Revision process for the International statistical classification of diseases and related health problems

The International classification of diseases and related health problems, 11th revision (ICD-11) includes an organized system of linked biomedical concepts and hierarchical coding tables called linearizations, of which the most important is the ICD-11 for Mortality and Morbidity Statistics. A publicly accessible web-based platform supports the dynamic maintenance of ICD-11 content, including proposals for modifications, based on scientific evidence and clinical relevance. This paper describes how proposals submitted through the platform are reviewed by the ICD-11 Medical and Scientific Advisory Committee. We analysed World Health Organization data on proposals to modify ICD-11 entities submitted between 2021 and 2025, according to proposal source, subject area, proposal type, time to decision and outcome. The advisory committee reviewed 256 proposals concerning 92% (24/26) of ICD-11 chapters. Proposals were submitted by international bodies, individual practitioners, patient advocacy groups and scholarly societies, with similar acceptance rates across groups. The most common proposal type was the addition of an entry, which had an acceptance rate 65% (81/125); followed by the deletion of an obsolete entity, which had an acceptance rate of 77% (44/57). The mean time to decision was 13.8 months. Overall, 69% (176/256) of proposals were recommended for adoption. These findings indicate that the advisory committee's review process is functioning adequately, with reasonable acceptance rates following scientific scrutiny. Outreach should be considered to encourage submissions in chapters with few updates between 2021 and 2025. Turnaround time may improve with the expansion of the advisory committee's membership and clearer guidance on proposal quality.