Concurrent validity between field tests and cardiopulmonary exercise testing in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Maximal treadmill cardiopulmonary exercise testing is the gold standard for assessing functional capacity in patients with idiopathic pulmonary fibrosis (IPF). PURPOSE: Primarily to investigate the concurrent validity between three field tests and cardiopulmonary exercise testing in these patients. METHODS: Patients performed the cardiopulmonary exercise testing, a six-minute walk test, an incremental shuttle walk test, and, the Glittre-ADL test. For cardiopulmonary exercise testing, the ten seconds with the higher average of the peak oxygen uptake obtained within the last 30 seconds were considered; for six-minute walk test and incremental shuttle walk test, the longer distance; and for the Glittre-ADL test, the shorter time spent. Concurrent validity was assessed using different regression models based on the best adjustment of the data. RESULTS: Twenty-two patients with IPF were assessed, aged: 68 ± 8.1 years, 13 male. Patients presented a peak oxygen uptake of 16.5 ± 3.6 mL.kg-1.min1, achieving a distance of 512.6 ± 102.8 meters in the six-minute walk test and 415.7 ± 125.1 meters in incremental shuttle walk test. The walking distance in the six-minute walk test and the incremental shuttle walk test explained, respectively, 64% and 56% peak oxygen uptake variance observed in the cardiopulmonary exercise testing (R2 = 0.64,p < .001; R2 = 0.56,p < .001). The time spent in the Glittre-ADL test was 233.4 ± 88.7 seconds and explained 47% of the peak oxygen uptake variance observed in cardiopulmonary exercise testing (R2 = 0.47,p = .001). CONCLUSION: The six-minute walk test, incremental shuttle walk test, and Glittre-ADL test were considered valid tests to explain the peak oxygen uptake variance obtained by the cardiopulmonary exercise testing in patients with IPF.

In-Person Versus Remote 6-Minute Walk and Incremental Shuttle Walk Distances in Advanced Lung Disease.

BACKGROUND: Field-based walk tests conducted remotely may provide an alternative method to a facility-based assessment of exercise capacity for people with advanced lung disease. This prospective study evaluated the level of agreement in the distance walked between a 6-min walk test (6MWT) and an incremental shuttle walk test performed by using standard in-person procedures and test variations and settings. METHODS: Adults with advanced lung disease underwent 4 study visits: (i) one in-person standard 6MWT (30-m corridor) and one in-person treadmill 6MWT, (ii) a remote 6MWT in a home setting (10-m corridor), (iii) 2 in-person standard incremental shuttle walk tests (10-m corridor), and (iv) a remote incremental shuttle walk test in a home setting (10-m corridor). A medical-grade oximeter measured heart rate and oxygen saturation before, during, and for 2 min after the tests. RESULTS: Twenty-eight participants were included (23 men [82%]; 64 (57-67) y old; 19 with interstitial lung disease [68%] and 9 with COPD [32%]; and 26 used supplemental oxygen (93%) [exertional [Formula: see text] of 0.46 ± 0.1]). There was no agreement between the tests. Greater walking distances were achieved with standard testing procedures: in-person 6MWT versus treadmill 6MWT (355 ± 68 vs 296 ± 97; P = .001; n = 28), in-person 6MWT versus remote 6MWT (349 ± 68 vs 293 ± 84; P = .001; n = 24), and in-person incremental shuttle walk test versus remote incremental shuttle walk test (216 ± 62 vs 195 ± 63; P = .03; n = 22). CONCLUSIONS: Differences in the distance walked may have resulted from different track lengths, widths, and walking surfaces. This should be considered in test interpretation if tests are repeated under different conditions.

What are the determinants of change in walking fitness in patients with a history of depression following cardiac rehabilitation?

