Cost-Effective but Unaffordable Paradox / Nonmarginal Health Opportunity Cost Method
This method addresses the problem where a treatment is cost-effective based on standard thresholds but is too expensive to fund without displacing significant health benefits from other services. It adjusts the cost-effectiveness threshold to reflect the real impact on population health when large-budget treatments are adopted.
At a glance
Use when
Evaluating high-budget-impact interventions such as gene therapies or widespread screening programs; when standard cost-effectiveness suggests adoption but budget impact is concerning
Avoid when
Assessing low-cost or marginal innovations; when budget impact is negligible; in systems with flexible or expanding budgets
Inputs
Cost-effectiveness ratio of the intervention, budget impact, current healthcare budget, estimates of health opportunity costs (e.g., health forgone per dollar not spent), scale of adoption
Outputs
Adjusted cost-effectiveness threshold, estimate of health forgone due to budget displacement, recommendation on affordability despite cost-effectiveness
How it works
The method extends standard health opportunity cost reasoning by modeling nonmarginal budget impacts, recognizing that high-cost interventions can strain healthcare budgets and lead to greater forgone health benefits than marginal analyses assume. It adjusts cost-effectiveness thresholds dynamically based on the scale of budget impact, using empirical or modeled estimates of opportunity costs beyond the margin. Originated in Lomas, Claxton, Martin, and Soares (Value in Health, 2018).
- HTA domains
- Costs & Economic Evaluation
- Categories
- Cost-effectiveness Modelling
- Assumptions
- Healthcare budgets are fixed in the short term; displacing existing services leads to measurable health losses; opportunity costs increase nonlinearly with budget impact
- Strengths
- Accounts for real-world budget constraints; improves realism over marginal analysis; supports decisions on high-cost therapies; bridges economic theory and practical affordability
- Limitations
- Requires reliable data on opportunity costs; complex to implement; limited empirical validation in diverse systems; may be sensitive to assumptions about budget elasticity
- Also known as
- Nonmarginal Health Opportunity Cost Method, Cost-Effective but Unaffordable Paradox
Questions this answers
- › Is a cost-effective intervention affordable within the current budget without causing significant health opportunity costs?
- › How should cost-effectiveness thresholds be adjusted for high-budget-impact technologies?
- › What is the true health opportunity cost of adopting a nonmarginal intervention?
- › How can HTA bodies reconcile cost-effectiveness with budget impact?
- › When does affordability override cost-effectiveness in decision-making?
- › How can decision rules be adapted for transformative but expensive therapies?
References & sources
Similar by meaning
- WHO-CHOICE Generalized Cost-Effectiveness Analysis (updated methodology)
- Affordability Decision Rules Framework (budget-impact threshold categorisation)
- Norwegian severity classes and severity-weighted cost-effectiveness thresholds (Magnussen approach)
- Methods for the Estimation of the NICE Cost-Effectiveness Threshold (Claxton supply-side threshold)
- Generalized Risk-Adjusted Cost-Effectiveness (GRACE)
Beta record. Based on the original catalogue summary; primary-source enrichment pending.