The competency of any intelligent agent is bounded by its formal account of the world in which it operates. Clinical AI lacks such an account. Existing frameworks address evaluation, regulation, or system design in isolation, without a shared model of the clinical world to connect them. We introduce the Clinical World Model, a framework that formalizes care as a tripartite interaction among Patient, Provider, and Ecosystem. To formalize how any agent, whether human or artificial, transforms information into clinical action, we develop parallel decision-making architectures for providers, patients, and AI agents, grounded in validated principles of clinical cognition. The Clinical AI Skill-Mix operationalizes competency through eight dimensions. Five define the clinical competency space (condition, phase, care setting, provider role, and task) and three specify how AI engages human reasoning (assigned authority, agent facing, and anchoring layer). The combinatorial product of these dimensions yields a space of billions of distinct competency coordinates. A central structural implication is that validation within one coordinate provides minimal evidence for performance in another, rendering the competency space irreducible. The framework supplies a common grammar through which clinical AI can be specified, evaluated, and bounded across stakeholders. By making this structure explicit, the Clinical World Model reframes the field's central question from whether AI works to in which competency coordinates reliability has been demonstrated, and for whom.

翻译：任何智能体的能力边界由其运行世界的形式化描述所界定。临床人工智能缺乏这样的描述。现有框架孤立地处理评估、监管或系统设计问题，缺乏连接这些要素的共享临床世界模型。我们提出临床世界模型（Clinical World Model）这一框架，将照护形式化为患者、提供者与生态系统三方交互。为了形式化任何智能体（无论是人类还是人工智能）如何将信息转化为临床行动，我们基于经过验证的临床认知原则，构建了提供者、患者与AI智能体的并行决策架构。临床AI技能混合（Clinical AI Skill-Mix）通过八个维度将能力具象化：五个维度定义临床能力空间（病情、阶段、照护环境、提供者角色与任务），三个维度指定AI介入人类推理的方式（分配权限、面向主体与锚定层级）。这些维度的组合乘积产生数十亿个独立能力坐标。一个核心结构意涵是：在单一坐标内的验证几乎不能为其他坐标的性能提供证据，这使得能力空间不可约简。该框架提供了一套通用语法，使临床AI能够在各利益相关方之间被明确指定、评估与约束。通过将这一结构显性化，临床世界模型将该领域的核心问题从"AI是否有效"重构为"在哪些能力坐标上，且为谁验证了可靠性"。