Methodologies used in the development of the international classification of functioning, disability and health core sets: a systematic scoping review

Objectives To systematically examine the methodologies used in the development of International Classification of Functioning, Disability and Health (ICF) Core Sets (CSs) across all developmental phases, and to identify methodological variation in stakeholder involvement, geographical representation, consensus procedures and validation approaches to inform the future development of ICF CSs. Design Scoping review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) and Joanna Briggs Institute methodological guidance. Setting Literature published between January 2001 and July 2024. Publications were identified through PubMed, supplemented by reference list screening and author contact where necessary. Participants We identified 170 relevant publications related to the development, validation and implementation, covering 34 CS across diverse health conditions. Eligible publications comprised preparatory studies (eg, systematic reviews, patient perspective studies, expert surveys), protocol/discussion papers, consensus conference reports, validation and implementation studies. Results Most publications originated from Europe. The comprehensive CS averaged 97 ICF categories (SD 29) and the brief CS 26 (SD 12). In 38% of the studies, the focus was only on validity research. Variations were observed in patient and expert involvement during development. Considerable variation was observed in stakeholder involvement, geographical representation, consensus procedures and validation approaches across developmental phases. Conclusion This review demonstrates substantial methodological diversity in ICF CS development across the different phases. While the developmental framework proposed by Selb et al was generally reflected across studies, considerable variation existed in how developmental phases were operationalised. Future ICF CS developments may benefit from stakeholder involvement, more balanced geographical representation, and continued attention to validation and implementation activities.