Incidence trends of pediatric inflammatory bowel disease in Finland, 1987-2003, a nationwide study

Pregnancy period and early-life risk factors for inflammatory bowel disease: a Northern Finland birth cohort 1966 study

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) has not been fully elucidated. The aim of this study was to analyze the pregnancy period, perinatal period, and infancy period risk factors for IBD in a well-characterized birth cohort from Northern Finland.

METHODS

The Northern Finland Birth Cohort 1966 (NFBC1966) population comprises mothers living in the two northernmost provinces of Finland, Oulu, and Lapland, with dates of delivery between Jan 1st and Dec 31st, 1966 (12 055 mothers, 12 058 live-born children, 96.3% of all births during 1966). IBD patients were identified using hospital registries (from 1966 to 2020) and Social Insurance Institution (SII) registry reimbursement data for IBD drugs (from 1978 to 2016). The data were analyzed by Fisher's exact test and logistic regression.

RESULTS

In total, 6972 individuals provided informed consent for the use of combined SII and hospital registry data. Of those, 154 (2.1%) had IBD (113 [1.6%] had ulcerative colitis (UC), and 41 (0.6%) had Crohn's disease (CD)). According to multivariate analysis, maternal smoking > 10 cigarettes/day during pregnancy was associated with a nearly 6-fold increased risk of CD in the offspring (OR 5.78, 95% CI 1.70-17.3). Breastfeeding (OR = 0.18, 95% CI 0.08-0.44) and iron supplementation during the first year of life (OR = 0.43, 95% CI 0.21-0.89) were negatively associated with CD.

CONCLUSIONS

Smoking during pregnancy was associated with the risk of CD while Breastfeeding and oral iron supplementation at infancy were negatively associated with the risk of CD later in life.

Correlation of Socioeconomic and Environmental Factors With Incidence of Crohn Disease in Children and Adolescents: Systematic Review and Meta-Regression

BACKGROUND

The worldwide incidence of Crohn disease (CD) in childhood and adolescence has an increasing trend, with significant differences between different geographic regions and individual countries. This includes an increase in the incidence of CD in countries and geographic regions where CD was not previously prevalent. In response to the increasing incidence, the pediatric care landscape is facing growing challenges.

OBJECTIVE

This systematic review and meta-analysis were undertaken to comprehensively delineate the incidence rates of CD in pediatric populations across different countries and to explore potential influencing factors.

METHODS

We performed a systematic review of PubMed and Embase (via Ovid) for studies from January 1, 1970, to December 31, 2019. In addition, a manual search was performed in relevant and previously published reviews. The results were evaluated quantitatively. For this purpose, random effects meta-analyses and meta-regressions were performed to investigate the overall incidence rate and possible factors influencing the incidence.

RESULTS

A qualitative synthesis of 74 studies was performed, with 72 studies included in the meta-analyses and 52 in the meta-regressions. The results of our meta-analysis showed significant heterogeneity between the individual studies, which cannot be explained by a sample effect alone. Our findings showed geographical differences in incidence rates, which increased with increasing distance from the equator, although no global temporal trend was apparent. The meta-regression analysis also identified geographic location, UV index, and Human Development Index as significant moderators associated with CD incidence.

CONCLUSIONS

Our results suggest that pediatric CD incidence has increased in many countries since 1970 but varies widely with geographic location, which may pose challenges to the respective health care systems. We identified geographic, environmental, and socioeconomic factors that contribute to the observed heterogeneity in incidence rates. These results can serve as a basis for future research. To this end, implementations of internationally standardized and interoperable registries combined with the dissemination of health data through federated networks based on a common data model, such as the Observational Medical Outcomes Partnership, would be beneficial. This would deepen the understanding of CD and promote evidence-based approaches to preventive and interventional strategies as well as inform public health policies aimed at addressing the increasing burden of CD in children and adolescents.

TRIAL REGISTRATION

PROSPERO International prospective register of systematic reviews CRD42020168644; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=168644.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2020-037669.

Characteristics and Treatment Outcomes of Transition among Patients with Inflammatory Bowel Disease

PURPOSE

This study aimed to assess disease characteristics and outcomes of transition in patient care among adolescent patients with inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Data from patients younger than 18 years who were diagnosed with IBD (Crohn's disease, ulcerative colitis, or intestinal Behçet's disease) were investigated. We categorized the patients into two groups: transition IBD group (Group A, diagnosed in pediatric care followed by transfer to/attendance in adult IBD care) and non-transition group (Group B, diagnosed and followed up in pediatric care or adult IBD care without transfer).

RESULTS

Data from a total of 242 patients [Group A (n=29, 12.0%), Group B (n=213, 88.0%)] were analyzed. A significantly higher number of patients was diagnosed at an earlier age in Group A than in Group B (p<0.001). Group A patients had more severe disease in terms of number of disease flare ups (p=0.011) and frequency of bowel-related complications (p<0.001). Multiple linear regression analysis showed that Group B patients had more medical non-compliance than Group A patients (β=2.31, p=0.018). After transition, IBD-related admission frequency, emergency admission frequency, disease flare frequency, and medical non-compliance were significantly improved.

CONCLUSION

The transition IBD group had more severe disease. Medical non-compliance was lower in the transition IBD group. Clinical outcomes improved after transition.

Risk Factors of Cancer in Pediatric-Onset Inflammatory Bowel Disease in Denmark and Finland

OBJECTIVES

Pediatric-onset inflammatory bowel disease (pIBD) increases the risk of developing several different cancer forms. In this case-control study, we aimed to assess the impact of medical treatment and disease activity on the risk of developing disease-associated cancer (DAC) and treatment-associated cancer (TAC).

METHODS

In a previous study, we identified 27 cases of DAC (colorectal cancer, small bowel cancer, and cholangiocarcinoma) and 28 TAC (lymphoma and skin cancer) in 6689 patients with pIBD in Denmark and Finland during the period 1992-2015. In this study, the patient charts were reviewed manually. Cancer-free patients from another population-based pIBD cohort were included as controls. We recorded data on phenotype, medical treatment, surgery, and relapses. Logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals (95% CI) to estimate the relative risk.

RESULTS

We included 16 cases with DAC, 21 with TAC, and 331 controls. For DAC, lower frequencies of IBD-relapses were associated with an increased risk of cancer (OR 0.2 [95% CI: 0.04-0.8]). For TAC, we found an increased risk in patients receiving thiopurines at any point during the follow-up period (aOR: 11.7 [95% CI: 2.1-116.2]) and an association with proportion of follow-up time being exposed to thiopurines (aOR 5.6 [95% CI: 1.1-31.5]).

CONCLUSIONS

In this nation-wide study, covering all pIBD patients from Denmark and Finland, we found that pIBD patients treated with thiopurines had an increased risk of TAC.

Epidemiology, validation, and clinical characteristics of inflammatory bowel disease: the ABIS birth cohort study

BACKGROUND

Birth cohort studies with linked register-based data on inflammatory bowel disease (IBD) provide opportunities to prospectively study early-life determinants of the disease. However, register-based data often lack information on clinical characteristics and rely on diagnostic algorithms. Within the All Babies in Southeast Sweden (ABIS) cohort, we examined the validity of a register-based definition of IBD, its incidence, and clinical and therapeutic characteristics at diagnosis.

METHODS

We followed 16,223 children from birth (1997-1999) until the end of 2020 for the diagnosis of IBD as defined by a minimum of two diagnostic codes for IBD in the Swedish National Patient Register (NPR). We described the incidence and cumulative incidence of IBD. Through a medical record review of cases diagnosed by the end of 2017, we examined the positive predictive value (PPV) for IBD and described its clinical characteristics and treatment.

RESULTS

By 2020, at an average age of 22.2 years, 113 participants (0.74%, 95% confidence interval [CI] = 0.61-0.89) had a register-based diagnosis of IBD, corresponding to an incidence of 31.3 per 100,000 person-years of follow-up; the incidence for Crohn's disease (CD) was 11.1 per 100,000 person-years and 15.8 for ulcerative colitis (UC). Of 77 participants with a register-based definition of IBD by the end of 2017, medical records were identified for 61 participants, of whom 57 had true IBD (PPV = 93%; 95%CI = 0.87-1.00). While oral 5-aminosalicylic acid treatment was equally common in newly diagnosed CD and UC patients, biologics were more often used for newly diagnosed CD. The median faecal calprotectin levels were 1206 mg/kg at diagnosis and 93 mg/kg at the last follow-up (P < 0.001).

CONCLUSIONS

In this population-based sample of Swedish children and young adults the cumulative IBD incidence was 0.74. The validity of register-based definition of IBD was high and supports using such data to identify IBD patients in cohort studies.

Residential mobility and childhood inflammatory bowel disease: a nationwide case-control study

PURPOSE

To examine the association of residential mobility, as a proxy for environmental influences, with childhood inflammatory bowel disease (IBD) risk.

METHODS

Using nationwide register-based dataset, all 2038 IBD cases in Finland diagnosed at ages less than 15 years in 1992-2016 were individually matched by sex and age with five controls employing risk set sampling. Complete residential histories of the subjects were constructed from birth until the index date (diagnosis date of the case). Movement patterns were assessed by age, distance, and demographics of the departure and destination municipalities. Conditional logistic regression was employed to estimate the association between movements and IBD risk.

