Validation of a decision-analytic model for the cost-effectiveness analysis of a risk-stratified National Breast Screening Programme in the United Kingdom

Background: This study follows structured frameworks to assess the internal and external validity of a decision-analytic model-based cost-effectiveness of approaches to implement a risk-stratified national breast screening programme (risk-NBSP) in the United Kingdom (UK). Methods: A pre-defined set of steps were used to conduct the process of validation of a published decision-analytic model-based cost-effectiveness analysis of a risk-NBSP (UK healthcare perspective; lifetime horizon; costs (GBP; 2019). Internal validation was assessed in terms of: descriptive validity; technical validity; face validity. External validation was assessed in terms of: operational validation; convergent validity (or corroboration); predictive validity. Results: The results outline the findings of each step of internal and external validation. The positive aspects of the model in meeting internal validation requirements are shown. The limitations of MANC-RISK-SCREEN are described. Conclusion: Following a transparent and structured validation process, MANC-RISK-SCREEN has been shown to have good internal validity and satisfactory external validity. We suggest that MANC-RISK-SCREEN provides a robust decision-analytic model to assess the cost-effectiveness of risk-NBSP from the UK perspective.