148 Figure 2. Mean scores of the SWAL-QOL total score and subscales with standard error from baseline (M0) up to 2 years (M24) after treatment in patients with head and neck cancer *: p<0.05 in comparison to baseline SWAL-QOL: Quality of Life in Swallowing Disorders questionnaire Eating duration evaluated with Linear Mixed Model The factors alcohol, comorbidity, HPV status, age, and the interaction between timing of assessment and tumor stage were not associated with eating duration, and were therefore removed from the model. The factors sex, smoking, weight loss, tumor site, treatment, tumor stage, and timing of assessment were associated with a worse eating duration (Table 2). The eating duration was worse in females in comparison to males (+4.15). Furthermore, smoking (+11.23 in comparison to nonsmokers) and losing weight before treatment (+7.56 for >5 kg in comparison to no weight loss), and more advanced tumor stage (stage III-IV) (+11.01 for stage IV in comparison to stage I),34 were associated with a worse eating duration. The eating duration increased from baseline to 3 months after treatment (+8.15), remained significantly worse 6 months after treatment (+6.67), and did not return to baseline 12 and 24 months after treatment (+1.33 and +6.11, respectively). In addition, significant interactions were found for timing of assessment with tumor site and treatment, indicating that the course over time differed between different tumor sites and different treatment modalities (Figure 3). Patients with a tumor located in the oropharynx or oral cavity showed a worsening in eating duration 3 and 6 months after treatment, after which the numbers did not return to baseline 12 and 24 months after treatment. Patients with a