The use of ICD codes to identify IBD subtypes and phenotypes of the Montreal classification in the Swedish National Patient Register

Increasing Rates of Bowel Resection Surgery for Stricturing Crohn's Disease in the Biologic Era

BACKGROUND

The era of biologics is associated with declining rates of surgery for Crohn's disease (CD), but the impact on surgery for stricturing CD is unknown. Our study aimed to assess nationwide trends in bowel resection surgery for obstruction in CD since the introduction of infliximab for CD in 1998.

METHODS

Using the Nationwide Inpatient Sample, we performed a nationwide analysis, identifying patients hospitalized for CD who underwent bowel resection for an indication of obstruction between 1998 and 2020 (era of biologics). Longitudinal trends in all CD-related resections and resection for obstruction were evaluated. Multivariable logistic regression identified patient and hospital characteristics associated with bowel resection surgery for obstruction.

RESULTS

Hospitalizations for all CD-related resections decreased from 12.0% of all hospitalizations in 1998 to 6.9% in 2020, while hospitalizations for CD-related resection for obstructive indication increased from 1.3% to 2.0%. The proportion of resections for obstructive indication amongst all CD-related bowel resections increased from 10.8% in 1998 to 29.1% in 2020. In the multivariable models stratified by elective admission, the increasing year was associated with risk of resection for obstructive indication regardless of urgency (nonelective model: odds ratio, 1.01; 95% CI, 1.00-1.02; elective model: odds ratio, 1.06; 95% CI, 1.04-1.08).

CONCLUSIONS

In the era of biologics, our findings demonstrate a decreasing annual rate of CD-related bowel resections but an increase in resection for obstructive indication. Our findings highlight the effect of medical therapy on surgical rates overall but suggest limited impact of current medical therapy on need of resection for stricturing disease.

Estimated Glomerular Filtration Rate and the Risk of Inflammatory Bowel Disease in Adults: A Swedish Population-Based Study

BACKGROUND

Kidney complications are common in patients with long-standing inflammatory bowel disease (IBD). Whether kidney complications, defined as low estimated glomerular filtration rate (eGFR), may predispose to later IBD is unknown.

METHODS

We analyzed the association between eGFR and the risk of being subsequently diagnosed with IBD among 1 612 160 adults from Stockholm. The exposure was categories of eGFR, with 90 to 104 mL/min/1.73 m2 as the reference. Cox regression models were used to investigate the association between eGFR, IBD, and IBD subtypes. Subgroup analyses included age strata, sex, education, and comorbidities. To explore the possibility of detection bias or reverse causation, we estimated IBD hazard ratios (HRs) after excluding cases and individuals censored during early years of follow-up.

RESULTS

During a median of 9 years of follow-up, we detected 9663 cases of IBD (3299 Crohn's disease, 5072 ulcerative colitis, 1292 IBD unclassified). Lower eGFR levels were associated with higher IBD risk (for eGFR 30-59 mL/min/1.73 m2: adjusted HR, 1.15; 95% confidence interval [CI], 1.01-1.33; and for eGFR <30 mL/min/1.73 m2: adjusted HR, 1.65; 95% CI, 1.16-2.37). This association was stronger in magnitude for Crohn's disease (for eGFR 30-59 mL/min/1.73 m2: HR, 1.33, 95% CI, 1.04-1.72; and for eGFR <30 mL/min/1.73 m2: HR, 2.25; 95% CI, 1.26-3.99). Results were consistent across strata of age, comorbidities, and attained education but suggested the association between eGFR and IBD to be stronger in women (P for interaction <.05). Results attenuated but were robust to exclusion of early IBD cases.

CONCLUSIONS

We observed an association between reduced eGFR and the risk of developing IBD, which was stronger in magnitude for Crohn's disease.

Impact of inflammatory bowel disease on the risk of acute coronary syndrome: A Swedish Nationwide Cohort Study

BACKGROUND

There are conflicting data on the risk of acute coronary syndrome (ACS) in patients with inflammatory bowel disease (IBD). Only a few previous reports include patients diagnosed during the last decade.

AIM

To assess and compare the risk of ACS between patients with IBD and the general population.

METHODS

In this cohort study, we used nationwide registers to identify patients diagnosed with IBD in Sweden 2003-2021. Every patient was matched by birth year, sex, calendar year and area of residence with up to 10 general population comparators. The primary outcome was incident ACS. We used semi-parametric Cox proportional hazard models to estimate hazard ratios (HRs).

RESULTS

We identified 76,517 patients with IBD (Crohn's disease [CD], N = 22,732; ulcerative colitis [UC], N = 42,194 and IBD-unclassified, N = 11,591) and 757,141 comparators. During a median follow-up of 8 years, 2546 patients with IBD (37.5/10,000 person-years) were diagnosed with ACS compared with 19,598 (28.0/10,000 person-years) among comparators (HR 1.30; 95% confidence interval 1.24-1.35) after adjustments for confounding factors, and approximately one extra case of ACS in 100 IBD patients followed for 10 years. The highest HRs for ACS were in patients with elderly onset IBD (≥60 years) and among patients with CD or UC with extra-intestinal manifestations. No increased HRs were observed in patients diagnosed with IBD before the age of 40.

CONCLUSION

In this contemporary cohort of patients with IBD, exposed to modern IBD care, there was an increased risk for ACS compared with individuals from the general population.

Increased Risk of Inflammatory Bowel Disease Among Patients With Nontyphoidal Salmonella Infections: A Population-Based Cohort Study

BACKGROUND

Despite the known association between microorganisms and development of inflammatory bowel disease (IBD), the role of nontyphoidal Salmonella (NTS) in IBD is not adequately addressed. We aimed at elucidating the relationship between NTS infection and the risk of IBD.

METHODS

Based on the National Health Insurance Research Database in Taiwan, this retrospective cohort study enrolled patients with NTS infection (exposure group; n = 4651) and those without NTS infection (comparator group; n = 4651) who were propensity score matched (1:1) by demographic data, medications, comorbidities, and index date. All patients were followed until IBD onset, individual mortality, or December 31, 2018. Cox proportional hazards regression analysis was performed to determine the hazard ratios and 95% confidence intervals (CIs). Sensitivity analyses were used for cross-validation.

RESULTS

The NTS group demonstrated an increased risk of IBD compared with the non-NTS groups (adjusted hazard ratio [aHR], 2.12; 95% CI, 1.62-2.78) with a higher risk of developing ulcerative colitis in the former (aHR, 2.27; 95% CI, 1.69-3.04). Nevertheless, the small sample size may contribute to lack of significant difference in Crohn's disease. Consistent findings were noted after excluding IBD diagnosed within 6 months of NTS infection (aHR, 2.28; 95% CI, 1.71-3.03), excluding those with enteritis/colitis before index date (aHR, 1.85; 95% CI, 1.28-2.68), excluding those using antibiotics for 1 month in the year before IBD onset (aHR, 1.81; 95% CI, 1.34-2.45), inverse probability of treatment weighting (aHR, 1.64; 95% CI, 1.31-2.04), and inclusion of individuals regardless of age (n = 10 431; aHR, 1.83; 95% CI, 1.53-2.19).

CONCLUSIONS

Patients with NTS were associated with an increased risk of developing IBD, especially ulcerative colitis.

Histologic Activity in Inflammatory Bowel Disease and Risk of Serious Infections: A Nationwide Study

BACKGROUND & AIMS

Individuals with inflammatory bowel disease (IBD) are at increased risk of serious infections, but whether this risk varies by histologic disease activity is unclear.

