Validation of 6 min step test and 4-m gait speed in children: A randomized cross-over study

Reliability and validity of six-minute step test in patients with heart failure

Exercise intolerance is the hallmark consequence of advanced chronic heart failure (HF). The six-minute step test (6MST) has been considered an option for the six-minute walk test because it is safe, inexpensive, and can be applied in small places. However, its reliability and concurrent validity has still not been investigated in participants with HF with reduced ejection fraction (HFrEF). Clinically stable HFrEF participants were included. Reliability and error measurement were calculated by comparing the first with the second 6MST result. Forty-eight hours after participants underwent the 6MST, they were invited to perform a cardiopulmonary exercise test (CPET) on a cycle ergometer. Concurrent validity was assessed by correlation between number of steps and peak oxygen uptake (V̇O2 peak) at CPET. Twenty-seven participants with HFrEF (60±8 years old and left ventricle ejection fraction of 41±6%) undertook a mean of 94±30 steps in the 6MST. Intra-rater reliability was excellent for 6MST (ICC=0.9), with mean error of 4.85 steps and superior and inferior limits of agreement of 30.6 and -20.9 steps, respectively. In addition, strong correlations between number of steps and CPET workload (r=0.76, P<0.01) and peak V̇O2 (r=0.71, P<0.01) were observed. From simple linear regression the following predictive equations were obtained with 6MST results: V̇O2 peak (mL/min) = 350.22 + (7.333 × number of steps), with R2=0.51, and peak workload (W) = 4.044 + (0.772 × number of steps), with R2=0.58. The 6MST was a reliable and valid tool to assess functional capacity in HFrEF participants and may moderately predict peak workload and oxygen uptake of a CPET.

The 3 Minute Step Test is a validated field test to evaluate the functional exercise capacity in children aged 6 to 12

BACKGROUND

Field tests are useful to assess the functional exercise capacity. The 6minute walking test (6MWT) is the most common field test even if alternatives are needed. The main aim of the study was to verify if the 3minute step test (3MST) is a valid tool to measure the functional exercise capacity and can surrogate the 6MWT in healthy children from 6- to 12-years-old.

METHODS

This randomized cross-over trial recruited 30 healthy children from 6 to 12 years. One 6MWT and two 3MST (3MST₁ and 3MST₂) were performed randomly on 3 consecutive days. The variables were the distance (6MWT), the number of steps (3MST) and the cardiorespiratory parameters.

RESULTS

The distance walked during 6MWT was very strongly correlated to the number of steps during the 3MST (3MST₁: rho=0.833; P<0.001 and 3MST₂: rho=0.868; P<0.001). Heart rate (HR) was lower than the theoretical maximal HR at the end of both tests. The change in HR and perceived fatigue were significantly higher after the 3MST. A learning effect was observed in the 3MST (+8 steps; P<0.001).

CONCLUSIONS

The 3MST is validated and can be a surrogate for the 6MWT in healthy children population between 6 and 12 years old. A training test is required in these children.

Testes funcionais validados em indivíduos hospitalizados e não hospitalizados: revisão sistemática

Objetivo: Realizar uma revisão sistemática sobre os testes funcionais validados em diferentes perfis de indivíduos hospitalizados e não hospitalizados e avaliar as evidências psicométricas para confiabilidade e validade. Métodos: Trata-se de uma revisão sistemática. Foram utilizadas as bases de dados EMBASE, MEDLINE, Lilacs e SciELO com as palavras-chave Functional Tests (Walk Test, Gait Speed Test, Chair Stand Test, Timed Up And Go, Step Test),Validation Studies as Topic e sinônimos. Foram incluídos estudos de validação de testes funcionais em indivíduos hospitalizados ou não hospitalizados que utilizaram os critérios de validade e/ou confiabilidade e relacionaram os testes a diferentes variáveis. Esses artigos poderiam ser observacionais longitudinais ou de corte transversal ou estudos de validação que utilizaram dados de ensaios clínicos. Foram excluídos os artigos que não apresentaram características importantes da amostra e a descrição do teste. Resultados: A pesquisa resultou em 36.150 artigos, e 89 foram incluídos. Os estudos foram organizados em tabelas com informações como autor, ano; critérios de validação; amostra; teste; variáveis associadas; resultados. A qualidade dos artigos foi avaliada por meio da Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Conclusão: Os testes funcionais são válidos e confiáveis para a avaliação de indivíduos hospitalizados e não hospitalizados, estando associados à força muscular, capacidade de caminhar, controle postural, atividades de vida diária, risco de quedas, hospitalização e mortalidade.