Implementing ICD-11 for Hospital Discharge Coding in Chile: Key Findings for Semantic Interoperability

Abstract Goal: Assess the diagnostic consistency between physicians and coders in the use of the International Classification of Diseases, 11th Revision (ICD-11). Materials and Methods A study was conducted at the San Juan de Dios Hospital in Curico between March and June 2025, incorporating ICD-11 coding into the clinical services of medicine and psychiatry. Eight physicians and two coders were trained in ICD-11, and the national Deisy ICD-11 platform was utilised to validate diagnoses. A total of 457 hospital discharges were analysed to compare diagnostic coding performed by physicians, coders, and a gold standard reference. Results For the primary diagnosis, agreement with the coder was 96% (439/457) and with the gold standard was 93% (424/457). For secondary diagnoses, agreement exceeded 90% across all evaluated fields. The Cohen's kappa coefficient between physicians and the coder was 0.963. The main errors were due to omissions in post-coordination and incorrect placement of the external cause code. The gold standard reviewed 100% of the records for which information was available. Conclusions This pilot study showed high diagnostic agreement among physicians, coders, and the national reference for coding hospital discharges. However, relevant gaps were identified in post-coordination, in the recording of external causes, and in the standardisation of review criteria. These findings provide initial evidence to guide future strategies for implementing ICD-11 in hospital morbidity.