METHODS

This was a national population-based study of 55,626 individuals diagnosed with IBD in 1990 to 2016 with longitudinal data on ileocolorectal biopsy specimens followed up through 2016. Serious infections were defined as having an inpatient infectious disease diagnosis in the Swedish National Patient Register. We used Cox regression to estimate hazard ratios (HRs) for serious infections in the 12 months after documentation of histologic inflammation (vs histologic remission), adjusting for social and demographic factors, chronic comorbidities, prior IBD-related surgery, and hospitalization. We also adjusted for IBD-related medications in sensitivity analyses.

RESULTS

With histologic inflammation vs remission, there was 4.62 (95% CI, 4.46-4.78) and 2.53 (95% CI, 2.36-2.70) serious infections per 100 person-years of follow-up, respectively (adjusted HR [aHR], 1.59; 95% CI, 1.48-1.72). Histologic inflammation (vs remission) was associated with an increased risk of serious infections in ulcerative colitis (aHR, 1.68; 95% CI, 1.51-1.87) and Crohn's disease (aHR, 1.59; 95% CI, 1.40-1.80). The aHRs of sepsis and opportunistic infections were 1.66 (95% CI, 1.28-2.15) and 1.71 (95% CI, 1.22-2.41), respectively. Overall, results were consistent across age groups, sex, and education level, and remained largely unchanged after adjustment for IBD-related medications (aHR, 1.47; 95% CI, 1.34-1.61).

CONCLUSIONS

Histologic inflammation of IBD was an independent risk factor of serious infections, including sepsis, suggesting that achieving histologic remission may reduce infections in IBD. The study was approved by the Stockholm Ethics Review Board (approval numbers 2014/1287-31/4, 2018/972-32, and 2021-06209-01).

Absolute and Relative Risks of Kidney and Urological Complications in Patients With Inflammatory Bowel Disease

INTRODUCTION

The burden of kidney and urological complications in patients with inflammatory bowel disease (IBD) remains poorly characterized.

METHODS

We analyzed association between developing IBD (as a time-varying exposure) and relative risks of receiving diagnoses of chronic kidney disease (CKD), acute kidney injury (AKI), or kidney stones, and experiencing a clinically-relevant decline in estimated glomerular filtration rate (eGFR) (CKD progression; composite of kidney failure or an eGFR decline ≥30%) in 1,682,795 individuals seeking healthcare in Stockholm, Sweden, during 2006-2018. We quantified 5- and 10-year absolute risks of these complications in a parallel matched cohort of IBD cases and random controls matched (1:5) on sex, age, and eGFR.

RESULTS

During median 9 years, 10,117 participants developed IBD. Incident IBD was associated with higher risks of kidney-related complications compared with non-IBD periods: hazard ratio (HR) (95% confidence interval) was 1.24 (1.10-1.40) for receiving a CKD diagnosis and 1.11 (1.00-1.24) for CKD progression. For absolute risks, 11.8% IBD cases had a CKD event within 10-year. Of these, 6.4% received a CKD diagnosis, and 7.9% reached CKD progression. The risks of AKI (HR 1.97 [1.70-2.29]; 10-year absolute risk 3.6%) and kidney stones (HR 1.69 [1.48-1.93]; 10-year absolute risk 5.6%) were also elevated. Risks were similar in Crohn's disease and ulcerative colitis.

DISCUSSION

More than 10% of patients with IBD developed CKD within 10-year from diagnosis, with many not being identified through diagnostic codes. This, together with their elevated AKI and kidney stone risks, highlights the need of established protocols for kidney function monitoring and referral to nephrological/urological care for patients with IBD.

Long-term risk of arrhythmias in patients with inflammatory bowel disease: A population-based, sibling-controlled cohort study

BACKGROUND

Although previous evidence has suggested an increased risk of cardiovascular disease (CVD) in patients with inflammatory bowel disease (IBD), its association with arrhythmias is inconclusive. In this study, we aimed to explore the long-term risk of arrhythmias in patients with IBD.

METHODS AND FINDINGS

Through a nationwide histopathology cohort, we identified patients with biopsy-confirmed IBD in Sweden during 1969 to 2017, including Crohn's disease (CD: n = 24,954; median age at diagnosis: 38.4 years; female: 52.2%), ulcerative colitis (UC: n = 46,856; 42.1 years; 46.3%), and IBD-unclassified (IBD-U: n = 12,067; 43.8 years; 49.6%), as well as their matched reference individuals and IBD-free full siblings. Outcomes included overall and specific arrhythmias (e.g., atrial fibrillation/flutter, bradyarrhythmias, other supraventricular arrhythmias, and ventricular arrhythmias/cardiac arrest). Flexible parametric survival models estimated hazard ratios (aHR) with 95% confidence intervals (95% CIs), after adjustment for birth year, sex, county of residence, calendar year, country of birth, educational attainment, number of healthcare visits, and cardiovascular-related comorbidities. Over a median of approximately 10 years of follow-up, 1,904 (7.6%) patients with CD, 4,154 (8.9%) patients with UC, and 990 (8.2%) patients with IBD-U developed arrhythmias, compared with 6.7%, 7.5%, and 6.0% in reference individuals, respectively. Compared with reference individuals, overall arrhythmias were increased in patients with CD [54.6 versus 46.1 per 10,000 person-years; aHR = 1.15 (95% CI [1.09, 1.21], P < 0.001)], patients with UC [64.7 versus 53.3 per 10,000 person-years; aHR = 1.14 (95% CI [1.10, 1.18], P < 0.001)], and patients with IBD-U [78.1 versus 53.5 per 10,000 person-years; aHR = 1.30 (95% CI [1.20, 1.41], P < 0.001)]. The increased risk persisted 25 years after diagnosis, corresponding to 1 extra arrhythmia case per 80 CD, 58 UC, and 29 IBD-U cases over the same period. Patients with IBD also had a significantly increased risk of specific arrhythmias, except for bradyarrhythmias. Sibling comparison analyses confirmed the main findings. Study limitations include lack of clinical data to define IBD activity, not considering the potential role of IBD medications and disease activity, and the potential residual confounding from unmeasured factors for arrhythmias.

CONCLUSIONS

In this study, we observed that patients with IBD were at an increased risk of developing arrhythmias. The excess risk persisted even 25 years after IBD diagnosis. Our findings indicate a need for awareness of this excess risk among healthcare professionals.

Increasing healthcare costs in inflammatory bowel disease 2007-2020 in Sweden

BACKGROUND

Inflammatory bowel disease has been linked to increasing healthcare costs, but longitudinal data on other societal costs are scarce.

AIM

To assess costs, including productivity losses, in patients with prevalent Crohn's disease (CD) or ulcerative colitis (UC) in Sweden between 2007 and 2020.

METHODS

We linked data from national registers on all patients with CD or UC and a matched (sex, birthyear, healthcare region and education) reference population. We assessed mean costs/year in Euros, inflation-adjusted to 2020, for hospitalisations, out-patient visits, medications, sick leave and disability pension. We defined excess costs as the mean difference between patients and matched comparators.

RESULTS

Between 2007 and 2020, absolute mean annual societal costs in working-age (18-64 years) individuals decreased by 17% in CD (-24% in the comparators) and by 20% in UC (-27% in comparators), due to decreasing costs from sick leave and disability, a consequence of stricter sick leave regulations. Excess costs in 2007 were dominated by productivity losses. In 2020, excess costs were mostly healthcare costs. Absolute and excess costs increased in paediatric and elderly patients. Overall, costs for TNF inhibitors/targeted therapies increased by 274% in CD and 638% in UC, and the proportion treated increased from 5% to 26% in CD, and from 1% to 10% in UC.

CONCLUSION

Between 2007 and 2020, excess costs shifted from productivity losses to direct healthcare costs; that is, the patients' compensation for sickness absence decreased, while society increased its spending on medications. Medication costs were driven both by expanding use of TNF inhibitors and by high costs for newer targeted therapies.