AIMS: This study aims to investigate the demographic, clinical and service level factors determining change in walking fitness in cardiac rehabilitation (CR) patients with a history of depression following the CR programme. METHODS AND RESULTS: National Audit of Cardiac Rehabilitation (NACR) clinical data were used to identify 1476 patients with a history of depression who had their pre and post incremental shuttle walk test (ISWT) recorded between 1st Jan 2016 and 31st Jan 2020. A multiple linear regression was conducted to examine the determinants of change in walking fitness (m) following CR. Mean age was 61 (SD 10.45) and mean ISWT distance at baseline and outcome were 352.06m (SD 169.48) and 463.43m (SD 197.65), respectively. Multivariate analysis revealed that change in walking distance reduced by 1.6m for each year increase in age at baseline (P < 0.001). Females and unemployed patients had less improvement in walking fitness (23.1m and 21.5m, respectively). Having a body mass index >30 was associated with lower improvement (24.2m, p < 0.001), while physically active patients had 14.6m higher change. Higher baseline ISWT quintiles were associated with less improvement, and increased waiting time to start CR was associated with reduced change in walking fitness following CR. CONCLUSION: Older age, female gender, unemployment, higher baseline BMI, longer waiting time, and lower physical activity were associated with reduced walking fitness improvement in patients with a history of depression. Targeted intervention and prompt access to CR can optimize outcomes.

Functional exercise capacity in patients with ankylosing spondylitis.

OBJECTIVE: This study aimed to measure the functional exercise capacity of patients with ankylosing spondylitis (AS) with the incremental shuttle walk test (ISWT), and to determine the factors associated with this test. METHODS: This cross-sectional study included 54 patients with AS (29 males, 25 females). The ISWT was performed to determine functional exercise capacity. The number of completed shuttles was recorded, and the total incremental shuttle walk distance (ISWD) was calculated. Disease activity was assessed with the Bath AS Disease Activity Index (BASDAI), physical functioning was assessed with the Bath AS Functional Index (BASFI), and spinal mobility was assessed with the Bath AS Mobility Index (BASMI). Upper body and core endurance were assessed by sit-up and push-up tests. Tests were performed in a single session in the order listed. RESULTS: The mean ISWD of the patients was 462.41 ± 97.96 m, and the subjects reached 50.48% of the predicted ISWD. The ISWD of male subjects was significantly higher than that of females (p < .05). At the end of the test, male subjects reached 60.87% of the age-predicted maximal heart rate, and female subjects reached 55.25%. There was a significant positive moderate correlation between ISWD and height (r = 0.535, p < .01), sit-up test (r = 0.617, p < .01), and push-up test (r = 0.495, p < .01), while there was a negative weak correlation between BASFI (r = -0.344, p = .011) and BASMI (r = -0.280, p = .040). CONCLUSION: The study showed that functional exercise capacity as assessed by the ISWT decreased in patients with AS. ISWT performance was associated with sex, height, functionality, spinal mobility, and muscular endurance.

Assessment of exercise capacity using field walking tests in patients after the Fontan procedure: A case-control study.

BACKGROUND: Despite the frequent use of the 6-minute walk test (6MWT), exercise capacity has not been assessed with the incremental shuttle walk test (ISWT) in patients who have undergone the Fontan procedure. It is unclear whether these tests cause clinically relevant cardiorespiratory responses in these patients. OBJECTIVES: We aimed to assess cardiorespiratory responses to the 6MWT and ISWT in Fontan patients, compare the responses with those in the controls, and examine the agreement between the two field tests. METHODS: Submaximal exercise capacity was assessed using the 6MWT, maximal exercise capacity using the ISWT, quadriceps isometric muscle strength with a hand dynamometer, and body composition using a bioelectrical impedance device. RESULTS: Twenty-one Fontan patients (16.42±6.63 years, 5F/16M) and 21 controls (16.57±4.30 years, 7F/14M) were included. While body composition was similar between the groups (p>0.05), quadriceps isometric muscle strength and 6MWT and ISWT distance were lower in the Fontan patients than in the controls (p<0.05). In both the 6MWT and ISWT, pre- and post-test heart rate (HR), oxygen saturation (SpO2), dyspnea, and leg fatigue differed significantly between the Fontan patients and the controls (p<0.05). In addition, the ISWT resulted in a more significant change in HR, SpO2, and leg fatigue than the 6MWT in the Fontan patients (p<0.05). Bland-Altman plots for the 6MWT vs. the ISWT indicated agreement between the two tests. CONCLUSION: There were remarkable changes in HR, SpO2, dyspnea, and leg fatigue in both tests. With similar safety to the 6MWT but with more caution applied for adverse events, the ISWT can also be performed as a field test to evaluate exercise capacity and identify more pronounced exercise-induced responses (especially oxygen desaturation) in Fontan patients.

