Abstract
<sec> <title>BACKGROUND</title> <p>Pre-deployment failure, where digital health technologies do not progress to implementation despite technical maturity, clinical validation, and user testing, remains poorly understood and undertheorised.</p> </sec> <sec> <title>OBJECTIVE</title> <p>This study introduces the Software as a Medical Device (SaMD) Trap, a sociotechnical theory that explains how regulated digital health innovations can fail before implementation and adoption</p> </sec> <sec> <title>METHODS</title> <p>The theory was developed through a qualitative case study of a digital health tool created within a funded research programme. Data comprised 11 semi-structured interviews involving seven stakeholder groups and 17 months of programme meeting minutes. A sociotechnical analysis was conducted to identify mechanisms contributing to pre-deployment failure.</p> </sec> <sec> <title>RESULTS</title> <p>Three interacting mechanisms were identified. Invisible Regulatory Infrastructure reflects limited regulatory literacy and insufficient access to regulatory expertise and support. Sequential Gatekeeping describes how regulatory, governance, and compliance requirements emerge progressively and cannot be addressed independently. Temporal Misalignment occurs when regulatory and implementation timelines extend beyond the duration of research funding cycles. Together, these mechanisms explain why technically viable and clinically validated digital health systems may be unable to transition into routine practice. The theory also generated a set of testable propositions and informed the development of the SaMD Readiness Scoping Tool, designed to assess regulatory feasibility during project planning.</p> </sec> <sec> <title>CONCLUSIONS</title> <p>The SaMD Trap provides a novel sociotechnical explanation for pre-deployment failure in regulated digital health. By identifying the mechanisms that hinder implementation before deployment begins, the theory offers a foundation for future empirical testing and highlights the importance of considering regulatory readiness alongside technical and clinical development during the design and funding of digital health innovations.</p> </sec>