RESULTS

Overall, residential movement was associated with a slightly decreased odds ratio (OR) for childhood IBD (OR 0.97, 95% confidence interval (CI) 0.95-1.00 for each movement). Further examination showed reduced ORs for moving to rural municipalities (OR 0.94, 95% CI 0.90-0.98) and to distances less than 50 km (OR 0.96, 95% CI 0.93-0.99). In disease subtype analyses, the effect mainly persisted in ulcerative colitis.

CONCLUSIONS

Our findings suggest lower childhood IBD risk associated with residential mobility. The effect was found in ulcerative colitis, but not in Crohn's disease. Movements to nearby and rural areas may reduce IBD risk, though this requires further investigation.

Men with Crohn's disease may have an increased risk for head and neck squamous cell carcinoma - a nationwide register study

OBJECTIVE

Our goal was to study inflammatory bowel disease (IBD) patients' risk of head and neck squamous cell carcinoma (HNSCC), compared to general population.

MATERIALS AND METHODS

We performed a retrospective nationwide register-based study of Finnish individuals diagnosed with IBD between the years 1995 and 2015. The standardized incidence ratio (SIR) of HNSCC was calculated by comparing the cohort's complementary age-year-sex-person-year incidence to that of the whole Finnish population.

RESULTS

About 70,567 patients were diagnosed with IBD (Crohn's disease or ulcerative colitis). Later, 89 of them were diagnosed with HNSCC with mean time of 6.82 years. The incidence of HNSCC was increased in IBD patients compared to the Finnish population expectation (SIR 1.3, 95% CI 1.065-1.614, P = 0.062). When calculating Crohn's disease and ulcerative colitis separately as well as men and women separately, the incidence was particularly increased for men with Crohn's disease (SIR 1.951, 95% CI 1.216-2.935, P = 0.025).

CONCLUSION

An increased risk for HNSCC was found in men with Crohn's disease compared to the Finnish population expectations.

CLINICAL RELEVANCE

This study provides information that would improve follow-up protocols and treatment guidelines of IBD.

Increasing incidence of inflammatory bowel disease with greatest change among the elderly: a nationwide study in Finland, 2000-2020

BACKGROUND AND AIMS

The incidence of inflammatory bowel disease (IBD) is stabilising in many western countries. Some still show increasing incidence. Our objective was to determine the latest trends in IBD incidence and prevalence in Finland and compare these among different age groups and between different geographical areas.

METHODS

We used a nationwide registry of the Social Insurance Institute of Finland to identify new IBD cases during the period 2000-2020. Crude, age-specific and age-standardised incidence rates were calculated. Prevalence was estimated using valid reimbursements from the same database in 2000-2020.

RESULTS

We identified 42,498 new IBD cases. The crude annual incidence increased in ulcerative colitis (UC) from 20 to 35 (IRR 1.03, CI 1.02-1.03), in Crohn's disease (CD) from 8 to 13 (IRR 1.02, CI 1.02-1.03) and in IBD overall from 28 to 48 per 100,000 person-years (IRR 1.02, CI 1.02-1.03). Men had higher incidence than women in UC, but in CD the incidence was equal. The incidence of IBD increased in all age groups, except for small children. The increase in both UC and CD was most marked among the elderly aged over 70. A north-south gradient was discernible. The crude prevalence of IBD increased from 376 to 972 per 100,000 (PRR 1.05, CI 1.05-1.05).

CONCLUSIONS

The incidence of IBD, UC and CD is increasing in Finland. The increase is most notable in the elderly. Current prevalence of IBD is 1%.

Predictors of surgical intervention in patients with inflammatory bowel disease (two-center study)

Background

Sixty percent of Crohn’s disease (CD) patients require intestinal resection, and 20% of ulcerative colitis (UC) patients undergo proctocolectomy for medically refractory disease. Scarcity of literature about predictors for surgical intervention in inflammatory bowel disease (IBD) encouraged the conduction of this study to assess risk factors for surgical intervention in IBD patients.

Results

This cohort study included 80 Egyptian inflammatory bowel disease patients recruited from two medical centers. Patients were classified into two groups, 40 patients each, according to their need for surgical intervention to control inflammatory bowel disease. The two groups were compared regarding age of onset, type and location of disease, smoking, extraintestinal manifestations, perianal disease, granuloma, severity scores, stool calprotectin, complete blood count, erythrocyte sedimentation rate, C-reactive protein, and serum albumin at diagnosis for Crohn’s disease patients.

Twelve ulcerative colitis and 28 Crohn’s disease patients required surgical intervention in the form of total colectomy (30%), fistulectomy (32.5%), resection anastomosis (17.5%) or abscess drainage (20%). Perianal disease, smoking, and disease severity scores showed high significant differences (P value < 0.001); disease type and presence of granuloma showed statistically significant difference (P value < 0.05) between both groups. But, patient age at onset, location of the disease or extraintestinal manifestation had no statistical significance (P value > 0.5). Surgical interventions were more likely to be needed in patients with higher stool calprotectin level, C-reactive protein, erythrocyte sedimentation rate, and lower serum albumin for Crohn’s disease patients (P value < 0.001 for each).

Conclusion

Smoking, perianal disease, higher severity scores, stool calprotectin, C-reactive protein, and erythrocyte sedimentation rate levels are predictors of surgical treatment.

Bridge study protocol: an international, observational cohort study on the transition of healthcare for adolescents with chronic conditions

INTRODUCTION

More than 10% of adolescents live with a chronic disease or disability that requires regular medical follow-up as they mature into adulthood. During the first 2 years after adolescents with chronic conditions are transferred to adult hospitals, non-adherence rates approach 70% and emergency visits and hospitalisation rates significantly increase. The purpose of the Bridge study is to prospectively examine associations of transition readiness and care experiences with transition success: young patients' health, health-related quality of life (HRQoL) and adherence to medical appointments as well as costs of care. In addition, we will track patients' growing independence and educational and employment pathways during the transition process.

METHODS AND ANALYSIS

Bridge is an international, prospective, observational cohort study. Study participants are adolescents with a chronic health condition or disability and their parents/guardians who attended the New Children's Hospital in Helsinki, Finland, or the Royal Children's Hospital (RCH) in Melbourne, Australia. Baseline assessment took place approximately 6 months prior to the transfer of care and follow-up data will be collected 1 year and 2 years after the transfer of care. Data will be collected from patients' hospital records and from questionnaires completed by the patient and their parent/guardian at each time point. The primary outcomes of this study are adherence to medical appointments, clinical health status and HRQoL and costs of care. Secondary outcome measures are educational and employment outcomes.

ETHICS AND DISSEMINATION

The Ethics Committee for Women's and Children's Health and Psychiatry at the Helsinki University Hospital (HUS/1547/2017) and the RCH Human Research Ethics Committee (38035) have approved the Bridge study protocol. Results will be published in international peer-reviewed journals and summaries will be provided to the funders of the study as well as patients and their parents/guardians.

TRIAL REGISTRATION NUMBER

NCT04631965.

Incidence of pediatric inflammatory bowel disease within the Vaccine Safety Datalink network and evaluation of association with rotavirus vaccination

BACKGROUND

Recent studies have reported an increase in Inflammatory bowel disease (IBD) incidence in young children, highlighting the need to better understand risk factors for the development of IBD. Licensed for use in infants in 2006, the oral, live-attenuated rotavirus vaccine has biologic plausibility for instigating inflammation of the gut mucosa as a pathway to immune dysregulation.

METHODS

Over a ten-year period, we evaluated incidence of IBD within a cohort of children under the age of ten, enrolled in seven integrated healthcare delivery systems. We conducted a nested case-control study to evaluate the association between rotavirus vaccination and IBD using conditional logistic regression. Cases were confirmed via medical record review and matched to non-IBD controls on date of birth, sex, and study site.

RESULTS

Among 2.4 million children under the age of 10 years, 333 cases of IBD were identified with onset between 2007 and 2016. The crude incidence of IBD increased slightly over the study period (p-value for trend = 0.046). Of the 333 cases, 227 (68%) were born prior to 2007. Forty-two cases born in 2007 or later, with continuous enrollment since birth were included in the case-control study and matched to 210 controls. The adjusted odds ratio for any rotavirus vaccination in IBD cases, compared to matched controls, was 0.72 (95% confidence interval 0.19-2.65).

CONCLUSIONS

Data from this large pediatric cohort demonstrate a small overall increase in IBD incidence in young children over a ten-year period. The data suggest that rotavirus vaccination is not associated with development of IBD.

Association of Baseline Luminal Narrowing With Ileal Microbial Shifts and Gene Expression Programs and Subsequent Transmural Healing in Pediatric Crohn Disease

BACKGROUND

Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures.

MATERIALS AND METHODS

Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH.

RESULTS

After controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression.

CONCLUSIONS

Pediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.

A Systematic Review and Meta-analysis of Paediatric Inflammatory Bowel Disease Incidence and Prevalence Across Europe

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] is often one of the most devastating and debilitating chronic gastrointestinal disorders in children and adolescents. The main objectives here were to systematically review the incidence and prevalence of paediatric IBD across all 51 European states.

