Determinants of healthy lifestyle behaviours in colorectal cancer survivors: a systematic review.

Purpose: Identifying and selecting determinants of health behaviours is an important step in the design of behaviour change interventions. Many colorectal cancer (CRC) survivors experience disease- and treatment-related complaints, which may make it difficult to implement behavioural changes. In this systematic review, we aimed to identify determinants of a healthy lifestyle, i.e. dietary behaviours and physical activity, in CRC survivors who finished treatment.

Methods: We searched Web of Science, PubMed and PsychINFO, to retrieve quantitative and qualitative studies on determinants of a healthy lifestyle in CRC survivors who finished treatment. Synonyms of the following search terms were used: 'CRC survivors', 'lifestyle', 'physical activity', 'nutrition' and 'determinant'. The level of evidence for each determinant was classified as 'convincing', 'moderately convincing' or 'unconvincing' based on consistency of findings between studies and quality of studies assessed with the Mixed Methods Appraisal tool.

Results: Twenty-one studies were retrieved of which twenty were classified as 'high-quality studies' and one as 'low-quality study'. Determinants that were convincingly associated with less healthy lifestyle behaviours were smoking, depression, body image distress/consciousness, experiencing pain, dealing with symptoms and bad health status. A good functional status was convincingly associated with more healthy lifestyle behaviours. Determinants with convincing evidence for an association with less or more healthy lifestyle behaviours were time and other priorities, knowledge, motivation, (false) beliefs, perceived and expected outcomes, skills, social support, social norms and influence, access to facilities and equipment and weather.

Conclusion: Interventions for changing health behaviours in CRC survivors who finished treatment could use these determinants to tailor and personalize the intervention to the target group.