Decreased incremental shuttle walk test distance characterized by fibrocavitary lesions in non-tuberculous mycobacterial pulmonary disease.

BACKGROUND: Patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) have impaired exercise capacity, but the underlying factors are unknown. We investigated the characteristics of patients with NTM-PD and impaired exercise capacity. METHODS: In total, 149 patients with NTM-PD participated in this study. Patients completed the incremental shuttle walk test (ISWT) to assess exercise capacity. Peripheral muscle strength and pulmonary function were also assessed. Radiological findings were classified into three phenotypes: non-cavitary nodular bronchiectatic (NC-NB) form, cavitary nodular bronchiectatic form, and fibrocavitary (FC) form. RESULTS: The median ISWT distance (ISWD) and %ISWD were 450 meters and 88%. Participants were classified into three groups according to %ISWD, with %ISWD <60% as the severely decreased group, 60%-80% as the moderately decreased group, and >80% as the normal or mildly decreased group. In a comparison of %ISWD among phenotypes, FC form had significantly lower %ISWD than those with NC-NB form. In the severely decreased group, peripheral muscle strength and pulmonary function were significantly lower than the other two groups. From a radiological standpoint, significantly more patients had FC form in the group with severely decreased %ISWD. CONCLUSIONS: Decreased ISWD is characterized by a deterioration in physical function and the presence of FC lesions in NTM-PD.

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.

Pulmonary Rehabilitation in Noncystic Fibrosis Bronchiectasis.

BACKGROUND: Current guidelines for the treatment of noncystic fibrosis bronchiectasis (NCFB) recommend pulmonary rehabilitation (PR), but to date, there are few studies that have proven its effectiveness. OBJECTIVE: The main objective of this study was to examine the effect of PR on pulmonary function tests and exercise capacity. METHOD: The aim of this study was to systematically review the effects of PR in NCFB on (1) forced expiratory volume in the first second (FEV1) and (2) exercise capacity evaluated by the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT). This meta-analysis was undertaken according to PRISMA recommendations. RESULTS: This pair-wise meta-analysis included data obtained from studies that enrolled 529 NCFB patients. The FEV1 assessment after PR between the active and control group did not show any significant increase (FEV1 difference 0.084 mL; CI: -0.064, +0.233; p = 0.264), and there was an increasing trend (188 mL; CI: -0 to 0.009, +0.384) at the limits of statistical significance (p = 0.061). Walked distance showed a significant increase in the PR group compared to the control group (ISWT distance difference 070.0 m; CI: 55.2, 84.8; p < 0.001), and this finding was confirmed before and after PR both by the ISWT (68.85 m greater than baseline; CI: 40.52, 97.18; p < 0.001) and by the 6MWT (37.7 m greater than baseline; CI: 20.22, 55.25; p < 0.001). CONCLUSIONS: PR improves exercise tolerance in NCFB patients, but it has a modest impact on respiratory function.