METHODS

We undertook a systematic review and meta-analysis based on PubMed, CINAHL, the Cochrane Library, searches of reference lists, grey literature and websites, covering the period from 1970 to 2018.

RESULTS

Incidence rates for both paediatric Crohn's disease [CD] and ulcerative colitis [UC] were higher in northern Europe than in other European regions. There have been large increases in the incidence of both paediatric CD and UC over the last 50 years, which appear widespread across Europe. The largest increases for CD have been reported from Sweden, Wales, England, the Czech Republic, Denmark and Hungary, and for UC from the Czech Republic, Ireland, Sweden and Hungary. Incidence rates for paediatric CD have increased up to 9 or 10 per 100 000 population in parts of Europe, including Scandinavia, while rates for paediatric UC are often slightly lower than for CD. Prevalence reported for CD ranged from 8.2 per 100 000 to approximately 60 and, for UC, from 8.3 to approximately 30.

CONCLUSIONS

The incidence of paediatric IBD continues to increase throughout Europe. There is stronger evidence of a north-south than an east-west gradient in incidence across Europe. Further prospective studies are needed, preferably multinational and based on IBD registries, using standardized definitions, methodology and timescales.

Infliximab and its biosimilar produced similar first-year therapy outcomes in patients with inflammatory bowel disease

AIM

Tumour necrosis factor α inhibitors (anti-TNFα) are the main therapy for moderate to severe inflammatory bowel disease (IBD) in children. Biosimilars to the original drug infliximab are now available, but there are few reports on their real-life use. We compared the outcomes of patients treated with infliximab and its biosimilar, CT-P13.

METHODS

We collected outcome data on anti-TNFα-naive patients who started infliximab in the Children's Hospital, University of Helsinki, Finland, in 2015-2016. We studied 51 paediatric patients with IBD at a median age of 12 (range 4-16): 65% had Crohn disease, 23 received the original infliximab drug and 28 received the biosimilar. During 2015, infliximab was introduced to all treatment-naïve patients, and during 2016, all treatment-naïve patients received the biosimilar.

RESULTS

We found no statistically significant differences between the two drug products related to the outcome of the therapy during the first year. There were no significant differences in the trough levels between the treatment groups. Likewise, the proportion of patients with therapy enhancement was comparable between the two treatment groups.

CONCLUSION

The first-year therapy outcomes of infliximab and its biosimilar were comparable. There were no alarming signs of differences in safety.

A systematic review on randomized controlled trials: Coaching elements of digital services to support chronically ill adolescents during transition of care

AIMS

To define digital health services that have been studied among chronically ill adolescents and to describe e-health coaching elements that may have an impact on transition outcomes.

DESIGN

Systematic review without meta-analysis.

DATA SOURCES

MEDLINE (Ovid), Pub Med, Scopus and CINAHL on 28 May 2018.

REVIEW METHODS

Peer-reviewed articles published between January 2008-May 2018 were reviewed following the Cochrane Handbook for Systematic Reviews of Interventions and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement.

RESULTS

Twelve randomized controlled trials were included. The interventions varied significantly in duration and content. E-coaching that included human and social support showed positive impact on transition outcomes. Digital health services incorporated into usual care provide efficient and accessible care.

CONCLUSION

E-coaching elements enable tailoring and personalization and present a tool for supporting and motivating chronically ill adolescents during transition of care. Future research should evaluate the effectiveness of e-coaching elements.

IMPACT

Digital services are considered a means for increasing adolescents' motivation for self-care and for increasing their accessibility to health care. The coaching elements in digital services consist of a theoretical basis, human support, interactive means and social support. Included interventions varied in terms of duration, dose, content and design. Our results may serve the development of digital health services for adolescents in transition. E-coaching can be used to engage and motivate chronically ill adolescents to improve health behaviour and self-management during transition of care.

Orofacial granulomatosis: a questionnaire study among Norwegian dental clinicians

Aims

To evaluate awareness on orofacial granulomatosis (OFG) and oral Crohn disease (oral CD) among Norwegian dental clinicians.

Methods

A precoded questionnaire (QuestBack) was sent electronically to dentists and dental hygienists treating children and adolescents in the public dental service (PDS) in Norway. Data on the clinicians’ knowledge of OFG and oral CD related to working experience were analysed by Chi square tests and bivariate logistic regression analyses.

Results

A total of 1097 clinicians were invited to participate, 778 dentists and 319 dental hygienists; 48.2% returned the completed form. Fifty-four percent of the participants had ≥ 10 year experience of clinical practice. Two-thirds (68.4%) of the dentists and all but one of the dental hygienists graduated in Norway. Approximately half of the respondents were aware of OFG (41.2%) and oral CD (57.8%). One-quarter (24.6%) reported that they most likely had seen a patient with OFG and 20.6% with oral CD. Recently graduated dentists (≤ 10 years ago) were more aware of OFG and oral CD than those who graduated > 10 years ago (p ≤ 0.001). Regarding dental hygienists, this difference was observed for OFG only (p < 0.05). Country of education did not affect the clinicians’ reported knowledge. Approximately 90% would refer a patient suspected of having OFG or oral CD either to a dental specialist or to a physician.

Conclusion

The high prevalence of clinicians observing OFG and oral CD in this study may indicate that OFG and/or oral CD are under-reported and that OFG in particular is more common than hitherto believed. The high frequency of awareness was promising for the benefit of the patients.

Pediatric to adult inflammatory bowel disease transition: the Asian experience

Many tertiary inflammatory bowel disease (IBD) centers recognize that a structured transition program is fundamental for an IBD unit. However, the path to ensuring a seamless transition for all stakeholders is often fraught with challenges. In this review, we go through current evidence, identify the requirementsof a successful transition program, and the barriers to seamless transfer. We also aim to shed light on differences in needs between the Western and Asian adolescent IBD populations. Majority of healthcare providers viewed having a structured transition program to be very important. The lack of a standard protocol led us to come up with a list of requirements ofa successful program. These include: multidisciplinary team meetings, alternating visits between the adultand pediatric clinics, proper documentation of records, and determining the ideal timing for transfer. The difficulties forthe Asian adolescent IBD population may be attributed to the reliance on parental support to make decisions regarding medicaltreatment. Lastly, there are various physician, patient and disease factors which are barriers to seamless transition. These includethe lack of proper documentation, and lack of patient self-efficacy. We also propose a standardized template for documentation of medical records for IBD patients.

Urban-associated diseases: Candidate diseases, environmental risk factors, and a path forward

BACKGROUND

Cities are home to over half the global population; that proportion is expected to rise to 70% by mid-century. The urban environment differs greatly from that in which humans evolved, with potentially important consequences for health. Rates for allergic, inflammatory and auto-immune diseases appear to rise with urbanization and be higher in the more urbanized nations of the world which has led some to suggest that cities promote the occurrence of these diseases. However, there are no syntheses outlining what urban-associated diseases are and what characteristics of cities promote their occurrence.

OBJECTIVES

To synthesize the current understanding of "urban-associated diseases", and discover the common, potentially modifiable features of cities that may be driving these associations.

METHODS

We focus on any diseases that have been associated with cities or are particularly prominent in today's urban societies. We draw on expertise across diverse health fields to examine the evidence for urban connections and drivers.

DISCUSSION

We found evidence for urban associations across allergic, auto-immune, inflammatory, lifestyle and infectious disease categories. Some conditions (e.g. obesity and diabetes) have complex relationships with cities that have been insufficiently explored. Other conditions (e.g. allergies and asthma) have more evidence demonstrating their relationship with cities and the mechanisms driving that association. Unsurprisingly, air pollution was the characteristic of cities most frequently associated with disease. Other identified urban risk factors are not as widely known: altered microbial exposure and a disconnect from environmental microbiomes, vitamin D deficiency, noise and light pollution, and a transient, over-crowded, impoverished population. However, many complexities and caveats to these relationships beg clarification; we highlight the current knowledge gaps and outline ways to fill those gaps. Identifying urban-associated diseases and their drivers will allow us to prepare for the urban-disease burden of the future and create healthy cities that mitigate that disease burden.

Incidence of Paediatric Stricturing Duodenal Crohn Disease: A 19-Year Population-based Cohort Study

OBJECTIVES

Stricturing duodenal Crohn disease (CD) is a rare but serious presentation of CD causing significant morbidity. We aim to provide the first robust incidence data and case studies on this severe presentation in children.

METHODS

A regional cohort of prospectively acquired incident cases of paediatric CD diagnosed <16 years of age in South-East Scotland was captured over a 19-year period (1999-2018). A retrospective review was conducted on the medical records of all patients together with a review of the available literature and consensus guidelines. Incidence rates for all CD and for duodenal stricturing CD were calculated.

RESULTS

A total of 247 new cases of paediatric CD were diagnosed within the study period. Median age at diagnosis was 12.5 years with 62% male predominance. Overall paediatric CD incidence rate was 5.70/100,000/year with a specific duodenal B2 phenotype disease incidence rate of 0.05/100,000/year; representing 0.8% of incident cases at diagnosis. Two incident cases of stricturing duodenal CD presented with systemic symptoms of weight loss, abdominal pain, anorexia, and lethargy, together with persistent vomiting suggestive of obstruction. Both cases partially responded to intensive medical therapy but eventually required laparoscopic gastroduodenostomy. A detailed literature search confirmed there are no paediatric incidence data, guidelines, or case reports relating to duodenal stricture as either a presentation or complication of CD.

