PLoS ONE (Jan 2015)
Correlation of six-minute walking performance with quality of life is domain- and gender-specific in healthy older adults.
Abstract
We analyzed the relationship between performance on the 6-min walk test (6MWT) and health-related quality of life (HRQoL) in older subjects. Our secondary aim was to determine the distance to be completed on the 6MWT for the subject to achieve a score of 50 on the Short Form (36) Health Survey (SF-36). Associations were tested using linear correlation and multivariate linear regression. Participants were 130 healthy older individuals. The predictive performance of the 6MWT based on an SF-36 score of 50 was assessed using a receiver operating characteristic curve and its area under curve (AUC). Associations were observed between physical functioning, role-emotional, social functioning, vitality, general health score, and 6MWT performance in women, after adjusting for confounding variables (coefficients: 0.57, 0.38, 0.40, and 0.46, respectively; p < 0.05). No association was found for men. The distance for the 6MWT to predict an SF-36 score of 50 was 481 m for men in the physical functioning (AUC: 0.79) and role-physical (AUC: 0.84) domains, and 420 m for women in role-emotional (AUC: 0.75), role-physical (AUC: 0.80), and general health (AUC: 0.80) domains. Our results indicate that superior 6MWT performance may be associated with better HRQoL in several domains in only healthy older women. No association between 6MWT performance and role-emotional, mental health, or vitality domains was found. We suggest that a score of 50 is represented by a 6MWT distance of 481 m for men and 420 m for women, at least in the role-physical domain.