Interlaboratory variability of rotational chair test results II: Analysis of simulated data

Abstract

Standardization of rotational chair testing across laboratories has not been achieved because of differences in test protocol and analysis algorithms. The Interlaboratory Rotational Chair Study Group was formed to investigate these differences. Its first study demonstrated significant variability in calculated results using actual patient data files. No estimation of accuracy could be made, however, because the "true" values of response parameters were unknown. In this study we used simulated "patient" data files to further explore the differences among analysis algorithms. We found a high degree of agreement and accuracy across laboratories using automated analysis of high signal-to-noise/low-artifact data for gain, phase, and asymmetry. Variability increased significantly for the lower signal-to-noise ratio/higher artifact files. Operator intervention generally improved accuracy and decreased variability, but there were cases in which operator intervention reduced accuracy.

Rotational Chair (ROTO) Instead of Electronystagmography (ENG) as the Primary Vestibular Test

“…3,4é Another potential criticism of rotation chair testing is its reproducibility; however, modern computerized algorithms have demonstratedéhighérateséoféagreementéamongélaboratories. 5 Although both central and peripheral abnormalities can cause "peripheral" findings on ROTO, the amount of overlap will ultimately be defined through additional clinicallaboratory correlation studies such as the current report. Ideally a prospective controlled method could be devised.…”

“…Yet, even in the absence of a computerized chair, rotational testing of the VOR can be accomplished with manual rotation 3 , 4 . Another potential criticism of rotation chair testing is its reproducibility; however, modern computerized algorithms have demonstrated high rates of agreement among laboratories 5 …”