Methodological considerations in cross-sectional studies validating the International Classification of Functioning, Disability and Health (ICF) Core-Sets: a systematic review

Abstract

Purpose: To describe and analyze the methodological characteristics and quality of cross-sectionalstudies that have validated an ICF-CS. Materials and methods: A systematic review was conducted to identify empirical studies publishedin English that validated any ICF-CS using a cross-sectional design. Databases searched included Webof Science, Scopus, CINAHL, PubMed, Embase, and PsycINFO. The search was conducted in November2022 with an update in October 2023. Two independent reviewers coded studies that met theinclusion criteria and assessed their methodological quality and risk of bias using the AXIS tool.Synthesis was performed by calculating frequencies and percentages. Results: 87 articles validating 24 ICF-CSs were analyzed. Most articles showed strengths in consistencybetween study objectives and the outcome variables measured. However, a large majority did notreport sample size calculation (up to 94.2% in Delphi studies), and few validation studies wereconducted in the WHO regions of Africa and the Eastern Mediterranean. Conclusions: The quality of cross-sectional studies validating ICF-CSs was satisfactory, although severalarticles did not describe aspects such as sample size calculation. Validity evidence for ICF-CS studiescould be improved by conducting more multicenter studies, replicating ICF-CS validation studies indifferent WHO regions, and through synthesis of existing research.