Performance on the iSTEP and 10 m-ISWT in boys with haemophilia.

INTRODUCTION: Boys with haemophilia (BwH) have improved health outcomes. Measures of physical function in haemophilia are not challenging or sensitive enough to reflect physical limitations or guide rehabilitation. To identify meaningful tests, we aimed to: evaluate the performance of BwH on two physical performance measures: iSTEP and 10 m-ISWT; identify factors which predict performance and compare BwH to their unaffected peers. METHODS: BwH completed both iSTEP and 10 m-ISWT. Disease severity, age, BMI, HJHS, lower limb muscle torque, time spent in moderate to vigorous physical activity, sedentary time, were included as factors to predict performance. Results were compared to unaffected peers. RESULTS: 43 boys median age 10 (10 mild/moderate, 26 severe, 7 inhibitors) were recruited. BwH were less likely to complete the iSTEP and performed less well on the 10 m-ISWT than age matched peers. Ceiling effects were apparent for iSTEP, but not the 10 m-ISWT test. Age was the only significant predictor for performance in the iSTEP, with older boys being more likely to achieve a higher level or complete the test. Greater age, lower BMI, milder disease severity and more time spent in MVPA all predicted better performance on the 10 m-ISWT, with BMI and habitual physical activity a potential rehabilitation focus for underperforming individuals. HJHS and muscle strength did not predict performance on either test. CONCLUSION: Despite the space need to conduct the 10 m-ISWT, it appears to be a superior performance measure than the iSTEP in BwH and provides clinically meaningful information, which can be interpreted using age-specific normative reference equations.

Incremental shuttle walk test: is it able to detect exercise-induced bronchospasm in young adult asthmatics?

OBJECTIVE: To determine the accuracy of incremental Shuttle Walking Test (ISWT) in detecting exercise-induced bronchospasm (EIB) in adults with asthma and to verify whether there is an association of the drop in FEV1 between ISWT and cardiopulmonary exercise testing with constant-load CPET-CL. METHODS: In this cross-sectional study 32 individuals with asthma performed two ISWTs, an incremental cardiopulmonary exercise test (CPET-I) and a constant-load cardiopulmonary exercise test (CPET-CL) with na interval of 48 h between tests. Spirometric measurements were obtained 5, 10, 15, 20 and 30 min after exercise; an FEV1 decline > 10% was considered EIB. RESULTS: Fifteen individuals had EIB in both tests [χ2 = 9.41; κ = 0.46 p < 0.002 (95% CI: 0.201-0.708)], with moderate agreement. There was a significant correlation between the greatest variation in the drop in FEV1 between the ISWT and the CPET-CL (r = 0.48; p < 0.01). There was a significant difference for ventilation maintenance time above 40% of Maximum Voluntary Ventilation between the groups of positive EIB (p = 0.001) and negative EIB (p = 0.001) and for ventilatory demand (positive EIB group) (p = 0.008) between ISWT vs CPET-CL. Moreover, assuming CPET-CL as the criterion test, ISWT presented a sensitivity of 62.5% and specificity was 100%. CONCLUSION: ISWT showed moderate accuracy in detecting EIB in adults with asthma and was able to show similar metabolic and ventilatory demand presented in CPET-CL.

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.

Feasibility, safety and acceptability of select outcome measures in a physiotherapy study protocol for boys with haemophilia.

