Development and Temporal Stability of the Composite Occupational Recorded Burden Index (CORBI): A Composite Index for Occupational Surveillance Using Administrative Records

Objective: Develop CORBI and assess temporal stability using administrative records. Methods: We analyzed 314,140 occupational injury and disease records from a Spanish mutual insurance society (2022–2025). After exclusions, 239,140 episodes formed 208 occupation-by-recorded-sex cells with at least 100 episodes. CORBI combined four equally weighted dimensions. Development-period parameters were applied to 2025; threshold sensitivity was assessed. Results: Among 113 comparable cells, Spearman correlation was 0.677, mean absolute change was 4.26 points, 88.5% remained in the same or an adjacent quartile, and 14 of the top 20 remained. Rankings differed from a trauma-centered comparator. Across thresholds, rank correlations with the primary solution were 0.994–0.998. Conclusions: CORBI summarizes multidimensional recorded occupational burden and may support preventive review. It does not estimate incidence, exposure, causality, individual risk, or national prevalence; temporal stability does not constitute external validation.