0.70; 95% CI, 0.42-1.18; UC: RI, 2.41; 95% CI, 0.62-9.40). CONCLUSIONS: Health services use in Canada increases after transfer from pediatric to adult care for outpatient visits, emergency department use, and laboratory tests, but not hospitalizations. This study has implications for the planning and budgeting of care for adolescents transitioning to adult care.

Dementia Population Risk Tool (DemPoRT): study protocol for a predictive algorithm assessing dementia risk in the community.

INTRODUCTION: The burden of disease from dementia is a growing global concern as incidence increases dramatically with age, and average life expectancy has been increasing around the world. Planning for an ageing population requires reliable projections of dementia prevalence; however, existing population projections are simple and have poor predictive accuracy. The Dementia Population Risk Tool (DemPoRT) will predict incidence of dementia in the population setting using multivariable modelling techniques and will be used to project dementia prevalence. METHODS AND ANALYSIS: The derivation cohort will consist of elderly Ontario respondents of the Canadian Community Health Survey (CCHS) (2001, 2003, 2005 and 2007; 18 764 males and 25 288 females). Prespecified predictors include sociodemographic, general health, behavioural, functional and health condition variables. Incident dementia will be identified through individual linkage of survey respondents to population-level administrative healthcare databases (1797 and 3281 events, and 117 795 and 166 573 person-years of follow-up, for males and females, respectively, until 31 March 2014). Using time of first dementia capture as the primary outcome and death as a competing risk, sex-specific proportional hazards regression models will be estimated. The 2008/2009 CCHS survey will be used for validation (approximately 4600 males and 6300 females). Overall calibration and discrimination will be assessed as well as calibration within predefined subgroups of importance to clinicians and policy makers. ETHICS AND DISSEMINATION: Research ethics approval has been granted by the Ottawa Health Science Network Research Ethics Board. DemPoRT results will be submitted for publication in peer-review journals and presented at scientific meetings. The algorithm will be assessable online for both population and individual uses. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03155815, pre-results.

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.

Validation of an algorithm to identify children with biopsy-proven celiac disease from within health administrative data: An assessment of health services utilization patterns in Ontario, Canada.

IMPORTANCE: Celiac disease (CD) is a common pediatric illness, and awareness of gluten-related disorders including CD is growing. Health administrative data represents a unique opportunity to conduct population-based surveillance of this chronic condition and assess the impact of caring for children with CD on the health system. OBJECTIVE: The objective of the study was to validate an algorithm based on health administrative data diagnostic codes to accurately identify children with biopsy-proven CD. We also evaluated trends over time in the use of health services related to CD by children in Ontario, Canada. STUDY DESIGN AND SETTING: We conducted a retrospective cohort study and validation study of population-based health administrative data in Ontario, Canada. All cases of biopsy-proven CD diagnosed 2005-2011 in Ottawa were identified through chart review from a large pediatric health care center, and linked to the Ontario health administrative data to serve as positive reference standard. All other children living within Ottawa served as the negative reference standard. Case-identifying algorithms based on outpatient physician visits with associated ICD-9 code for CD plus endoscopy billing code were constructed and tested. Sensitivity, specificity, PPV and NPV were tested for each algorithm (with 95% CI). Poisson regression, adjusting for sex and age at diagnosis, was used to explore the trend in outpatient visits associated with a CD diagnostic code from 1995-2011. RESULTS: The best algorithm to identify CD consisted of an endoscopy billing claim follow by 1 or more adult or pediatric gastroenterologist encounters after the endoscopic procedure. The sensitivity, specificity, PPV, and NPV for the algorithm were: 70.4% (95% CI 61.1-78.4%), >99.9% (95% CI >99.9->99.9%), 53.3% (95% CI 45.1-61.4%) and >99.9% (95% CI >99.9->99.9%) respectively. It identified 1289 suspected CD cases from Ontario-wide administrative data. There was a 9% annual increase in the use of this combination of CD-associated diagnostic codes in physician billing data (RR 1.09, 95% CI 1.07-1.10, P<0.001). CONCLUSIONS: With its current structure and variables Ontario health administrative data is not suitable in identifying incident pediatric CD cases. The tested algorithms suffer from poor sensitivity and/or poor PPV, which increase the risk of case misclassification that could lead to biased estimation of CD incidence rate. This study reinforced the importance of validating the codes used to identify cohorts or outcomes when conducting research using health administrative data.

