Long-term reliability of the incremental shuttle walking test in clinically stable cardiovascular disease patients

doi:10.1016/j.physio.2009.11.010

Physiotherapy

Volume 96, Issue 3, September 2010, Pages 222-227

https://doi.org/10.1016/j.physio.2009.11.010 Get rights and content

Abstract

Objective

The incremental shuttle walking test (ISWT) is a valuable tool for assessing changes in patients’ functional capacity during cardiac rehabilitation. However, studies have only assessed its test–retest reliability in the short term. The purpose of this study was to examine long-term test–retest reliability of the ISWT in clinically stable cardiac patients.

Design

Test–retest reliability assessment.

Setting

Continuous, community-based phase IV cardiac rehabilitation centre.

Participants

Thirty patients with cardiovascular disease (15 males, 15 females; age 55 to 80 years) volunteered to participate in the study.

Interventions

Participants undertook two ISWTs, a minimum of 8 weeks apart.

Main outcome measures

ISWT performance in metres.

Results

Overall, the mean distance walked in the pre-test was 502 ± 161 m and this did not differ from test to retest. The intraclass correlation coefficient was 0.80, indicating good test–retest reliability. Using the Bland and Altman method, there was a small mean test–retest difference (−7 m). The 95% limits of agreement were large, ranging from −203 m to 189 m.

Conclusions

Over long test–retest durations, there appears to be no learning effect in the ISWT, negating the need for a practice walk. The long-term random variation in the ISWT test is larger than in previous studies, probably due to greater physiological and psychological variation in the participants over 8 weeks compared with that seen in day-to-day testing. Factors influencing long-term test–retest reliability of the ISWT require further elucidation.

Introduction

Functional capacity is an important predictor of mortality and morbidity in patients with cardiovascular disease (CVD). One aim of cardiac rehabilitation should be to increase functional capacity. However, to verify such changes objectively, there is a need for reliable functional capacity tests that can be carried out by nurses and physiotherapists.

Graded exercise tests aim to provoke a physiological response to continuously increasing incremental exercise levels [1], [2]. The requirements of the cardiorespiratory system are challenged as the intensity increases, and the body's ability to cope with these demands can be investigated to provide an insight into aerobic capacity.

Several cardiorespiratory assessment tests and functional measurements have been developed to determine prognosis, prescribe exercise and assess the efficacy of cardiac rehabilitation. Several walk tests based either on a specific time (2-minute, 5-minute, 6-minute, 9-minute and 12-minute walk test), distance (100 m, half mile, 2 km walk test) or walking speed [self-paced, 6-minute and controlled-paced incremental shuttle walking test (ISWT)] are used to assess the functional capacity of cardiac patients, the effectiveness of a cardiac rehabilitation programme and the prognosis of CVD [3].

The British Association for Cardiac Rehabilitation (BACR) recommends use of the ISWT to assess and monitor functional capacity in patients with chronic heart failure, patients who have experienced a myocardial infarction, and patients who have undergone cardiovascular surgery or pacemaker insertion [4], [5], [6], [7], [8].

The ISWT has been used to track changes in functional capacity during cardiac rehabilitation programmes [8], [9], [10], [11]. These studies typically use a single test at the beginning of rehabilitation and compare the distances walked with a post-rehabilitation test. While the ISWT appears to be able to assess changes in functional capacity in patients with CVD, only short-term (up to 7 days) test–retest reliability of the test has been assessed [9], [12], [13]. Given that cardiac rehabilitation programmes typically last for 6 to 12 weeks, long-term reliability is clearly of great importance.

If the ISWT is to be used to assess changes in functional capacity during cardiac rehabilitation, it is necessary to evaluate its long-term reliability. The primary aim of this study was to assess the test–retest reliability of a modified version of the ISWT over 8 weeks in clinically stable CVD patients.

Section snippets

Methods

Thirty CVD patients (15 males and 15 females; age 55 to 80 years) volunteered to participate in this study. Patients were verbally recruited by instructors prior to two consecutive exercise classes. All patients were defined as clinically stable, according to the BACR criteria [14].

