The effect of liquid consistency on penetration-aspiration: a Bayesian analysis of two large datasets.

The analysis used barium liquids and PAS scores, and did not assess downstream outcomes such as pneumonia. Dataset 1 combined two industry-funded projects and dataset 2 included many healthy participants, and the diagnostic groups were not balanced. Moderately and extremely thick liquids were taken by teaspoon, limiting bolus volume to 4-6 ml, while thin, slightly thick, and mildly thick liquids were sipped from cups, so smaller bolus volume may explain part of the safety benefit. Thicker liquids were always tested later in the protocol, so practice or fatigue effects cannot be ruled out. Patient-selected sip volumes meant bolus volume could not be analysed. Barium contrast differed in taste from regular liquids. Worsening was rare but occurred, including participants whose worst thin-liquid score was PAS 7 and who showed silent aspiration on thicker liquids.

Two source projects were funded by Nestlé Health Science, which also funded both authors' manuscript preparation and the open access publication fee. Project 2 was funded by the National Institute of Deafness and Other Communication Disorders. The second author was the principal investigator of the source projects.

Do not conclude that thickened liquids are always safe or that they prevent pneumonia. The study measured swallowing safety scores on barium liquids, not clinical outcomes, and a small number of participants had worse airway invasion on thicker liquids.