Trends in Epidemiology of Pediatric Inflammatory Bowel Disease in Canada: Distributed Network Analysis of Multiple Population-Based Provincial Health Administrative Databases.

OBJECTIVES: The incidence of pediatric-onset inflammatory bowel disease (IBD) is increasing worldwide. We used population-based health administrative data to determine national Canadian IBD incidence, prevalence, and trends over time of childhood-onset IBD. METHODS: We identified children <16 years (y) diagnosed with IBD 1999-2010 from health administrative data in five provinces (Alberta, Manitoba, Nova Scotia, Ontario, Quebec), comprising 79.2% of the Canadian population. Standardized incidence and prevalence were calculated per 100,000 children. Annual percentage change (APC) in incidence and prevalence were determined using Poisson regression analysis. Provincial estimates were meta-analyzed using random-effects models to produce national estimates. RESULTS: 5,214 incident cases were diagnosed during the study period (3,462 Crohn's disease, 1,382 ulcerative colitis, 279 type unclassifiable). The incidence in Canada was 9.68 (95% CI 9.11 to 10.25) per 100,000 children. Incidence was similar amongst most provinces, but higher in Nova Scotia. APC in incidence did not significantly change over the study period in the overall cohort (+2.06%, 95% CI -0.64% to +4.76%). However, incidence significantly increased in children aged 0-5y (+7.19%, 95% +2.82% to +11.56%). Prevalence at the end of the study period in Canada was 38.25 (95% CI 35.78 to 40.73) per 100,000 children. Prevalence increased significantly over time, APC +4.56% (95% CI +3.71% to +5.42%). CONCLUSIONS: Canada has amongst the highest incidence of childhood-onset IBD in the world. Prevalence significantly increased over time. Incidence was not statistically changed with the exception of a rapid increase in incidence in the youngest group of children.

Health Services Utilization, Specialist Care, and Time to Diagnosis with Inflammatory Bowel Disease in Immigrants to Ontario, Canada: A Population-Based Cohort Study.

BACKGROUND: Canada has amongst the highest incidence of inflammatory bowel disease (IBD) in the world, and the highest proportion of immigrants among G8 nations. We determined differences in prediagnosis delay, specialist care, health services use, and risk of surgery in immigrants with IBD. METHODS: All incident cases of IBD in children (1994-2009) and adults (1999-2009) were identified from population-based health administrative data in Ontario, Canada. Linked immigration data identified those who arrived to Ontario after 1985. We compared time to diagnosis, postdiagnosis health services use (IBD specific and related), physician specialist care in immigrants and nonimmigrants, and risk of surgery between immigrants and nonimmigrants. RESULTS: Thousand two hundred two immigrants were compared with 22,990 nonimmigrants. Immigrants had similar time to diagnosis as nonimmigrants for Crohn's (hazard ratio [HR] 1.002; 95% confidence intervals [CIs] 0.89-1.12) and ulcerative colitis (HR 1.073; 95% CI 0.95-1.21). For outpatient visits, immigrants with IBD were seen by gastroenterologists more often than nonimmigrants. Immigrants had greater IBD-specific outpatient health services use after diagnosis (odds ratio 1.24; 95% CI 1.15-1.33), emergency department visits (odds ratio 1.57, 95% CI 1.30-1.91), and hospitalizations (odds ratio 1.19; 95% CI 1.02-1.40). In immigrants, there was lower risk of surgery for Crohn's (HR 0.66, 95% CI 0.43-0.99) and ulcerative colitis (HR 0.52, 95% CI 0.31-0.87). CONCLUSIONS: Immigrants to Canada had greater outpatient and specialty care and lower risk of surgery, with no delay in diagnosis, indicating appropriate use of the health system.

The Impact of Sparse Follow-up on Marginal Structural Models for Time-to-Event Data.

