Development, reliability, and validation of an infant mammalian penetration-aspiration scale

A penetration-aspiration scale exists for assessing airway protection in adult videofluoroscopy and fiberoptic endoscopic swallowing studies; however, no such scale exists for animal models. The aim of this study was threefold: (1) develop a penetration-aspiration scale (PAS) for infant mammals, (2) test the scale's intra- and interrater reliabilities, and (3) validate the use of the scale for distinguishing between abnormal and normal animals. After discussion and reviewing many videos, the result was a 7-point infant mammal PAS. Reliability was tested by having five judges score 90 swallows recorded with videofluoroscopy across two time points. In these videos, the frame rate was either 30 or 60 frames per second and the animals were either normal, had a unilateral superior laryngeal nerve (SLN) lesion, or had hard palate local anesthesia. The scale was validated by having one judge score videos of both normal and SLN lesioned pigs and testing the difference using a t test. Raters had a high intrarater reliability [average κ = 0.82, intraclass correlation coefficient (ICC) = 0.92] and high interrater reliability (average κ = 0.68, ICC = 0.66). There was a significant difference in reliability for videos captured at 30 and 60 frames per second for scores of 3 and 7 (P <0.001). The scale was also validated for distinguishing between normal and abnormal pigs (P <0.001). Given the increasing number of animal studies using videofluoroscopy to study dysphagia, this scale provides a valid and reliable measure of airway protection during swallowing in infant pigs that will give these animal models increased translational significance.