Demographic, Lifestyle, and Clinical Factors Associated with Accelerometer-Based Physical Activity in Patients with Head and Neck Cancer: A Prospective Cohort Study.

PURPOSE: This study aimed to objectively assess changes in total physical activity (PA) and moderate-to-vigorous physical activity (MVPA) from head and neck cancer (HNC) diagnosis up to two years post-treatment, and to identify demographic, lifestyle, and clinical factors associated with total PA and MVPA levels and their trajectories. METHODS: Data were derived from the prospective NET-QUBIC cohort. PA and MVPA were measured using a waist-worn accelerometer (ActiGraph wGT3X) before treatment and at 6, 12, and 24 months post-treatment. Linear mixed models were used to examine changes in total PA and MVPA and to identify factors associated with these changes. RESULTS: In total, 517 patients were included. Univariable analyses showed higher total PA and MVPA at 24 months compared with baseline. In multivariable analyses, overall time effects were not significant, but alcohol use and sex showed time-dependent associations. Alcohol users were more active at baseline than non-users, whereas activity levels became comparable during follow-up. Females had higher total PA at baseline, but males showed consistently higher total PA and MVPA after treatment. Comorbidities, older age, and smoking were associated with lower total PA and MVPA, while a WHO performance score of one or two was associated with lower total PA. CONCLUSIONS: Total PA and MVPA did not significantly change over time after adjustment, although trajectories differed by alcohol use and sex. Comorbidities, older age, smoking, and higher WHO performance score were consistently associated with lower activity levels. These findings may inform risk profiles and support tailored rehabilitation strategies for patients with HNC.