BACKGROUND: There is a lack of functional performance measures for children and young people with haemophilia (CYPwH) with associated control data from typically developing boys (TDB). The literature advocates development of a core set of outcome measures for different chronic conditions. As medical treatment improves, CYPwH are experiencing better outcomes; therefore, more challenging measures are required to monitor physical performance. Such testing is not performed routinely, due to practical and safety concerns. AIM: Evaluate the feasibility, safety and acceptability of select outcome measures as part of a study protocol testing CYPwH; including myometry, 10 metre incremental shuttle walk test (10-m ISWT), iSTEP (an incremental step test, with data from TDB), and 1 week of accelerometry-wear at home. METHODS: Sixty-six boys aged 6-15 years with mild, moderate or severe haemophilia A or B (including inhibitors) attending routine clinics at Great Ormond Street Hospital were approached to participate. Descriptive statistics and content analysis were used to assess outcomes of feasibility, safety and acceptability, which included recruitment/retention rates, protocol completion within routine appointment timeframes, performance testing without serious adverse events/reactions (SAE/SARs), and acceptability to CYPwH of high-level performance measures. RESULTS: Outcomes were met: 43 boys completed testing at clinic review (Jan-Nov 2018) within a 10-month timeframe, retention was 95% at completion of protocol and no SAE/SARs were reported throughout testing. CONCLUSION: Feasibility, safety and acceptability of the study protocol have been established in this population. Both high-level performance tests, iSTEP and 10-m ISWT, were an acceptable addition to boys' routine clinic appointments and could be safe, acceptable choices of outcome measure as part of a core set of tests for CYPwH. Further investigation of the psychometric properties for the iSTEP is now justified, in order for it to be used as a standardised, validated, reliable outcome measure in clinical or research settings. TRIAL REGISTRATION: Retrospectively registered on September 3, 2019, on ClinicalTrials.gov (ID: NCT04076306 ).

Is the 10 m incremental shuttle walk test a useful test of exercise capacity for patients referred to cardiac rehabilitation?

BACKGROUND: Field exercise tests are a feasible alternative to the symptom-limited exercise test for measuring exercise capacity in patients attending cardiac rehabilitation. AIMS: To evaluate the criterion validity of the 10 m incremental shuttle walk test (ISWT) as a useful tool for measurement of exercise capacity for patients eligible for cardiac rehabilitation. METHODS: Fifteen patients eligible for cardiac rehabilitation completed a treadmill symptom-limited exercise test and two ISWTs with the order of testing randomised. Associations between the symptom-limited exercise test and the ISWT were explored and the ability of the ISWT to predict symptom-limited exercise test duration estimated. RESULTS: There was a moderate to high association ( r2 ⩾0.72) between ISWT duration and distance, and symptom-limited exercise test duration; and a moderate association between ISWT peak heart rate and end of test oxygen saturation and these outcomes on the symptom-limited exercise test (0.47⩽ r2 ⩽0.67). However, prediction of symptom-limited exercise test duration based on the ISWT produced wide 95% confidence intervals, for example, ranging from 9.1 to 16.3 minutes for an individual who completes the ISWT. Order of testing did not affect the results and the association between the ISWT and symptom-limited exercise test was similar for both the first (ISWT 1) and second test (ISWT 2) ISWT. CONCLUSIONS: The results provide support for the ISWT as a convenient field test of exercise capacity in a cardiac rehabilitation population, but not as a surrogate to predict symptom-limited exercise test duration for individuals. A single ISWT may provide as good an estimate of exercise capacity as repeating the test.

Comparação das distâncias previstas e percorridas no incremental shuttle walking test em idosos comunitários / Comparación de las distancias predichas y recorridas en la incremental shuttle walking test en ancianos comunitarios / Comparison of predicted and covered distances in the incremental shuttle walking test in older adults

RESUMO O objetivo deste estudo foi avaliar a validade externa de três equações de referência para o cálculo da distância a ser percorrida no incremental shuttle walking test (ISWT) por idosos comunitários, e, por fim, identificar qual equação prediz melhor a distância nessa faixa etária. Foram selecionados 84 idosos cadastrados nas Unidades Básicas de Saúde de Diamantina, Minas Gerais. Os voluntários foram submetidos ao ISWT e a distância percorrida em metros até a interrupção do teste foi registrada e utilizada para comparação com as equações de predição. Os voluntários apresentaram média de idade de 73,15±5,89 anos e alguns comprometimentos de saúde comuns dessa faixa etária, sendo a maioria mulheres e praticantes de atividade física. A análise estatística demonstrou que houve interação entre os fatores, ou seja, existe diferença entre as distâncias obtidas pelo ISWT e as distâncias obtidas pelas equações. Houve diferença também nas comparações entre os sexos (p<0,05) e a Equação 1 apresentou maior força de correlação (p<0,0001; r=0,414) com a distância real percorrida em relação às outras equações. Portanto, este estudo demonstrou uma diferença na comparação das distâncias real e calculadas por três equações de predição do ISWT, sugerindo que as equações utilizadas podem superestimar a distância percorrida pelos idosos, e que entre essas a Equação 1 apresentou uma predição mais próxima da distância percorrida para a amostra de idosos avaliada.

