Reliability and validity of an audio signal modified shuttle walk test

BACKGROUND: The audio signal in the conventionally accepted protocol of shuttle walk test (SWT) is not well-understood by the patients and modification of the audio signal may improve the performance of the test. OBJECTIVES: The aim of this study is to study the validity and reliability of an audio signal modified SWT, called the Singla-Richa modified SWT (SWT(SR)), in healthy normal adults. PATIENTS AND METHODS: In SWT(SR), the audio signal was modified with the addition of reverse counting to it. A total of 54 healthy normal adults underwent conventional SWT (CSWT) at one instance and two times SWT(SR) on the same day. The validity was assessed by comparing outcomes of the SWT(SR) to outcomes of CSWT using the Pearson correlation coefficient and Bland–Altman plot. Test-retest reliability of SWT(SR) was assessed using the intraclass correlation coefficient (ICC). The acceptability of the modified test in comparison to the conventional test was assessed using Likert scale. RESULTS: The distance walked (mean ± standard deviation) in the CSWT and SWT(SR) test was 853.33 ± 217.33 m and 857.22 ± 219.56 m, respectively (Pearson correlation coefficient - 0.98; P < 0.001) indicating SWT(SR) to be a valid test. The SWT(SR) was found to be a reliable test with ICC of 0.98 (95% confidence interval: 0.97–0.99). The acceptability of SWT(SR) was significantly higher than CSWT. CONCLUSIONS: The SWT(SR) with modified audio signal with reverse counting is a reliable as well as a valid test when compared with CSWT in healthy normal adults. It better understood by subjects compared to CSWT.