Employing the International Classifications of Functioning, Disability, and Health to identify relevant categories for disability evaluation in older adults from the research perspective: a systematic review

The objective of this study was to identify relevant aspects for disability evaluation used in scientific literature for older adults. We employed a systematic review methodology as outlined by the ICF Research Branch. The methodology consists of four steps: 1) identifying studies that focus on disability evaluation among older adults; 2) identifying disability measures used in these studies; 3) linking the concepts contained in these measures to ICF categories; 4) conducting frequency analysis. A total of 1942 concepts contained in disability measures from 137 studies were extracted. About 97.7% of the concepts could be linked, and 1862 concepts were linked to 52 second-level ICF categories. Of these, 44 categories found in at least 5% of the studies (range 5.1-85.4%) were selected to develop an outcome set that represents the relevant categories, including five categories in the Body Functions component and 39 categories from the Activities and Participation component. The relevant categories identified in our study reflect the essential areas that measure disability for older adults, providing a scientific basis for developing an ICF Core Set for disability evaluation, in combination with further empirical study and expert survey. Information from the outcome set is also valuable for providing a standardized minimal set for disability measurement, which can be used for data comparison across different studies and the development of an ICF-based disability measurement tool.