Resultados y reproducibilidad a corto plazo de la prueba de lanzadera incremental (Incremental Shuttle Walking Test) en pacientes con enfermedad renal crónica en hemodiálisis / Results and short-term reproducibility of the Incremental Shuttle Walking Test in patients with chronic kidney disease on hemodialysis

RESUMEN Antecedentes: La prueba de lanzadera incremental ha sido empleada para determinar la capacidad física en pacientes con enfermedad renal crónica. Sin embargo, su aplicabilidad y reproducibilidad ha sido poco estudiada en pacientes bajo tratamiento de hemodiálisis. El objetivo de este estudio fue evaluar el rendimiento y reproducibilidad de la prueba de lanzadera incremental en pacientes con enfermedad renal crónica en hemodiálisis. Material y métodos: Se incluyeron pacientes con enfermedad renal crónica en diálisis y sujetos sin enfermedad renal crónica. Cada individuo realizó dos pruebas de lanzadera incremental con un intervalo de 30 minutos. Se registró la distancia recorrida, velocidad máxima, frecuencia cardiaca y el esfuerzo percibido. La reproducibilidad se analizó mediante el cálculo del coeficiente de correlación intraclase y el error estándar de la media. Mediante el método de Bland-Altman, se calculó la discordancia de la distancia recorrida y la frecuencia cardiaca pico. Además, se calculó el cambio mínimo detectable para todos los parámetros de la prueba de lanzadera incremental. Un valor de p=<0,05 se consideró significativo. Resultados: 68 sujetos entraron al estudio (34 pacientes con enfermedad renal crónica y 34 sujetos en el grupo control). Los pacientes con enfermedad renal crónica caminaron una menor distancia recorrida respecto al grupo control (-40%; p=<0,0001). En ambos grupos, se encontró una excelente confiabilidad test/retest en todas las medidas de resultado (cálculo del coeficiente de correlación intraclase >0,80). Los registros del error estándar de medición y cambio mínimo detectable para la distancia recorrida fueron de 26,0 m y 72,1 m, respectivamente. El método de Bland-Altman para la distancia recorrida mostró una diferencia media de -0,9 m con límites de concordancia entre 65,5 y -63,7 m. Conclusión: Los pacientes con enfermedad renal crónica en hemodiálisis presentan un menor rendimiento durante la prueba de lanzadera incremental comparado con individuos sin enfermedad renal crónica. Las medidas de resultado de la prueba de lanzadera incremental presentan una alta reproducibilidad test/retest a corto plazo en este grupo de pacientes.

ABSTRACT Introduction: The Incremental Shuttle Walk Test has been used to determine physical capacity in patients with chronic kidney disease. However, its applicability and reproducibility have seldom been studied in hemodialysis patients. The objective of this study was to evaluate the performance and reproducibility of the incremental shuttle walk test in patients with chronic kidney disease on hemodialysis. Methods: Patients with chronic kidney disease on dialysis and subjects without chronic kidney disease were included. Each individual performed two Incremental Shuttle Walk Test with an interval of 30 minutes. We recorded the distance traveled, maximum speed, heart rate and perceived effort. Reproducibility was analyzed by calculating the intraclass correlation coefficient and the standard error of the mean. Using the Bland-Altman analysis, we calculated the discrepancy of the distance traveled and the peak heart rate. The minimum detectable change was also calculated for all parameters of the incremental shuttle walk test. A value of p=<0.05 was considered significant. Results: 68 subjects entered the study (34 were patients with chronic kidney disease, and 34 subjects constituted the control group). Patients with chronic kidney disease walked a shorter distance than those in the control group (-40%; p=<0.0001). In both groups, excellent test-retest reliability was found in all outcome measurements (intraclass correlation coefficient calculation >0.80). The standard error of measurement and the minimum detectable change for the distance traveled were 26.0 m and 72.1 m, respectively. The Bland-Altman analysis for the distance traveled showed a mean difference of -0.9 m with limits of agreement between 65.5 and -63.7 m. Conclusion: Patients with chronic kidney disease on hemodialysis show lower performance during the incremental shuttle walk test, compared to individuals without chronic kidney disease. The outcome measurements of the Incremental Shuttle Walk Test show high test-retest reproducibility in the short run in this group of patients.

