Refinement and validation of the IDIOM score for predicting the risk of gastrointestinal cancer in iron deficiency anaemia

Endoscopic findings and predictors of gastrointestinal lesions in children with iron deficiency anemia

Iron deficiency anemia (IDA) can be caused by occult gastrointestinal (GI) blood loss; however, the endoscopic findings in children with anemia are unclear. The study aimed to determine the frequency and factors related to lesions in children with IDA undergoing endoscopy. We retrospectively analyzed the clinical and endoscopic findings of children with a laboratory-based diagnosis of IDA. Of 58 patients, 36 (62.1%) had upper GI tract lesions, with erosive gastritis being the most common lesion. Further, 26 patients underwent concomitant colonoscopy, and 12 (46.2%) had lower GI tract lesions. Overall, 44 (75.9%) patients had lesions in either the upper or lower GI tract. Helicobacter pylori infection was detected in 13 patients (22.4%). Patients with lesions found by endoscopy had significantly lower hemoglobin level (8.9 vs. 10.0 g/dL, p = 0.047) and mean corpuscular volume (75.5 vs. 80.9 fL, p = 0.038). The proportion of patients with previous treatment for IDA was also higher in those with lesions on endoscopy. In multivariate analysis, age of ≥10 years (odds ratio [OR], 6.00; 95% confidence Interval [CI], 0.56-10.75) and positive fecal occult blood test (FOBT) findings (OR, 2.25; 95% CI, 0.14-4.52) were factors related to GI lesions. The presence of GI symptoms was not associated with GI lesions. A high proportion of GI lesions were found by endoscopy in children with IDA in this study. Endoscopy should be considered in children with IDA even without GI symptoms, especially in older children, and those with positive FOBT results.

The Diagnostic Accuracy of a Fecal Immunochemical Test in Detecting Colorectal Cancer and Advanced Precancerous Colorectal Neoplasia in Patients with Iron Deficiency: A Protocol for Systematic Review and Meta-Analysis

Background. Iron deficiency (ID) is a common micronutrient deficiency and the leading cause of anemia worldwide. ID can be caused by chronic occult blood loss from colorectal neoplasia including colorectal cancer (CRC) and advanced precancerous colorectal lesions. Current guidelines recommend colonoscopy in both men and postmenopausal women presenting with ID anemia (IDA). However, there is controversy on the investigation of patients presenting with a lower risk of CRC including younger women with ID and those with nonanemic ID (NAID). There is a need for a triaging tool to identify which ID patients may benefit from colonoscopy. The fecal immunochemical test (FIT) is sensitive for CRC screening in an asymptomatic population, but its role in ID patients is unclear. The aim of this study is to conduct a systematic review to determine the diagnostic accuracy of FIT for detecting CRC and advanced precancerous neoplasia in individuals presenting with ID with or without anemia. Methods and Analysis. This protocol conforms with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A comprehensive search of the MEDLINE, Embase, and Web of Science databases will be undertaken for studies published after 2010 which involve patients with ID, who completed a FIT in the 6 months prior to colonoscopy, with FIT sensitivity and specificity calculated against the reference standard colonoscopy. The search will be limited to studies conducted after 2010 to reduce variability in colonoscopy quality. Risk of bias assessment will be conducted using the Quality Assessment of Diagnostic Accuracy Studies version 2. FIT sensitivity and specificity will be the primary measure of diagnostic accuracy, and data will be analysed using a random effects meta-analysis. Discussion. This review and meta-analysis will be the first to systematically explore the value of the FIT as a triaging tool for patients with ID. This trial is registered with CRD42022367162.

Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

MR1: ESGE recommends small-bowel capsule endoscopy as the first-line examination, before consideration of other endoscopic and radiological diagnostic tests for suspected small-bowel bleeding, given the excellent safety profile of capsule endoscopy, its patient tolerability, and its potential to visualize the entire small-bowel mucosa.Strong recommendation, moderate quality evidence. MR2: ESGE recommends small-bowel capsule endoscopy in patients with overt suspected small-bowel bleeding as soon as possible after the bleeding episode, ideally within 48 hours, to maximize the diagnostic and subsequent therapeutic yield.Strong recommendation, high quality evidence. MR3: ESGE does not recommend routine second-look endoscopy prior to small-bowel capsule endoscopy in patients with suspected small-bowel bleeding or iron-deficiency anemia.Strong recommendation, low quality evidence. MR4: ESGE recommends conservative management in those patients with suspected small-bowel bleeding and high quality negative small-bowel capsule endoscopy.Strong recommendation, moderate quality evidence. MR5: ESGE recommends device-assisted enteroscopy to confirm and possibly treat lesions identified by small-bowel capsule endoscopy.Strong recommendation, high quality evidence. MR6: ESGE recommends the performance of small-bowel capsule endoscopy as a first-line examination in patients with iron-deficiency anemia when small bowel evaluation is indicated.Strong recommendation, high quality evidence. MR7: ESGE recommends small-bowel capsule endoscopy in patients with suspected Crohn's disease and negative ileocolonoscopy findings as the initial diagnostic modality for investigating the small bowel, in the absence of obstructive symptoms or known bowel stenosis.Strong recommendation, high quality evidence. MR8: ESGE recommends, in patients with unremarkable or nondiagnostic findings from dedicated small-bowel cross-sectional imaging, small-bowel capsule endoscopy as a subsequent investigation if deemed likely to influence patient management.Strong recommendation, low quality evidence. MR9: ESGE recommends, in patients with established Crohn's disease, the use of a patency capsule before small-bowel capsule endoscopy to decrease the capsule retention rate.Strong recommendation, moderate quality evidence. MR10: ESGE recommends device-assisted enteroscopy (DAE) as an alternative to surgery for foreign bodies retained in the small bowel requiring retrieval in patients without acute intestinal obstruction.Strong recommendation, moderate quality evidence. MR11: ESGE recommends DAE-endoscopic retrograde cholangiopancreatography (DAE-ERCP) as a first-line endoscopic approach to treat pancreaticobiliary diseases in patients with surgically altered anatomy (except for Billroth II patients).Strong recommendation, moderate quality evidence.

The Development of a Clinical Decision-Support Web-Based Tool for Predicting the Risk of Gastrointestinal Cancer in Iron Deficiency Anaemia—The IDIOM App

To facilitate the clinical use of an algorithm for predicting the risk of gastrointestinal malignancy in iron deficiency anaemia—the IDIOM score, a software application has been developed, with a view to providing free and simple access to healthcare professionals in the UK. A detailed requirements analysis for intended users of the application revealed the need for an automated decision-support tool in which anonymised, individual patient data is entered and gastrointestinal cancer risk is calculated and displayed immediately, which lends itself to use in busy clinical settings. Human-centred design was employed to develop the solution, focusing on the users and their needs, whilst ensuring that they are provided with sufficient details to appropriately interpret the risk score. The IDIOM App has been developed using R Shiny as a web-based application enabling access from different platforms with updates that can be carried out centrally through the host server. The application has been evaluated through literature search, internal/external validation, code testing, risk analysis, and usability assessments. Legal notices, contact system with research and maintenance teams, and all the supportive information for the application such as description of the population and intended users have been embedded within the application interface. With the purpose of providing a guide of developing standalone software medical devices in academic setting, this paper aims to present the theoretical and practical aspects of developing, writing technical documentation, and certifying standalone software medical devices using the case of the IDIOM App as an example.

Modelling the episodes of care for iron deficiency anemia patients in a secondary-care center using continuous-time multistate Markov chain

BACKGROUND

Despite the high prevalence of gastro-intestinal (GI) cancer in iron deficiency anemia (IDA), some IDA patients do not complete all the necessary GI investigations at the initial referral. As a result, existing cancers are diagnosed at a later referral with worse prognosis. The potential to detect GI cancer early depends on minimizing the delay time spent between the two consecutive referrals, where a patient did not complete investigations at the first referral, but at the second is diagnosed with positive GI cancer. This retrospective longitudinal study aims to highlight the proper methods to model these referrals.

METHODS

Using anonymized data of 168 episodes of care for IDA patients at an IDA clinic in a secondary care setting, continuous-time multi-state Markov chain is employed to determine the transition rates among three observed states for IDA patients at the IDA clinic, "incomplete investigations," "negative GI cancer," and "positive GI cancer" and to estimate the delay time.

