Visual Analysis of Swallowing Efficiency and Safety (VASES): Establishing Criterion-Referenced Validity and Concurrent Validity

Validity and Reliability of Dysphagia Outcome Severity Scale (DOSS) When Used to Rate Flexible Endoscopic Evaluations of Swallowing (FEES)

The Dysphagia Outcome and Severity Scale is used both clinically and within dysphagia research, internationally. Although it was developed using videofluoroscopic swallowing studies, it is frequently used to rate Flexible Endoscopic Evaluations of Swallowing. The validity and reliability of DOSS-use with FEES, however, has not previously been evaluated. This study investigated the validity and rater reliability of clinicians using DOSS to rate FEES. Eleven Speech-Language Pathologists (SLPs) with varied dysphagia experience were recruited to review and DOSS-rate 17 soundless FEES (198 bolus swallows) recorded from 11 heterogenic dysphagic patients (2 cases with repeat FEES) and 4 healthy adults. The SLPs DOSS-ratings were compared against the initial comprehensive dysphagia evaluation (including patient diagnosis, interview, cranial nerve and complete FEES assessment) with Functional Oral Intake Scale (FOIS) and DOSS outcome measures. The SLPs were blinded to patient details and comprehensive dysphagia examination. Re-randomised rating of FEES cases occurred two weeks later (intra rater reliability). Criterion validity for DOSS-ratings (compared against comprehensive dysphagia evaluation with FOIS and DOSS) were strong-very strong (rs = 0.858 and 0.936 respectively; p < 0.001). Inter rater reliability demonstrated high agreement (α = 0.891), also intra rater reliability demonstrated almost perfect agreement (Kw = 0.945). This study's results, with strong-very strong criterion validity and high rater reliability by SLPs, adds to the evidence for DOSS-use with FEES. Future validity research comparing DOSS with both FEES and VFSS simultaneously is recommended.

Confidence, Accuracy, and Reliability of Penetration-Aspiration Scale Ratings on Flexible Endoscopic Evaluations of Swallowing by Speech Pathologists

This study investigated rater confidence when rating airway invasion with the penetration-aspiration scale (PAS) on flexible endoscopic evaluations of swallowing (FEES), raters' accuracy against a referent-standard, inter-rater reliability, and potential associations between clinician confidence, experience, and accuracy. Thirty-one clinicians who use FEES in their daily practice were asked to judge airway invasion with the PAS and to rate their confidence that their score was correct (0-100) for 40 video clips, five in each of the 8 PAS categories. We found that raters were most confident in rating PAS 1, 7, and 8. The average confidence score across all videos was 76/100. Confidence did not have a significant relationship with accuracy against the referent-standard. Accuracy was highest for PAS 1 (92%), followed by PAS 8 (80%), PAS 7 (77%), and PAS 4 (72%). Accuracy was below 60% for PAS 2, 3, 5, and 6, the lowest being for PAS 3 (49%). Mean accuracy for all ratings, compared to referent-standard ratings, was highest for the intermediate group (71%), followed by expert (68%) and novice (65%). In general, we found that certain PAS scores tend to be rated more accurately, and that participating SLPs had varied confidence in PAS ratings on FEES. Potential reasons for these findings as well as suggested next steps are discussed.

Characterizing the Validity of Using VASES to Derive DIGEST-FEES Grades

INTRODUCTION

Visual Analysis of Swallowing Efficiency and Safety (VASES) and Dynamic Imaging Grade of Swallowing Toxicity for Flexible Endoscopic Evaluation of Swallowing (DIGEST-FEES) are two complimentary methods for assessing swallowing during FEES. Whereas VASES is intended to facilitate trial-level ratings of pharyngeal residue, penetration, and aspiration, DIGEST-FEES is intended to facilitate protocol-level impairment grades of swallowing safety and efficiency. The aim of this study was to assess the validity of using VASES to derive DIGEST-FEES impairment grades.

METHODS

DIGEST-FEES grades were blindly analyzed from 50 FEES - first using the original DIGEST-FEES grading method (n = 50) and then again using a VASES-derived DIGEST-FEES grading method (n = 50). Weighted Kappa (κw) and absolute agreement (%) were used to assess the relationship between the original DIGEST-FEES grades and VASES-derived DIGEST-FEES grades. Spearman's correlations assessed the relationship between VASES-derived DIGEST-FEES grades with measures of construct validity.

RESULTS

Substantial agreement (κw = 0.76-0.83) was observed between the original and VASES-derived grading methods, with 60-62% of all DIGEST-FEES grades matching exactly, and 92-100% of DIGEST-FEES grades within one grade of each other. Furthermore, the strength of the relationships between VASES-derived DIGEST-FEES grades and measures of construct validity (r = 0.34-0.78) were similar to the strength of the relationships between original DIGEST-FEES grades and the same measures of construct validity (r = 0.34-0.83).

CONCLUSION

Findings from this study demonstrate substantial agreement between original and VASES-derived DIGEST-FEES grades. Using VASES to derive DIGEST-FEES also appears to maintain the same level of construct validity established with the original DIGEST-FEES. Therefore, clinicians and researchers may consider using VASES to increase the transparency and standardization of DIGEST-FEES ratings. Future research should seek to replicate these findings and explore the simultaneous use of VASES and DIGEST-FEES in a greater sampling of raters and across other patient populations.

