Scoring the Penetration-Aspiration Scale (PAS) in Two Conditions: A Reliability Study

A widely applied metric for identifying airway invasion events is the Penetration-Aspiration Scale (PAS). PAS scores are often included as primary outcome measures in clinical interventional studies, applied to characterize airway protection in a particular disease, used to establish a normal referent for control group comparisons without dysphagia, and as determinants or predictors of clinical outcomes. Despite the widespread use of the PAS, there is variability in scoring condition. One common method used in research studies includes rater scores applied to each single swallow that occurred during a modified barium swallow study (MBSS) of the same patient. A second common method includes raters scoring single swallow segments that have been spliced from full MBSS from different patients. These single swallow segments are then randomly distributed and the rater is blinded to all swallows that occurred during that patient MBSS. The potential effects of different scoring conditions on rater reliability and score accuracy have not been studied and may have high relevance for the conclusion drawn from the result. The primary aim of this investigation is to determine the impact of two scoring conditions on rater reliability and score accuracy: 1. Contextual, unblinded scoring condition and 2. Randomized, blinded condition. Results of the present study show that no statistically significant differences in PAS rater reliability and score accuracy were found between the two scoring conditions. If findings from this pilot study are reproduced in larger sample sizes, the time and intensity involved in splicing and randomizing MBSS for scoring may not be necessary.