RESUMEN El objetivo de este estudio fue evaluar la validez externa de tres ecuaciones de referencia para calcular la distancia recorrida de la incremental shuttle walking test (ISWT) para ancianos comunitarios, así como identificar la ecuación que mejor predice la distancia en este grupo de edad. Se seleccionaron a 84 ancianos inscritos en las Unidades Básicas de Salud de Diamantina, Minas Gerais (Brasil). Se aplicaron a los voluntarios la ISWT, y la distancia recorrida en metros hasta la interrupción de la prueba se registró y se utilizó para comparar con las ecuaciones de predicción. Los voluntarios tenían un promedio de edad de 73,15±5,89 años y algunos problemas de salud habituales en este grupo de edad, de los cuales la mayoría fue mujeres y practicantes de actividad física. El análisis estadístico mostró que hubo una interacción entre los factores, es decir, existe una diferencia entre las distancias obtenidas por ISWT y las distancias obtenidas por las ecuaciones. También hubo una diferencia en las comparaciones entre los sexos (p<0,05), y la Ecuación 1 mostró una mayor fuerza de correlación (p<0,0001; r=0,414) con la distancia real recorrida en relación con las otras ecuaciones. Por lo tanto, este estudio demostró una diferencia en la comparación de las distancias reales y calculadas por tres ecuaciones de predicción de ISWT, lo que sugiere que las ecuaciones utilizadas pueden sobreestimar la distancia recorrida por los ancianos y que entre estas la Ecuación 1 presentó una predicción más cercana a la distancia recorrida por la muestra evaluada.

ABSTRACT Our study aimed to evaluate the external validity of three reference equations for estimating the distance to be covered in the incremental shuttle walking test (ISWT) by older adults and to identify which equation best predicts the distance for this age group. In total, 84 older adults registered in the Health Centers of Diamantina, state of Minas Gerais, Brazil, were selected. The volunteers were subjected to the ISWT and the distance covered, in meters, until the interruption of the test was recorded and compared with the prediction equations. The volunteers had a mean age of 73.15±5.89 years and some health problems common to this age group, were mostly women, and physically active. Statistical analysis showed an interaction between the factors, that is, a difference between the distances covered the ISWT and the distances obtained by the equations. The analysis showed a difference between the men and women (p<0.05) and Equation 1 showed a greater correlation strength (p<0.0001; r=0.414) with the distance covered compared to the other equations. Therefore, our study showed a difference in the comparison of the distances covered and those estimated by three ISWT prediction equations, suggesting that the equations used may overestimate the distance covered by older adults, and that, Equation 1 showed a prediction closer to the distance covered by the older adults of the sample.

Evaluating the need for two incremental shuttle walk tests during a maintenance exercise program in people with COPD.

OBJECTIVE: To determine if there was an increase in walk distance when two incremental shuttle walk tests (ISWTs) were performed at the commencement of a maintenance exercise program (0 month) and at three, six and 12-month assessments. DESIGN: A prospective, longitudinal, repeated measures study in COPD. SETTING: Single site, hospital outpatient physiotherapy department. PARTICIPANTS: Forty-eight participants (22 males) with COPD participated in the study: [baseline characteristics: mean (SD): FEV1 59 (19) % predicted; age 65 (8) years; BMI 26 (6) (kg/m(2))]. INTERVENTION: Participants completed two ISWTs at zero, three, six and twelve months. OUTCOMES: Incremental shuttle walk distance (ISWD). RESULTS: There was a significant increase in walk distance between two ISWTs at zero month (17 metres (95% CI: 7 to 26) and three months (18 metres (95% CI: 6 to 30), but not at six or 12 months. CONCLUSION: The increase in walk distance when a second ISWT was performed at zero and three months indicates the need to perform two ISWTs when participants are naïve to the test and at the three-month reassessment during a 12-month maintenance exercise program.

Physical activity monitoring: addressing the difficulties of accurately detecting slow walking speeds.

