Physician-scientists link clinical investigation with biomedical discovery, yet sustaining research engagement across training and early career remains challenging. We conducted a structured evidence synthesis of physician-scientist training in China and selected comparator systems. PubMed and Web of Science searches covering 2010-2025 yielded 3,639 records; after deduplication, screening, and adjudication, 90 primary empirical studies were included, comprising 73 with direct physician-scientist evidence and 17 with supportive residency-context evidence. Research exposure varied across pathways and programs. Chinese residency studies documented substantial training burden, while formal protected research time was not consistently identified in reviewed residency settings, positioning residency as a plausible constraint on research continuity without establishing causality. The transition from structured training toward research independence also emerged as a recurrent vulnerability involving discontinuities in protected research opportunity, mentorship, and career-development support. Across systems, protected research opportunity, transition support, funding continuity, and early-career support recurred as structural features, with implementation varying by system, institution, program, and career stage. These findings support research continuity as an organizing framework and identify structural mechanisms warranting prospective evaluation rather than universal prescription.