All participants were attending a community-based phase IV cardiac rehabilitation programme at the University of Essex. The programme provides additional phase IV cardiac rehabilitation capacity in the local area,

Results

The mean age of participants was 67 ± 8 years. Most participants (60%) were elective post-revascularisation patients (coronary artery bypass graft or percutaneous transluminal coronary angioplasty), 17% were post-myocardial-infarction patients, and the other patients had stable angina or heart failure. Fifty-three percent of patients were β-blocked, but none of the participants changed their medication from pre-test to post-test (Table 1). Paired-samples t-tests showed that body mass remained

Discussion

Functional capacity patterns of CVD patients are usually established by the end of hospital outpatient (phase III) cardiac rehabilitation, and remain stable during community-based phase IV cardiac rehabilitation [8]. Assessment of functional capacity in CVD patients is important for assessing the effectiveness of exercise interventions and in exercise prescription. The ISWT is an affordable alternative to treadmill testing, but its reliability has only been tested over short test–retest

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Effects of multicomponent exercise training intervention on hemodynamic and physical function in older residents of long-term care facilities: A multicenter randomized clinical controlled trial
2021, Journal of Bodywork and Movement Therapies
Citation Excerpt :
According to Pan American Health Organization (PAHO), age-related adaption in physical function, cognitive capacity, and cardiovascular function are the most typical changes remarked in the older aged population (Moza et al., 2015). The aging process affects the cardiovascular system, leading to several changes in the heart and arteries (Pepera et al. 2010, 2015; Sandercock et al., 2013; Cardoso et al., 2017), including increased vascular stiffness (Lakatta and Levy 2003; Franklin 2006) and an increase in the levels of blood pressure (Mozaffarian et al., 2015). Systolic hypertension is the most common subtype of hypertension in the middle-age and third-age population (Franklin 2006) and a major risk factor for the development of cardiovascular and cerebrovascular diseases, even early death (Picco et al., 2016).
To assess hemodynamic and physical function responses during a two-month multicomponent group exercise program (MCEP) in residents of long-term care facilities.
40 older long-term care residents were randomly allocated equally to an intervention (IG; n = 20; 80 ± 7 years) and control group (CG; n = 20; 79 ± 7 years); they all submitted to hemodynamic (blood pressure and heart rate) and functional assessments before and after the MCEP. The IG performed a twice-weekly, two-months multicomponent exercise program composed of functional mobility, balance, muscle strength, and flexibility exercises; while the CG did not perform any exercise intervention.
There was a statistically significant decrease in systolic blood pressure (7.25 ± 14.64 mmHg; t = 2.2; effect size = 0.34; p < 0.05) following a two-month MCEP as compared with baseline. In all functional measurements (balance, mobility) were significantly improved after the MCEP (p < 0.05).
These data indicate that a two-month MCEP can improve systolic blood pressure and functionality in older residents of long-term care facilities.
Interpreting Meaningful Change in the Distance Walked in the 10-Metre ISWT in Cardiac Rehabilitation
2019, Heart Lung and Circulation
The interpretability of change in exercise test scores is an important measurement property. This study aimed to provide a framework for the interpretation of individual change scores of the 10 metre incremental shuttle walk test (ISWT) in cardiac rehabilitation.
In a quantitative pre-post design study, 52 patients who were referred to a hospital outpatient department for cardiac rehabilitation participated in this study. Participants completed two ISWTs prior to cardiac rehabilitation. Post cardiac rehabilitation, participants completed a global rating of change score and two ISWTs. Change scores were analysed for smallest detectable change (SDC) and minimum important change (MIC).
The SDC for an individual was 47 metres. The predicted MIC for participants to report an improvement ranged from 70 to 92 metres. The predicted MIC for participants who did not report a deterioration in the global rating of change (i.e., those who reported unchanged or improved) ranged from 16 to 42 metres.
The MIC for patients who report any improvement in physical fitness and functional capacity is 70 metres. These results suggest that over an 8-week program, patients would need to improve by at least seven shuttles to perceive an improvement in their physical fitness and functional capacity. Patients with small increases in the 10-metre ISWT distance may still report deterioration in their physical fitness and functional capacity.
