Normative reference values, determinants and regression equations for the incremental shuttle walk test (ISWT) in healthy Asian population aged 21 to 80 years.

BACKGROUND: The validated Incremental Shuttle Walk Test (ISWT) is widely used for evaluating maximal exercise capacity, with the distance-walked (IWSD) as the primary outcome. However, there are no normative reference values (NRV) and reference equations to predict ISWD for the Singaporean population. OBJECTIVES: This study aims to establish the NRV and reference equations for ISWD in healthy Singaporeans aged 21 to 80 and investigate the determining variables during ISWT. METHODS: This cross-sectional study recruited community-dwelling healthy subjects aged 21-80 from the community via convenience sampling. Each subject completed two trials of the ISWT according to the standard protocol. Variables measured during the trials included ISWD, pre-and post-test heart rate (HR), oxygen saturation, blood pressure (BP), modified Borg's dyspnoea score and Borg's rate of perceived exertion (RPE). RESULTS: 199 healthy Singaporean (females = 114, males = 85) participated in the study. The overall median ISWD was 660.0 metres (m) [interquartile range (IQR):440.0-850.0]. The age-stratified mean ISWD ranged from 430.0 m (IQR:350.0-450.0) (aged 60-80) to 480.0 m (IQR:438.0-650.0) (aged 40-59) to 780.0 m (IQR:670.0-960.0) (aged 21-39). Gender, age, weight, height and HR change (highest post-test HR minus pre-test HR) were the most significant variables (p < 0.001). IWSD (m) = 651.4(Height, m) +89.7(Gender, male = 1; female = 0) -6.31(Age, years) -3.61(Weight, kilograms) +2.54(HR change, beats per minute); R2 = 0.741. Previously published ISWT reference equations cannot accurately predict the ISWD in the Singaporean population. CONCLUSIONS: This study investigated the ISWD NRV and established reference equations for healthy Singaporeans aged 21-80. The information would be beneficial in setting performance benchmarks to guide physical assessment, intervention and rehabilitation.

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 (ICC=0.99, 95% CI 0.97-1.0, p<0.001; SEM=0.85 m, MDC=2.35 m). The intra-rater reliability of both Raters A (ICC=0.92, 95% CI 0.53-0.98, p=0.003; SEM=35 m, MDC=97 m) and B (ICC=0.90, 95% CI 0.76-0.96, p<0.001; SEM=32 m, 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 VO2max 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.

Normative reference values and regression equations to predict the 6-minute walk distance in the Asian adult population aged 21-80 years.

Summary at a glance: The 6-min walk test (6MWT) is a widely used field walking test. This study reports the normative reference values (NRV) of distance walked during 6MWT (6MWD) in healthy Singaporeans (aged 21-80) and updates the 6MWD reference equations. This information may facilitate the interpretation of the 6MWD in clinical populations. Ethics approval: The Singapore Institute of Technology-Institutional Review Board (SIT-IRB Project Number: 2019099) approved this study to be carried out from June 2019 to January 2021. All participants gave written informed consent before data collection began. Background: The six-minute walk test (6MWT) is a widely adopted submaximal field-walking test to evaluate functional exercise capacity. This validated test is a reliable, safe, inexpensive, and straightforward assessment tool commonly used as an outcome measure, using the distance walked (6MWD) as the primary outcome. An earlier study has established the normative reference values (NRV) and equation in healthy Singaporeans - however, the small sample size and narrow age range curb adequate representation of the adult population profile. Objectives: This study aims to update the NRV and reference equations to predict the distance walked during 6MWT (6MWD) for healthy Singaporeans aged 21-80. Methods: This cross-sectional study recruited community-dwelling healthy subjects aged 21-80 via convenience sampling. Each subject completed two trials of 6MWT according to the standard protocol. Primary outcome measures included 6MWD, pre-and post-test heart rate (HR), oxygen saturation, and blood pressure (BP). Results: 172 healthy Singaporeans (females=90, males=82) participated. The overall mean 6MWD was 578.00±75.38 metres. The age-stratified mean 6MWD ranged from 601.3±71.79 metres (aged 21-39) to 519.02±55.42 metres (aged 60-80). Age, gender, and percentage maximum HR predicted (%PredHRmax) were the most significant variables (p<0.001). 6MWD reference equation=288.282(height,m)+27.463×Gender (male=1;female=0)+4.349(%predHRmax)+1.191 (HR reserve, bpm) -185.431-1.343(age,years)-1.614 (weight, kg), R2=58%. Applying equations from other studies to the Singaporean population resulted in an overestimation of the 6MWD. Conclusion: This study updated the NRV and reference equations of 6MWD for healthy Singaporeans aged between 21-80 years. This update revises the local benchmarks of 6MWD in Singapore, a widely adopted outcome measure.

The Chinese (Mandarin) instructions of the 6-minute walk test: A validation study.

BACKGROUND/OBJECTIVE: To date, a validated Chinese (Mandarin) six-minute walk test (6MWT) translated instruction is not available. Translation of the Chinese 6MWT instruction is done in an ad hoc manner within the Chinese-speaking populations. This study aimed to develop a set of valid and reliable Chinese (Mandarin) instructions of the 6MWT. METHODS: Translation was performed from the original English instruction via the recommended "Process of translation and adaptation of instruments" by the World Health Organization to generate the Chinese instructions. The Chinese instructions were tested with 52 healthy adult participants for its validity. Each participant underwent three 6MWTs and a cardiopulmonary exercise test. Randomization allowed participants to undergo the walk test in both the original English and the new Chinese instructions. Face and content validity, intra-rater and inter-rater reliability of the Chinese instructions of the 6MWT were established through the translation process. Criterion validity was established by analyzing the results of the 6MWT and cardiopulmonary exercise test. RESULTS: Intraclass correlation coefficient for inter-rater reliability was excellent ( ICC = 0 . 999 , 95% confidence interval = 0 . 996 -1.000). Similarly, the intra-rater reliability across the three raters was high (R1: ICC = 0 . 996 , 95% confidence interval ( CI )= 0 . 812 -1.000; R2: ICC = 1 . 000 , 95% CI = 0 . 994 -1.000; R3: ICC = 1 . 000 , 95% CI = 0 . 998 -1.000). The 6-min walk distances collected from the Chinese and English instructed trials correlated positively with the maximal oxygen consumption ( r = 0 . 315 , p = 0 . 023 ; r = 0 . 309 , p = 0 . 026 ). CONCLUSION: This is the first study to develop and validate the Chinese (Mandarin) instructions of the 6MWT, and the translation is as reliable and valid as the original English instructions.