The absolute reliabitily of two different tandem gait tests with minimal detectable change

Abstract

[Purpose] In this study, we examined the absolute reliability of two different tandem gait tests with minimal detectable change (MDC). [Subjects] The subjects were 28 healthy adults (mean age 63.4 ± 7.7 years). [Methods] The subjects walked 5 m with tandem gait, and we examined tandem gait time (TGT) and tandem gait index (TGI: add TGT to double-missed steps). We calculated standard error of measurement (SEM) of TGT and TGI in 4 different ways. Moreover, we examined measurement error of TGT and TGI by 95% confidence intervals of minimal detectable change (MDC95) obtained from SEM. [Results] MDC95 of TGT were 3.4-3.5 sec, and of TGI were 4.1-4.3. [Conclusion] We consider that the changes of TGT and TGI in this study were measurement errors, as the variances of measurement error found by the calculation method were too small for clinical application.