Field Medical excellence in rare diseases: A narrative review and six-pillar conceptual framework
Rare diseases create distinctive challenges for scientific communication and health-system organization because of small patient populations, heterogeneous phenotypes, limited natural history data, fragmented referral pathways, and persistent diagnostic delays. This narrative review aimed to synthesize the literature on Medical Science Liaison (MSL) practice and rare-disease ecosystems and to propose a pragmatic framework for Field Medical excellence. A targeted search of PubMed and publicly available professional guidance repositories was conducted through July 2026 using terms related to Medical Affairs, MSL competencies, rare diseases, diagnostic delay, real-world evidence, center development, scientific insights, and impact measurement. Sources were selected for conceptual relevance rather than exhaustive coverage. The synthesis identified six interdependent domains through which Field Medical can create scientific and system-level value: Scientific Mastery, Insight Intelligence, Center Development, System Navigation, Strategic Partnership, and Impact Measurement. The framework emphasizes scientific independence, contextual interpretation of uncertain evidence, longitudinal stakeholder engagement, translation of field insights into action, and evaluation through outcome-oriented indicators rather than activity counts alone. It is intended as an organizing model, not as a validated competency instrument. Future studies should test its content validity, feasibility, and association with measurable improvements in diagnostic readiness, research feasibility, stakeholder capability, and patient-centered care pathways.