CONCLUSIONS

Duodenal structuring disease is a rare but serious presentation of CD causing significant morbidity and not currently covered in the paediatric literature or consensus guidelines. Best practice medical and surgical management remain uncertain and require further research.

The incidence of cancer and mortality in paediatric onset inflammatory bowel disease in Denmark and Finland during a 23-year period: a population-based study

BACKGROUND

Recent studies report increased risks of both cancer and mortality in paediatric onset inflammatory bowel disease (pIBD) but the reproducibility of this is unknown.

AIM

To estimate the risk of cancer and mortality in the Danish and Finnish pIBD population in a 23-year period compared to the general population.

METHODS

The pIBD population was defined as individuals registered in the national patient registries with a diagnosis of Crohn's disease (CD), ulcerative colitis (UC) or IBD-unclassified before their 18th birthday from 1992 to 2014. This cohort was cross referenced with the national cancer and mortality registries identifying all pIBD patients who subsequently developed cancer and/ or died and followed up to the end of 2014. Risk estimates are presented as standardised incidence ratios calculated based on incidence figures from the populations.

RESULTS

Six thousand six hundred and eight-nine patients with pIBD were identified (median age at follow-up 22.3 years; median follow-up: 9.6 years [interquartile range: 4.8-16.0]). Seventy-two subsequently developed cancer and 65 died. The standardised incidence ratio of cancer in general was 2.6 (95% CI: 1.8-3.7) and 2.5 (95% CI: 1.8-3.4) in CD and UC, respectively. The standardised mortality ratios were 2.2 (95% CI: 1.4-3.4) and 3.7 (95% CI: 2.7-5.0) in CD and UC, respectively. The leading causes for mortality were cancer, suicide and infections.

CONCLUSIONS

We found an increased risk of cancer and mortality in pIBD. This underlines the importance of cancer surveillance programs and assessment of mental health in the standard of care in adolescent pIBD patients.

Presence of Mycobacterium avium Subspecies paratuberculosis Monitored Over Varying Temporal and Spatial Scales in River Catchments: Persistent Routes for Human Exposure

Mycobacterium avium subspecies paratuberculosis (Map) was monitored by quantitative PCR over a range of temporal and spatial scales in the River Tywi catchment. This study shows the persistence of Map over a 10-year period with little change, which correlates with the recognised levels of Johne’s disease in British herds over that period (aim 1). Map was quantified within the river at up to 10⁸ cell equivalents L⁻¹ and was shown to be consistently present when monitored over finer timescales (aim 4). Small wastewater treatment plants where the ingress of human-associated Map might be expected had no significant effect (aim 2). Map was found for the first time to be located in natural river foams providing another route for spread via aerosols (aim 5). This study provides evidence for the environmental continuum of Map from the grazing infected animal via rain driven runoff through field drains and streams into main rivers; with detection at a high frequency throughout the year. Should Map need to be monitored in the future, we recommend that weekly or monthly sampling from a fixed location on a river will capture an adequate representation of the flow dynamics of Map in a catchment (aim 3). The human exposure to Map during this process and its impact on human health remains unquantified.

Pediatric Chronic Inflammatory Bowel Disease in a German Statutory Health INSURANCE-Incidence Rates From 2009 to 2012

OBJECTIVE

The incidence of pediatric inflammatory bowel disease (PIBD) varies over time and geographic region. We attempted to generate incidence rates form German health insurance data.

METHODS

We used health care data for 2009-2015 provided by BARMER, a major statutory health insurance company in Germany, insuring approximately 8% of the pediatric population. We applied a Canadian case definition for PIBD based on International Classification of Diseases coding, documentation of (ileo)colonoscopy and the number of PIBD related visits, without external validation for Germany. An internal validation of the specificity of the diagnosis by checking whether the identified incident cases had also prescriptions of PIPD specific drugs was performed.

RESULTS

In 2012, 187 pediatric patients were newly diagnosed, accounting for an overall PIBD incidence of 17.41 (95% CI 15.08-20.10) per 100,000 insured children and adolescents from 0 to 17.9 years per year compared with 13.65/100,000 (95% CI 11.63-16.01) in 2009. The age-specific incidence showed a steep increase as of the age of 7 years. The PIBD prevalence in 2012 was 66.29/100,000.

CONCLUSIONS

In conclusion, the incidence of PIBD in 0 to 17.9-year-olds in Germany with health BARMER health insurance in 2012 is among the highest reported in the literature.

Changes in inflammatory bowel disease subtype during follow-up and over time in 44,302 patients

AIM

To investigate inflammatory bowel disease (IBD) register-based subtype classifications over a patient's disease course and over time.

METHODS

We examined International Classification of Diseases coding in patients with ≥2 IBD diagnostic listings in the National Patient Register 2002-2014 (n = 44,302).

RESULTS

18% of the patients changed diagnosis (17% of adults, 29% of children) during a median follow-up of 3.8 years. Of visits with diagnoses of Crohn's disease (CD) or ulcerative colitis (UC), 97% were followed by the same diagnosis, whereas 67% of visits with diagnosis IBD-unclassified (IBD-U) were followed by another IBD-U diagnosis. Patients with any diagnostic change changed mostly once (47%) or twice (31%), 39% from UC to CD, 33% from CD to UC and 30% to or from IBD-U. Using a classification algorithm based on the first two diagnoses ('incident classification'), suited for prospective cohort studies, the proportion adult patients with CD, UC, and IBD-U 2002-2014 were 29%, 62%, and 10% (43%, 45%, and 12% in children). A classification model incorporating additional information from surgeries and giving weight to the last 5 years of visits ('prevalent classification'), suited for description of a study population at end of follow-up, classified 31% of adult cases as CD, 58% as UC and 11% as IBD-U (44%, 38%, and 18% in children).

CONCLUSIONS

IBD subtype changed in 18% during follow-up. The proportion with CD increased and UC decreased from definition at start to end of follow-up. IBD-U was more common in children.

Trends and Attributable Costs of Anorectal Involvement in Pediatric Crohn's Disease

BACKGROUND

Pediatric Crohn's disease (CD) with anorectal involvement has not been well characterized. We sought to describe trends in the prevalence of pediatric CD with anorectal involvement and its influence on health-care utilization.

MATERIALS AND METHODS

Patients (<21 y of age) with an International Classification of Diseases, Ninth Revision diagnosis of CD (555.X) were identified in the Kid's Inpatient Database (2003, 2006, 2009, 2012) and stratified by anorectal involvement based on the International Classification of Diseases, Ninth Revision diagnosis and procedural codes. Patient characteristics and resource utilization (length of stay [LOS] and costs) were compared between CD patients with and without anorectal involvement using univariate and multivariable analyses. Propensity score matching was used to estimate attributable LOS and costs.

RESULTS

There were 26,029 patients with CD identified in the study interval. Of these, 1706 (6.6%) had anorectal involvement. Those with anorectal disease were younger (age 16 versus 17 y old), more likely to be male (59.4% versus 49.9%) and black or Hispanic (24.7% versus 18.2%), and were more commonly treated in urban teaching hospitals compared with rural or nonteaching hospitals (83.2% versus 70.9%) (P < 0.001 for all). The proportion of patients with anorectal involvement increased over time (odds ratio 1.03, 95% confidence interval 1.02-1.05). After propensity score matching, attributable LOS and costs were 0.5 d and approximately $1600, respectively.

CONCLUSIONS

There has been an increase in the proportion of pediatric CD hospitalizations with anorectal manifestations. This pattern of disease is associated with longer hospitalization and higher costs compared with CD alone. Further research is required to understand the underlying etiology of these observed trends.

Current global trends in the incidence of pediatric-onset inflammatory bowel disease

AIM

To perform a comprehensive review and provide an up-to-date synopsis of the incidence and trends of inflammatory bowel disease (IBD).

METHODS

We systematically searched the MEDLINE (source PubMed), EMBASE and Cochrane Library databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (period: 1985-2018) to identify studies reporting population-based data on the incidence of pediatric-onset (< 19 years at diagnosis) IBD in full manuscripts. Two authors carried out screening and data extraction. Choropleth interactive maps and temporal trends were used to illustrate the international differences and incidences of and changes in IBD and subtypes.

RESULTS

In total, one hundred forty studies reporting data from 38 countries were considered in this review. The highest annual pediatric incidences of IBD were 23/100000 person-years in Europe, 15.2/100000 in North America, and 11.4/100000 in Asia/the Middle East and Oceania. The highest annual incidences of Crohn's disease (CD) were 13.9/100000 in North America and 12.3/100000 in Europe. The highest annual incidences of ulcerative colitis (UC) were 15.0/100000 in Europe and 10.6/100000 in North America. The highest annual incidences of IBD-unclassified (IBD-U) were 3.6/100000 in Europe and 2.1/100000 in North America. In the time-trend analyses, 67% of CD, 46% of UC and 11% of IBD-U studies reported an increasing incidence (P < 0.05). The risk of IBD is increasing among first-generation of migrant populations.

