Rethinking Residue: Determining the Perceptual Continuum of Residue on FEES to Enable Better Measurement


The goal of this work was to better understand perceptual judgments of pharyngeal residue on flexible endoscopic evaluation of swallowing (FEES) and the influence of a visual analog scale (VAS) versus an ordinal scale on clinician ratings. The intent was to determine if perceptual judgments of residue were more accurately described by equal or unequal intervals. Thirty-three speech language pathologists rated pharyngeal residue from 75 FEES videos representing a wide range of residue severities for thin liquid, applesauce, and cracker boluses. Clinicians rated their impression of the overall residue amount in each video on a VAS and, in a different session, on a five-point ordinal scale. Residue ratings were made in two separate sessions separated by several weeks. Statistical correlations of the two rating methods were carried out and best-fit models were determined for each bolus type. A total of 2475 VAS ratings and 2473 ordinal ratings were collected. Residue ratings from both methods (VAS and ordinal) were strongly correlated for all bolus types. The best fit for the data was a quadratic model representing unequal intervals, which significantly improved the r 2 values for each bolus type (cracker r 2 = 0.98, applesauce r 2 = 0.99, thin liquid r 2 = 0.98, all p < 0.0001). Perceptual ratings of pharyngeal residue demonstrated a statistical relationship consistent with unequal intervals. The present findings support the use of a VAS to rate residue on FEES, allowing for greater precision as compared to traditional ordinal rating scales. Perceptual judgments of pharyngeal residue reflected unequal intervals, an important concept that should be considered in future rating scales.

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  1. 1.

    Neubauer PD, Rademaker AW, Leder SB. The yale pharyngeal residue severity rating scale: an anatomically defined and image-based tool. Dysphagia. 2015;30(5):521–8.

  2. 2.

    Kaneoka AS, Langmore SE, Krisciunas GP, Field K, Scheel R, McNally E, et al. The boston residue and clearance scale: preliminary reliability and validity testing. Folia Phoniatr Logop. 2013;65(6):312–7.

  3. 3.

    Farneti D. Pooling score: an endoscopic model for evaluating severity of dysphagia. Acta Otorhinolaryngol Ital. 2008;28(3):135–40.

  4. 4.

    Zraick RI, Liss JM, Dorman MF, Case JL, LaPointe LL, Beals SP. Multidimensional scaling of nasal voice quality. J Speech Lang Hear Res. 2000;43(4):989–96.

  5. 5.

    Toner MA, Emanuel FW. Direct magnitude estimation and equal appearing interval scaling of vowel roughness. J Speech Hear Res. 1989;32(1):78–82.

  6. 6.

    Gerratt B, Rosenbek JT, Wertz R, Boysen A. Use and perceived value of perceptual and instrumental measures in dysarthria management. In: Moore C, Yorkston K, Beukelman Brookes D, editors. Dysarthria and apraxia of speech. Baltimore: Brookes; 1991. p. 77–93.

  7. 7.

    Gerratt BR, Kreiman J, Antonanzas-Barroso N, Berke GS. Comparing internal and external standards in voice quality judgments. J Speech Hear Res. 1993;36(1):14–20.

  8. 8.

    Kreiman J, Gerratt BR, Precoda K, Berke GS. Individual differences in voice quality perception. J Speech Hear Res. 1992;35(3):512–20.

  9. 9.

    Ahearn EP. The use of visual analog scales in mood disorders: a critical review. J Psychiatr Res. 1997;31(5):569–79.

  10. 10.

    Averbuch M, Katzper M. Assessment of visual analog versus categorical scale for measurement of osteoarthritis pain. J Clin Pharmacol. 2004;44(4):368–72.

  11. 11.

    Eadie TL, Doyle PC. Direct magnitude estimation and interval scaling of naturalness and severity in tracheoesophageal (TE) speakers. J Speech Lang Hear Res. 2002;45(6):1088–96.

  12. 12.

    Carlsson AM. Assessment of chronic pain. I. Aspects of the reliability and validity of the visual analogue scale. Pain. 1983;16(1):87–101.

  13. 13.

    Kempster GB, Gerratt BR, Verdolini Abbott K, Barkmeier-Kraemer J, Hillman RE. Consensus auditory-perceptual evaluation of voice: development of a standardized clinical protocol. Am J Speech Lang Pathol. 2009;18(2):124–32.

  14. 14.

    Eadie TL, Doyle PC. Direct magnitude estimation and interval scaling of pleasantness and severity in dysphonic and normal speakers. J Acoust Soc Am. 2002;112(6):3014–21.