Evaluation of Post-Swallow Residue with Visual Analysis of Swallowing Efficiency and Safety in Patients with Idiopathic Parkinson's Disease

Objectives: Dysphagia is common in idiopathic Parkinson's disease (IPD) and is associated with impairments in both swallowing safety and swallowing efficiency. The goals of this study were to define post-swallow residue patterns in people with IPD and describe pathophysiological endoscopic findings affecting residue accumulation. Methods: This was a prospective single-blinded cross-sectional cohort study of patients with the diagnosis of IPD recruited from a Movement Disorder Clinic. Clinical variables included patient age, cognitive function, and measures of disease severity, and laryngoscopic examinations with a flexible endoscopic evaluation of swallowing (FEES) were completed for each patient. Visual Analysis of Swallowing Efficiency and Safety (VASES) was used to analyze FEES. Post-swallow residue outcomes and non-residue endoscopic outcomes including the Bowing index, Penetration Aspiration Scale (PAS) score, premature leakage, and build-up phenomenon were evaluated. Multiple regression models were used to evaluate factors affecting the residue at different anatomic levels. Results: Overall 53 patients completed the study. The multiple regression analyses showed a relation between (1) the presence of residue at the level of oropharynx and epiglottis with premature leakage, (2) the presence of residue at the level of the laryngeal vestibule and vocal folds with build-up phenomenon, and (3) the presence of residue at the level of the hypopharynx, laryngeal vestibule, and subglottis with airway invasion. Conclusion: Residue pattern during FEES is associated with specific swallow dysfunctions in IPD. Using residue localization and quantification may be a helpful tool in assessing the impact of targeted swallowing interventions in patients with IPD and dysphagia.

Quantifying Impairments in Swallowing Safety and Efficiency in Progressive Supranuclear Palsy and Parkinson's Disease

Dysphagia is a largely inevitable symptom in both progressive supranuclear palsy (PSP) and Parkinson's disease (PD). To date, comparative studies in these diseases have failed to detect differences in the severity of impairments in swallowing safety or efficiency, potentially due to small sample sizes and outcome measures with low sensitivity. Therefore, this study sought to address these limitations by using novel measurement methodology to comprehensively compare swallowing safety and efficiency impairments between these populations in order to better understand whether differences may exist and guide clinical management. Twenty-four participants with PSP and 24 with PD were matched for disease duration and completed flexible endoscopic evaluations of swallowing. A visual analog scale and penetration-aspiration scale quantified swallowing safety and efficiency. Bayesian multilevel models compared the frequency, severity, and variability of swallowing impairments. Individuals with PSP demonstrated greater impairments in swallowing safety, including deeper and more variable airway invasion and more frequent vocal fold and subglottic residue. Swallowing efficiency was also more impaired among individuals with PSP, including more frequent hypopharyngeal residue (with solids) and more severe residue in the oropharynx (with thin liquids and solids) and hypopharynx (with thin liquids). When airway or pharyngeal residue was present, similar within-subject variability of the amount of residue was appreciated across anatomic landmarks. This is the first study comparing the frequency, severity, and variability of swallowing impairments between PSP and PD populations. Our findings demonstrate more pronounced impairments in swallowing safety and efficiency for PSP compared to PD. These findings provide a clinically relevant characterization of swallowing measures using novel methodological and statistical approaches attempting to resolve some limitations of prior studies.

Normative Reference Values for FEES and VASES: Preliminary Data From 39 Nondysphagic, Community-Dwelling Adults

PURPOSE

The aim of this study was to establish preliminary reference values for the Visual Analysis of Swallowing Efficiency and Safety (VASES)-a standardized rating methodology used to evaluate swallowing safety and efficiency for flexible endoscopic evaluation of swallowing (FEES).

METHOD

FEES were completed in nondysphagic, community-dwelling adults using a standardized protocol of 15 swallowing trials that varied by bolus size, consistency, contrast agent, and swallowing instructions. FEES were blindly analyzed using VASES. Primary outcome measures included bolus location at swallow onset, Penetration-Aspiration Scale (PAS) scores, and percentage-based residue ratings for six anatomic landmarks. Secondary outcome measures included sip size, bite size, and number of swallows.

RESULTS

Thirty-nine healthy adults completed the study, yielding an analysis of 584 swallows. Swallows were initiated with the bolus in the pharynx for 41.8% of trials. PAS 1 was the most common score, accounting for 75.3% of trials, followed by PAS 3, which accounted for 18.8% of trials. When residue was present (> 0%), the amount was relatively small across all anatomic landmarks, with median residue ratings of 2.0% (oropharynx), 1.5% (hypopharynx), 3.0% (epiglottis), 3.0% (laryngeal vestibule), and 3.5% (vocal folds). Five events of aspiration were observed, which were characterized by subglottic residue ratings of 1%, 3%, 10%, 24%, and 90%. The average sip size of self-selected volume cup sips of water was 19.8 ml, and the average bite size of a 3.0-g saltine cracker was 1.33 g. Moreover, 78% of the trials in this study protocol (except 90-ml trials) were completed in a single swallow.

DISCUSSION

The results from this study provide preliminary norms for VASES that could be used as a reference when assessing functional swallowing outcomes during FEES. While this is an important first step in establishing norms for FEES and VASES, clinicians and researchers should be mindful that the normative reference values from this study are from a relatively small study sample (N = 39), with most people below the age of 60 years (n = 30). Future research should expand on these norms by including a greater number of people across the age continuum and with greater racial, ethnic, and gender diversity.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23504325.