Determinants of cancer patients' involvement in treatment decision-making based on the COM-B model: A cross-sectional study

Cancer patients' involvement in treatment decision-making is affected by various factors, with the mechanisms not readily understood. This study explores the underlying mechanisms based on the Capability, Opportunity, Motivation and Behavior (COM-B) model and literature review.A cross-sectional survey was conducted and 300 cancer patients conveniently recruited from three tertiary hospitals validly completed the self-administered questionnaires. Structural equation modeling (SEM) approach was used to test the hypothesized model.The findings generally supported the hypothesized model, which could explain 45% of the variance in cancer patients' involvement in treatment decision-making. Cancer patients' health literacy and perceived facilitation of involvement from health professionals had direct and indirect effects on their actual involvement, with the total effect β = 0.594, β = 0.223, P < 0.001, respectively. Patients' views of involvement in treatment decision-making had a direct effect on their actual involvement (β = 0.296, P < 0.001) and completely mediated the relationship between self-efficacy and their actual involvement (β = 0.040, P < 0.05).Findings support the COM-B model's explanatory potential in the context of cancer patients' involvement in treatment decision-making.