Effects of Puree Type and Color on Ratings of Pharyngeal Residue, Penetration, and Aspiration during FEES: A Prospective Study of 37 Dysphagic Outpatient Adults.

The raters agreed strongly on residue above the voice box, but much less on residue lower in the throat and on penetration and aspiration, so some of the differences found could be disagreement between raters rather than real differences between foods. Most patients had no or only mild swallowing impairment, so this says little about people with more severe dysphagia, and in particular about aspiration risk in that group. Only 37 patients at one clinic took part, and the amount of residue seen is a visual estimate, not a measurement of how much food was actually left behind. The authors state the effects were small to medium and that it is not yet clear whether differences of this size would change clinical decisions or management. The study was not set up to compare blue with green coloring, so nothing here says which color would be better. Where the two raters disagreed, the first author made the deciding rating, and that person is a developer of the rating tool used, so not every score was fully independent.

Nothing to declare: the authors report no conflicts of interest and the study had no sponsor or funder. It was approved as a quality improvement project, and the ethics board did not require written or verbal consent from the patients.

Treat this as a finding about measurement, not about swallowing. Colouring a puree did not make anyone aspirate more; it made clinicians rate more residue, and residue here is an estimate made by eye from the video. A higher residue score on a coloured puree does not mean the patient actually cleared less food.