One of These Things Is Not Like the Others: The Idea of Precedence in Health Technology Assessment and Coverage Decisions

The document from 2005 examines the role of analogical and precedent-based reasoning in health technology assessment (HTA) and coverage decisions for new health technologies such as intracytoplasmic sperm injection (ICSI), genetic tests for breast cancer (BRCA1/2), and sildenafil (Viagra). It describes a decision-making cycle with three phases: taking stock of existing services, applying precedents to new technologies, and integrating new decisions into the system. The paper highlights the importance of case-based reasoning for qualitative evaluation and the need for consistent application of precedent-based rationales. It also discusses the economic aspects of technologies like ICSI, with costs estimated at $3,500 per episode in Nova Scotia, and the debate over Viagra's coverage due to its cost and perception as a lifestyle drug. The document suggests that formalizing the process of analogical reasoning could lead to more credible and defensible coverage decisions, but it requires a multidisciplinary approach and careful development to reconcile normative and instrumental evaluation criteria.