Prediction equations for 6-minute walk distance in apparently healthy Nigerians

Abstract

KEYWORDS 6-minute walk distance; 6-minute walk test; predicted equationsAbstract The aims of this study were to determine the 6-minute walk distance (6MWD), establish prediction equations for the 6MWD in apparently healthy Nigerians, evaluate any effects regarding participant sex, and compare measured 6MWDs with the predicted 6MWD from reference equations derived from other populations. Four hundred and twenty two (422) apparently healthy Nigerians participated in the study. The 6-minute walk test was carried out according to the American Thoracic Standard-standardized protocol. The 6MWD obtained from the study was compared with reference values from other foreign populations. There were no significant differences between the mean age and mean weight of the male and female participants. However, significant difference existed in the mean height and mean body mass index (BMI; p < 0.001) of these participants. Male participants covered a statistically significant longer distance than female participants (p < 0.001). The mean 6MWD measured in Nigerian participants (517.6 AE 72.2 m) was statistically lower than 6MWD in Americans, Brazilians, and Tunisians and was higher than in Arabians (p 0.002), respectively. The 6-MWD in healthy Nigerians cannot be predicted by established reference equations from other populations. The regression equations established in this study may better predict the distance for Nigerians.

Development of reference equations for the six-minute walk distance of school-aged Nigerian children

“…Also, none of previously published reference equations satisfactorily predicted our cohort's 6MWD. Our data adds to existing published ones for Nigerian adolescents (21) and adults, (8,22) thus completing Nigerian references spanning school-age to adulthood, while also filling an acknowledged paucity of 6MWT data from sub-Saharan Africa. (9,15) The 6MWT is a valid and reliable measure of functional exercise capacity widely used in adults and children with disorders like asthma, congenital heart diseases, sickle cell disorders and others.…”

“…(4,5) The gold-standard objective measure of functional capacitythe maximal oxygen consumption (VO 2max ) from a cardiopulmonary exercise test (CPET)-( 6) requires sophisticated equipment and expertise largely unavailable in developing countries. (4,7,8) But, the sixminute walk test (6MWT), which evolved from pre-existing field walk tests, (1, 9, 10) is a cheap but valid and reliable potential alternative measure of functional capacity using the self-paced distance walked in six minutes (six-minute walk distance, 6MWT) on a smooth hard surface. It is widely used for the functional evaluation, prognostication and rehabilitation of pediatric and adult populations with cardiopulmonary and cardiopulmonary disorders (4,7,(10)(11)(12)(13) However, its clinical utility in sub-Saharan Africa is limited largely because of lack of locally-derived normative standards.…”

“…(14)(15)(16)(18)(19)(20) The American Thoracic Society (ATS) and European Respiratory Society (ERS) thus recommend development of reference standards from local populations. (7) In Nigeria, although reference standards are available for adolescents (21) and adults (8,22), none is available in pre-adolescents school-age children. This cross-sectional study thus determined the mean 6MWD of healthy 6 to 11-year-old Nigerian children, its predictors (including chest circumference, which has not been previously evaluated) and reference equations; we also assessed the predictive performance of previously published equations.…”

Limitations of 6‐minute walk test reference values for spinal muscular atrophy

“…Pairwise comparisons among the six adult equations, adjusting for multiple comparisons, revealed three studies (McKay, 19 Chetta, 22 and Palaniappan 2 ) were significantly different from all other studies. Three studies (Ajiboye, 21 Fernandes,23 and Shrestha 25 ) were not significantly different from each other (P > .05). All three of these studies had lower predicted distances which resulted in higher % predicted distance values when the clinical data was applied.…”

“…After removing duplicates and non‐English studies, and performing a title and abstract review for relevance, the total number of articles to be considered for review was 47 (19 pediatric) (Supporting Information Table S1). Once strict inclusion and exclusion criteria were applied, three pediatric and six adult studies were included for analysis (Table ). The most widely used normative datasets in neuromuscular disorders including SMA did not meet strict inclusion criteria and were not considered candidate studies for analyses …”