RESULTS

Once in the state of incomplete investigations, an estimated mean delay time of 3.1 years (95% CI: 1.2, 5) is spent before being diagnosed with positive GI cancer. The probability that a "positive GI diagnosis" is next after the state of "incomplete investigation" is 17%, compared with 11% when it is followed in the state of negative GI cancer. Defining the survival as the event of not being in the state of "positive GI cancer," the survival rate of IDA patients with negative GI cancer is always higher than those with incomplete investigations. Finally, being diagnosed with positive GI cancer is always preceded by the prediction of being considered "very high risk" at the earlier visit.

CONCLUSION

A baseline model was proposed to represent episodes of care for IDA patients at a secondary care center. Preliminary results highlight the importance of completing the GI investigations, especially in IDA patients, who are at high risk of GI cancer and fit to go through the investigations.

Small Bowel Malignancies in Patients Undergoing Capsule Endoscopy for Iron Deficiency Anemia

Small bowel malignancies are rare and usually asymptomatic or symptoms are nonspecific. Therefore, small bowel tumors are difficult to diagnose. In patients with iron deficiency anemia (IDA) who have negative bidirectional endoscopy results, the small bowel may be considered the source of bleeding. However, in asymptomatic IDA patients with negative bidirectional endoscopy results, evidence supporting the routine use of capsule endoscopy (CE) is insufficient. CE can be considered in selected patients with recurrent or persistent IDA. The frequency of small bowel malignancies is low in patients undergoing CE for IDA, but the usefulness of CE for the diagnosis of small bowel malignancies in younger age groups with IDA has been reported. For patients with risk factors for small bowel malignancy, investigation of the small bowel should be considered. Efforts should be made to prevent adverse events, such as capsule retention or capsule aspiration, through meticulous history taking and endoscopic capsule delivery as necessary.

Broad external validation of a multivariable risk prediction model for gastrointestinal malignancy in iron deficiency anaemia

BACKGROUND

Using two large datasets from Dorset, we previously reported an internally validated multivariable risk model for predicting the risk of GI malignancy in IDA-the IDIOM score. The aim of this retrospective observational study was to validate the IDIOM model using two independent external datasets.

METHODS

The external validation datasets were collected, in a secondary care setting, by different investigators from cohorts in Oxford and Sheffield derived under different circumstances, comprising 1117 and 474 patients with confirmed IDA respectively. The data were anonymised prior to analysis. The predictive performance of the original model was evaluated by estimating measures of calibration, discrimination and clinical utility using the validation datasets.

RESULTS

The discrimination of the original model using the external validation data was 70% (95% CI 65, 75) for the Oxford dataset and 70% (95% CI 61, 79) for the Sheffield dataset. The analysis of mean, weak, flexible and across the risk groups' calibration showed no tendency for under or over-estimated risks in the combined validation data. Decision curve analysis demonstrated the clinical value of the IDIOM model with a net benefit that is higher than 'investigate all' and 'investigate no-one' strategies up to a threshold of 18% in the combined validation data, using a risk cut-off of around 1.2% to categorise patients into the very low risk group showed that none of the patients stratified in this risk group proved to have GI cancer on investigation in the validation datasets.

CONCLUSION

This external validation exercise has shown promising results for the IDIOM model in predicting the risk of underlying GI malignancy in independent IDA datasets collected in different clinical settings.

British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults

Iron deficiency anaemia (IDA) is a major cause of morbidity and burden of disease worldwide. It can generally be diagnosed by blood testing and remedied by iron replacement therapy (IRT) using the oral or intravenous route. The many causes of iron deficiency include poor dietary intake and malabsorption of dietary iron, as well as a number of significant gastrointestinal (GI) pathologies. Because blood is iron-rich it can result from chronic blood loss, and this is a common mechanism underlying the development of IDA-for example, as a consequence of menstrual or GI blood loss.Approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract. Therefore optimal management of IDA requires IRT in combination with appropriate investigation to establish the underlying cause. Unexplained IDA in all at-risk individuals is an accepted indication for fast-track secondary care referral in the UK because GI malignancies can present in this way, often in the absence of specific symptoms. Bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract, though radiological scanning is an alternative in some situations for assessing the large bowel. In recurrent or refractory IDA, wireless capsule endoscopy plays an important role in assessment of the small bowel.IDA may present in primary care or across a range of specialties in secondary care, and because of this and the insidious nature of the condition it has not always been optimally managed despite the considerable burden of disease- with investigation sometimes being inappropriate, incorrectly timed or incomplete, and the role of IRT for symptom relief neglected. It is therefore important that contemporary guidelines for the management of IDA are available to all clinicians. This document is a revision of previous British Society of Gastroenterology guidelines, updated in the light of subsequent evidence and developments.

