Test-retest variability in normal swallowing.

The test-retest variability of the modified barium swallow study using videofluoroscopy was analyzed. Sixteen normal subjects (8 men, 8 women) were organized into 2 age groups: middle-aged group (mean, 45 years) and old-age group (mean, 66 years). Nine durational measures of the swallow were evaluated. There were no statistically significant differences for any of the measures between the initial test and a retest conducted days later. The findings suggest that, on the whole, normal subjects perform similarly on test and a retest. However, the variability displayed by these normal subjects may be clinically significant, indicating that test-retest swallowing duration measures require careful interpretation.