The impact of risk factors on the amount of time taken to reach an endpoint is a common parameter of interest. Hazard ratios are often estimated using a discrete-time approximation, which works well when the by-interval event rate is low. However, if the intervals are made more frequent than the observation times, missing values will arise. We investigated common analytical approaches, including available-case (AC) analysis, last observation carried forward (LOCF), and multiple imputation (MI), in a setting where time-dependent covariates also act as mediators. We generated complete data to obtain monthly information for all individuals, and from the complete data, we selected "observed" data by assuming that follow-up visits occurred every 6 months. MI proved superior to LOCF and AC analyses when only data on confounding variables were missing; AC analysis also performed well when data for additional variables were missing completely at random. We applied the 3 approaches to data from the Canadian HIV-Hepatitis C Co-infection Cohort Study (2003-2014) to estimate the association of alcohol abuse with liver fibrosis. The AC and LOCF estimates were larger but less precise than those obtained from the analysis that employed MI.

Asthma, type 1 and type 2 diabetes mellitus, and inflammatory bowel disease amongst South Asian immigrants to Canada and their children: a population-based cohort study.

BACKGROUND: There is a high and rising rate of immune-mediated diseases in the Western world. Immigrants from South Asia have been reported to be at higher risk upon arrival to the West. We determined the risk of immune-mediated diseases in South Asian and other immigrants to Ontario, Canada, and their Ontario-born children. METHODS: Population-based cohorts of patients with asthma, type 1 diabetes (T1DM), type 2 diabetes (T2DM), and inflammatory bowel disease (IBD) were derived from health administrative data. We determined the standardized incidence, and the adjusted risk of these diseases in immigrants from South Asia, immigrants from other regions, compared with non-immigrant residents of Ontario. The risk of these diseases in the Ontario-born children of immigrants were compared to the children of non-immigrants. RESULTS: Compared to non-immigrants, adults from South Asia had higher risk of asthma (IRR 1.56, 95%CI 1.51-1.61) and T2DM (IRR 2.59, 95%CI 2.53-2.65). Adults from South Asia had lower incidence of IBD than non-immigrants (IRR 0.32, 95%CI 0.22-0.49), as did immigrants from other regions (IRR 0.29, 95%CI 0.20-0.42). Compared to non-immigrant children, the incidence of asthma (IRR 0.66, 95%CI 0.62-0.71) and IBD (IRR 0.47, 95%CI 0.33-0.67) was low amongst immigrant children from South Asia. However, the risk in Ontario-born children of South Asian immigrants relative to the children of non-immigrants was higher for asthma (IRR 1.75, 95%CI 1.69-1.81) and less attenuated for IBD (IRR 0.90, 95%CI 0.65-1.22). CONCLUSION: Early-life environmental exposures may trigger a genetic predisposition to the development of asthma and IBD in South Asian immigrants and their Canada-born children.

Inflammatory bowel disease in immigrants to Canada and their children: a population-based cohort study.

OBJECTIVES: The risk of inflammatory bowel disease (IBD) contributed by the environment can be elucidated by assessing the risk in migrants from low prevalence to Western countries. The incidence of IBD in immigrants to Canada and their Canadian-born children was compared with nonimmigrants. METHODS: A population-based cohort of IBD patients derived from health administrative data was linked to immigration data to determine the standardized incidence of IBD in immigrants to Ontario, Canada, by region of birth between 1994 and 2010. The hazard contributed by younger age at immigration was determined. Incidence for Ontario-born children of immigrant mothers was compared with the children of nonimmigrants. RESULTS: In 2,144,660 immigrants, incidence of IBD was 7.3/100,000 person-years compared with 23.9/100,000 in 12,036,921 nonimmigrants (incidence rate ratio (IRR) 0.34, 95% CI 0.26-0.44). Incidence was lowest risk in East Asians (IRR 0.14, 95% CI 0.11-0.18) and highest in Western Europeans/North Americans (IRR 0.59, 95% CI 0.46-0.75). Increased age at immigration was associated with decreased risk of IBD (HR 0.986, 95% CI 0.982-0.990), a 14% increased risk per younger decade of life at immigration. Children of immigrants from the Middle East/North Africa, South Asia, Sub-Saharan Africa, and North America/Western Europe had similar risk of IBD as children of nonimmigrants; however, the incidence remained lower among children of immigrants from other regions. CONCLUSIONS: Younger age at arrival to Canada increased the risk of IBD in immigrants. Canadian-born children of immigrants from some regions assumed the high Canadian incidence of IBD, indicating that the underlying risk is activated with earlier life exposure to the Canadian environment in certain groups.

