Structural Validity, Internal Consistency, and Rater Reliability of the Modified Barium Swallow Impairment Profile: Breaking Ground on a 52,726-Patient, Clinical Data Set

Purpose: The purpose of this study was to extend the assessment of the psychometric properties of the Modified Barium Swallow Impairment Profile (MBSImP). Here, we re-examined structural validity and internal consistency using a large clinical-registry data set and formally examined rater reliability in a smaller data set. Method: This study consists of a retrospective structural validity and internal consistency analysis of MBSImP using a large data set (N = 52,726) drawn from the MBSImP Swallowing Data Registry and a prospective study of the interrater and intrarater reliability of a subset of studies (N = 50) rated by four MBSImPtrained speech-language pathologists. Structural validity was assessed via exploratory factor analysis. Internal consistency was measured using Cronbach's alpha for each of the multicomponent MBSImP domains, namely, the oral and pharyngeal domains. Interrater reliability and intrarater reliability were measured using the intraclass correlation coefficient (ICC). Results: The exploratory factor analysis showed a two-factor solution with factors precisely corresponding to the scale's oral and pharyngeal domains, consistent with findings from the initial study. Component 17, that is, the esophageal domain, did not load onto either factor. Internal consistency was good for both the oral and pharyngeal domains (alpha oral = .81, alpha pharyngeal = .87). Interrater reliability was found to be good with ICCinterrater = .78 (95% confidence interval [CI; .76, .80]). Intrarater reliability was good for each rater, ICCRater-1 = .82 (95% CI [.77, .86]), ICCRater-2 = .83 (95% CI [.79, .87]), ICCRater-3 = .87 (95% CI [.83, .90]), and ICCRater-4 = .87 (95% CI [.83, .90]). Conclusions: This study leverages a large-scale, clinical data set to provide strong, generalizable evidence that the MBSImP assessment method has excellent structural validity and internal consistency. In addition, the results show that MBSImP-trained speech-language pathologists can demonstrate good interrater and intrarater reliability.