Identifying the concepts contained in outcome measures of clinical trials on stroke using the international classification of functioning, disability and health as a reference

Objectives: To systematically identify and quantify the concepts contained in outcome measures in stroke trials using the International Classification of Functioning, Disability and Health (ICF) as a reference. Methods: Randomized controlled trials between 1992 and 2001 were located in MEDLINE and selected according to predefined criteria. Outcome measures were extracted and concepts contained in the outcome measures were linked to the ICF. Results: A random sample of 160 (50%) of 320 eligible studies was included. A total of 148 standardized health status measures were identified. Of 11283 extracted concepts, 91% could be linked to the ICF. The most used ICF categories for each component were d450 walking (70%) for activities and participation, b525 defecation functions (62%) for body functions, and e399 support and relationships, unspecified (30%) for environmental factors. Conclusion: The ICF provides a useful reference to identify and quantify the concepts contained in outcome measures used in stroke trials. Outcome measurement in stroke refers to an enormous variety of concepts; for comparability of research findings agreement on what should be measured is needed.