ECG changes during ISWTs in adult patients commencing CR: a retrospective case note review.

The incremental shuttle walk test (ISWT) is a valid, reliable submaximal exercise test used in the assessment of patients prior to cardiac rehabilitation (CR). Simultaneous electrocardiogram (ECG) measurements would provide important information on the safety of the test, and adequacy of subsequent cardiac risk stratification. Risk stratification is recommended to assess patients' suitability for cardiac rehabilitation. For example, ST-segment depression >2 mm from baseline during testing would place a person in a high-risk category. However, such ECG measurements are rarely undertaken in clinical practice. The aim of the study was to investigate the incidence of ECG changes during an ISWT, and report on the possible impact of these findings on subsequent cardiac risk stratification. A retrospective case note review was undertaken for the year 2017. Baseline clinical characteristics from eligible patients were gathered including those with ischaemic heart disease, heart failure, transplant and valve replacement, along with ECG measurements during the ISWT. The impact of ECG findings on cardiac risk stratification was calculated, based on risk stratification developed by the American Association of Cardiovascular and Pulmonary Rehabilitation. The safety of the ISWT was measured by the absence of major ECG changes. Data were gathered for 295 patients. Minor ECG changes were identified during the ISWT in 189 patients (64.1%), with no major changes. The presence of silent myocardial ischaemia (ST-segment depression) had an impact on cardiac risk stratification in 27 patients. There was a statistically significant positive association between ST-segment depression with cardiac risk stratification (p<0.001). In conclusion, the ISWT is safe in terms of ECG changes. The impact of ECG findings on cardiac risk stratification is significant and worthy of further consideration.

Clinical outcomes vary between the Shuttle Walk Test and Stress Test in patients with coronary artery disease.

Purpose: The purpose of this study was to determine if the Incremental Shuttle Walk Test (ISWT) can elicit similar patient responses as a treadmill stress test in patients with coronary artery disease (CAD). Methods: Both the stress test and the ISWT were performed by 172 participants, aged 60.67±10.23 years. We screened participants for unstable angina, severe aortic stenosis, uncontrolled hypertension, and excluded if unable to walk on a treadmill. Outcome measures (signs and symptoms) included: i) patient-reported chest pain; ii) patient-reported breathlessness/exhaustion and not being able to keep up with test protocol; and iii) able to reach target HRmax. Additionally, EKG changes during the stress test were monitored for ST changes or arrhythmias. Results: During the stress test, 15 participants reported chest pain, 23 participants reached target HRmax. No participants reported chest pain and 2 participants reached target HRmax during the ISWT. Participants reporting chest pain had a higher mean BMI and significant difference in METS (p < 0.001) during the stress test and walking distance (p = 0.03) when compared with patients who did not report chest pain during the stress test. Breathlessness and not being able to keep up with protocol were the most commonly reported in both tests. Changes in EKG were observed in 38 participants in the stress test. Conclusion: A maximal effort stress test is better at eliciting ischemic signs and symptoms and a superior tool for diagnosis of progression or severity of CAD than the ISWT. Appropriate selection of exercise tests is important in the clinical setting.

Enhancing the assessment of cardiorespiratory fitness using field tests.

