Implementing a Risk-Stratified National Breast Screening Programme in the United Kingdom: A Model-Based Cost-effectiveness Analysis

Abstract Background: Risk-stratified breast screening, in which women are offered different screening intervals based on their breast cancer risk, has been proposed as a way to improve the benefits of screening in the United Kingdom National Breast Screening Programme (UK-NBSP). The aim of this study was to explore the cost-effectiveness of potential risk-stratified breast screening strategies in the UK-NBSP. Methods: An existing validated discrete event simulation model (MANC-RISK-SCREEN) was used to evaluate the cost-effectiveness of 3 risk-stratified NBSPs (risk 1, risk 2, and risk 3) compared with the current UK-NBSP, 2-yearly screening, and no screening [lifetime horizon; health service perspective; costs (£; at 2024 prices)]. MANC-RISK-SCREEN was modified to account for bias in risk prediction and allocation to risk categories (risk misclassification). Uncertainty in the results due to model inputs was quantified using probabilistic sensitivity analysis and one-way sensitivity analyses. Results: At a cost-effectiveness threshold of £20,000 per quality-adjusted life year, 2-yearly screening was most likely to be cost-effective, followed by a risk-stratified approach whereby women at high risk (>8% 10-year risk) were screened annually and women at moderate risk (5%–8% 10-year risk) biannually. When risk misclassification was accounted for, the ranking of risk-stratified screening strategies improved relative to universal strategies. Conclusions: If 2-yearly screening is infeasible due to resource constraints, implementing a risk-stratified approach in the existing NBSP in the United Kingdom would be a cost-effective use of healthcare resources. Impact: Implementation of risk-stratified breast screening in the UK national screening program has the potential to improve cancer detection at a reasonable additional resource use and cost.