Budget impact analysis of Gastric Alimetry® in patients with chronic gastric symptoms in the United Kingdom National Health Service

Technical Summary: Budget Impact Analysis of Gastric Alimetry® in the UK NHS

Problem Statement
Chronic gastric symptoms, particularly those associated with gastroparesis (GP) and functional dyspepsia (FD), impose a significant burden on the United Kingdom National Health Service (NHS). These conditions are characterized by overlapping symptoms (e.g., chronic epigastric pain, early satiation) but are differentiated primarily by the presence of delayed gastric emptying in GP. However, current diagnostic pathways lack a gold standard, relying on gastric emptying tests that suffer from low reproducibility. This diagnostic ambiguity often leads to "trial-and-error" therapies, repetitive investigations (blood tests, endoscopy, imaging), and high-cost resource utilization, including frequent emergency department (A&E) visits, hospital admissions, and invasive nutritional support. Furthermore, the arbitrary diagnosis of GP based on delayed emptying tests can inadvertently incentivize escalation to high-cost interventions (e.g., surgeries, feeding tubes) even for patients with Functional Dyspepsia who present with identical symptom severity. There is a critical evidence gap regarding the economic impact of integrating innovative diagnostic tools, such as Gastric Alimetry®, into the UK NHS.

Methodology
The study developed a Budget Impact Analysis (BIA) to compare the financial implications of the current standard of care against a scenario incorporating the Gastric Alimetry system over a 5.4-year time horizon (65 months).

• Perspective: The analysis adopted the UK NHS and personal social services perspective, focusing on direct healthcare costs within England.
• Data Sources: Resource utilization data and unit costs were primarily derived from the English Hospital Episodes Statistics (HES) database, covering a cohort of 66,215 adult patients diagnosed with GP or FD between April 2023 and March 2024. Cost reduction assumptions were based on a retrospective evaluation of Gastric Alimetry in a New Zealand cohort study (Varghese et al.).
• Model Structure: The model compared two scenarios:
  1. Standard of Care: Current diagnostic and management pathways.
  2. Gastric Alimetry Integration: A pathway where Gastric Alimetry (Body Surface Gastric Mapping) replaces standard motility testing (gastric emptying scintigraphy) as the primary functional test after anatomical exclusion.
• Assumptions: The base case assumed a conservative 10% uptake rate (6,612 patients) across 10 UK sites. The model excluded baseline investigations (assumed comparable), blood tests, medication costs, and specific disease-specific treatments (e.g., neurostimulators) to maintain a conservative estimate.
• Analysis Types: A base case analysis was performed, followed by one-way deterministic sensitivity analyses (varying costs by ±5%) and scenario analyses (varying patient uptake rates and site numbers, and including Chronic Nausea and Vomiting Syndrome patients).

Key Contributions

• First UK NHS BIA: This study provides the first formalized Budget Impact Analysis for Gastric Alimetry within the operational context of the UK NHS.
• Quantification of Savings: It quantifies the potential financial impact of shifting from a trial-and-error diagnostic approach to one guided by objective body surface gastric mapping (BSGM).
• Resource Utilization Modeling: The model explicitly links improved diagnostic clarity (phenotyping) to reductions in specific high-cost categories, including hospital admissions, nutritional support (feeding tubes and Total Parenteral Nutrition), secondary care investigations, A&E visits, and gastroenterology appointments.

Results
The base case analysis projected a net cost saving of £49,973,080 to the UK NHS over the 5.4-year period for the cohort of 66,215 patients.

• Cost Breakdown: The introduction of Gastric Alimetry incurred a new cost of £5,385,400 (testing fees and hardware investment). However, this was offset by significant reductions in other areas:
  • Hospital Admissions: The largest source of savings (£40,020,801 reduction), corresponding to 22,220 fewer admissions.
  • Nutrition Support: A reduction of £9,257,292, driven by fewer feeding tube insertions and TPN days.
  • Investigations: A reduction of £3,768,921 in secondary care tests (e.g., gastroscopies, CT/MRI scans).
  • Appointments and A&E: Smaller but notable reductions in gastroenterology appointments and A&E visits.
• Per-Patient Impact: The model estimated a net saving of approximately £7,548 per patient tested.
• Sensitivity and Scenario Analysis: The findings were robust across various assumptions. Even with a 1% uptake rate, the model showed a net profit of nearly £5 million. Including patients with Chronic Nausea and Vomiting Syndrome (CNVS) increased the projected net savings to over £200 million. Variations in cost inputs (±5%) resulted in net savings ranging between £48 million and £52 million.

Significance and Claims
The paper claims that integrating Gastric Alimetry into the NHS demonstrates substantial financial value and supports efficient resource allocation. The authors assert that the technology's ability to distinguish between GP and FD through objective biomarkers allows clinicians to:

1. Reclassify Patients: Safely reclassify patients with normal spectral metrics from high-cost GP pathways to lower-cost FD pathways, reducing redundant investigations and hospitalizations.
2. Avoid Invasive Escalation: Guide clinicians away from invasive, high-cost interventions (such as tube insertion or surgery) that are often pursued under ambiguous GP diagnoses.
3. Optimize Management: Enable earlier implementation of multidisciplinary treatment strategies (dietary and psychological) for FD patients.

The study concludes that these findings provide evidence to support the adoption of Gastric Alimetry, aligning with the NHS's strategic focus on health innovation and the National Institute for Health and Care Excellence (NICE) mandate for cost-effective technologies. The authors note that while the model is based on conservative assumptions and New Zealand-derived reduction rates, the substantial projected savings highlight the potential for the technology to improve patient care and reduce the economic burden of chronic gastric symptoms in the UK.