The applicability of the international classification of functioning, disability, and health to study lifestyle and quality of life of colorectal cancer survivors.

Background: Well-designed studies on lifestyle and health-related quality of life (HRQoL) in colorectal cancer survivors based on a biopsychosocial instead of a traditional biomedical approach are warranted. We report on the applicability of the International Classification of Functioning, Disability, and Health (ICF) as useful biopsychosocial framework to improve research on how lifestyle influences colorectal cancer survivors' HRQoL, using the Energy for life after ColoRectal cancer (EnCoRe) study as an example.

Methods: The ICF was used to develop a conceptual model for studying lifestyle and colorectal cancer survivors' HRQoL, by identifying relevant factors from literature and mapping them within the ICF. Subsequently, this model was used for selection of measurement instruments and biomarkers. By linking meaningful concepts within selected measures to the ICF, we could assess the ICF coverage of our developed conceptual model.

Results: Within selected measures, 450 meaningful concepts were identified, of which 88% were linked to the ICF. The linking process resulted in 132 distinctive ICF categories assigned (38% within "Body Functions," 2% within "Body Structures," 46% within "Activities and Participation," and 14% within "Environmental Factors").

Conclusions: The selected EnCoRe study measures broadly cover ICF domains relevant to colorectal cancer survivors, stressing the relevance of using a biopsychosocial approach for studying this population's HRQoL.

Impact: The developed conceptual model will guide data analyses and interpretation, and facilitate early transfer of results for development, evaluation, and implementation of personalized multidisciplinary lifestyle interventions. We recommend the ICF as an invaluable framework for improving the quality and scope of HRQoL studies.