Correlates of physical activity among colorectal cancer survivors: results from the longitudinal population-based profiles registry

Physical activity can improve health of cancer survivors. To increase physical activity levels among colorectal cancer (CRC) survivors, we need to understand which factors affect physical activity. Therefore, this study examined the longitudinal relationship between symptom-related, functioning-related, and psychological barriers and socio-demographic and clinical factors with physical activity among CRC survivors. CRC survivors identified from the population-based Eindhoven Cancer Registry (ECR) diagnosed between 2000 and 2009 were included. Survivors completed validated questionnaires measuring moderate-to-vigorous physical activity (MVPA) and barriers in 2010(T1), 2011(T2), and 2012(T3). Linear-mixed models and linear regression techniques were used. Response rates were 74 % (N = 2451, T1); 47 % (N = 1547, T2); and 41 % (N = 1375, T3). Several factors were negatively associated with MVPA: symptom-related barriers (e.g., fatigue, dyspnea, chemotherapy side effects, pain, appetite loss, and weight loss); psychological barriers (i.e., depressive symptoms and anxiety); functioning-related barriers (e.g., low physical or role functioning, unfavorable future perspective); socio-demographic (i.e., older age, female, no partner); and clinical factors (i.e., obesity). However, no within-subject effects were significantly associated with MVPA. Groups of functioning-related barriers, socio-demographic factors, symptom-related barriers, psychological barriers, and clinical factors explained 11, 3.9, 3.8, 2.4, and 2.2 % of the variance in MVPA at T1, respectively. Several functioning-related and symptom-related barriers and few socio-demographic factors were associated with physical activity among CRC survivors. Future interventions to promote physical activity among CRC survivors could benefit by taking into account functioning aspects and symptoms of cancer and its treatment, and assess the causal direction of these associations.