Identifying the concepts contained in outcome measures of clinical trials on breast cancer using the International Classification of Functioning, Disability and Health as a reference.

OBJECTIVES: To systematically identify and quantify the concepts contained in outcome measures of clinical breast cancer trials using the International Classification of Functioning, Disability and Health (ICF) as a reference. METHODS: Randomized controlled trials between 1991 and 2000 were located in MEDLINE and selected according predefined criteria. The outcome measures were extracted and the concepts contained in the outcome measures were linked to the ICF. RESULTS: A total of 640 trials were included. Ninety-four different health status questionnaires were extracted. Three questionnaires were breast cancer-specific and 12 cancer-specific. Of 19,692 extracted concepts, 88% could be linked to the ICF. The most used ICF categories within the components body structures, body functions, and activities and participation were structure of the reproductive system (s630), sensations associated with the digestive system (b535), and looking after one's health (d570) with frequencies of 64%, 46% and 14%, respectively. No category of the environmental factors component reached a frequency of 10%. CONCLUSION: The ICF provides a useful reference to identify and quantify the concepts contained in outcome assessment used in clinical breast cancer trials. There seems to be a lack of health concepts evaluating specific aspects of disability and participation in breast cancer. Similarly, environmental factors with an impact on individual life of breast cancer survivors seem to be poorly represented.