CONCLUSION

Globally, the incidence of IBD varies greatly by geographical areas. The steadily increasing incidence of pediatric IBD over time indicates its emergence as a global disease, suggesting that studies should investigate the environmental risk factors among pediatric cohorts.

Development and validation of novel algorithms to identify patients with inflammatory bowel diseases in Israel: an epi-IIRN group study

Background

Before embarking on administrative research, validated case ascertainment algorithms must be developed. We aimed at developing algorithms for identifying inflammatory bowel disease (IBD) patients, date of disease onset, and IBD type (Crohn's disease [CD] vs ulcerative colitis [UC]) in the databases of the four Israeli Health Maintenance Organizations (HMOs) covering 98% of the population.

Methods

Algorithms were developed on 5,131 IBD patients and 2,072 controls, following independent chart review (60% CD and 39% UC). We reviewed 942 different combinations of clinical parameters aided by mathematical modeling. The algorithms were validated on an independent cohort of 160,000 random subjects.

Results

The combination of the following variables achieved the highest diagnostic accuracy: IBD-related codes, alone if more than five to six codes or combined with purchases of IBD-related medications (at least three purchases or ≥3 months from the first to last purchase) (sensitivity 89%, specificity 99%, positive predictive value [PPV] 92%, negative predictive value [NPV] 99%). A look-back period of 2-5 years (depending on the HMO) without IBD-related codes or medications best determined the date of diagnosis (sensitivity 83%, specificity 68%, PPV 82%, NPV 70%). IBD type was determined by the majority of CD/UC codes of the three recent contacts or the most recent when less than three contacts were recorded (sensitivity 92%, specificity 97%, PPV 97%, NPV 92%). Applying these algorithms, a total of 38,291 IBD patients were residing in Israel, corresponding to a prevalence rate of 459/100,000 (0.46%).

Conclusion

The application of the validated algorithms to Israel's administrative databases will now create a large and accurate ongoing population-based cohort of IBD patients for future administrative studies.

Low childhood high density lipoprotein cholesterol levels and subsequent risk for chronic inflammatory bowel disease

BACKGROUND AND AIMS

Several genetic and environmental risk factors have been linked to chronic inflammatory bowel disease (IBD). The incidence of IBD has significantly increased in developed countries during last decades. The aim of the present study was to examine childhood risk factors for subsequent IBD diagnosis in a longitudinal cohort study of children and adolescents.

METHODS

A Finnish study population consisting of 3551 children and adolescents originally evaluated as part of the Cardiovascular Risk in Young Finns study in 1980. At baseline, participant BMI, insulin, lipid, C-reactive protein and blood pressure levels, socioeconomic position, dietary habits, and physical activity, were evaluated. In addition, information was gathered on rural residency, severe infections, breast feeding, parental smoking and birth weight. Subsequent IBD diagnosis status was evaluated based on nationwide registries on hospitalisations and drug imbursement decisions.

RESULTS

Altogether, 49 participants (1.4%) had IBD diagnosed during the 34 years of register follow-up, of which 31 had ulcerative colitis, 12 Crohn's disease and 6 undetermined colitis. In univariate analyses, significant correlations were observed between childhood HDL-cholesterol (risk ratio (95% CI) for 1-SD change (0.58 (0.42-0.79)) and CRP concentrations (1.20 (1.01-1.43)) with IBD. The inverse association between HDL-cholesterol and IBD remained significant (0.57 (0.39-0.82)) in a multivariable model including data on age, sex and CRP. In addition, a weighted genetic z-score of 71 single nucleotide polymorphisms associated with elevated HDL-cholesterol levels was significantly lower in IBD patients, P=0.01).

CONCLUSION

Low childhood HDL-cholesterol levels are associated with subsequent IBD diagnosis. In addition, a genetic risk score associated with low HDL-cholesterol levels predict later IBD suggesting that HDL-cholesterol metabolism might have a role in the pathogenesis of IBD.

Malignancy and Mortality in Pediatric-onset Inflammatory Bowel Disease: A Systematic Review

BACKGROUND

Cancer and death are the most severe outcomes that affect patients with inflammatory bowel disease (IBD). These outcomes are even more severe if they occur at a young age but are rare, even in the general population. We conducted a systematic review to provide an overview of all reported pediatric (PIBD) patients with severe outcome.

METHODS

A literature search identified publications that reported development of cancer or fatal outcome in PIBD patients. Studies were eligible for inclusion when (1) article written in English, (2) original data, (3) individual patient information, (4) full text available, (5) study population consisting of patients diagnosed with IBD under the age of 19 years, and (6) who developed malignancy or fatality at any point later in life.

RESULTS

A total of 98 included studies comprised data of 271 PIBD patients who developed cancer and/or fatal outcome at any point later in life. Meta-analysis demonstrated an increased risk for cancer in PIBD patients (pooled standardized incidence ratio 2.23, 95% CI: 1.98-2.52). The most frequent type of non-fatal cancer was lymphoma, whereas colorectal carcinomas were the most frequently reported type of fatal cancer in PIBD patients and were particularly associated with primary sclerosing cholangitis. The majority of patients with noncancer-related fatal outcomes were diagnosed with ulcerative colitis and most often died due to infectious complications or severe disease-associated complications.

CONCLUSIONS

The data in this review confirm that PIBD associated malignancy and mortality are rare and detailed clinical characteristics are limited. Prospective and international collaborations are needed to obtain more detailed patient-specific information, which is necessary to investigate the relationship between severe outcomes in PIBD patients and the currently used therapeutic strategies. 10.1093/ibd/izx104_video1izx104_Video5754026434001.

Detailed Follow-up Study of Pediatric Orofacial Granulomatosis Patients

OBJECTIVES

Orofacial granulomatosis (OFG) is a chronic inflammatory condition affecting the orofacial area. Its connection to Crohn disease (CD) is debated. Our aim was to describe a cohort of pediatric patients with OFG in detail, study the long-term behavior of OFG, and evaluate factors predicting CD in patients with OFG.

METHODS

We invited patients diagnosed with OFG at 2 university hospitals, Finland for a follow-up appointment. Patients (n = 29) were examined by a dentist and an otorhinolaryngologist using a structural schema. Orofacial findings were also recorded using digital photographing. Patients filled in questionnaires about general health and special diets. Patients' nutrition was evaluated from food records. The findings were compared between patients with OFG only and OFG with CD.

RESULTS

Patients with CD had more findings in the orofacial area (total score for orofacial findings median 11) compared to patients with OFG only (total score median 7.5). There was no statistically significant difference in the type of lesions between these groups, except the upper lip was more often affected in patients with CD (n = 11) than in patients with OFG only (n = 0). Most of the patients had normal otorhinolaryngological findings. All patients with elevated anti-Saccharomyces cerevisiae antibody A levels had CD (n = 6) and they presented with more orofacial findings (total score) than patients with normal levels of anti-S cerevisiae antibody A (P = 0.0311).

CONCLUSIONS

Long-term follow-up of pediatric-onset patients with OFG shows good prognosis. Patients with OFG do not seem to have otorhinolaryngological comorbidity. Anti-S cerevisiae antibody A may serve as a factor to indicate the possible presence of underlying CD in patients with OFG, but further studies are requested.

The Characteristics and Long-term Outcomes of Pediatric Crohn's Disease Patients with Perianal Disease

BACKGROUND

Data on the outcomes of children with perianal Crohn's disease are limited. We aimed to assess phenotypic features at diagnosis and long-term disease-specific outcomes of this phenotype.

METHODS

The medical records of 296 pediatric onset patients with Crohn's disease, diagnosed from 2001 to 2015, were reviewed retrospectively. Baseline characteristics included age, sex, severity indices, laboratory data, endoscopic findings, and anthropometric measurements. Main outcome measures included time to first flare, hospitalization, surgery, and biological therapy.

RESULTS

Of the 296 included patients (median age 14.2 years), 70 (24%) had nonfistulizing perianal findings, whereas only 40 (13%) had fistulizing perianal disease at diagnosis. Perianal involvement was associated with female sex (P = 0.01), whereas fistulizing perianal disease resulted in a greater use of immunomodulators (P = 0.01). Time to hospitalization was shorter for both nonfistulizing and fistulizing perianal disease (hazard ratio [HR] 1.66 and 1.34, respectively, P = 0.027) and time to biological therapy (HR 2.1 and 1.7, respectively, P = 0.002). There were no differences in time to first flare or surgery. During a median follow-up of 8.5 years, additional 26 patients (10%) developed fistulizing perianal disease after a median time of 3.5 years. The presence of nonfistulizing disease at diagnosis was a significant risk factor for the development of fistulizing perianal disease (HR 3.4, P = 0.002). At the end of follow-up, complicated disease was more common in patients with any perianal involvement (P = 0.01).

CONCLUSIONS

Pediatric patients with Crohn's disease with both nonfistulizing and fistulizing disease have worse clinical outcomes. Nonfistulizing disease is a risk factor for the development of fistulizing disease over time.

Perianal Pediatric Crohn Disease Is Associated With a Distinct Phenotype and Greater Inflammatory Burden

OBJECTIVES

Data on the outcomes of children with perianal Crohn disease (pCD) are limited, although its presence is often used for justifying early use of biologics. We aimed to assess whether pCD in children is associated with more severe outcomes as found in adults.