OBJECTIVE: To establish normative values and reference equations of the 6-minute walk test (6MWT), incremental shuttle walk test (ISWT) and unsupported upper limb exercise test (UULEX) for Portuguese adults. DESIGN: Cross-sectional study. Descriptive statistics and differences between age decades and genders were explored using univariate general linear models to compute reference values. Reference equations were established with a forward stepwise multiple regression. SETTING: General community. PARTICIPANTS: In total, 645 adult volunteers without disabilities [43% male, mean age 55.1 (standard deviation 23.6) years] were recruited from the university campus and surrounding community. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Data on age, gender, height, weight, body mass index and smoking status were collected using a structured questionnaire. Physical activity was evaluated using the Brief Physical Activity Assessment Tool. Participants performed two repetitions of the 6MWT, ISWT and UULEX, and the best repetition was used for analysis. RESULTS: Overall, performance was better in males than in females, and decreased with age. Participants' performance was significantly reduced after the sixth decade of life compared with the other decades (P<0.001). Reference equations were: 6MWT=226.93-(5.00×age)+(360.41×height), R2=71%; ISWT=393.81-(17.98×age)+(185.64×gender)+(775.88×height), R2=83%; and UULEX=16.71-(0.14×age)+(2.66×gender), R2=57%. CONCLUSION: Leg or arm exercise field tests are affected significantly by age and gender. These results will aid health professionals to interpret the results of field tests obtained from healthy or diseased adult populations.

Understanding the measurement properties of the incremental shuttle walk test in patients with severe asthma.

BACKGROUND AND OBJECTIVE: We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO2pk ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma. METHODS: Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis. RESULTS: A total of 50 patients (32 females, mean (SD), age: 54 (13) years, forced expiratory volume in 1 s (FEV1 ): 1.9 (0.8) L and body mass index (BMI): 32 (6) kg/m2 ) completed all five tests. The mean (SD) ISWT distance for each test was 400 (156), 418 (142) and 438 (157) m (P = 0.001), respectively. There was a strong correlation between the ISWT distance with VO2pk derived from ITM (r = 0.74, P < 0.001) and ICE (r = 0.75, P < 0.001). CONCLUSION: There was a small increase in the mean ISWT distance on sequential testing. In clinical practice, the coefficient of repeatability and heteroscedasticity need to be considered when assessing whether a true change has occurred within an individual patient. The ISWT has validity compared to VO2pk on both ICE and ITM, but they are not interchangeable.

What factors are associated with patients walking fitness when starting cardiac rehabilitation?

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Interpreting Meaningful Change in the Distance Walked in the 10-Metre ISWT in Cardiac Rehabilitation.

BACKGROUND: 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 10metre incremental shuttle walk test (ISWT) in cardiac rehabilitation. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

Reference equation for the incremental shuttle walk test in Japanese adults.

BACKGROUND: The incremental shuttle walk test (ISWT) is widely used in clinical and research settings. However, there are no reference equations to predict the walk distance achieved in the ISWT (ISWD) for healthy Japanese adults. We aimed to establish a reference equation for the ISWD prediction in Japanese adults. METHODS: The sample comprised 590 healthy Japanese subjects (237 male). All subjects performed the ISWT twice, and their anthropometric and demographic data were collected, including gender, age, height, weight, and body mass index (BMI). RESULTS: Subjects walked 640 [490-793] m in the ISWT. The ISWD correlated (p < 0.001 for all) with age (r = - 0.51), gender (r = 0.56), weight (r = 0.39), and height (r = 0.62), but not with BMI (r = - 0.01, p = 0.74). The stepwise multiple regression model showed that age, gender, and height were independent contributors to the ISWT in healthy subjects, explaining 50% of the variability. The reference equation for the ISWD was: ISWD(m) = - 4.894 - 4.107 × Age (years) + 131.115 × Gender + 4.895 × Height (cm), where male gender = 1. CONCLUSION: We have established a reference equation for the ISWD prediction in Japanese adults. The prediction accuracy was high (R2 = 50%), and a reference equation was established using anthropometric and demographic variables that can be easily assessed in clinical settings. The reference equation developed in this study will be useful for evaluating the magnitude of exercise intolerance in Japanese adults.

Validation of the Incremental Shuttle Walk Test as a Clinical End Point in Bronchiectasis.