Long-term Risk of Stroke in Patients With Inflammatory Bowel Disease: A Population-Based, Sibling-Controlled Cohort Study, 1969-2019

BACKGROUND AND OBJECTIVES

Patients with inflammatory bowel disease (IBD) are at an increased risk of thromboembolic events, but evidence on the long-term risk of stroke remains scarce. We aimed to explore whether patients with a biopsy-confirmed IBD had an increased long-term risk of stroke.

METHODS

This cohort included all patients with biopsy-confirmed IBD in Sweden between 1969 and 2019 and up to 5 matched reference individuals per patient who were randomly selected from the general population and IBD-free full siblings. The primary outcome was incident overall stroke; secondary outcomes were ischemic and hemorrhagic strokes. Stroke was identified from the Swedish National Patient Register by using both primary and secondary diagnoses. Adjusted hazard ratios (aHRs) for stroke were estimated by flexible parametric survival models.

RESULTS

A total of 85,006 patients with IBD (including Crohn disease [CD, n = 25,257], ulcerative colitis [UC, n = 47,354], and IBD-unclassified [IBD-U, n = 12,395]), 406,987 matched reference individuals, and 101,082 IBD-free full siblings were included in the analysis. We observed 3,720 incident strokes in patients with IBD (incidence rate [IR] 32.6 per 10,000 person-years) and 15,599 in reference individuals (IR 27.7; aHR 1.13, 95% CI 1.08-1.17). The elevated aHR remained increased even 25 years after diagnosis, corresponding to 1 additional stroke case per 93 patients with IBD until then. The excess aHR was mainly driven by ischemic stroke (aHR 1.14; 1.09-1.18) rather than hemorrhagic stroke (aHR 1.06; 0.97-1.15). The risk of ischemic stroke was significantly increased across IBD subtypes (CD [IR 23.3 vs 19.2; aHR 1.19; 1.10-1.29], UC [IR 25.7 vs 22.6; aHR 1.09; 1.04-1.16], and IBD-U [IR 30.5 vs 22.8; aHR 1.22; 1.08-1.37]). Similar results were found when patients with IBD were compared with their siblings.

DISCUSSION

Patients with IBD were at an increased risk of stroke, especially of ischemic events, irrespective of the IBD subtype. The excess risk persisted even 25 years after diagnosis. These findings highlight the need for clinical vigilance about the long-term excess risk of cerebrovascular events in patients with IBD.

Higher Fiber Intake is Associated with Reduced Risk of Related Surgery among Individuals with Inflammatory Bowel Disease in a Prospective Cohort Study

BACKGROUND

Evidence for the effects of dietary fiber on adverse outcomes in individuals with inflammatory bowel disease (IBD) is insufficient and controversial.

OBJECTIVES

We aimed to prospectively explore the association between dietary fiber intake and the risk of IBD-related surgery.

METHODS

We identified 5580 individuals with diagnosed IBD [Crohn disease (CD, n = 1908) and ulcerative colitis (UC, n = 3672)] at baseline in the UK Biobank via electronic medical records and self-reported information. Dietary fiber intake was estimated by a partial fiber score derived from a valid food frequency questionnaire. IBD-related surgery (enterotomy, perianal surgery, and others) was ascertained via inpatient data. Cox proportional model was applied to estimate hazard ratios with 95% confidence intervals (CIs) of dietary fiber in quartiles for the risk of IBD-related surgery.

RESULTS

During a mean follow-up period of 11.2 y, we documented 624 IBD-related surgery among 5580 individuals with IBD (mean age, 57.3; 52.8% females). Compared with individuals in the lowest quartiles, those with second to fourth quartiles of fiber intake were associated with 23% (95% CI: 5%, 38%, P = 0.015), 29% (95% CI: 11%, 43%, P = 0.003), and 28% (95% CI: 10%, 43%, P = 0.005) reduced risk (P-trend = 0.002) of IBD-related surgery. Similar associations were observed in CD (P-trend = 0.005) but not UC (P-trend = 0.131). We observed inverse associations of fiber in vegetables and fruits (P-trend = 0.017 and 0.007) but positive associations of fiber in bread (P-trend = 0.046) with the risk of IBD-related surgery.

CONCLUSIONS

Higher intake of fiber is associated with reduced IBD-related surgery risk in patients with IBD with CD but not UC.

Ambient Air Pollution and Risk of Enterotomy, Gastrointestinal Cancer, and All-Cause Mortality among 4,708 Individuals with Inflammatory Bowel Disease: A Prospective Cohort Study

BACKGROUND

Previous studies indicated that air pollution plausibly increases the risk of adverse outcomes in inflammatory bowel disease (IBD) via proinflammatory mechanisms. However, there is scant epidemiological data and insufficient prospective evidence assessing associations between ambient air pollution and clinical outcomes of IBD.

OBJECTIVES

We aimed to investigate the associations between ambient air pollution and clinical outcomes among individuals with IBD.

METHODS

Leveraging data from the UK Biobank, we included 4,708 individuals with IBD recruited in the period 2006-2010 in this study. A land use regression model was used to assess annual mean concentrations of ambient air pollutants nitrogen including oxides (NO x ), nitrogen dioxide (NO 2 ), and particulate matter (PM) with aerodynamic diameter ≤ 10 μ m (PM 10 ) and PM with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ). Individuals with IBD were followed up for incident clinical outcomes of enterotomy, gastrointestinal cancer, and all-cause mortality, ascertained via death registry, inpatient, primary care, and cancer registry data. Cox proportional hazard model was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the magnitude of the associations.

RESULTS

During a mean follow-up of 12.0 y, 265 enterotomy events, 124 incident gastrointestinal cancer, and 420 death events were documented among individuals with IBD. We found that each interquartile range (IQR) increase in exposure to PM 2.5 was associated with increased risk of enterotomy (HR = 1.16 ; 95% CI: 1.00, 1.34, p = 0.043 ), whereas an IQR increase in exposure to NO x (HR = 1.10 ; 95% CI: 1.01, 1.20, p = 0.016 ), NO 2 (HR = 1.16 ; 95% CI: 1.03, 1.29, p = 0.010 ), PM 10 (HR = 1.15 ; 95% CI: 1.03, 1.30, p = 0.015 ), and PM 2.5 (HR = 1.14 ; 95% CI: 1.02, 1.28, p = 0.019 ) was associated with increased risk of all-cause mortality among individuals with IBD. We did not observe any significant associations between air pollutants and gastrointestinal cancer in the primary analyses. Consistent results were observed in subgroup and sensitivity analyses.

CONCLUSIONS

Ambient pollution exposure was associated with an increased risk of enterotomy and all-cause mortality among individuals with IBD, highlighting the important role of environmental health in improving the prognosis of IBD. https://doi.org/10.1289/EHP12215.

Ustekinumab Versus Anti-tumour Necrosis Factor Alpha Agents as Second-Line Biologics in Crohn's Disease

BACKGROUND

There are little data on positioning biologics in Crohn's disease (CD).

AIMS

We aimed to assess the comparative effectiveness and safety of ustekinumab vs tumour necrosis factor-alpha (anti-TNF) agents after first-line treatment with anti-TNF in CD.

METHODS

We used Swedish nationwide registers to identify patients with CD, exposed to anti-TNF who initiated second-line biologic treatment with ustekinumab or second-line anti-TNF therapy. Nearest neighbour 1:1 propensity score matching (PSM) was used to balance the groups. The primary outcome was 3-year drug survival used as a proxy for effectiveness. Secondary outcomes included drug survival without hospital admission, CD-related surgery, antibiotics, hospitalization due to infection and exposure to corticosteroids.

