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Systematic review with meta-analysis: the adverse effects of tobacco smoking on the natural history of Crohn's disease.

Tobacco smoking is a well‐established risk factor for the development of Crohns disease, and this may lead to a more complicated disease course. However, recent evidence suggests that many patients with Crohns disease are unaware of this fact.

Systematic review with meta-analysis: the effect of tobacco smoking on the natural history of ulcerative colitis

Tobacco smoking is associated with a reduced risk of developing ulcerative colitis (UC). A high proportion of UC patients perceive a benefit in disease outcomes secondary to smoking. However, the effects of smoking on the natural history of UC are uncertain.

Enhancing Diagnostic Performance of Symptom-Based Criteria for Irritable Bowel Syndrome by Additional History and Limited Diagnostic Evaluation

OBJECTIVES:Symptom-based criteria to diagnose irritable bowel syndrome (IBS) positively perform only modestly. Our aim was to assess whether including other items from the clinical history and limited diagnostic evaluation improves their performance.METHODS:We collected complete symptom, colonoscopy, and histology data from 318 consecutive, unselected adult patients with lower gastrointestinal (GI) symptoms in secondary care. All participants underwent colonoscopy, with relevant organic findings recorded. The reference standard used to define the presence of true IBS was patient-reported lower abdominal pain or discomfort associated with a change in bowel habit, in the absence of organic GI disease. Sensitivity, specificity, and positive and negative likelihood ratios (LRs), with 95% confidence intervals, were calculated for Rome III criteria, as well as for modifications, incorporating nocturnal stools, results of simple blood tests (hemoglobin and C-reactive protein (CRP)), measures of somatization, and/or affective disorders (hospital anxiety or depression scale (HADS) score).RESULTS:The sensitivity and specificity of the Rome III criteria for identifying IBS was 69.6%, and 82.0%, respectively, with positive and negative LRs of 3.87 and 0.37, respectively. Clinically useful enhancements in positive LRs were provided by combining Rome III criteria with: (a) high level of somatization (7.27); (b) normal hemoglobin and CRP with HADS score of ≥8 (5.04); (c) normal hemoglobin and CRP with a high level of somatization (7.56); or (d) no nocturnal passage of stool with a high level of somatization (17.3). Specificity was ≥95% with each of these modifications.CONCLUSIONS:Incorporating nocturnal stools, somatization, and affective disorders from the clinical history, and hemoglobin and CRP measurements, enhances the positive LR and specificity of symptom-based Rome III criteria for IBS.

Cyclic vomiting syndrome is a prevalent and under-recognized condition in the gastroenterology outpatient clinic

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder (FGID) characterized by intermittent episodes of nausea and vomiting. Our aim was to report its prevalence and associated features.

Validation and modification of a diagnostic scoring system to predict microscopic colitis.

Abstract Objective: Many patients with diarrhoea undergo colonoscopy. If this is macroscopically normal, random biopsies are obtained to rule out microscopic colitis (MC), but most patients have functional disease. Accurate predictors of MC could avoid the need to take biopsies in a substantial proportion of patients, saving money for the health service. We validated a previously described diagnostic scoring system for MC, and incorporated further variables to assess whether this improved performance. Material and methods: Consecutive adults with loose stools undergoing colonoscopy in Leeds, UK were included. Demographic and symptom data were collected prospectively. The diagnostic scoring system described previously was applied. In addition, the incorporation of further variables, including drugs associated with MC, number of stools, nocturnal passage of stools, and duration of loose stools, into the scoring system was assessed. Sensitivities, specificities, and positive and negative predictive values were calculated. Results: Among 242 patients (mean age 51.0 years, 163 (67.4%) female), 26 (10.7%) of whom had MC, a cut off of ≥4 on the original scoring system had a sensitivity of 92.3% and specificity of 35.2%. Nocturnal passage of stools and duration of loose stools <6 months were significant predictors of MC. Incorporating these variables in a new scoring system with a cut off of ≥6 identified MC with 95.7% sensitivity and 46.0% specificity. Conclusions: Incorporating nocturnal passage of stools and duration of loose stools into the scoring system may improve ability to predict MC, and avoid random colonic biopsies in a greater proportion of patients with loose stools.

Derivation and validation of a diagnostic test for irritable bowel syndrome using latent class analysis

The accuracy of symptom‐based diagnostic criteria for irritable bowel syndrome (IBS) is modest.

The Importance of Smoking Cessation in Improving Disease Course in Crohn’s Disease

To the Editor: We read the article by Nunes et al. ( 1 ) with interest. Th e authors studied the eff ect of smoking cessation on the natural history of Crohn’s Disease (CD). Th eir prospective study demonstrated that patients with CD who continue to smoke are more likely to experience a relapse of disease activity, compared with nonsmokers. Interestingly, the incidence of relapse was ameliorated in those who stopped smoking, with a similar rate of relapse to patients who had never smoked. Th ese fi ndings are similar to the results of our systematic review and meta-analysis of 33 studies that examined the eff ect of smoking on CD ( 2 ). We found that risk of disease relapse was signifi cantly higher among current smokers vs. never smokers (odds ratio (OR) 1.85; 95% confi dence interval (CI) 1.33–2.57) and ex-smokers (OR 2.05; 95% CI 1.38–3.04), but there was no diff erence between ex-smokers and never smokers (OR 0.90; 95% CI 0.59– 1.39). Although the studies we included were not randomized, using these data to calculate a number needed to treat suggest that only seven people with CD would need to stop smoking to prevent one fl are of disease activity, which compares favorably with many available medical therapies. We also found that smoking led to a signifi cant increase in the rates of relapse of disease activity aft er surgery and increased the need for fi rst or second surgery. Smoking is therefore a modifi able risk factor for a worse disease course in CD and should be targeted to reduce the number of comLeeds , Leeds , UK . Correspondence: Alexander C. Ford, MBChB, MD, FRCP , Leeds Gastroenterology Institute, St James’s University Hospital , Room 125, 4th Floor, Bexley Wing, Beckett Street , Leeds LS9 7TF , UK . E-mail: alexf12399@yahoo.com