BACKGROUND: A validated clinical end point is needed to assess response to therapies in bronchiectasis. OBJECTIVES: The goal of this study was to assess the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) as a clinical end point in bronchiectasis. METHODS: In clinically stable patients (n = 30), the ISWT was performed twice, 6 months apart. Correlation between the St. George's Respiratory Questionnaire (SGRQ) and the ISWT (n = 94) was performed. The 1-year gentamicin study was reanalyzed to assess the area under the curve (percent change of ISWT with a ≥ 4 unit improvement in total SGRQ). ISWT was performed prior to and following 14 days of antibiotics for an exacerbation (94 oral courses and 30 IV courses, n = 124) and reanalysis of the 1-year gentamicin study (n = 57). RESULTS: The ISWT did not significantly change over 6 months while clinically stable. The ISWT correlated inversely with the SGRQ (rs = -0.60; P < .0001), Bronchiectasis Severity Index score (rs = -0.44; P < .0001), and sedentary time (rs = -0.48; P = .0007) but correlated with physical activity (rs = 0.42; P = .004). The area under the curve for percent change in ISWT with ≥ 4 unit improvement in SGRQ was 0.79 (95% CI, 0.66-0.91; P = .001). A threshold of 5% improvement in the ISWT had a 92% sensitivity but 50% specificity, and from the responsiveness studies would capture 73% of all patients. CONCLUSIONS: This study confirmed the ISWT to be reliable, valid, and responsive to change in patients with bronchiectasis. The authors propose that a minimum clinically important difference of 5% improvement in the ISWT would be a useful objective end point to assess therapies in bronchiectasis.

Incremental Shuttle Walking Test Distance Is Reduced in Patients With Pulmonary Hypertension in World Health Organisation Functional Class I.

Background: There is increasing interest in screening for and diagnosing pulmonary hypertension earlier in the course of disease. However, there is limited data on cardiopulmonary abnormalities in patients with pulmonary hypertension newly diagnosed in World Health Organization Function Class (WHO FC) I. Methods: Data were retrieved from the ASPIRE registry (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral center) for consecutive treatment naïve patients diagnosed with pulmonary hypertension by cardiac catheterization between 2001 and 2010 who underwent incremental shuttle walk exercise testing. Results: Eight hundred and ninety-five patients were diagnosed with Group 1-5 pulmonary hypertension. Despite the absence of symptoms, patients in WHO FC I (n = 9) had a significant reduction in exercise capacity (Incremental shuttle walk distance percent predicted (ISWD%pred) 65 ± 13%, Z score -1.77 ± 1.05), and modest pulmonary hypertension with a median (interquartile range) pulmonary artery pressure 31(20) mmHg and pulmonary vascular resistance 2.1(8.2) Wood Units, despite a normal diffusion of carbon monoxide adjusted for age and sex (DLco)%pred 99 ± 40%. Compared to patients in WHO FC I, patients in WHO FC II (n = 162) had a lower ISWD%pred 43 ± 22 and lower DLco%pred 65 ± 21%. Conclusion: Our results demonstrate that patients with newly diagnosed pulmonary hypertension with no or minimal symptomatic limitation have a significant reduction of exercise capacity.

Validity, responsiveness and minimum clinically important difference of the incremental shuttle walk in idiopathic pulmonary fibrosis: a prospective study.

The incremental shuttle walk (ISW) is well validated in COPD but limited psychometric data restrict its use in idiopathic pulmonary fibrosis (IPF). Study 1: 50 patients performed the ISW and 6 min walk test (6MWT). Study 2: 72 patients completed the ISW before and after pulmonary rehabilitation (PR). The ISW correlated strongly with 6MWT distance (r=0.81,p<0.0001). Mean (95% confidence interval) improvement in ISW with PR was 54 (38 to 70) m with an effect size of 0.29. Distribution-based and anchor-based minimum clinically important difference (MCID) estimates ranged from 31 to 46 m. The ISW is valid and responsive in IPF, with an anchor-based MCID estimate similar to that observed in chronic obstructive pulmonary disease. TRIAL REGISTRATION NUMBER: Pre-results; NCT02530736, NCT02436278.