RESULTS

Some 312 patients remained after PSM. Drug survival at 3 years was 35% (95% CI 26-44%) in ustekinumab compared to 36% (95% CI 28-44%) in anti-TNF-treated patients (p = 0.72). No statistically significant differences were observed between the groups in 3-year survival without hospital admission (72% vs 70%, p = 0.99), surgery (87% vs 92%, p = 0.17), hospital admission due to infection (92% vs 92%, p = 0.31) or prescription of antibiotics (49% vs 50%, p = 0.56). The proportion of patients continuing second-line biologic therapy did not differ by reason for ending first-line anti-TNF (lack of response vs intolerance) or by type of first-line anti-TNF (adalimumab vs infliximab).

CONCLUSION

Based on data from Swedish routine care, no clinically relevant differences in effectiveness or safety of second-line ustekinumab vs anti-TNF treatment were observed in patients with CD with prior exposure to anti-TNF.

Long-term risk of inflammatory bowel disease after endoscopic biopsy with normal mucosa: A population-based, sibling-controlled cohort study in Sweden

BACKGROUND

Although evidence suggests a persistently decreased risk of colorectal cancer for up to 10 years among individuals with a negative endoscopic biopsy result (i.e., normal mucosa), concerns have been raised about other long-term health outcomes among these individuals. In this study, we aimed to explore the long-term risk of inflammatory bowel disease (IBD) after an endoscopic biopsy with normal mucosa.

METHODS AND FINDINGS

In the present nationwide cohort study, we identified all individuals in Sweden with a lower or upper gastrointestinal (GI) biopsy of normal mucosa during 1965 to 2016 (exposed, n = 200,495 and 257,192 for lower and upper GI biopsy, respectively), their individually matched population references (n = 989,484 and 1,268,897), and unexposed full siblings (n = 221,179 and 274,529). Flexible parametric model estimated hazard ratio (HR) as an estimate of the association between a GI biopsy of normal mucosa and IBD as well as cumulative incidence of IBD, with 95% confidence interval (CI). The first 6 months after GI biopsy were excluded to avoid detection bias, surveillance bias, or reverse causation. During a median follow-up time of approximately 10 years, 4,853 individuals with a lower GI biopsy of normal mucosa developed IBD (2.4%) compared to 0.4% of the population references. This corresponded to an incidence rate (IR) of 20.39 and 3.39 per 10,000 person-years in the respective groups or 1 extra estimated IBD case among 37 exposed individuals during the 30 years after normal GI biopsy. The exposed individuals had a persistently higher risk of overall IBD (average HR = 5.56; 95% CI: 5.28 to 5.85), ulcerative colitis (UC, average HR = 5.20; 95% CI: 4.85 to 5.59) and Crohn's disease (CD, average HR = 6.99; 95% CI: 6.38 to 7.66) than their matched population references. In the sibling comparison, average HRs were 3.27 (3.05 to 3.51) for overall IBD, 3.27 (2.96 to 3.61) for UC, and 3.77 (3.34 to 4.26) for CD. For individuals with an upper GI biopsy of normal mucosa, the average HR of CD was 2.93 (2.68 to 3.21) and 2.39 (2.10 to 2.73), compared with population references and unexposed full siblings, respectively. The increased risk of IBD persisted at least 30 years after cohort entry. Study limitations include lack of data on indications for biopsy and potential residual confounding from unmeasured risk or protective factors for IBD.

CONCLUSIONS

Endoscopic biopsy with normal mucosa was associated with an elevated IBD incidence for at least 30 years. This may suggest a substantial symptomatic period of IBD and incomplete diagnostic examinations in patients with early IBD.

Histological remission in inflammatory bowel disease and risk of adverse pregnancy outcomes: A nationwide study

BACKGROUND

Inflammatory bowel disease (IBD) has been linked to adverse pregnancy outcomes, but it is unclear how risks vary by histological activity.

METHODS

We performed a nationwide study of Swedish women diagnosed with IBD 1990-2016 and a pre-pregnancy (<12 months) colorectal biopsy with vs. without histological inflammation (1223 and 630 births, respectively). We also examined pregnancy outcomes in 2007-2016 of women with vs. without clinically active IBD (i.e., IBD-related hospitalization, surgery, or medication escalation) <12 months before pregnancy (2110 and 4993 births, respectively). Accounting for smoking, socio-demographics, and comorbidities, generalized linear models estimated adjusted risk ratios (aRRs) for preterm birth (<37 gestational weeks) and small-for-gestational age (SGA, <10th percentile weight for age).

FINDINGS

Of infants to women with vs. without histological inflammation, 9.6% (n = 117) and 6.5% (n = 41) were preterm, respectively (aRR = 1.46; 95%CI = 1.03-2.06). Histological inflammation was associated with preterm birth in ulcerative colitis (UC) (aRR = 1.64; 95%CI = 1.07-2.52), especially extensive colitis (aRR = 2.37; 95%CI = 1.12-5.02), but not in Crohn's disease (aRR = 0.99; 95%CI = 0.55-1.78). Of infants to women with vs. without histological inflammation, 116 (9.6%) and 56 (8.9%), respectively, were SGA (aRR = 1.09; 95%CI = 0.81-1.47). Clinically active disease before pregnancy was linked to preterm birth (aRR = 1.42; 95%CI = 1.20-1.69), but not to SGA birth (aRR = 1.13; 95%CI = 0.96-1.32). Finally, of infants to women without clinical activity, histological inflammation was not significantly associated with preterm birth (aRR = 1.20; 95%CI = 0.68-2.13).

INTERPRETATION

Histological and clinical activity in IBD, especially in UC, were risk factors for preterm birth. Further research is needed to determine the importance of pre-pregnancy histological activity in women without clinically-defined disease activity.

FUNDING

The Swedish Society of Medicine.

Colorectal Cancer in Childhood-onset Inflammatory Bowel Disease: A Scandinavian Register-based Cohort Study, 1969-2017

Through linkage of data from Danish and Swedish national registers we identified 6937 patients with childhood (&lt;18 years)-onset Crohn disease (CD), 8514 patients with childhood-onset ulcerative colitis (UC) and up to 10 times as many matched (sex, age, residence) reference individuals 1969-2017. During follow-up to a median age of 27 (interquartile range = 21-39) years, 25 (0.36%) CD patients were diagnosed with colorectal cancer (CRC) versus 43 (0.06%) reference individuals, and 113 (1.33%) UC patients versus 45 (0.05%) reference individuals. The hazard ratio (HR) for CRC was 6.46 (95% CI = 3.95-10.6) in CD and 32.5 (95% CI = 23.0-45.9) in UC and increased with decreasing age at diagnosis. The HR for CRC was increased for all phenotypes, but with higher estimates for colonic CD [17.9 (95% CI = 7.43-43.3)] and UC with extensive/pancolitis [36.3 (95% CI = 22.8-57.8)]. The relative risk of CRC was increased for all phenotypes of childhood-onset inflammatory bowel disease. Age at onset may be considered an additional risk factor when implementing surveillance programs.

Colorectal cancer in elderly-onset inflammatory bowel disease: a 1969-2017 Scandinavian register-based cohort study

BACKGROUND

Previous research indicates that the increased relative risk of colorectal cancer (CRC) in inflammatory bowel disease (IBD) is limited to young-onset IBD.

AIM

To estimate risks of incident CRC and death from CRC in elderly-onset IBD METHODS: Patients diagnosed with IBD at age ≥ 60 years between 1969 and 2017 were identified using Danish and Swedish National Patient Registers and histopathology data. We linked data to Cancer and Causes of Death Registers and used Cox regression to estimate hazard ratios (HRs) for CRC diagnosis and death compared to matched (by sex, age, and region) IBD-free individuals.

