Variability in quantitative outcomes of instrumental swallowing assessments in adults: a scoping review

To map scientific evidence on the variability of quantitative parameters extracted by instrumental swallowing assessment tests in adults, using the coefficient of variation.

The methodological procedures recommended by the Joanna Briggs Institute and the extension for scoping reviews of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA-ScR) were followed.

The search was carried out in the Pubmed/Medline, Lilacs, Cochrane Library, Embase, Web of Science, Scopus and CINAHL databases, as well as in Google Scholar to consult the gray literature.

Two blind and independent reviewers screened the articles by title and abstract. Subsequently, the articles were read in full and selected according to the eligibility criteria. Data were extracted according to a standardized instrument.

363 studies were found, 13 of which were eligible. Most studies had a sample size of less than 30 participants and were made up of healthy individuals. The instrumental exams used were diverse: videofluoroscopy, electrical impedance tomography, laryngeal sensors, high-resolution manometry and surface electromyography. The studies searched for intra-individual variability and the coefficient of variation ranged from low to high variability, as the instruments, parameters and collection procedures were very heterogeneous and non-standardized.

Intra-individual variability of the quantitative outcomes of instrumental swallowing assessments in adults ranged from low to high according to the exam, outcome, presence or absence of underlying disease, consistency and volume of the bolus.