METHODS

Data were extracted from the ImageKids database, a prospective, multicenter, longitudinal cohort study. The study enrolled 246 children at disease onset or thereafter. All patients underwent comprehensive clinical, endoscopic, and radiologic evaluation at enrollment; 98 children had repeat evaluation at 18 months.

RESULTS

Of the 234 included patients (mean age 14.2 ± 2.4 years; 131 [56%] boys), 57 (24%) had perianal findings, whereas only 21 (9%) had fistulizing perianal disease. Children with pCD had reduced weight and height z scores compared with non-pCD patients (-0.9 vs -0.35, P = 0.03 and -0.68 vs -0.23, respectively; P = 0.04), higher weighted pediatric CD activity index (32 [interquartile range 16-50] vs 20 [8-37]; P = 0.004), lower serum albumin (3.6 ± 0.7 vs 4.5 ± 0.8, P = 0.016), and higher magnetic resonance enterography global inflammatory score (P = 0.04). Children with pCD had more rectal (57% vs 38%, P = 0.04), and jejunal involvement (31% vs 11% P = 0.003) and a higher prevalence of granulomas (64% vs 23%, P = 0.0001). Magnetic resonance enterography-based damage scores did not differ between groups. Patients with skin tags/fissures only, had similar clinical, endoscopic, and radiologic characteristics as patients with no perianal findings.

CONCLUSIONS

Pediatric patients with pCD with fistulizing disease have distinct phenotypic features and a predisposition to a greater inflammatory burden.

Inflammatory bowel disease incidence in Czech children: A regional prospective study, 2000-2015

AIM

To examine the incidence and trends in pediatric inflammatory bowel diseases (IBDs) over 2000-2015 and project the incidence to 2018.

METHODS

A 16-year prospective study of IBD patients < 19 years of age was conducted in the Czech Republic (the Pilsen region). All incident IBD cases within a well-defined geographical area were retrieved from a prospectively collected computerized clinical database. Historical Czech data were used for comparison (1990-2001). Our catchment population was determined from the census data. We calculated the incidence by relating the number of newly diagnosed cases to the size of the pediatric population-at-risk in each calendar year. Age/sex, disease type, place of residence, and race/ethnicity were identified.

RESULTS

In total, 170 new IBD cases [105 Crohn’s disease (CD), 48 ulcerative colitis (UC), and 17 IBD-unclassified (IBD-U)] were identified. The median age at IBD diagnosis was 14.2 years, 59.4% were males, and 97.1% were Caucasians. A male preponderance of IBD (P = 0.026) and CD (P = 0.016) was observed. With 109209 person-years in the catchment area, the average incidence of IBD per 100000 person-years was 10.0 (6.2 for CD, 2.8 for UC, and 1.0 for IBD-U) for children aged 0 to 19 years; for those aged 0 to 15 years, the incidence rate was 7.3 (4.6 for CD, 2.0 for UC, and 0.7 for IBD-U). An increase in incidence with age was observed (P = 0.0003). Over the 16-year period, the incidence increased for IBD patients (P = 0.01) and CD in particular (P < 0.0001), whereas the incidence for UC (P = 0.09) and IBD-U (P = 0.339) remained unchanged. IBD-projected data from 2016 to 2018 were 12.1, 12.3 and 12.6 per 100000 person-years, respectively.

CONCLUSION

Pediatric-onset IBD incidence is around its highest point. The increase, which is particularly pronounced for CD, may be challenging to relate to causes of pediatric disease.

A rising incidence and poorer male outcomes characterise early onset paediatric inflammatory bowel disease

BACKGROUND

The incidence of paediatric inflammatory bowel disease diagnosed before age 10 years is reportedly increasing, but national data are limited.

AIM

To characterise the epidemiology, phenotype and clinical outcomes of children diagnosed with inflammatory bowel disease before age 10 years, and compare with data from children diagnosed aged 10-16 years.

METHODS

A review of all Irish cases of early onset inflammatory bowel disease (diagnosis <10 years, EO-IBD) presenting between January 2000 and December 2014 was undertaken and compared to a cohort of later onset paediatric inflammatory bowel disease patients (diagnosis between 10 and 16 years, LO-IBD). Diagnostic investigations, phenotype, treatments, and long-term clinical and surgical outcomes were analysed.

RESULTS

One hundred and ninety children (99 male) with EO-IBD were identified; 92 (48%) CD, 77 (41%) UC and 21 (11%) IBDU. The incidence of EO-IBD increased by 0.6 per 100 000 per year (0.8-3.2 per 100 000 per year), with a significant increase in UC by 0.06 per 100 000 per year (P=.02). Males with CD had more upper GI disease (L4a; 48% vs 21%; P=.007), more extensive disease distribution (L3±L4; 31% vs 11%; P=.05) and more severe disease activity at presentation (52% vs 31%; P=.05) than females. Fewer patients with early onset than later onset Crohn's disease had ileocolonic disease (L3; 10% vs 20%; P<.001). More relapses were observed in the first year post-diagnosis in early onset than later onset IBD (1.02 vs 0.5 mean relapses; P<.001).

CONCLUSIONS

EO-IBD is increasing in incidence. Males have more extensive and severe disease phenotypes, and younger patients have higher relapse rates than older children. Further research to explain these findings is warranted.

What is the optimal surgical strategy for complex perianal fistulous disease in pediatric Crohn's disease? A systematic review

PURPOSE

Perianal fistulous disease is present in 10-15% of children with Crohn's disease (CD) and is frequently complex and refractory to treatment, with one-third of patients having recurrent lesions. We conducted a systematic review of the literature to examine the best surgical strategy or strategies for pediatric complex perianal fistulous disease (CPFD) in CD.

METHODS

We searched CENTRAL, MEDLINE, EMBASE, and CINAHL for studies discussing at least one surgical strategy for the treatment of pediatric CPFD in CD. Reference lists of included studies were hand-searched. Two researchers screened all studies for inclusion, quality assessed each relevant study, and extracted data.

RESULTS

One non-randomized prospective and two retrospective studies met our inclusion criteria. Combined use of setons and infliximab therapy shows promise as a first-line treatment. A specific form of fistulectomy, "cone-like resection," also shows promise when combined with biologics. Endoscopic ultrasound to guide medical and surgical management is feasible in the pediatric population, though it is unclear if it improves outcomes.

CONCLUSION

There is a paucity of evidence regarding the treatment of CPFD in the pediatric population, and further research is required before recommendations can be made as to what, if any, surgical management is optimal.

Inflammatory Bowel Disease Incidence is on the Continuous Rise Among All Paediatric Patients Except for the Very Young: A Nationwide Registry-based Study on 28-Year Follow-up

BACKGROUND AND AIMS

The burden of inflammatory bowel disease [IBD] in health care is high. We conducted research on the temporal changes in the incidence of paediatric IBD [PIBD] using nationwide registry-based data in Finland.

METHODS

All PIBD cases diagnosed at less than 20 years of age during 1987-2014 [in total, 5415 patients] were retrieved from a database documenting reimbursements for drug costs. Incidence rates were calculated by dividing the number of annual new PIBD cases by the size of the paediatric population at risk during each calendar year. Temporal trends in the incidences of PIBD and its subtypes, ulcerative colitis [UC] and Crohn's disease [CD], were estimated using Poisson regression analyses.

RESULTS

The mean annual incidence of PIBD increased from 7/100000 for the years 1987-1990 to 23/100000 for the years 2011-2014. The average rate of increase was 4.1% (95% confidence interval [CI]: 3.6-4.5) per annum. In the period 2000-2014, the increase rate in the annual incidence of UC [3.8%; 95% CI: 2.7-5.0], was steeper than for CD [2.5%; 95% CI: 1.0-3.8]. The most pronounced increase occurred in UC among adolescents aged 16-19 years [4.8%; 95% CI: 2.9-6.7]. For children less than 10 years of age, the rate of change remained low. Approximately 0.17% of the birth cohort for the years 1999-2000 was diagnosed with PIBD by the age of 14 years.

CONCLUSION

The incidence of PIBD is primarily increasing among adolescents, challenging the identification of the possible environmental triggers for the disease.

Clinical Use of Infliximab Trough Levels and Antibodies to Infliximab in Pediatric Patients With Inflammatory Bowel Disease

OBJECTIVES

Optimizing infliximab (IFX) treatment in pediatric patients with inflammatory bowel disease (IBD) by using serum infliximab (S-IFX) trough levels and antibodies to IFX is recommended. There is need for studies assessing this strategy in clinical practice.

METHODS

We retrospectively identified all pediatric patients with IBD (n = 146, median age 14.8 years) treated with IFX at our tertiary referral center from 2003 to 2014. All were analyzed for IFX trough levels (S-IFX, n = 475), and IFX antibody (IFX-Ab, n = 219) titers were included. Both were analyzed using enzyme-linked immunosorbent assay. We correlated these parameters with concurrently analyzed fecal calprotectin levels and the treatment outcome.