Evidence for improved prognosis of colorectal cancer diagnosed following the detection of iron deficiency anaemia

Iron deficiency anaemia (IDA) is common in colorectal cancer (CRC), especially, in right-sided CRC which is known to have an overall worse prognosis. The associations between diagnostic pathway (Bowel Cancer Screening Programme (BCSP), IDA, symptomatic) and tumour side/stage was assessed using logistic regression models in 1138 CRC cases presenting during 2010-2016 at a single secondary-care centre in the UK. In the IDA sub-group, the relationship between CRC stage and the event of having a blood count prior to CRC diagnosis was examined using Bayesian parametric survival model. IDA was found as the only significant predictor of right-sided CRC (OR 10.61, 95% CI 7.02-16.52). Early-stage CRC was associated with both the IDA (OR 1.65, 95% CI 1.18-2.29) and BCSP pathway (OR 2.42, 95% CI 1.75-3.37). At any age, the risk of detecting CRC at late-stage was higher in those without a previous blood count check (hazard ratio 1.53, 95% credibility interval 1.08-2.14). The findings of this retrospective observational study suggest a benefit from diagnosing CRC through the detection of IDA, and warrant further research into the prognosis benefit of systematic approach to blood count monitoring of the at-risk population.

Iron deficiency: a modern primer to diagnosis and management

PURPOSE OF REVIEW

Iron deficiency with anemia (IDA) and without anemia remain a diagnostic and management challenge. Iron deficiency has a broad spectrum of causes, including gastrointestinal malignancy. The purpose of this review is to summarize the value and limitations of current methods to diagnose iron deficiency and underline the relevance of contemporaneous evidence to guide the pretest probability of gastrointestinal disease.

RECENT FINDINGS

A number of biomarkers for iron deficiency exist, and all have their caveats. Serum ferritin remains the most pragmatic means of diagnosing iron deficiency. Hepcidin holds future promise as a marker of iron status during inflammatory states. Men and postmenopausal women with IDA have the highest overall prevalence of gastrointestinal malignancy (∼11%), while premenopausal women with IDA (<1.5%) and those with iron deficiency without anemia (<0.5%) have a very low risk. Noninvasive investigation with fecal immunochemical test and fecal calprotectin hold promise to guide further investigations in lower risk groups.

SUMMARY

Confirmation of iron deficiency remains a challenge. Appropriate risk stratification is the key to guiding judicious gastrointestinal investigation. Use of noninvasive tests may play an important role in lower risk groups. Risk prediction tools applicable to relevant populations are required.

The dedicated iron deficiency anaemia clinic: a 15-year experience

OBJECTIVE

To report our cumulative experience from a dedicated iron deficiency anaemia (IDA) clinic over the last 15 years-with particular emphasis on referral rate, uptake of investigation, impact on endoscopy services, diagnostic yield of gastrointestinal (GI) investigation and the issue of recurrent IDA.

METHOD

A series of analyses of a register of 2808 referrals to the Poole IDA clinic between 2004 and 2018.

RESULTS

The study population of 2808 had a sex ratio of 1.9 (female/male ratio) and a median age of 72 years (IQR: 60-79). A rising referral rate over the study period appears to be plateauing at around 2 cases per 1000 population per annum. On the basis of a snapshot audit, investigation of IDA may now account for over 20% of all diagnostic endoscopies.Overall, 86% of cases underwent examination of the upper and lower GI tract. Significant GI pathology was identified in 27% of the investigated cohort. Adenocarcinoma of the upper or lower GI tract was found in 8.3%, the majority in the right colon. The prevalence of recurrent IDA was estimated at 12.4%, and the results of investigation of this subgroup are reported.

CONCLUSION

Unexplained IDA is common, particularly in those over 60 years, and may be the first indication of underlying GI malignancy in over 8% of cases. Unresolved challenges include accommodating the resulting endoscopy workload, establishing a risk/benefit ratio for investigating those with major comorbidities and the management of recurrent IDA.