Peripheral arterial disease is a common condition, affecting around 20% of people over 60, where a build-up of fatty deposits in the arteries restricts blood supply to leg muscles. Chronic limb threatening ischaemia (CLTI) is a severe form of symptomatic PAD, defined by the presence of PAD in combination with rest pain, gangrene, or a lower limb ulceration (>2 weeks duration). More than half of patients with symptomatic PAD are expected to die, undergo amputation, or experience a major cardiovascular event within five years.
Given the high economic burden associated with PAD/CLTI, it is important to understand the impact of different treatment strategies on system-wide healthcare resource utilisation. The HEU were commissioned by Abbot Laboratories to produce an Excel-based budget impact model investigating the economic case for adopting a pathway change to decrease the proportion of patients who undergo amputation as an index treatment.
Two key objectives for the budget impact model were:
- To use real-world data from primary and secondary care to provide a system-wide picture of resource utilisation
- To provide a dynamic, user-friendly interface, so that the model can be used an effective communication tool
Methodology / approach
Using our experience of analysing and accessing NHS data sets, we identified the Kent Integrated Dataset (KID) as an appropriate source of data for the model. This covers patient’s activities and associated costs for a number of primary and secondary care providers in Kent and Medway. HEU’s data scientists and data engineers performed a retrospective analysis of routinely collected individual patient data from KID to compare healthcare resource utilisation for patients that received amputation with other index treatment options. This included consideration of: index procedure admissions, subsequent PAD/CLTI procedure admissions, community care appointments, primary care appointments, outpatient care appointments, admissions due to major cardiovascular events, and antithrombotic therapy prescriptions.
We used National Vascular Registry data to determine the number of patients requiring index treatment for PAD/CLTI across England and Wales. We programmed functionality to generate a bespoke set of results for an individual arterial centre, ICS, or the whole of England and Wales, at the click of a button.
The key model result was the net budget impact for the pathway change. This represents the total cost difference (from an NHS and NHS-funded Personal Social Services perspective) between the current pathway for newly incident PAD and/or CLTI and the proposed reduced amputation pathway. For England and Wales, the net budget impact was negative, indicating that the reduced amputation strategy could result in a large annual cost reduction for treating newly incident PAD and/or CLTI. Similar results were observed across the modelled regions. Deterministic sensitivity analysis, using standard deviations from the KID analysis, indicated that the model results were robust to individual parameter uncertainty.
We aim to collaborate with Abbot and experts in PAD/CLTI to publish the results of the model in a peer reviewed journal. This will help promote the economic case for change for implementing a reduced amputation strategy in England and Wales.
The client praised the dynamic and visual capabilities of the economic model, as well as the thoroughness of the accompanying technical report.
‘(The technical report) was very clear with strengths and limitations’