90 determine the cause of the reduced swallowing sensation. Individuals differ in what they find important, and expectations about one’s progress after treatment may change over time and in response to personal circumstances. Patients may develop a degree of adaptation over time, in which their PRO outcomes improve, but swallowing dysfunction stays the same or worsens.11 Their subjective feeling of QoL also depends on satisfaction with, physical, material, emotional, and social wellbeing, and their development and activity. Objective observations record only what is observed; they are a representation of how something is.42 The MAT, for example, reflects a complex process of oral muscle movements and coordination, which is difficult to answer with one single question in a questionnaire. Unfortunately, the loss of teeth, dental decay and periodontal health were not assessed in this research, and may play an important role in oral functioning as well.37 Strengths and limitations A limitation of this study was that the number of salivary flow measurements performed was smaller in comparison to the masticatory performance and swallowing measurements. Therefore, it is possible that these measurements are less reliable due to insufficient power. The salivary flow measurements were much more time consuming, and difficulties occurred with the attachment of the Lashley cups. Therefore, it was chosen to combine the submandibular flow with the parotid flow, and use the total flow to determine the associations between objective and subjective measures. Although these associations regarding xerostomia were higher in comparison to those of masticatory performance and swallowing measurements, a prerequisite should be that the objective test is easy and fast to perform, in order to be a valuable addition to PROs. A recommendation would therefore be to use an easy and fast test for measuring saliva flow, for example by spitting saliva produced over a period of time in a plastic tube, with and without stimulation.43 The SWAL-QOL questionnaire is especially designed to detect swallowing problems. However, there is a close relationship between swallowing and mastication, as seen in multiple items such as ‘food selection’, ‘eating duration’, ‘eating desire’, and ‘fear of eating’. This relationship also comes across in many items of, e.g., the MDADI questionnaire.44 When the focus is on swallowing specific problems, it is therefore recommended to use swallowing specific questions only, in combination with an objective swallowing test. As shown in previous research, the reliability of the MAT, WST, EORTC QLQ-H&N35, and SWAL-QOL was high, with a reliability of 0.886 for the MAT, and 0.893 and 0.923 for the WST. The reliability of the questionnaires was between 0.75 and 0.95, indicating that all measures are reliable to use in patients with HNC.15,20,26,31,32 This study provides insight in the (weak) association between these objective and subjective measures. The results are