  15. 15.

    Cheng T. Direct magnitude estimation versus visual analogue scaling in the perceptual rating of hypernasality. University of Hong Kong, Pokfulam, Hong Kong; 2006.

  16. 16.

    Yiu EM, Ng CY. Equal appearing interval and visual analogue scaling of perceptual roughness and breathiness. Clin Linguist Phon. 2004;18(3):211–29.

  17. 17.

    Stevens SS. Psychophysics. New York: Wiley; 1975.

  18. 18.

    Helou LB, Solomon NP, Henry LR, Coppit GL, Howard RS, Stojadinovic A. The role of listener experience on Consensus Auditory-perceptual Evaluation of Voice (CAPE-V) ratings of postthyroidectomy voice. Am J Speech Lang Pathol. 2010;19(3):248–58.

  19. 19.

    Kelly AM, Leslie P, Beale T, Payten C, Drinnan MJ. Fibreoptic endoscopic evaluation of swallowing and videofluoroscopy: does examination type influence perception of pharyngeal residue severity? Clin Otolaryngol. 2006;31(5):425–32.

  20. 20.

    Pisegna JM, Langmore S. Measuring Residue: Categorical Ratings Versus a Visual Analog Scale. Dysphagia Research Society Annual Convention; March, 12, 2015; Chicago, IL, 2015.

  21. 21.

    Higgin J, Green S. Cochrane handbook for systematic reviews of interventions: the cochrane collaboration. Blackwell: Wiley; 2008.

  22. 22.

    Rousson V, Gasser T, Seifert B. Assessing intrarater, interrater and test-retest reliability of continuous measurements. Stat Med. 2002;21(22):3431–46.

  23. 23.

    Baylis A, Chapman K, Whitehill TL, Group TA. Validity and reliability of visual analog scaling for assessment of hypernasality and audible nasal emission in children with repaired cleft palate. Cleft Palate Craniofac J. 2015;52(6):660–70.

  24. 24.

    McDonald J. Handbook of biological statistics. 3rd ed. Baltimore: Sparky House Publishing; 2014.

  25. 25.

    Brancamp TU, Lewis KE, Watterson T. The relationship between nasalance scores and nasality ratings obtained with equal appearing interval and direct magnitude estimation scaling methods. Cleft Palate Craniofac J. 2010;47(6):631–7.

  26. 26.

    Schiavetti N, Martin RR, Haroldson SK, Metz DE. Psychophysical analysis of audiovisual judgments of speech naturalness of nonstutterers and stutterers. J Speech Hear Res. 1994;37(1):46–52.

  27. 27.

    Southwood M, Weismer G. Listener judgments of the bizarreness, acceptability, naturalness, and normalcy of the dysarthria associated with amyotrophic lateral sclerosis. J Med Speech-Lang Pathol. 1993;1:151–61.

  28. 28.

    Stokes ME, Davis CS, Koch GG. Categorical data analysis using the SAS system, vol. 8. 2nd ed. Cary: SAS Institute; 2000. p. 626.

  29. 29.

    Pisegna JM, Kaneoka A, Langmore S. Danger Zones: Rating Residue in 3 Zones to Identify Those At Risk for Penetration/Aspiration on FEES. Dysphagia Research Society; February 26, 2016; Phoenix, AZ2016.

  30. 30.

    Brunier G, Graydon J. A comparison of two methods of measuring fatigue in patients on chronic haemodialysis: visual analogue vs Likert scale. Int J Nurs Stud. 1996;33(3):338–48.

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The lead author would like to thank Dr. Elizabeth Hoover and Dr. Wendy Coster for their input and guidance in the development of this research. We are also grateful for the participation in this investigation by speech pathologists across the United States.


Salary and tuition support was provided to the first and last authors from National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under Award Number R01DC012584 (PI: Kumar). The Department of Speech, Language, and Hearing of Sargent College (Boston University) also provided financial support for this research via the Dudley Allen Sargent Research Fund.

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Correspondence to Jessica M. Pisegna.

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Portions of this manuscript were presented at the Dysphagia Research Society in Portland, Oregon on Saturday, March 4, 2017.

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Pisegna, J.M., Kaneoka, A., Leonard, R. et al. Rethinking Residue: Determining the Perceptual Continuum of Residue on FEES to Enable Better Measurement. Dysphagia 33, 100–108 (2018).

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  • Deglutition
  • FEES
  • Pharyngeal residue
  • Ratings
  • Visual analog scale
  • Prothetic continuum