RESULTS

Among 7869 patients with Crohn's disease followed for 54,220 person-years, and 21,224 patients with ulcerative colitis (UC) followed for 142,635 person-years, 2.10% and 1.90% were diagnosed with CRC, compared to 2.26% and 2.34% of reference individuals (median follow-up 6 and 7 years). The incidence of CRC was elevated during the first year after IBD diagnosis: 4.36 (95% CI = 3.33-5.71) in Crohn's disease and 2.48 (95% CI = 2.03-3.02) in UC, but decreased after the first year of follow-up: 0.69 (95% CI = 0.56-0.86) and 0.78 (95% CI = 0.69-0.88). Once diagnosed with CRC, the risk of CRC death was similar for IBD patients and the general population.

CONCLUSION

The excess risk of CRC in elderly-onset IBD was probably due to bias and not observed beyond the first year. From 2010, the HR for CRC diagnosis more than 1 year after initial IBD diagnosis was lower than in the largely unscreened reference population, supporting the benefit of endoscopic screening and surveillance in patients with IBD.

Associations between inflammatory bowel disease, social isolation, and mortality: evidence from a longitudinal cohort study

Background

Social well-being of patients with inflammatory bowel disease (IBD) is garnering increased attention; however, the impact of social isolation remained poorly understood.

Objectives

We investigated the joint association of social isolation and IBD with premature deaths to articulate the profound impact of social isolation in IBD prognosis.

Design

Longitudinal cohort study.

Methods

We leveraged data of 486,014 participants from UK Biobank (including 5791 with IBD), the mean follow-up was 11.84 years. Diagnoses of IBD and its subtypes of Crohn's disease (CD) and ulcerative colitis were confirmed with the combination of self-reporting, primary care, and hospital admission data. Social isolation was measured by the frequency of meeting family/friends, leisure and social activity, and communal/solitary living. Mortality was ascertained through data linkage with national death registries. Multivariable Cox regression models were conducted to estimate hazard ratio (HR) and 95% confidence interval (CI).

Results

Comparing non-isolated non-IBD population, the HRs of mortality in patients with IBD who were socially isolated or not were 2.06 (95% CI: 1.69, 2.51) and 1.33 (95% CI: 1.21, 1.45), respectively. The excess risk of death was observed in socially isolated patients with IBD (HR = 1.69, 95% CI: 1.36, 2.11), particularly among patients with CD (HR = 2.06, 95% CI: 1.48, 2.87) than their non-isolated counterparts. Data from subgroup and sensitivity analyses were consistent with those from the primary analysis.

Conclusion

Socially isolated patients with IBD especially CD increases the risk of premature death. Preventing social isolation might be a promising approach to improve IBD prognosis.

Plain language summary

Social isolation as a risk factor to excess mortality in patients with IBD: findings from a longitudinal cohort study Social isolation is prevalent in individuals with inflammatory bowel disease (IBD); however, its potential health impact on IBD prognosis has not been quantitatively well examined. In this study, we explored the association between social isolation and subsequent death, with the focus on patients with IBD.We leveraged data of 486,014 participants (including 5791 with IBD) from UK Biobank. We measured social isolation by the frequency of meeting family/friends, leisure and social activity, and communal/solitary living. We ascertained patients with IBD and mortality by self-report data and data linkage with primary care, hospital, and national death registry. Participants were followed up for a mean of 11.84 years.Comparing non-isolated non-IBD population, we found that patients with IBD who were deemed as socially isolated or not were associated with a 2.06-fold (1.69-2.51) and 1.33-fold (1.21-1.45) risk of death, respectively. Furthermore, we revealed that socially isolated patients with IBD and subtype Crohn's disease (CD) had 69% (36-111%) and 106% (48-187%) increased risk of premature death compared with their non-isolated counterparts, respectively.Social isolation merits attention in IBD care and management. Patients with IBD, especially CD, are more likely to be affected when socially isolated. Targeted social support strategies ought to be devised to improve IBD prognosis.

Association of Celiac Disease and Inflammatory Bowel Disease: A Nationwide Register-Based Cohort Study

INTRODUCTION

To determine the risk of inflammatory bowel disease (IBD) in patients with celiac disease (CeD) (and vice versa ) compared with general-population comparators.

METHODS

Using Swedish histopathology and healthcare register data, we identified 48,551 patients with CeD and 83,529 with IBD diagnosed in 1969-2016. Each patient was compared with age- and sex-matched general-population comparators (CeD: n = 240,136; IBD: n = 408,195). Cox regression estimated hazard ratios (HRs) for IBD in patients with CeD and vice versa . Our main analyses were limited to events beyond the first year of follow-up to reduce potential surveillance bias.

RESULTS

During follow-up, 784 (1.6%) patients with CeD were diagnosed with IBD compared with 1,015 (0.4%) matched comparators. In patients with CeD, the HR for IBD was 3.91 (95% confidence interval [CI] 3.56-4.31), with largely similar HRs for Crohn's disease (4.36; 3.72-5.11) and ulcerative colitis (3.40; 3.00-3.85). During follow-up, 644 (0.8%) patients with IBD and 597 (0.1%) comparators were diagnosed with CeD. The HR for CeD in patients with IBD was 5.49 (95% CI 4.90-6.16), with the highest risk estimates seen in ulcerative colitis (HR = 6.99; 6.07-8.05), and the HR for Crohn's disease was 3.31 (2.69-4.06). In patients with CeD and IBD, the diagnostic interval was usually &lt;1 year; however, HRs of 3-4 were seen even after 10 years of follow-up. During 20 years of follow-up, 2.5% of patients with CeD developed incident IBD, and 1.3% of patients with IBD developed CeD.

DISCUSSION

The bidirectional association between CeD diagnosis and IBD warrants attention in the initial assessment and follow-up of these conditions. Their co-occurrence, independent of temporal sequence, suggests shared etiology.

Probability of Stoma in Incident Patients With Crohn's Disease in Sweden 2003-2019: A Population-based Study

BACKGROUND

Surgery rates in patients with Crohn's disease have decreased during the last few decades, and use of antitumor necrosis agents (anti-TNF) has increased. Whether these changes correlate with a decreased probability of stoma is unknown. The objective of this study was to investigate the incidence of stoma in patients with Crohn's disease over time.

METHODS

Through linkage of national registers, we identified patients who were diagnosed with Crohn's disease in 2003-2014 and were followed through 2019. We compared formation and closure of stomas over the calendar periods of diagnosis (2003-2006, 2007-2010, and 2011-2014).

RESULTS

In a nationwide cohort of 18,815 incident patients with a minimum 5 years of follow-up, 652 (3.5%) underwent formation of a stoma. This was mostly performed in conjunction with ileocolic resection (39%). The 5-year cumulative incidence of stoma formation was 2.5%, with no differences between calendar periods (P = .61). Less than half of the patients (44%) had their stoma reversed. Stomas were more common in elderly-onset compared with pediatric-onset disease: 5-year cumulative incidence 3.6% vs 1.3%. Ileostomies were most common (64%), and 24.5% of the patients who underwent stoma surgery had perianal disease at end of follow-up. Within 5 years of diagnosis, 0.8% of the incident patients had a permanent stoma, and 0.05% had undergone proctectomy. The time from diagnosis to start of anti-TNF treatment decreased over calendar periods (P < .001).

CONCLUSIONS

Despite increasing use of anti-TNF and a low rate of proctectomy, the cumulative incidence of stoma formation within 5 years of Crohn's disease diagnosis has not decreased from 2003 to 2019.

Age determines the risk of familial inflammatory bowel disease-A nationwide study

BACKGROUND AND AIMS

To estimate familial aggregation of inflammatory bowel disease (IBD), we performed a nationwide, case-control study and examined the odds for patients with IBD (vs controls) to have a first-degree relative (FDR) with IBD, by age of diagnosis, type of family history and IBD subtype. To assess the incidence of future IBD in relatives of incident IBD patients, we performed a cohort study.