Efficacy and tolerability of initiating, or switching to, infliximab biosimilar CT-P13 in inflammatory bowel disease (IBD): a large single-centre experience

Abstract Objectives: Recently, the infliximab biosimilar (CT-P13) received market authorisation for inflammatory bowel disease (IBD), allowing cost benefits when switching to CT-P13. We aim to assess the efficacy and safety of switching from originator infliximab to CT-P13 for new and existing patients. Material and methods: Treatment response, remission, primary and secondary loss of response rates, and adverse events in patients who initiated infliximab originator in the 12 months pre-switch (n = 53) were compared with the patients who initiated CT-P13 in the 12 months post-switch (n = 69). Sustained responses were compared for existing infliximab originator patients who switched to CT-P13 (n = 191) and those who continued with the originator (n = 19). Results: There was no difference in remission (58.1% vs. 47.4%, p = .37), response (12.6% vs. 10.5%, p = .80), secondary loss of response (24.6% vs. 42.1%, p = .10), or adverse events (4.7% vs. 0% p = 1.0) between those who switched to CT-P13 and those who continued infliximab originator. There was no difference in remission (42.0% vs. 26.4%, p = .074), response (21.7% vs. 22.6%, p = .91), primary non-response (5.8% vs. 15.1%, p = .09), secondary loss of response (21.7% vs. 22.6%, p = .91), or adverse events (8.7% vs. 11.3%, p = .63) in those who initiated CT-P13 compared with infliximab originator. Conclusions: There was no difference in the efficacy and safety of infliximab originator and CT-P13 during the first 12 months after switching.

Letter: smoking as a modifiable risk factor for a complicated course in Crohn's disease

SIRS, We read the paper by De Bie et al. with interest. The authors examined patient-awareness of the effects of smoking on the natural history of inflammatory bowel disease (IBD). The majority of IBD patients seemed unaware of the fact that smokers have an increased risk of developing Crohn’s disease, an increased likelihood of requiring surgery, and higher rates of recurrence after surgery. Given that the association between smoking and an increased risk of developing Crohn’s disease was reported over 30 years ago, the results from this recent article were surprising to us. Only 37% of patients with Crohn’s disease taking part in the study were aware that smoking is a risk for development of the disease. Furthermore, only 30% and 27% of patients, respectively, were aware of the link between smoking and higher rates of surgical intervention or post-operative recurrence. Although the study was conducted in only one specialist centre in Belgium, it highlights that doctors should not assume that patients with Crohn’s disease are aware of the negative effects of smoking on the natural history of their disease. Patients should therefore be educated about the risks of smoking in Crohn’s disease. Physicians may be hampered in their attempts to do this by conflicting information from previous studies that have examined this issue, as well as uncertainty about the magnitude of the detrimental effect of smoking on the course of Crohn’s disease. This suggests that a definitive summary of the evidence in order to estimate the overall effect of smoking on the course of Crohn’s disease is required. This will give healthcare professionals summary statistics to quote to patients in order to encourage smoking cessation. A recent cost-utility analysis demonstrated that smoking cessation strategies in Crohn’s disease were all more cost-effective than no active intervention. Smoking is therefore an important modifiable environmental risk factor for a complicated course in Crohn’s disease that can be targeted, hopefully leading to a reduction in the number of flare-ups of disease activity, in-patient admissions and surgical interventions, thereby reducing the costs of managing the disease.

Editorial: latent class analysis to improve confidence in the diagnosis of IBS – authors’ reply

using symptom-based criteria and absence of organic lower GI disease after colonoscopy as the reference standard. In the Canadian cohort, this model revealed sensitivity of 44.7% and specificity of 85.3% with a maximum positive likelihood ratio (LR) of 3.93 after construction of a receiver operating characteristic (ROC) curve. Results in the UK cohort were similar with sensitivity of 52.5%, specificity of 84.3%, and maximum LR of 4.15 after construction of ROC curve. The model is an important step towards a more definitive symptom-based diagnostic criterion for IBS. The idea to use statistical modelling to diagnose IBS was first described by Kruis et al. in 1984, whose scoring system used logistic regression combined with laboratory testing to produce impressive diagnostic accuracy for IBS. At the time, however, Kruis’s model was not easily applied due to technological limitations and thus was not used widely. Current smartphone and Internet computing capabilities allow for statistical modelling, such as the one proposed by Sood et al., to be readily and easily applied. The model presented by Sood et al. could be improved by the addition of laboratory tests. In its current form, the sensitivity and specificity are not optimal, and may be below what many might consider ideal for clinical practice. The authors acknowledge that the accuracy of their tool may be improved by including basic laboratory tests such as C-reactive protein and faecal calprotectin as well as emerging IBS biomarkers. Although adding these and other tests would make the model more complex, it would improve the overall performance of this promising diagnostic tool and may also appeal more widely to patients and clinicians who worry about the chances, however unlikely, of missing an organic disease.