Reference values for cardiopulmonary exercise testing in healthy subjects - an updated systematic review.

Introduction: Reference values for cardiopulmonary exercise testing (CPET) parameters provide the comparative basis for answering important questions concerning the normalcy of exercise responses in patients, and significantly impacts the clinical decision-making process. Areas covered: The aim of this study was to provide an updated systematic review of the literature on reference values for CPET parameters in healthy subjects across the life span. A systematic search in MEDLINE, Embase, and PEDro databases were performed for articles describing reference values for CPET published between March 2014 and February 2019. Expert opinion: Compared to the review published in 2014, more data have been published in the last five years compared to the 35 years before. However, there is still a lot of progress to be made. Quality can be further improved by performing a power analysis, a good quality assurance of equipment and methodologies, and by validating the developed reference equation in an independent (sub)sample. Methodological quality of future studies can be further improved by measuring and reporting the level of physical activity, by reporting values for different racial groups within a cohort as well as by the exclusion of smokers in the sample studied. Normal reference ranges should be well defined in consensus statements.

Reference value for the 6-minute walk test in children and adolescents: a systematic review.

INTRODUCTION: The 6-minute walk test is a submaximal exercise test used to quantify the functional exercise capacity in clinical populations. It measures the distance walked within a period of 6-minutes. Obtaining reference values in the pediatric population is especially demanding due to factors as the development stage and age. RV provide a comparative basis for answering questions concerning the normality of health status, exercise responses and functional exercise capacity in patients. Areas covered: The aim of this review is to provide an overview of reference values and reference value prediction equations for the 6-minute walk test in the children and in adolescent pediatric population and of the methodology used to obtain them. A total of 22 studies from MEDLINE, EMBASE and Cinahl were included containing healthy participants aged ≤18 years. Reported reference values ranged from 383 m ± 41 m to 799 m ± 54 m. The prediction equation 6MWD = (4.63*height(cm))-(3.53*weight(kg))+(10.42*age)+56.32 yields the highest R2 value (0.6). Expert commentary: It is impossible to present a single best reference value. A flow-chart is presented to aid the selection of reference values or reference value prediction equations. Consensus regarding testing procedures should lead to an update and stricter application of the current guidelines.