OBJECTIVE: To test the accuracy of a multi-sensor activity monitor (SWM) in detecting slow walking speeds in patients with chronic obstructive pulmonary disease (COPD). BACKGROUND: Concerns have been expressed regarding the use of pedometers in patient populations. Although activity monitors are more sophisticated devices, their accuracy at detecting slow walking speeds common in patients with COPD has yet to be proven. METHODS: A prospective observational study design was employed. An incremental shuttle walk test (ISWT) was completed by 57 patients with COPD wearing an SWM. The ISWT was repeated by 20 patients wearing the same SWM. RESULTS: Differences were identified between metabolic equivalents (METS) and between step-count across five levels of the ISWT (p < 0.001). Good within monitor reproducibility between two ISWT was identified for total energy expenditure and step-count (p < 0.001). CONCLUSIONS: The SWM is able to detect slow (standardized) speeds of walking and is an acceptable method for measuring physical activity in individuals disabled by COPD.

Capacidade de exercício e seu valor prognóstico no pós-operatório de cirurgia cardíaca / Physical exercise capacity and its prognostic value in postoperative cardiac surgery

INTRODUÇÃO: O valor prognóstico da capacidade de exercício em pacientes submetidos à cirurgia de revascularização miocárdica (CRM) necessita de esclarecimentos. OBJETIVOS: Avaliar a capacidade de exercício e o seu valor prognóstico em pacientes com doença arterial coronariana, submetidos à cirurgia de revascularização miocárdica eletiva. MATERIAIS E MÉTODOS: Foram avaliados 21 pacientes e 29 controles. Dois incremental shuttle walk test (ISWT) e dois testes de caminhada de 6 min (TC6) foram realizados randomicamente em dias alternados. A força de preensão manual (FPM) foi também avaliada. RESULTADOS: A FPM em valores percentuais (78,4 ± 16 vs. 97,2 ± 15%), o TC6 em metros (412 ± 79 vs. 601 ± 7 m) e em valores percentuais (72 ± 13 vs. 110 ± 11%) e o ISWT em metros (257 ± 90 vs. 517 ± 138 m) e em valores percentuais (53 ± 16 vs. 108 ± 16%) foram significativamente (p < 0,05) inferiores nos pacientes. Onze pacientes apresentaram complicações pós-operatórias (grupo C) e dez evoluíram bem (grupo SC). O grupo C apresentou idade mais avançada (57 ± 6 vs. 71 ± 7 anos; p < 0,05), FPM inferior (33 ± 6 vs. 41 ± 9 kgf) e ISWT inferior (208 ± 81 vs. 311 ± 66 m). Não houve diferenças significativas para o TC6. A regressão logística selecionou o ISWT como determinante do prognóstico dos pacientes (p = 0,04). CONCLUSÃO: Os pacientes à espera de CRM eletiva apresentam significativa redução da capacidade de exercício e o ISWT apresentou valor prognóstico significativo discriminando os pacientes com complicações pós-operatórias.

INTRODUCTION: The prognostic value of exercise capacity in patients undergoing coronary artery bypass grafting (CABG) needs clarification. OBJECTIVES: To assess exercise capacity and its prognostic value in patients with coronary artery disease undergoing elective CABG. MATERIALS AND METHODS: We evaluated 21 patients and 29 controls. Two incremental shuttle walk test (ISWT) and two tests of 6-min walk test (6MWT) were performed randomly on alternate days. The handgrip strength (FPM) was also evaluated. RESULTS: The FPM in percentages (78.4 ± 16 vs. 97.2 ± 15%), the 6MWT in meters (412 ± 79 vs. 601 ± 7 m) and percentage values (72 ± 13 vs. 110 ± 11%) and the ISWT in meters (257 ± 90 vs. 517 ± 138 m) and percentage values (53 ± 16 vs. 108 ± 16%) were significantly (p < 0.05) lower in patients. Eleven patients had postoperative complications (group C) and 10 had a good outcome (group SC). The group C showed significantly (p < 0.05), older age (57 ± 6 vs. 71 ± 7 years old), FPM lower (33 ± 6 vs. 9 ± 41 kgf) and ISWT lower (208 ± 81 vs. 311 ± 66 m). There were no significant differences for the 6MWT. Logistic regression analysis comparing the ISWT and 6MWT selected ISWT as a determinant of prognosis of patients (p = 0.04). CONCLUSION: Patients waiting for elective CABG have significantly reduced exercise capacity and ISWT had significant prognostic value discriminating patients with postoperative complications.