Comparisons of thickened beverages using line spread measurements.

Concerns about the preparation of thickened beverages for patients with dysphagia highlight the need for objective measurements with application to clinical settings. This cross-sectional study examined the line spread test (distance a liquid flows) to determine reproducibility of the measurements and whether specific line spread measurements can differentiate nectar- and honey-like thickness levels in the National Dysphagia Diet. Two common thickeners were tested in three different beverages. Replication of preparation procedures allowed comparison of product/beverage line spread results to viscometer-determined viscosity measured at a similar temperature and time to thicken. Analysis of variance showed a significant two-way interaction for both levels of thickness, indicating that line spread measurements differentiated products mixed with different beverages. Standard deviations and confidence intervals confirmed that measurements were highly repeatable. Line spread distance (cm) and viscosity measured in centipoise (cP) for a similar product/beverage statistically correlated with one another, suggesting that line spread and viscometry provided some similar information about thickness across the six product/beverage combinations tested.