The intra- and inter-rater reliability of the tragus wall distance (TWD) measurement in non-pathological participants ages 18–34

Abstract

Objectives

To assess intra-rater and inter-rater reliability of the tragus wall distance (TWD) measurement in non-pathologic individuals aged 18–34. Background: Physical therapists evaluate posture as a component of health status. A literature review suggests need for reliable clinical tools to assess head position. Methods: The TWD measurement is the horizontal distance between the tragus, the auricular cartilaginous flap anterior to the external auditory meatus, and a wall. Sixty-three adults aged 18–34 years were consecutively assigned to three raters for double-blinded repeated measures of TWD distance. Statistical analyses included descriptive statistics of the sample, interclass correlation coefficient (ICC), analysis of variance (ANOVA), t-tests (p < 0.05), and Pearson correlation coefficients to quantify correlations between raters and repeated measures. Results: ANOVA results for intra-rater reliability indicated consistency among individual raters. All raters demonstrated significant correlations across repeated measures, ICC = 0.92–0.94. ANOVA and t-test results did not support inter-rater reliability. However, ICC = 0.90, standard error of measurement = 0.22, and Pearson R = 0.84 supported inter-rater reliability. The evidence suggests that although the absolute TWD measurement values may not be reliable among raters, relative change between TWD measures demonstrates high inter-rater reliability. Conclusions: TWD measurement has high intra-rater reliability. TWD measurement of a single patient by multiple raters is not supported.