A Transparent Method for Medicolegal Decision-Making: The FAIR Framework for Individualized Attribution in Occupational Disease.

OBJECTIVE: To present and evaluate Factor Attribution for Integrated Risk (FAIR), a framework for proportional attribution of excess disease risk in occupational medicine. FAIR aligns epidemiologic evidence with medicolegal thresholds (>50%, ≥20%) and distinguishes population-level causal evidence from case-level apportionment. METHODS: FAIR integrates structured evidence appraisal, extraction of relative risks and baseline incidence, and Shapley value-based partitioning of excess risk across determinants. Attribution outputs are interpreted against medicolegal thresholds. The framework was applied to three exposure-disease pairs: mesothelioma, cutaneous squamous cell carcinoma, and bladder cancer. RESULTS: FAIR reproduced established attribution hierarchies: asbestos >50%, occupational ultraviolet radiation 30-40%, and solvents 20-25%. Sensitivity analyses varying baseline incidence and model specification showed stable attribution (<±7%). CONCLUSIONS: FAIR provides a transparent approach for translating epidemiologic evidence into threshold-aligned individual attribution in occupational disease assessment.