What factors are associated with patients walking fitness when starting cardiac rehabilitation?
2019, IJC Heart and Vasculature
Citation Excerpt :
It is reliable and strongly correlated with CPET results validated in cardiac and pulmonary populations undergoing rehabilitation programmes [12–15]. Some studies have used the ISWT to investigate potential determinants of walking fitness in conventional cardiac populations [16,17] identifying several personal characteristics as significant predictors of fitness, including gender, age, body mass index, physical activity status, employment and marital status [15,17,19]. The impact of comorbidities, which often occur together with the diagnosis of HF, particularly in elderly patients, have not yet been investigated for their impact in determining walking fitness in terms of distance achieved using the ISWT.
Patients with heart failure (HF) are now a priority group for cardiac rehabilitation (CR). A fundamental component of CR is increasing physical fitness through exercise training. Even though studies show fitness benefits, there is little evidence in routine populations of individual factors that may influence fitness. This study aims to evaluate the extent to which demographics and clinical measures predict physical fitness in patients with HF and develop reference values to guide practice.
Data from the National Audit Cardiac Rehabilitation (NACR) was analysed. 2047 patients (73% male) with HF completed an incremental shuttle walk test (ISWT). Backward regression accounting for patient characteristics and new comorbidity groups were used to identify predictors of distance using ISWT. Reference values were produced from the percentiles of the ISWT distance.
Population age was 64.43 years (12.39 SD) with an average ISWT distance of 278.57 m (SD 158.57). Demographics, risk factors and comorbidities explained 26% of the variance in distance (adjusted R² = 0.256, p value < 0.001). Diuretics (−33.01 m ±8.07 SD) and socioeconomic status (9.12 m ±2.91 SD) were significant predictors of baseline walking fitness. Furthermore, respiratory obstructions, musculoskeletal issues and metabolic diseases were associated with reduced walking distance of 29.8 m, 26.6 m and 18.4 m respectively.
Use of diuretics, socioeconomic status and presence of comorbidities were significant predictors of walking performance in patients with HF who attended CR and were fit enough to carry out an ISWT. Reference values, to aid clinical practice, were developed that included age, gender and comorbidities status.
The 10 m incremental shuttle walk test is a highly reliable field exercise test for patients referred to cardiac rehabilitation: A retest reliability study
2016, Physiotherapy (United Kingdom)
Citation Excerpt :
Measurement error can be estimated for an individual score or around a change score for either a group, such as a cardiac rehabilitation group or for an individual within a program. Previous research has demonstrated that for change scores within a group the minimum amount of change required to be interpreted as real change over and above measurement error after the completion of one 10 m ISWT ranged from 36 m in a mixed cardiac rehabilitation group in a single session [2], to 44 m in a group who were attending a community based maintenance cardiac rehabilitation program and completed the testing over a minimum of eight weeks [3] to 56 m for a group of patients following coronary artery bypass surgery who completed the tests within one week [4]. For an individual, after one test an improvement in test score required to be interpreted as more than measurement error ranged from 53 m in individuals with heart failure in a single session [7] to 122 m [4] to 203 m [3].
To determine the retest reliability of the 10 m incremental shuttle walk test (ISWT) in a mixed cardiac rehabilitation population.
Participants completed two 10 m ISWTs in a single session in a repeated measures study. Ten participants completed a third 10 m ISWT as part of a pilot study.
Hospital physiotherapy department.
62 adults aged a mean of 68 years (SD 10) referred to a cardiac rehabilitation program.
Retest reliability of the 10 m ISWT expressed as relative reliability and measurement error. Relative reliability was expressed in a ratio in the form of an intraclass correlation coefficient (ICC) and measurement error in the form of the standard error of measurement (SEM) and 95% confidence intervals for the group and individual.
There was a high level of relative reliability over the two walks with an ICC of .99. The SEM_agreement was 17 m, and a change of at least 23 m for the group and 54 m for the individual would be required to be 95% confident of exceeding measurement error.