RESULTS

If IFX had no efficacy, or a loss of response occurred, 40 of 64 (63%) had trough levels <2.0 mg/L, with negative IFX-Ab in 37 of 59 (63%). If the S-IFX was very low (<0.2 mg/L), 4 of 36 still had negative IFX-Ab. Concurrent azathioprine therapy did not relate to IFX-Ab. Fecal calprotectin was significantly lower in patients with clinical remission or ongoing therapy compared with those with subsequent loss of efficacy: medians 95 μg/g (33-308) and 670 μg/g (264-1473), P < 0.0001. The S-IFX median was substantially higher in patients with either remission or ongoing therapy, compared with those with no or loss of efficacy: 3.7 mg/L (1.8-5.4) and 1.2 mg/L (0.03-4.4, P = 0.01), respectively.

CONCLUSIONS

Measuring IFX trough levels and fecal calprotectin has a potential impact on the treatment strategies and should be included in clinical routine. Low IFX trough levels associate with increased antibodies to IFX in most, but not in all cases.

Growth Pattern in Paediatric Crohn Disease Is Related to Inflammatory Status

OBJECTIVES

The respective role of disease activity and steroid therapy in growth impairment in paediatric-onset Crohn disease (CD) is still debated. Our aim was to investigate whether the growth pattern of children with CD was correlated with the inflammatory status during the disease course, regardless the cumulative duration of steroid therapy.

METHODS

One hundred and seven patients with a diagnosis of CD <17 years, followed during ≥2 years and for whom ≥2 height measures were available during follow-up, were identified between 1998 and 2010. Height, C-reactive protein (CRP), orosomucoid, and steroid therapy duration were collected at each visit. The relationship between the evolution of growth velocity and inflammatory status during follow-up was investigated using a linear mixed model with random coefficients.

RESULTS

Median age at diagnosis was 11.7 years (Q1-Q3: 9.8-13.5). Mean height for age (H/A) z score was 0.14 ± 1.29 at diagnosis and 0.05 ± 1.23 among the 75 patients who had reached their final height at maximal follow-up (median: 4.9 years; Q1-Q3: 3.8-6.4). Growth failure (H/A z score <-2) was present in 7 (8%) patients at diagnosis and 5 (5%) at maximal follow-up. Growth velocity was negatively correlated with the evolution of CRP (P < 0.0001) and orosomucoid (P < 0.0001) during follow-up. After adjustment for the cumulative duration of steroid therapy, these 2 correlations remained significant (CRP: P = 0.0008; orosomucoid: P < 0.0001).

CONCLUSIONS

Children with CD with uncontrolled inflammatory status have a lower growth velocity. The inflammatory status should be kept as close to normal as possible in paediatric-onset patients with CD to optimize their growth pattern.

Evolution of disease phenotype in pediatric-onset Crohn's disease after more than 10 years follow up-Cohort study

BACKGROUND

Pediatric-onset Crohn's disease (CD) is a heterogeneous disorder which is subjected to progression and complications in a substantial proportion of patients.

AIMS

We aimed to assess the progression in pediatric-onset CD phenotype on long term follow up.

METHODS

Medical charts of pediatric onset CD patients with at least 10 years follow-up were analyzed retrospectively. Disease phenotype was determined at diagnosis and during follow up at different time points. Phenotype was determined according to the Paris classification. The impact of possible predictors on phenotype progression was assessed as well as the association between different therapeutic regimens during disease course and phenotype progression.

RESULTS

Progression of disease location, behavior, and perianal involvement was observed in 20%, 38% and 20% of patients, respectively, after a median follow-up of 16.4 (±4.4) years. Microscopic ileocolonic disease at diagnosis was significant predictors for progression of disease extent. Treatment with anti tumor necrosis factor-ɑ agents and number of flares per years of follow-up were associated with progression of disease extent, behavior and perianal involvement.

CONCLUSION

Disease extent, behavior and prevalence of perianal disease change significantly over time in pediatric-onset CD. In our cohort, most clinical, laboratory and endoscopic parameters do not serve as predictors for long-term disease progression.

Surgical management of inflammatory bowel disease in China: a systematic review of two decades

Background/Aims

The past decades have seen increasing incidence and prevalence of inflammatory bowel disease (IBD) in China. This article aimed to summarize the current status and characteristics of surgical management for IBD in China.

Methods

We searched PubMed, Embase, and Chinese databases from January 1, 1990 to July 1, 2014 for all relevant studies on the surgical treatment IBD in China. Eligible studies with sufficient defined variables were further reviewed for primary and secondary outcome measures.

Results

A total of 74 studies comprising 2,007 subjects with Crohn's disease (CD) and 1,085 subjects with ulcerative colitis (UC) were included. The percentage of CD patients misdiagnosed before surgery, including misdiagnosis as appendicitis or UC, was 50.8%±30.9% (578/1,268). The overall postoperative complication rate was 22.3%±13.0% (267/1,501). For studies of UC, the overall postoperative complication rate was 22.2%±27.9% (176/725). In large research centers (n>50 surgical cases), the rates of emergency operations for CD (P=0.032) and in-hospital mortalities resulting from both CD and UC were much lower than those in smaller research centers (n≤50 surgical cases) (P=0.026 and P <0.001, respectively). Regarding the changes in CD and UC surgery over time, postoperative complications (P=0.045 for CD; P=0.020 for UC) and postoperative in-hospital mortality (P=0.0002 for CD; P=0.0160 for UC) both significantly improved after the year 2010.

Conclusions

The surgical management of IBD in China has improved over time. However, the rates of misdiagnosis and postoperative complications over the past two decades have remained high. Large research centers were found to have relatively better capacity for surgical management than the smaller ones. Higher quality prospective studies are needed in China.

The incidence of Crohn's disease and ulcerative colitis since 1995 in Danish children and adolescents <17 years - based on nationwide registry data

OBJECTIVE

Worldwide the incidence of pediatric Crohn's disease (CD) and ulcerative colitis (UC) is suspected to be increasing. Based on unselected nationwide register data the aim of this study is to examine the change in incidence of CD and UC in children and adolescents in Denmark.

MATERIALS AND METHODS

All children and adolescents <17 years with a diagnosis of CD or UC registered in the Danish National Patient Registry from 1 January 1995 to 31 December 2013 were included. Using a Poisson regression model we estimated the incidence rate ratio (IRR) for the annual change in the incidence adjusted for gender and age. The cumulative incidence was described using Kaplan-Meier survival analyses.

RESULTS

The IRR for CD was 1.052 (95% CI: 1.039-1.065), and for UC the IRR was 1.022 (95% CI: 1.011-1.033), adjusted for age and gender. The incidence rate of CD increased during the study period to 10.0 (95% CI: 7.5-13.2) per 100,000 person years for girls and 9.4 (95% CI: 7.0-13.2) for boys, in 2013. Similar, the incidence of UC increased to 7.2 (95% CI: 5.0-9.9) per 100,000 person years for girls and 6.2 (95% CI: 4.3-8.7) for boys.

CONCLUSIONS

In a period of 19 years from 1995 to 2013 we found an increasing incidence for pediatric UC and CD, especially pronounced for CD.

Fecal calprotectin in the prediction of postoperative recurrence of Crohn's disease in children and adolescents

BACKGROUND

Fecal calprotectin (FC) correlates with endoscopic recurrence of Crohn's disease (CD) in adults but has not been studied among children postoperatively. We aimed to analyze whether FC relates with postoperative CD recurrence in children.

METHODS

Altogether 51 postoperative endoscopies and FC measurements from 22 patients having undergone surgery for CD at age ≤18years were included.

RESULTS

Ileocecal resection (n=15), small bowel resection (n=6), or left hemicolectomy (n=1) was performed at median age of 15.1 (interquartile range 14.4-17.6) years. Following surgery, FC decreased significantly (659 vs. 103μg/g, p=0.001). During median follow-up of 5.7 (4.2-7.7) years, either endoscopic or histological recurrence occurred in 17 patients (77%). FC >139μg/g at time of endoscopy or FC increase of 79μg/g compared to first postoperative value was suggestive of endoscopic recurrence (Rutgeerts score i2-i4), while FC >101μg/g or increase of 21μg/g indicated histological recurrence. Best accuracy for prediction of recurrence was obtained by combining FC at endoscopy and the postoperative increase of FC. The corresponding AUROC values were 0.74 (95% 0.58-0.89) for endoscopic recurrence whereas 0.81 (95% CI 0.67-0.95) for histological recurrence.

CONCLUSION

FC is a useful surrogate marker of postoperative recurrence also in pediatric CD patients.

Incidence of Pediatric Inflammatory Bowel Disease in Finland: An Environmental Study

OBJECTIVES

The aim of this study was to explore possible environmental factors behind the regional differences in the incidence of pediatric inflammatory bowel disease (IBD).

METHODS

All of the patients diagnosed with IBD who were aged 0 to 14 years in Finland between 1987 and 2003 were identified from the Social Insurance Institution database. Finland was divided into squares of 250 × 250 m, and spatial variations of incidence rates were evaluated accordingly. The role of the environmental determinants (pediatric population density, agricultural industry, chemical contaminants of tap water and proximity to the sea or paper mills) in the geographic variations of the incidence rates was evaluated.

