# Cost-effectiveness of population-wide screening for intracranial aneurysms revisited in light of potential diagnostic developments

## TL;DR

This study evaluates whether population-wide screening for brain aneurysms is cost-effective, considering new diagnostic technologies and treatment costs.

## Contribution

The study identifies economic criteria for a hypothetical screening test to justify population-wide aneurysm screening.

## Key findings

- Population-wide screening for UIAs is unlikely to be cost-effective even with new blood screening technologies.
- A screening test priced at €225.72 could be cost-effective if willingness-to-pay is €50,000 per QALY gained.
- If the test also supports watchful waiting, the maximum cost-effective price increases to €294.19.

## Abstract

Preventive treatment of unruptured intracranial aneurysms (UIAs) has the potential to reduce aneurysmal subarachnoid hemorrhage (SAH) incidence. Population-wide screening (PWS) for UIAs has been disregarded, as it remains unclear how to manage low-risk UIAs. Higher cost for SAH treatment, along with improvements in UIA treatment decision-making, might improve the risk–benefit and cost–benefit ratios for PWS. Currently, blood-based screening tests for UIAs are under development and might be suitable for use in PWS.

This study sets out to identify what health economic criteria should be met by a hypothetical UIA screening test to justify PWS.

A Markov model was built to compare PWS versus standard of care. Model parameterization was done using real-world data derived from the population cared for by the RWTH Aachen University Hospital. Data in relation to SAH were derived from a prospective registry of consecutive SAH patients (n = 275). In addition, a database of newly diagnosed UIAs was retrospectively collected (n = 139). Incremental cost-effectiveness ratios (ICERs) were calculated to illustrate the annual cost per additional quality-adjusted life year (QALY). Sensitivity analyses were performed to determine at which price point the PWS strategy would become cost-effective based on different levels of willingness-to-pay (WTP).

In a one-way sensitivity analysis, the price of a hypothetical screening test was varied between €1 and €811.3 (mean cost of magnetic resonance angiography). In case of a WTP of €50,000 per QALY gained, the cost per test may be €225.72 and remain cost-effective. If the same test could also be used for watchful-waiting in low-risk patients (i.e. assess the risk of aneurysm growth), the price may increase up to €294.19. There is no price point at which PWS would become dominant and yield negative ICERs.

PWS for UIAs is unlikely to be cost-effective, even with new blood screening technologies. However, once patents expire, and price monopolies are broken, use of such technologies may become more attractive for health policymakers, depending on their WTP.