METHODS

Individuals diagnosed with IBD (N = 50,667) between 2003 and 2017 with at least one FDR were identified from Swedish national registers and compared to general population controls (N = 506,720) with at least one FDR. We used logistic regression to calculate adjusted odds ratios (ORs) and Cox regression to estimate hazard ratios (HRs).

RESULTS

Compared to controls, IBD cases more often had a mother (3.0% vs 0.9%, OR = 3.5; 95% CI: 3.3-3.7), father (2.9% vs 0.8%, OR = 3.5; 95% CI: 3.3-3.7), full sibling (5.3% vs 1.5%, OR = 3.6; 95% CI: 3.4-3.8) and child (2.4% vs 0.9%, OR = 2.6; 95% CI: 2.4-2.8) with IBD. The strength of association increased with the number of affected FDRs and was modified by subtype of IBD and age of diagnosis. Highest ORs were observed for paediatric IBD among paediatric-onset Crohn's disease (OR = 10.6; 95% CI: 8.2-13.5) and paediatric-onset ulcerative colitis (OR = 8.4; 95% CI: 6.4-10.9) cases. The 10-year cumulative incidence of IBD was 1.7% in full-siblings of incident IBD patients vs 0.4% among full-siblings of reference individuals.

CONCLUSION

The variations in the strength of familial IBD and future risk of IBD in FDRs support differences in genetic predisposition and call for targeted approaches in potential screening programmes.

A Systematic Review of Crohn's Disease Case Definitions in Administrative or Claims Databases

BACKGROUND

We sought to review Crohn's disease (CD) case definitions that use diagnosis, procedure, and medication claims.

METHODS

We searched PubMed and Embase from inception through January 31, 2022, using terms related to CD, inflammatory bowel disease, administrative claims, or validity. Each article was scrutinized by 2 authors independently screening and abstracting data. Collected data included participant characteristics, case definition characteristics, and case definition validity. When diagnostic accuracy was provided for multiple case definitions, we extracted the case definition selected by the authors. All diagnostic accuracy characteristics were captured.

RESULTS

We identified 30 studies that evaluated a case definition using claims data to identify CD patients. The most common case definition included counts of diagnosis codes (57%) followed by a combination of diagnosis codes and medications (20%). All but 1 study validated the case definition with a medical chart review. In 2 studies, the patient's primary care provider completed a survey to confirm disease status. The positive predictive value of the case definitions ranged from 18% (≥1 code at a single U.S. health plan) to 100% (≥1 code plus a relevant prescription at a U.S. hospital). More complex case definitions (eg, ≥1 code + prescription or ≥2 codes) had lower variability in positive predictive value (≥80%) and specificity (≥85%) than the ≥1 code requirement.

CONCLUSIONS

Health services researchers should validate case definitions in their research cohorts. When such validation cannot be performed, we recommend using a more complex case definition. Studies without a validated CD case definition should use sensitivity analyses to confirm the robustness of their results.

Ustekinumab treatment in ulcerative colitis: Real-world data from the Swedish inflammatory bowel disease quality register

BACKGROUND

Real-world data on clinical outcomes of ustekinumab in ulcerative colitis are lacking.

OBJECTIVE

To assess short- and long-term clinical outcomes of ustekinumab in ulcerative colitis.

METHODS

Adult ulcerative colitis patients without previous colectomy starting ustekinumab treatment up until 11 December 2020 were identified through the Swedish Inflammatory Bowel Disease Register (SWIBREG). Prospectively recorded data were extracted from the SWIBREG. The primary outcome was persistence to ustekinumab 16 weeks after treatment initiation. Secondary outcomes included drug persistence beyond week 16, clinical remission (defined as a patient-reported Mayo rectal bleeding subscore = 0 and stool frequency subscore ≤1), biochemical remission (defined as faecal-calprotectin <250 μg/g) and changes in health-related quality of life (HRQoL), as measured by the Short Health Scale (SHS). Logistic regression was used to identify potential predictors of ustekinumab persistence at 16 weeks.

RESULTS

Of the 133 patients with ulcerative colitis, only three were naïve to biologics and tofacitinib. The persistence rates of ustekinumab were 115/133 (86%) at 16 weeks and 89/133 (67%) at last follow-up, that is, after a median follow-up of 32 (interquartile range 19-56) weeks. The clinical remission rates were 17% at 16 weeks and 32% at the last follow-up. The corresponding rates for biochemical remission were 14% and 23%. The median faecal-calprotectin concentration decreased from 740 μg/g at baseline to 98 μg/g at the last follow-up (p < 0.01, n = 37). Improvement was seen in each dimension of the SHS between baseline and last follow-up (p < 0.01 for each dimension, n = 46). Male sex was associated with ustekinumab persistence at 16 weeks (adjusted odds ratio = 4.00, 95% confidence interval: 1.35-11.83).

CONCLUSION

In this nationwide real-world cohort of ulcerative colitis patients with prior drug failures, including other biologics and tofacitinib, ustekinumab was associated with high drug persistence rates and improvements in clinical, biochemical and HRQoL measures.

No Benefit of Continuing 5-Aminosalicylates in Patients with Crohn's Disease Treated with Anti-metabolite Therapy

BACKGROUND AND AIMS

5-aminosalicylates (5-ASA) are frequently used in the management of Crohn's disease (CD). We used a de-identified administrative claims database to compare patterns and outcomes of continuing versus stopping 5-ASA in patients with CD who escalated to anti-metabolite monotherapy.

METHODS

Patients with CD on 5-ASA who were new users of anti-metabolite monotherapy and followed for at least 12 months from OptumLabs® Data Warehouse. Three patterns of 5-ASA use were identified: stopped 5-ASA, short-term 5-ASA (use for < 6 months after starting anti-metabolites), or persistent 5-ASA (use for > 6 months after starting anti-metabolites). Outcomes (need for corticosteroids, risk of CD-related hospitalization and/or surgery, treatment escalation to biologic therapy) were compared using Cox proportional hazard analysis adjusting for key covariates, with a 12-month immortal time period.

RESULTS

Of 3036 patients with CD who were new-users of anti-metabolite monotherapy, 667 (21.9%), 626 (20.6%), and 1743 (57.4%) stopped 5-ASA, used 5-ASA transiently or persistently, respectively. Compared to patients who stopped 5-ASA after starting anti-metabolites, persistent 5-ASA use was associated with a higher risk of corticosteroid use (HR, 1.24 [1.08-1.42]), without an increase in risk of CD-related hospitalization (HR, 1.21 [0.98-1.49]), CD-related surgery (HR, 1.28 [0.90-1.80]) or treatment escalation (HR, 0.85 [0.62-1.20]). Sensitivity analyses using a 3-month window after initiation of anti-metabolites to classify patients as continuing vs. stopping 5-ASA showed similar results. Residual confounding by disease severity could not be excluded.

CONCLUSION

5-ASAs are frequently continued long-term even after escalation to anti-metabolite therapy in patients with CD but offer no clinical benefit over stopping 5-ASA.

Outcomes during delivery hospitalisations with inflammatory bowel disease

OBJECTIVE

To characterise inflammatory bowel disease (IBD) trends and associated risk during delivery hospitalisations.

DESIGN

Cross-sectional.

SETTING

US delivery hospitalisations.

POPULATION

Delivery hospitalisations in the 2000-2018 National Inpatient Sample.

METHODS

This study analysed a nationally representative hospital discharge database based on the presence of IBD. Temporal trends in IBD were analysed using joinpoint regression to estimate the average annual percent change (AAPC). IBD severity was characterised by the presence of diagnoses such as penetrating and stricturing disease and history of bowel resection. Risks for adverse outcomes were analysed based on presence of IBD. Poisson regression models were performed with unadjusted and adjusted risk ratios (aRR) as measures of effect.

