Page 85 - Functional impairment and cues for rehabilitation of head and neck cancer patients -

Fifth, participants unable to finish the solid without water were allowed to ingest water with it. The grams of water ingested were not added to the total amount because this would unwantedly increase the SPEAD-rate while taking water with the solid indicates worse swallowing capacity. For this reason, the SPEAD-rate should be considered an ordinal scale rather than an interval scale.
The SPEAD-test may have value in assessing swallowing capacity in dysphagia of other etiologies as well. Several swallowing tests have been developed for neurological patients, mainly focused on screening for dysphagia or aspiration after stroke (36, 37). Some also include the ingestion of a particular amount of water (38-40), or all three consistencies (41). During these tests, the patients ingests a small amount of the consistency and the observer checks whether signs of aspiration (e.g., coughing and voice change) occur. These tests, however, focus on safety rather than capacity. We therefore would like to encourage the evaluation of the reliability and validity of the SPEAD-test in populations with dysphagia due to other causes than HNC.
Limitations
This study has a few limitations. First, the study included a selected group of HNC patients who received a VFS as part of usual care. Therefore, the more severe cases of dysphagia might be overrepresented in this sample. However, since all HNC patients treated with chemoradiotherapy receive a post-treatment VFS at our institute, also patients with no to mild dysphagia were represented. In addition, the used patient population for this study is also the target population of the SPEAD-test, since the SPEAD-test will most likely be used in patients who will also receive a VFS. Given that, in this study, all patients received a VFS prior to the SPEAD-test does not imply that performing a VFS prior to the SPEAD-test is deemed mandatory, because when only the consistencies the patient also takes at home are tested no additional risk is created by performing the SPEAD-test.
Second, the intended use of the SPEAD-test is to measure the safe swallowing capacity. Therefore, similar to the advice patients receive for their daily situation, patients with (silent) aspiration on VFS (PAS 7 or 8) were advised to avoid the specific consistency during the SPEAD- test. Fourteen patients had (silent) aspiration (PAS of 7 or 8) on VFS, of who five (36%) did take the consistencies anyways. Therefore, in this study, not only safe swallows were analyzed.
Third, the observer was aware of the VFS result in this study, again, to ensure a safe swallow. We do not think that this led to any significant influence on the patients’ performance on the SPEAD-test because the patient was not spoken to during ingestion of the boluses. Analyses of the videos were only performed several weeks/months after the SPEAD-test, and we believe it is unlikely the observer at that point would recall specifics of the VFS results.
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The SPEAD-test to objectify swallowing capacity
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