The 10 m ISWT demonstrated good retest reliability and is sufficiently reliable to be applied in practice in this population without the use of a practice test.
Does the Incremental Shuttle Walking Test require maximal effort in healthy subjects of different ages?
2015, Physiotherapy (United Kingdom)
Citation Excerpt :
It was also shown in COPD that two ISWTs are needed to assess exercise capacity during a maintenance exercise program [13]. van Bloemendaal et al. found that the ISWT is a valid and reliable measure of functional walking capacity in patients after stroke [6], whilst Pepera et al. found that there appears to be no learning effect in the ISWT over long test–retest durations in patients with cardiovascular disease [9]. Despite the widespread use of the ISWT in diseased and/or functionally limited subjects, its use in subjects without any important disease/limitation or healthy subjects is less common [14–17].
To evaluate if the Incremental Shuttle Walking Test (ISWT) requires maximal effort in healthy subjects of different ages.
Cross-sectional.
University-based research laboratory.
331 healthy subjects separated into six groups according to age: G1, 18 to 28 years; G2, 29 to 39 years; G3, 40 to 50 years; G4, 51 to 61 years; G5, 62 to 72 years and; G6, 73 to 83 years.
Two ISWTs were performed and participants were permitted to run and to exceed 12 levels during the test, if necessary. Heart rate (HR) and symptoms of dyspnoea and fatigue were recorded before and after the test, and the percentage of age-predicted maximal HR (HR_max) was calculated. Maximal effort was defined as HR_max >90% of age-predicted HR_max.
Almost 31% of the subjects exceeded 12 levels in the ISWT. At the end of the test, all groups presented a median [interquartile range] HR greater than 90% of HR_max (G1: 100 [95 to 104]; G2: 100 [96 to 105]; G3: 103 [97 to 108]; G4: 99 [91 to 106]; G5: 96 [87 to 106] and G6: 96 [91 to 109]% HR_max). Regarding symptoms, all groups showed higher values after the test (P < 0.05). A multiple logistic regression analysis identified female gender, older age and a lower HR before the test as determinants of not achieving 90% of HR_max at the end of the test.
The ISWT requires maximal effort in healthy individuals, but for that it is necessary to extend the test beyond twelve levels. Female gender, older age and lower heart rate before the test are the determinants of not reaching maximal effort.
Measurement properties of the incremental shuttle walk test: A systematic review
2014, Chest
The incremental shuttle walk test (ISWT) was developed > 20 years ago and has been used to assess peak exercise capacity in a variety of chronic diseases. The aim of this systematic review is to describe the measurement properties of the ISWT in a clinical population.
Of 800 articles identified by electronic and hand searches, 35 were included. Twenty-one articles included data on the validity of the ISWT, 18 on the reliability, four on the responsiveness, and four on the interpretability.
Most of the studies were conducted in patients with COPD (n = 13) or cardiac disease (n = 8). For criterion validity, comparisons between distance covered during the ISWT and peak oxygen consumption reported correlations ranging from 0.67 to 0.95 (P < .01). Intraclass correlation coefficients for test-retest reliability ranged from 0.76 to 0.99. The ISWT was shown to be responsive to pulmonary rehabilitation and bronchodilator administration. The minimal clinically important difference (MCID) in patients with COPD was 48 m. Predictive equations for the distance in the ISWT are available for healthy individuals.
The ISWT can be considered a valid and reliable test to assess maximal exercise capacity in individuals with chronic respiratory diseases. The ISWT has been shown to be responsive to pulmonary rehabilitation and bronchodilator use in individuals with COPD, cystic fibrosis, and asthma. Further studies examining responsiveness and the MCID of the ISWT in patients with conditions other than lung diseases are required for the interpretation of interventions in other populations.

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Long-term reliability of the incremental shuttle walking test in clinically stable cardiovascular disease patients

Abstract

Objective

Design

Setting

Participants

Interventions

Main outcome measures

Results

Conclusions

Introduction

Section snippets

Methods

Results

Discussion

Chest

Coronary Health Care

Int J Cardiol

Physiotherapy

Arch Phys Med Rehab

Int J Cardiol

Coronary Health Care

Chest

Ability of exercise testing to predict cardiovascular and all-cause death in asymptomatic women: a 20-year follow-up of the lipid research clinics prevalence study

JAMA

Heart-rate profile during exercise as a predictor of sudden death

N Engl J Med

Shuttle walking test: a new approach for evaluating patients with pacemakers

Heart