OC.07.3: COST-EFFECTIVENESS OF TOP-DOWN VERSUS STEP-UP STRATEGIES IN PATIENTS WITH NEWLY DIAGNOSED ACTIVE LUMINAL CROHN'S DISEASE (CD)

Background Magnetic resonance enterography and enteric ultrasonography are used to image Crohn’s disease patients. Their diagnostic accuracy for presence, extent and activity of enteric Crohn’s disease was compared. Objective To compare diagnostic accuracy, observer variability, acceptability, diagnostic impact and cost-effectiveness of magnetic resonance enterography and ultrasonography in newly diagnosed or relapsing Crohn’s disease. Design Prospective multicentre cohort study. Setting Eight NHS hospitals. Participants Consecutive participants aged ≥ 16 years, newly diagnosed with Crohn’s disease or with established Crohn’s disease and suspected relapse. Interventions Magnetic resonance enterography and ultrasonography. Main outcome measures The primary outcome was per-participant sensitivity difference between magnetic resonance enterography and ultrasonography for small bowel Crohn’s disease extent. Secondary outcomes included sensitivity and specificity for small bowel Crohn’s disease and colonic Crohn’s disease extent, and sensitivity and specificity for small bowel Crohn’s disease and colonic Crohn’s disease presence; identification of active disease; interobserver variation; participant acceptability; diagnostic impact; and cost-effectiveness. Results Out of the 518 participants assessed, 335 entered the trial, with 51 excluded, giving a final cohort of 284 (133 and 151 in new diagnosis and suspected relapse cohorts, respectively). Across the whole cohort, for small bowel Crohn’s disease extent, magnetic resonance enterography sensitivity [80%, 95% confidence interval (CI) 72% to 86%] was significantly greater than ultrasonography sensitivity (70%, 95% CI 62% to 78%), with a 10% difference (95% CI 1% to 18%; p = 0.027). For small bowel Crohn’s disease extent, magnetic resonance enterography specificity (95%, 95% CI 85% to 98%) was significantly greater than ultrasonography specificity (81%, 95% CI 64% to 91%), with a 14% difference (95% CI 1% to 27%). For small bowel Crohn’s disease presence, magnetic resonance enterography sensitivity (97%, 95% CI 91% to 99%) was significantly greater than ultrasonography sensitivity (92%, 95% CI 84% to 96%), with a 5% difference (95% CI 1% to 9%). For small bowel Crohn’s disease presence, magnetic resonance enterography specificity was 96% (95% CI 86% to 99%) and ultrasonography specificity was 84% (95% CI 65% to 94%), with a 12% difference (95% CI 0% to 25%). Test sensitivities for small bowel Crohn’s disease presence and extent were similar in the two cohorts. For colonic Crohn’s disease presence in newly diagnosed participants, ultrasonography sensitivity (67%, 95% CI 49% to 81%) was significantly greater than magnetic resonance enterography sensitivity (47%, 95% CI 31% to 64%), with a 20% difference (95% CI 1% to 39%). For active small bowel Crohn’s disease, magnetic resonance enterography sensitivity (96%, 95% CI 92% to 99%) was significantly greater than ultrasonography sensitivity (90%, 95% CI 82% to 95%), with a 6% difference (95% CI 2% to 11%). There was some disagreement between readers for both tests. A total of 88% of participants rated magnetic resonance enterography as very or fairly acceptable, which is significantly lower than the percentage (99%) of participants who did so for ultrasonography. Therapeutic decisions based on magnetic resonance enterography alone and ultrasonography alone agreed with the final decision in 122 out of 158 (77%) cases and 124 out of 158 (78%) cases, respectively. There were no differences in costs or quality-adjusted life-years between tests. Limitations Magnetic resonance enterography and ultrasonography scans were interpreted by practitioners blinded to clinical data (but not participant cohort), which does not reflect use in clinical practice. Conclusions Magnetic resonance enterography has higher accuracy for detecting the presence, extent and activity of small bowel Crohn’s disease than ultrasonography does. Both tests have variable interobserver agreement and are broadly acceptable to participants, although ultrasonography produces less participant burden. Diagnostic impact and cost-effectiveness are similar. Recommendations for future work include investigation of the comparative utility of magnetic resonance enterography and ultrasonography for treatment response assessment and investigation of non-specific abdominal symptoms to confirm or refute Crohn’s disease. Trial registration Current Controlled Trials ISRCTN03982913. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 42. See the NIHR Journals Library website for further project information.

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

Health Technology Assessment ◽

10.3310/hta25230 ◽

2021 ◽

Vol 25 (23) ◽

pp. 1-138

Author(s):

Steven J Edwards ◽

Samantha Barton ◽

Mariana Bacelar ◽

Charlotta Karner ◽

Peter Cain ◽

...

Keyword(s):

Crohn’S Disease ◽

Cost Effectiveness ◽

Crohn's Disease ◽

Systematic Reviews ◽

Standard Care ◽

Clinical Impact ◽

Data Sources ◽

Economic Evaluations ◽

Top Down ◽

Prognostic Accuracy

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.

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