MAIN OUTCOME MEASURE

Prevalence of IBD and associated adverse outcomes.

RESULTS

Of 73 109 790 delivery hospitalisations, 89 965 had a diagnosis of IBD. IBD rose from 0.06% in 2000 to 0.21% in 2018 (AAPC 7.3%, 95% CI 6.7-7.9%). Among deliveries with IBD, IBD severity diagnoses increased from 4.1% to 8.1% from 2000 to 2018. In adjusted analysis, IBD was associated with increased risk for preterm delivery (aRR 1.50, 95% CI 1.47-1.53), severe maternal morbidity (aRR 1.93, 95% CI 1.83-2.04), venous thrombo-embolism (aRR 2.76, 95% CI 2.39-3.18) and surgical injury during caesarean delivery hospitalisation (aRR 5.03, 95% CI 4.76-5.31). In the presence of a severe IBD diagnosis, risk was further increased for all adverse outcomes.

CONCLUSION

IBD is increasing in the obstetric population and is associated with adverse outcomes. Risk is increased in the presence of a severe IBD diagnosis.

TWEETABLE ABSTRACT

Deliveries among women with inflammatory bowel disease are increasing. Disease severity is associated with adverse outcomes.

Identification of Childhood-Onset Inflammatory Bowel Disease in Swedish Healthcare Registers: A Validation Study

Purpose

The Swedish National Patient Register (NPR) is often used in observational studies of childhood-onset inflammatory bowel disease (IBD) (<18 years of age) and its subtypes, but the validity of previously used register-based algorithms for capturing childhood-onset IBD has never been examined.

Methods

We identified a random sample of 233 individuals with at least two first ever diagnostic listings of IBD in the NPR between 2002 and 2014. We calculated the test characteristics for different register-based definitions of IBD and its subtypes using the Copenhagen criteria and the revised Porto criteria as gold standard, both based on medical chart review. We made assumptions of the occurrence of undiagnosed IBD in the general child population based on available literature.

Results

Out of 233 individuals with at least two diagnostic listings of IBD, 216 had true IBD, resulting in a positive predictive value (PPV) = 93% (95% confidence interval (CI) 89–96), sensitivity = 88% (95% CI 83–92), specificity = 100% (95% CI 100–100), and negative predictive value (NPV) = 100% (95% CI 100–100). The PPV for the NPR-based definitions of IBD subtypes at time of first IBD diagnosis and at end of follow-up were 78% (95% CI 69–86) and 88% (95% CI 80–94), respectively, for Crohn’s disease and 74% (95% CI 63–83) and 71% (95% CI 60–80), respectively, for ulcerative colitis.

Conclusion

The validity of register-based definitions of childhood-onset IBD in the Swedish NPR is high and can be used to identify patients in observational research.

Association Between Inflammatory Bowel Disease and Spondyloarthritis: Findings from a Nationwide Study in Sweden

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] has been associated with spondyloarthritis [SpA], but population-based estimates are scarce. Here we compare the occurrence of SpA before and after a diagnosis of IBD with the general population, overall and by IBD subtype and age.

METHODS

We used a nationwide register-based cohort study of 39 203 patients diagnosed with IBD during 2006-2016, identified from Swedish registers and gastrointestinal biopsy data, and 390 490 matched reference individuals from the general population. Conditional logistic regression models were used to estimate odds ratios [ORs] for a prior [prevalent] SpA diagnosis and conditional Cox regression to calculate hazard ratios [HRs] for a subsequent [incident] SpA diagnosis in IBD patients.

RESULTS

IBD patients were more likely to have prevalent SpA at IBD diagnosis [2.5%] compared with reference individuals [0.7%] with an OR of 3.48 [95% CI: 3.23, 3.75]. They also more often received an incident diagnosis of SpA; during 23 341 934 person-years of follow-up in IBD patients, there were 1030 SpA events [5.0/1000 person-years] compared with 1524 SpA events in the reference group [0.72/1000 person-years], corresponding to an HR of 7.15 [95% CI: 6.60, 7.75]. In subgroup analyses, associations were most pronounced among patients with Crohn's disease ([OR = 5.20; 95% CI: 4.59, 5.89], and [HR = 10.55; 95% CI: 9.16, 12.15]) and paediatric onset IBD ([OR = 3.63; 95% CI: 2.35, 5.59] and [HR = 15.03; 95% CI: 11.01, 20.53]).

CONCLUSIONS

IBD patients more frequently experience SpA both before and after the diagnosis of IBD compared with the general population, supporting evidence of a shared pathophysiology. The variation in SpA comorbidity, across IBD subtypes and age groups, calls for targeted approaches to facilitate timely diagnosis and intervention.

Tumour necrosis factor inhibitors in Crohn's disease and the effect on surgery rates

AIM

Surgery is an important therapeutic option for Crohn's disease. The need for first bowel surgery seems to have decreased with the introduction of tumour necrosis factor inhibitors (TNFi; adalimumab or infliximab). However, the impact of TNFi on the need for intestinal surgery in Crohn's disease patients irrespective of prior bowel resection is not known. The aim of this work is to compare the incidence of bowel surgery in Crohn's disease patients who remain on TNFi treatment versus those who discontinue it.

METHOD

We performed a nationwide register-based observational cohort study in Sweden of all incident and prevalent cases of Crohn's disease who started first-line TNFi treatment between 2006 and 2017. Patients were categorized according to TNFi treatment retention less than or beyond 1 year. The study cohort was evaluated with regard to incidence of bowel surgery from 12 months after the first ever TNFi dispensation.

RESULTS

We identified 5003 Crohn's disease patients with TNFi exposure: 3748 surgery naïve and 1255 with bowel surgery prior to TNFi initiation. Of these patients, 7% (n = 353) were subjected to abdominal surgery during the first 12 months after the start of TNFi and were subsequently excluded from the main analysis. A majority (62%) continued TNFi for 12 months or more. Treatment with TNFi for less than 12 months was associated with a significantly higher surgery rate compared with patients who continued on TNFi for 12 months or more (hazard ratio 1.26, 95% CI 1.09-1.46; p = 0.002).

CONCLUSION

Treatment with TNFi for less than 12 months was associated with a higher risk of bowel surgery in Crohn's disease patients compared with those who continued TNFi for 12 months or more.

Mortality in patients with Crohn's disease in Örebro, Sweden 1963-2010

BACKGROUND

Some studies have suggested a reduced life expectancy in patients with Crohn's disease (CD) compared with the general population. The evidence, however, is inconsistent.

AIMS

Prompted by such studies, we studied survival of CD patients in Örebro county, Sweden.

METHODS

From the medical records, we identified all patients diagnosed with CD during 1963-2010 with follow-up to the end of 2011. We estimated: overall survival, net and crude probabilities of dying from CD, relative survival ratio (RSR), and excess mortality rate ratios (EMRR) at 10-year follow-up.

RESULTS

The study included 492 patients (226 males, 266 females). Median age at diagnosis was 32 years (3-87). Net and crude probabilities of dying from CD increased with increasing age and were higher for women. Net survival of patients aged ≥60 at diagnosis was worse for patients diagnosed during 1963-1985 (54%) than for patients diagnosed during 1986-1999 (88%) or 2000-2010 (93%). Overall, CD patients' survival was comparable to that in the general population [RSR = 0.98; 95% CI: (0.95-1.00)]. However, significantly lower than expected survival was suggested for female patients aged ≥60 diagnosed during the 1963-1985 [RSR = 0.47 (0.07-0.95)]. The adjusted model suggested that, compared with diagnostic period 1963-1985, disease-related excess mortality declined during 2000-2010 [EMRR = 0.36 (0.07-1.96)]; and age ≥60 at diagnosis [EMRR = 7.99 (1.64-39.00), reference: age 40-59], female sex [EMRR = 4.16 (0.62-27.85)], colonic localization [EMRR = 4.20 (0.81-21.88), reference: ileal localization], and stricturing/penetrating disease [EMRR = 2.56 (0.52-12.58), reference: inflammatory disease behaviour] were associated with poorer survival.

