Chinese (Mandarin) translation of the incremental shuttle walk test and its validity and reliability: A cross-sectional study.

Background/purpose: To date, there are no published validated Chinese versions of the incremental shuttle walk test (ISWT) instructions despite its wide clinical applications. Translation of the Chinese ISWT instruction is done in an ad-hoc manner within the Chinese-speaking populations, affecting the test's reliability and validity since translation can differ significantly between individuals. This warrants the need for psychometric testing of such translation.

Objectives: To develop a Chinese (Mandarin) version of the ISWT instructions (ISWT-CHN) that is conceptually equivalent to the original English version (ISWT-ENG) and establish its reliability and validity.

Methods: Forward and backward translations from the ISWT-ENG were done to generate the ISWT-CHN. Face and content validity was determined during the translation process. Intra-rater and inter-rater reliability of the ISWT-CHN, construct and criterion validity were established by analysing the ISWT and the gold standard cardiopulmonary exercise test results.

Results: The Item-Content validity index (I-CVI), Scale-level-Content validity index (S-CVI), and content validity ratio (CVR) of the ISWT-CHN were 1.0. Intra-class Correlation Coefficient (ICC) for inter-rater reliability between two raters were excellent ($\text{ICC}=0.99$, 95% CI 0.97-1.0, $p<0.001$; $\text{SEM}=0.85$ m, $\text{MDC}=2.35$ m). The intra-rater reliability of both Raters A ($\text{ICC}=0.92$, 95% CI 0.53-0.98, $p=0.003$; $\text{SEM}=35$ m, $\text{MDC}=97$ m) and B ($\text{ICC}=0.90$, 95% CI 0.76-0.96, $p<0.001$; $\text{SEM}=32$ m, $\text{MDC}=88$ m) were good. In a sample of 32 healthy participants, both ISWT-CHN and ISWT-ENG instruction results showed low-positive correlations with the VO${}_{2\max }$ determined from the cardiopulmonary exercise test (r = 0.439, $p<0.001$; $r=0.448$, $p<0.001$). There is a very high correlation between ISWT-ENG and ISWT-CHN results with no statistically significant differences ($r=0.967$, $p<0.001$). The construct and criterion validity of the ISWT-CHN were established.

Conclusion: This study developed the ISWT-CHN and showed that it is a valid and reliable measure conceptually comparable to the ISWT-ENG. It will benefit the determination of functional exercise capacity in Chinese-speaking populations.

Key messages: •This study is aimed to develop a Chinese (Mandarin) version of the ISWT instructions.•The ISWT Chinese translation is valid and reliable that is conceptually comparable to the original English instruction.•The translated ISWT-Chinese instruction will enable the use of ISWT among the Chinese-speaking populations.