RESULTS

During the study period, the overall incidence of pediatric IBD was 6.5 of 100,000 (95% confidence interval [CI] 6.1-6.9). The incidence in very sparsely populated areas (≤10 person-years per 250 × 250 m) was 9.2 of 100,000 (95% CI 6.3-13.1) and 5.6 of 100,000 (95% CI 4.8-6.4) in the districts with the highest population density (>800 person-years per 250 × 250 m). A nonsignificant trend toward the same direction was also seen for ulcerative colitis (trend P = 0.09). Chemical contaminant concentrations of tap water, residence near the seaside, or proximity to paper mills were not associated with the incidence of pediatric IBD.

CONCLUSIONS

Our findings suggest higher incidence rates of pediatric IBD in the districts with low compared with high density of child population, but the differences cannot be explained by variations in the environmental exposures evaluated here.

Progress in the treatment and outcome of pediatric inflammatory bowel disease patients

INTRODUCTION

The number of pediatric patients with inflammatory bowel disease (IBD), namely Crohn´s disease, ulcerative colitis and unclassified colitis, has rapidly increased in Western countries. Areas covered: This review discusses how the treatment of pediatric IBD patients has improved,with attention given to therapeutic quality and cost. The literature search covers Medline-PubMed and the Cochrane Library, with February 2016 as the last search dates. Similarly to what has been the trend in the management of adult IBD, pediatric IBD therapy has become more active than before. High use of immunosuppressants and the availability of biological therapeutic agents has helped to control the extensive and aggressive course of pediatric IBD. Full disease control at an early phase has advantages such as preserving normal child growth and development, maintaining overall good health and quality of life, as well as decreasing the psychosocial burden of the disease. Expert commentary: A key research direction is to tailor treatment modalities according to anticipated individual phenotype and disease course. Another is to reduce healthcare costs by decreasing the so-far high rate of surgery of pediatric IBD patients, and, instead, to develop a more active approach to treatment than before.

Symptoms suggestive of cow's milk allergy in infancy and pediatric inflammatory bowel disease

BACKGROUND

Risk factors of pediatric inflammatory bowel disease (PIBD) are incompletely understood. Recently, we reported that among patients with PIBD, a previous diagnosis of cow's milk allergy (CMA) and asthma occurred more frequently than among age- and sex-matched peers. We tested at a national level the hypothesis that CMA is associated with the risk of contracting PIBD.

METHODS

A nationwide birth cohort (n = 225,041), including all Finnish children born between 1999 and 2002, was followed up until July 1, 2014. We identified all children with a diagnosis of CMA, asthma, and PIBD from a national register; the data were based on certificates, including diagnostic criteria. The 95% confidence intervals (CI) for the incidence rates per 100,000 person-years were calculated assuming a Poisson distribution.

RESULTS

We identified 7,910 infants with CMA yielding a cumulative incidence of 3.5% by 2 years of age. The cumulative incidence of PIBD was 0.14% (n = 316) and that of asthma 6.6% (14,807). Children with CMA were more likely to develop PIBD than non-CMA children, incidence ratio 2.6 (95% CI 1.7-3.8). Children with a diagnosis of CMA contracted PIBD at a younger age than the respective non-CMA group (9 vs. 11 years, p < 0.05). The risk was more evident for ulcerative colitis than for Crohn's disease. The association between CMA and asthma was stronger than that between CMA and PIBD.

CONCLUSIONS

CMA in infancy is associated with subsequent development of asthma and PIBD. This suggests that in a subgroup of patients, CMA may share underlying background with PIBD, warranting thorough follow-up.

MR enterography: how to deliver added value

MR enterography (MRE) is increasingly vital to the diagnosis and follow-up of children with Crohn disease. This diagnostic test, which can provide valuable information regarding the presence of intestinal inflammation, intestinal and intra-abdominal complications, and extra-intestinal disease-related manifestations, has the potential to directly impact both medical and surgical decision-making. Consequently, it is imperative that the interpretation and reporting of these examinations provide as much clinical information as possible. This article reviews specific ways radiologists can provide added value when interpreting MRE examinations in the setting of pediatric Crohn disease by (1) establishing the true extent of disease involvement, (2) subjectively and objectively assessing response to medical treatment and (3) accurately characterizing disease-related complications.

Gut Microbiota Diversity and Human Diseases: Should We Reintroduce Key Predators in Our Ecosystem?

Most of the Human diseases affecting westernized countries are associated with dysbiosis and loss of microbial diversity in the gut microbiota. The Western way of life, with a wide use of antibiotics and other environmental triggers, may reduce the number of bacterial predators leading to a decrease in microbial diversity of the Human gut. We argue that this phenomenon is similar to the process of ecosystem impoverishment in macro ecology where human activity decreases ecological niches, the size of predator populations, and finally the biodiversity. Such pauperization is fundamental since it reverses the evolution processes, drives life backward into diminished complexity, stability, and adaptability. A simple therapeutic approach could thus be to reintroduce bacterial predators and restore a bacterial diversity of the host microbiota.

The emerging global epidemic of paediatric inflammatory bowel disease--causes and consequences

Two decades ago, paediatric inflammatory bowel disease (IBD) drew only modest interest from the international paediatric community. Since then, dramatically globally increasing incidence rates have made childhood-onset IBD a priority for most paediatric gastroenterologists. The emerging pandemia of paediatric IBD has fuelled a quest to identify the recent changes in early life exposures that could explain the increasing risk for IBD amongst today's children. Treatment of children with IBD should aim for symptom control but should also target restoration of growth and prevention of pubertal delay. The paediatric IBD phenotype seems to be characterized by more extensive disease location, and some comparative studies have suggested that childhood-onset IBD also represents a more severe phenotype than the adult-onset IBD form. In this review, we analyse recent global incidence trends of paediatric IBD. We present an update on the known and suggested risk factors that could explain the emerging global epidemia of paediatric IBD. We also draw attention to differences in treatment between children and adults with IBD. Finally, we highlight latest follow-up studies that question the proposed dynamic and aggressive nature of childhood-onset IBD.

Practice Variations in the Management of Inflammatory Bowel Disease Between Pediatric and Adult Gastroenterologists

BACKGROUND

Different practice guidelines and consensus statements for both pediatric- and adult-onset inflammatory bowel disease exist. Although variations in medical care among gastroenterologists are common, it is unknown whether there are fundamental differences between disciplines. The primary aim of the present study was to investigate differences in common practices across disciplines.

METHODS

This was a prospective, questionnaire-based survey of gastroenterologists attending gastroenterology meetings in Israel. The questionnaire covered attitudes to medical resources, diagnostic and follow-up measures as well as therapeutic approaches.

RESULTS

Overall, 120 (60%) of the approached adult gastroenterologists (AGs) and 49 (75%) pediatric gastroenterologists (PGs) completed the questionnaire. The 2 groups differed significantly in various practice areas. Pediatric patients are seen more frequently and for longer appointments. PGs tend to assess thiopurine metabolites (96% vs 47%) more often during treatment. There is a significant variation in practice between groups concerning infectious serology status and vaccinations. Methotrexate in Crohn patients is used more commonly by PGs (55% vs 22%). Long-term combination therapy of thiopurines and anti-tumor necrosis factorα agents is used more often by AGs. In patients with ulcerative colitis AGs use oral 5-aminosalicylic acid once daily (51% vs 21%) and add rectal agents from the first day of treatment (72% vs 35%) more often as compared with PGs.

CONCLUSIONS

This study demonstrates that common practices in inflammatory bowel disease patients differ significantly between adult and pediatric practitioners. These findings call for investigating the reasons for these differences and promoting strategies to diminish these gaps.

Pediatric Inflammatory Bowel Disease Among South Asians Living in British Columbia, Canada: A Distinct Clinical Phenotype

BACKGROUND

Inflammatory bowel disease (IBD) incidence is increasing among low-risk populations. This study examined a cohort of Canadian South Asian (SA) children with IBD to determine if their disease course differed from non-SA (NSA) children.

METHODS

Children of SA ethnicity diagnosed with IBD between 1997 and 2012 were identified and compared with NSA children. Data on duration and the type of presenting symptoms, disease phenotype, corticosteroid exposure (CS), exclusive enteral nutrition use, time to commencement of immunomodulator (IM), biologic therapy, and surgical intervention were extracted.

RESULTS

Overall, 160 SA children were identified and compared with 783 NSA patients (Crohn's disease [CD]: 44% versus 72%; ulcerative colitis [UC]: 43% versus 21%; IBD-Unclassified: 13% versus 7%; P < 0.001). SA patients were predominantly second-generation Canadians (92%) and had shorter symptom duration (2 versus 4 months; P < 0.001). SA CD patients were less likely to have a parent with IBD (1% versus 14%; P = 0.003). SA patients had more extensive colonic disease (CD: 55% versus 35%; P = 0.005; UC: 77% versus 58%; P = 0.006); SA CD patients presented with more complicated disease (B2/B3: 39% versus 27%; P = 0.006) and UC patients presented with more severe disease (49% versus 23%; P < 0.001). In SA CD patients, CS use was higher (70% versus 58%; P = 0.045), and IM and biologic therapy were commenced earlier (P = 0.027; P = 0.047). SA UC patients were more likely to need CS and IM (P = 0.024; P < 0.001).

CONCLUSIONS

These data describe an ethnically unique clinical phenotype, where SA children have a higher proportion of UC, shorter symptom duration, more extensive colonic disease, and are more likely to require earlier escalation of therapy.