Changing age demographics of inflammatory bowel disease in Ontario, Canada: a population-based cohort study of epidemiology trends.

BACKGROUND: International cohort studies have reported increased incidence of inflammatory bowel disease (IBD) in recent years, and Canada has among the highest rates of IBD in the world. This study assessed incidence and prevalence of IBD in Ontario, the most populous province of Canada, to determine changing trends in age of onset. METHODS: We used a population-based cohort derived from validated health administrative data consisting of all Ontario residents living with IBD from 1999 to 2008. We determined trends over time using Poisson regression analysis, assessing rates in 10-year age groups, children, adults, and the elderly. RESULTS: In 2008, 68,071 people were living with IBD among 12,738,350 people (standardized prevalence 534.3 per 100,000 people). Between 1999 and 2008, standardized IBD incidence increased from 21.3 to 26.2 per 100,000 (2.3% per yr, P < 0.0001). Incidence of Crohn's increased from 9.6 to 12.1 per 100,000 (1.9% per yr, P < 0.0001). Ulcerative colitis incidence increased from 10.7 to 12.1 per 100,000 (2.0% per yr, P < 0.0001). For IBD, incidence increased significantly in people younger than 10 years of age (9.7% per yr, P < 0.0001), 10 to 19 years of age (3.8% per yr, P < 0.0001), 30 to 39 years of age (1.8% per yr, P = 0.0006), 40 to 49 years of age (2.8% per yr, P = 0.0001), and 50 to 59 years of age (2.8% per yr, P < 0.0001). Incidence was stable in patients older than 65 years of age at diagnosis (-0.1% per yr, P = 0.73). Although incidence did not change significantly over time in adults 20 to 29 years, IBD incidence peaked in this age group. CONCLUSIONS: Ontario has among the highest prevalence of IBD in the world. Incidence of IBD increased between 1999 and 2008, owing to increased incidence in children and adults, with stable rates in elderly people. These findings demonstrate the changing age demographics and growing burden of IBD in Ontario, Canada.

Incidence, outcomes, and health services burden of very early onset inflammatory bowel disease.

BACKGROUND & AIMS: The Paris pediatric modification of the Montreal classification defines very early onset inflammatory bowel disease (VEO-IBD) as a form of IBD distinct from that of older children. We compared the incidence and outcomes of VEO-IBD with those of IBD in older children. METHODS: We performed a population-based retrospective cohort study of all children diagnosed with IBD in Ontario, Canada, from 1994 through 2009. Trends in standardized incidence were calculated using Poisson regression. We compared outpatient and emergency department visits, hospitalizations, and surgeries among children diagnosed with IBD when they were younger than age 6, ages 6-9.9, and older than age 10 years. Multivariable models were adjusted for income and stratified by sex. RESULTS: The incidence of IBD increased from 9.4 per 100,000 children (95% confidence interval [CI], 8.2-10.8/100,000 children) in 1994 to 13.2 per 100,000 children (95% CI, 11.9-14.6/100,000 children) in 2009 (P < .0001). The incidence increased by 7.4% per year among children younger than 6 years old and 6-9.9 years old, and by 2.2% per year among children ≥10 years old. IBD-related outpatient visits were less frequent among children <6 years old than ≥10 years old (odds ratio for female patients, 0.67; 95% CI, 0.58-0.78; odds ratio for male patients, 0.86; 95% CI, 0.75-0.98). Hazard ratios [HRs] for hospitalization were lower for children <6 years old (female HR, 0.70; 95% CI, 0.56-0.87; male HR, 1.12; 95% CI, 0.94-1.33) than for older children. HRs for surgery among children <6 years old with Crohn's disease were 0.35 for female patients (95% CI, 0.16-0.78) and 0.59 for male patients (95% CI, 0.34-0.99). HRs for children <6 years old with ulcerative colitis were 0.88 for female patients (95% CI, 0.47-1.63) and 0.42 for male patients (95% CI, 0.21-0.85). There was no difference in hospitalization or surgery rates among children 6-9.9 years old vs those ≥10 years old. CONCLUSIONS: Based on a retrospective cohort study, the incidence of VEO-IBD increased from 1994 through 2009. Children diagnosed with IBD before they were 6 years old used fewer health services and had lower rates of surgery than children diagnosed when they were 10 years or older.