Incremental shuttle walk test: Reference values and predictive equation for healthy Indian adults

Perioperative Exercise Testing in Pregnant and Non-Pregnant Women of Reproductive Age: A Systematic Review

BACKGROUND

Women have classically been excluded from the development of normal data and reference ranges, with pregnant women experiencing further neglect. The incidence of Caesarean section in pregnant women, and of general operative management in young women (both pregnant and non-pregnant), necessitates the formal development of healthy baseline data in these cohorts to optimise their perioperative management. This systematic review assesses the representation of young women in existing reference ranges for several functional exercise tests in common use to facilitate functional assessment in this cohort.

METHODS

Existing reference range data for the exercise tests the Six Minute Walk Test (6MWT), the Incremental Shuttle Walk Test (ISWT) and Cardiopulmonary Exercise Testing (CPET) in young women of reproductive age were assessed using the MEDLINE (Ovid) database, last searched December 2023. Results were comparatively tabulated but not statistically analysed given underlying variances in data.

RESULTS

The role of exercise testing in the perioperative period as an assessment tool, as well as its safety during pregnancy, was evaluated using 65 studies which met inclusion criteria.

CONCLUSION

There is a significant lack of baseline data regarding these tests in this population, especially amongst the pregnant cohort, which limits the application of exercise testing clinically.

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.

Technology-based Comprehensive Cardiac Rehabilitation Therapy (TaCT) for women with cardiovascular disease in a middle-income setting: A randomized controlled trial protocol

Women are underrepresented in cardiac rehabilitation (CR) despite the benefits, and this is exacerbated in lower-resource settings where CR is insufficiently available. In this randomized controlled trial, the effectiveness of the Technology-based Comprehensive Cardiac Rehabilitation Therapy (TaCT) electronic cardiac rehabilitation (eCR) intervention on functional capacity, risk factors, quality of life, heart-health behaviors, symptoms, and morbidity will be tested among women with CVD in a middle-income country. Following a pilot study, a single-center, single-blinded, 2 parallel-arm (1:1 SNOSE) superiority trial comparing an eCR intervention (TaCT) to usual care, with assessments pre-intervention and at 3 and 6 months will be undertaken. One hundred adult women will be recruited. Permuted block (size 10) randomization will be applied. The 6-month intervention comprises an app, website, SMS texts with generic heart-health management advice, and bi-weekly 1:1 telephone calls with a nurse trainee. Individualized exercise prescriptions will be developed based on an Incremental Shuttle Walk Test (primary outcome) and dietary plans based on 24 h dietary recall. A yoga/relaxation video will be provided via WhatsApp, along with tobacco cessation support and a moderated group chat. At 3 months, intervention engagement and acceptability will be assessed. Analyses will be conducted based on intent-to-treat. If results of this novel trial of women-focused eCR in a middle-income country demonstrate clinically-significant increases in functional capacity, this could represent an important development for the field considering this would be an important outcome for women and would translate to lower mortality.

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), R 2 = 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.

Cardiorespiratory fitness assessment and prediction of peak oxygen consumption by Incremental Shuttle Walking Test in healthy women

INTRODUCTION

Preliminary studies have showed that the Incremental Shuttle Walking Test (ISWT) is a maximal test, however comparison between ISWT with the cardiopulmonary exercise test (CEPT) has not yet performed in the healthy woman population. Furthermore, there is no regression equation available in the current literature to predict oxygen peak consumption (VO2 peak). Thus, this study aimed to compare the ISWT with CEPT and to develop an equation to predict peak oxygen uptake (VO2 peak) in healthy women participants.

METHODS

First, the VO2 peak, respiratory exchange ratio (R peak), heart rate max (HR max) and percentage of predicted HR max (% predicted HR max) were evaluated in the CEPT and ISWT (n = 40). Then, an equation was developed to predict the VO2 peak (n = 54) and its validation was performed (n = 20).

RESULTS

There were no significant differences between the ISWT and CEPT of VO2 peak, HR max and % predicted HR max values (P>0.05), except for R peak measure in the ISWT (1.22 ± 0.13) and CEPT (1.18 ± 0.1) (P = 0.022). Therefore, both tests showed a moderate positive correlation of VO2 peak (r = 0.51; P = 0.0007), HR max (r = 0.65; P<0.0001) and R peak (r = 0.55; P = 0.0002) and the Bland-Altman analysis showed agreement of VO2 peak (bias = -0.14). The distance walked on ISWT and age explained 36.3% (R2 Adjusted = 0.363) of the variance in VO2 peak. The equation developed was VO2 peak (predicted) = 19.793 + (0.02 x distance walked)-(0.236 x age). There was no statistically significant difference between the VO2 peak measured directly and the predicted, and the Bland-Altman analysis showed agreement (bias = 1.5 ml/kg/min).

CONCLUSION

ISWT is a maximal test showing similar results compared to the CEPT, and the predicted equation was valid and applicable for VO2 peak assessing in young adult healthy women.

The influence of South Asian ethnicity on the incremental shuttle walk test in UK adults

The objective of this study was to compare incremental shuttle walking test (ISWT) performance between South Asian and Caucasian British adults, identify predictors of ISWT distance and produce ethnicity-specific reference equations. Data from a mixed gender sample aged 40–75 years from Leicestershire, United Kingdom, were selected for analyses. Analysis of covariance determined differences in ISWT performance between South Asian and Caucasian British ethnic groups. Linear regressions identified predictors of ISWT distance, which determined the reference equations. In total, 144 participants took part in the study (79 South Asian (54 ± 8 years, 71% female) and 65 Caucasian British (58 ± 9 years, 74% female)). Distance walked for the ISWT was shorter for South Asian individuals compared with Caucasian British (451 ± 143 vs. 575 ± 180 m, p < 0.001). The ethnicity-specific reference equations for ISWT distance explained 33–50% of the variance (standard error of the estimate (SEE): 107–119 m) for South Asians and explained 14–58% of the variance (SEE: 121–169 m) for Caucasian British. Ethnicity univariately explained 12.9% of the variance in ISWT distance and was significantly associated with ISWT distance after controlling for age, gender, height, weight, dyspnoea and lung function (B = −70.37; 1 = Caucasian British, 2 = South Asian), uniquely explaining 3.7% of the variance. Predicted values for ISWT performance were lower in South Asian people than in Caucasian British. Ethnicity-specific reference equations should account for this.

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.