Limited evidence to strong evidence was found for reliability in various chronic conditions .
Little evidence was available for responsiveness and measurement error .
Studies showed large variability in test procedures despite existing guidelines for the performance of the 6MWT .
Evidence for measurement properties of the 6MWT  varies largely among chronic pediatric conditions .
BACKGROUND The Six-Minute Walk Test ( 6MWT ) is increasingly being used as a functional outcome measure for chronic pediatric conditions .
Knowledge about its measurement properties is needed to determine whether it is an appropriate test to use .
PURPOSE The purpose of this study was to systematic ally review all published clinimetric studies on the 6MWT in chronic pediatric conditions .
Effect of encouragement on walking test performance.
Walking tests , frequently used to document effects of treatment on exercise capacity , have never been st and ardised . We studied the effects of encouragement on walking test performance in a r and omised study that controlled for the nature of the underlying disease , time of day , and order effects . We r and omised 43 patients with chronic airflow limitation or chronic heart failure or both to receive or not receive encouragement as they performed serial two and six minute walks every fortnight for 10 weeks . Simple encouragement improved performance ( p less than 0.02 for the six minute walk ) , and the magnitude of the effect was similar to that reported for patients in studies purporting to show beneficial effects of therapeutic manoeuvres . Age and test repetition also affected performance . These results demonstrate the need for careful st and ardisation of the performance of walking tests , and suggest caution in interpreting studies in which st and ardisation is not a major feature of the study design
Limited evidence to strong evidence was found for reliability in various chronic conditions .
Little evidence was available for responsiveness and measurement error .
Studies showed large variability in test procedures despite existing guidelines for the performance of the 6MWT .
Evidence for measurement properties of the 6MWT  varies largely among chronic pediatric conditions .
BACKGROUND The Six-Minute Walk Test ( 6MWT ) is increasingly being used as a functional outcome measure for chronic pediatric conditions .
Knowledge about its measurement properties is needed to determine whether it is an appropriate test to use .
PURPOSE The purpose of this study was to systematic ally review all published clinimetric studies on the 6MWT in chronic pediatric conditions .