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. 2021 Mar;25(23):1–138. doi: 10.3310/hta25230

Prognostic tools for identification of high risk in people with Crohn's disease: systematic review and cost-effectiveness study.

Steven J Edwards, Samantha Barton, Mariana Bacelar, Charlotta Karner, Peter Cain, Victoria Wakefield, Gemma Marceniuk
PMCID: PMC8040347  PMID: 33783345

Abstract

BACKGROUND

Crohn's disease is a lifelong condition that can affect any segment of the gastrointestinal tract. Some people with Crohn's disease may be at higher risk of following a severe course of disease than others and being able to identify the level of risk a patient has could lead to personalised management.

OBJECTIVE

To assess the prognostic test accuracy, clinical impact and cost-effectiveness of two tools for the stratification of people with a diagnosis of Crohn's disease by risk of following a severe course of disease.

DATA SOURCES

The data sources MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were searched to inform the systematic reviews on prognostic accuracy, clinical impact of the prognostic tools, and economic evaluations. Additional data sources to inform the review of economic evaluations were NHS Economic Evaluation Database, Database of Abstracts of Reviews of Effects and the Health Technology Assessment Database.

REVIEW METHODS

Systematic reviews of electronic databases were carried out from inception to June 2019 for studies assessing the prognostic accuracy and clinical impact of the IBDX® (Crohn's disease Prognosis Test; Glycominds Ltd, Lod, Israel) biomarker stratification tool and the PredictSURE-IBD™ (PredictImmune Ltd, Cambridge, UK) tool. Systematic reviews of studies reporting on the cost-effectiveness of treatments for Crohn's disease were run from inception to July 2019. Two reviewers independently agreed on studies for inclusion, assessed the quality of included studies and validated the data extracted from studies. Clinical and methodological heterogeneity across studies precluded the synthesis of data for prognostic accuracy. A de novo economic model was developed to compare the costs and consequences of two treatment approaches - the 'top-down' and 'step-up' strategies, with step-up considered standard care - in people at high risk of following a severe course of Crohn's disease. The model comprised a decision tree and a Markov cohort model.

RESULTS

Sixteen publications, including eight original studies (n = 1478), were deemed relevant to the review of prognostic accuracy. Documents supplied by the companies marketing the prognostic tools were also reviewed. No study meeting the eligibility criteria reported on the sensitivity or specificity of the IBDX biomarker stratification tool, whereas one study provided estimates of sensitivity, specificity and negative predictive value for the PredictSURE-IBD tool. All identified studies were observational and were considered to provide weak evidence on the effectiveness of the tools. Owing to the paucity of data on the two tools, in the base-case analysis the accuracy of PredictSURE-IBD was assumed to be 100%. Accuracy of IBDX was assumed to be 100% in a scenario analysis, with the cost of the tests being the only difference between the analyses. The incremental analysis of cost-effectiveness demonstrated that top-down (via the use of PredictSURE-IBD in the model) is more expensive and generates fewer quality-adjusted life-years than step-up (via the standard care arm of the model).

LIMITATIONS

Despite extensive systematic searches of the literature, no robust evidence was identified of the prognostic accuracy of the biomarker stratification tools IBDX and PredictSURE-IBD.

CONCLUSIONS

Although the model indicates that standard care dominates the tests, the lack of evidence of prognostic accuracy of the two tests and the uncertainty around the benefits of the top-down and step-up treatment approaches mean that the results should be interpreted as indicative rather than definitive.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019138737.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 23. See the NIHR Journals Library website for further project information.

Plain language summary

Crohn’s disease is a condition in which parts of the digestive system become inflamed (swollen). People of any age can develop Crohn’s disease. It is a lifelong condition for which there is no cure. In the UK, Crohn’s disease affects about 1 in every 650 people. Any part of the digestive system can be affected, and the severity of the disease can vary from person to person. Symptoms come and go, and there can be times when there are no symptoms at all. Common symptoms of Crohn’s disease are diarrhoea, stomach-ache and blood in faeces. Treatment is given to reduce or control symptoms and to try to stop inflammation from coming back. Some people with Crohn’s disease are more likely than others to have more relapses and to develop complications of Crohn’s disease that might require surgery. This project looked at how well two tools worked at identifying people with Crohn’s disease who might develop complications or need surgery. Identifying those who have a higher chance of experiencing complications of Crohn’s disease could help them and their doctor to choose their treatment, with the goal of reducing the number of relapses and the risk of surgery in the longer term. In addition, the review assessed whether or not the tools offered value for money. We found limited evidence of how well the tools worked in identifying people who were more likely to develop complications of Crohn’s disease. The lack of evidence on the tools meant that the cost-effectiveness analysis could only assess the value for money of the treatment that is given in clinical practice at this time or of more intensive treatments for people who are more likely to develop complications. The analysis found that current standard care offers more value for money than intensive treatments for people with a higher chance of developing complications of Crohn’s disease.

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