CONCLUSION

CD-related excess mortality may vary with diagnostic period, age, sex and disease phenotype.Key summaryThere is inconsistent evidence on life expectancy of patients with Crohn's diseaseCrohn's disease-specific survival improved over time.Earlier diagnosis period, older age at diagnosis, female sex, colonic disease and complicated disease behaviour seems to be associated with excess Crohn's disease-related mortality.

Adult-onset inflammatory bowel disease and rate of serious infections compared to the general population: a nationwide register-based cohort study 2002-2017

OBJECTIVES

To investigate absolute and relative risk of serious infections in adult/elderly inflammatory bowel disease (IBD) diagnosed 2002-2017.

METHODS

Nationwide, register-based cohort study of Swedish patients with IBD compared with general population matched reference individuals with regard to time to first serious infection, equal to hospital admission. Multivariable Cox regression estimated hazard ratios (HRs) for any serious infection. Secondary outcomes included site-specific infections, opportunistic infections and sepsis.

RESULTS

We identified 47 798 individuals with IBD. During a follow-up of 329 000 person-years, they had 8752 first serious infections (26.6 per 1000 person-years). This compared with an incidence rate of 10.7 per 1000 person-years in matched reference individuals, corresponding to a 2.53-fold increased hazard of serious infections (95%CI = 2.47-2.59). The HR for serious infection in elderly-onset IBD was 2.01 (95%CI = 1.95-2.08). The relative hazard of serious infection was somewhat higher in Crohn's disease (2.94; 95%CI = 2.81-3.06) than in ulcerative colitis (2.24; 95%CI = 2.17-2.31). The HR for serious infections was high in the first year of follow-up (5.17; 95%CI = 4.93-5.42). Individuals with IBD were at a particularly high relative hazard of gastrointestinal and opportunistic infections. The HR for sepsis was 2.47 (95%CI = 2.32-2.63). The relative rates for serious infections in IBD increased in recent years.

CONCLUSIONS

Patients with adult-onset IBD are at increased risk of serious infections, particularly gastrointestinal and opportunistic infections. Relative rates were highest just after IBD diagnosis, and seem to have increased in recent years.

Test accuracy of faecal calprotectin for inflammatory bowel disease in UK primary care: a retrospective cohort study of the IMRD-UK data

OBJECTIVE

To estimate the test accuracy of faecal calprotectin (FC) for inflammatory bowel disease (IBD) in the primary care setting using routine electronic health records.

DESIGN

Retrospective cohort test accuracy study.

SETTING

UK primary care.

PARTICIPANTS

5970 patients (≥18 years) without a previous IBD diagnosis and with a first FC test between 1 January 2006 and 31 December 2016. We excluded multiple tests and tests without numeric results in units of µg/g.

INTERVENTION

FC testing for the diagnosis of IBD. Disease status was confirmed by a recorded diagnostic code and/or a drug code of an IBD-specific medication at three time points after the FC test date.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values for the differential of IBD versus non-IBD and IBD versus irritable bowel syndrome (IBS) at the 50 and 100 µg/g thresholds.

RESULTS

5970 patients met the inclusion criteria and had at least 6 months of follow-up data after FC testing. 1897 had an IBS diagnosis, 208 had an IBD diagnosis, 31 had a colorectal cancer diagnosis, 80 had more than one diagnosis and 3754 had no subsequent diagnosis. Sensitivity, specificity, and positive and negative predictive values were 92.9% (88.6% to 95.6%), 61.5% (60.2% to 62.7%), 8.1% (7.1% to 9.2%) and 99.6% (99.3% to 99.7%), respectively, at the threshold of 50 µg/g. Raising the threshold to 100 µg/g missed less than 7% additional IBD cases. Longer follow-up had no effect on test accuracy. Overall, uncertainty was greater for specificity than sensitivity. General practitioners' (GPs') referral decisions did not follow the anticipated clinical pathways in national guidance.

CONCLUSIONS

GPs can be confident in excluding IBD on the basis of a negative FC test in a population with low pretest risk but should interpret a positive test with caution. The applicability of national guidance to general practice needs to be improved.

A Novel Method for Quantifying Intestinal Inflammatory Burden in Inflammatory Bowel Disease Using Register Data

Background

The Swedish Quality Register for Inflammatory Bowel Disease (SWIBREG) contains clinical data for the study of inflammatory bowel disease (IBD). The Epidemiology Strengthened by histoPathology Reports in Sweden (ESPRESSO) cohort was recently established for the study of gastrointestinal histopathology. We aimed to develop and validate a histology score from ESPRESSO using clinical information from SWIBREG, and secondarily, to evaluate the association of the score on IBD-related hospitalization.

Methods

In a nationwide, population-based cohort study of patients with IBD during 1969-2017, we linked endoscopic inflammation in SWIBREG with histologic inflammation in ESPRESSO. We established a clinically interpretable model for predicting the endoscopic score from histology using scalable Bayesian rule lists to define a SNOMED-based histology score applicable to the ESPRESSO cohort. We also assessed the impact of baseline endoscopic and histology scores on time to IBD-related hospitalization.

Results

We identified 5225 individuals with IBD comprising 11,051 endoscopic assessments in SWIBREG linked to a histopathology record in ESPRESSO. We created predictive models to calculate a SNOMED-based histology score which predicted the endoscopic score. Split-sample validated areas under the ROC curves for the score predicting a non-zero endoscopic score were 0.80 (0.78-0.81) in UC, 0.70 (0.68-0.72) in CD, and 0.76 (0.73-0.78) in IBD-U. In a subset of 2741 individuals with an initial IBD diagnosis and a corresponding record in ESPRESSO with an endoscopic assessment in SWIBREG, the baseline endoscopic and histology scores were associated with time to IBD-related hospitalization (endoscopy log-rank UC p<0.001, CD p=0.020, IBD-U p<0.001; histology log-rank UC p=0.018, CD p=0.960, IBD-U p=0.034).

Conclusion

Histopathology data in ESPRESSO accurately predict endoscopic scores in SWIBREG. Baseline endoscopic and histologic scores were associated with time to IBD-related hospitalization, particularly in UC. The SNOMED-based histology score can be used as a measure of disease activity in future register-based IBD studies.

Validation of ulcerative colitis and Crohn's disease and their phenotypes in the Danish National Patient Registry using a population-based cohort

INTRODUCTION

The Danish National Patient Registry (DNPR) has been the source of several epidemiological studies of inflammatory bowel disease (IBD). However, the validation dates back to 1996 and lacks outpatient records and disease classification. The aim of this study was to update the validation and assess the validity and reliability of using the registry in disease classification.

METHODS

Validation of the registry was done using a population-based inception cohort of IBD patients from 2003 to 2011 consisting of 513 patients. Specificity and sensitivity were calculated for the diagnoses of Crohn's disease (CD) and ulcerative colitis (UC), age at diagnosis and disease classification according to the Montreal Classification at both time of diagnosis and end of follow-up.

RESULTS

The registry showed high validity and reliability in identifying CD and UC patients concerning correct age classification and identifying perianal disease. The registry showed inconsistent, unreliable results in further disease classification.

CONCLUSIONS

The DNPR has good validity and reliability in identifying patients with CD and UC, and defining the age of patients at diagnosis. However, categorising IBD patients according to the Montreal Classification should not be carried out using DNPR data in their current form, except when identifying CD patients with perianal disease.