Two-minute walk test performance by adults 18 to 85 years: normative values, reliability, and responsiveness

Abstract

Objectives: To provide (1) normative reference values for the 2-minute walk test (2MWT), (2) reference equations for the 2MWT, and (3) information on the reliability and responsiveness of the 2MWT across the adult lifespan.

Design: Cross-sectional study.

Setting: General community settings.

Participants: A population-based sample of adult participants (N=1137) contributed data to this study, which was part of the National Institutes of Health (NIH) Toolbox for the Assessment of Neurological and Behavioral Function Norming Project.

Interventions: Not applicable.

Main outcome measure: 2MWT.

Results: Overall, the distance participants walked ranged from 64.6 to 300.8m (mean, 180.9m). Men walked farther than did women (189.4m vs 176.0m; t=6.8; df=1,135; P<.001). Significant correlations were observed between the 2MWT and age (r=-.41), height (r=.29), weight (r=-.16), and body mass index (r=-.32). Age and body mass index were used in the linear regression modeling to predict the 2MWT distance (R(2)=.55-.56). Test-retest reliability of the 2MWT as characterized by the intraclass correlation coefficient was .82 (95% confidence interval, .76-.87). Based on a standard error of measurement of 15.3m, the minimum detectable change for the 2MWT was 42.5m.

Conclusions: The study presents norms of the 2MWT established by the NIH Toolbox. The norms can be used to determine the presence of limitations in walking endurance across the lifespan.

Keywords: Exercise test; Physical endurance; Psychometrics; Rehabilitation; Walking.