Learning effect on the six-minute walk test in patients enrolled in a hematopoietic stem cell transplantation program

Abstract

Introduction

The six-minute walk test (6MWT) is routinely used to assess functional capacity in clinical practice and research. However, in adults with hematologic malignancies enrolled in a hematopoietic stem cell transplantation (HSCT) program, its test–retest reliability, learning effect, and measurement error remain insufficiently characterized.

Objective

To determine the test–retest reliability, learning effect, and measurement error of the 6MWT in adults enrolled in an HSCT program.

Methods

This cross-sectional test–retest study included 45 adults receiving pre- or post-HSCT care who completed two standardized 6MWTs separated by 24 hours. Six-minute walk distance (6MWD) was the primary outcome. Test–retest reliability was assessed using the intraclass correlation coefficient (ICC), while measurement error was examined using Bland–Altman analysis, the standard error of measurement (SEM), and the minimal detectable change at the 95% confidence level (MDC⁹⁵).

Results

Mean 6MWD increased from 483.1 ± 120.6 m on the first test to 496.6 ± 124.5 m on the second, demonstrating a learning effect. The mean between-test difference was 13.4 m, with 95% limits of agreement ranging from − 10.9 to 37.8 m. Test–retest reliability was excellent (ICC = 0.995, 95% CI 0.991–0.997). The MDC⁹⁵ for the total sample was 24.17 m.

Conclusion

In adults enrolled in an HSCT program, the 6MWT demonstrated excellent test–retest reliability but also a measurable learning effect. These findings support repeating the test when establishing baseline functional capacity to improve the accuracy of longitudinal interpretation during physiotherapy assessment and follow-up.