The minimal clinically important difference in the treadmill six-minute walk test in active women with breast cancer during and after oncological treatments

Purpose To examine the minimal clinically important difference (MCID) in the treadmill 6-minute walk test (6MWT) in women with breast cancer. Materials and methods A secondary analysis of cross-sectional data from 112 women who were undergoing chemotherapy or had undergone anticancer treatment was conducted. Participants completed the 6MWT on a treadmill and the European Organization for Research and Treatment of Cancer Questionnaire (EORTC-QLQ-C30) twice, eight weeks apart. Change in the physical function domain of the EORTC-QLQ-C30 was used to classify the positive change subgroup (>= 5 points difference) and the unchanged subgroup (<5 points difference). This was combined with the distance difference from the 6MWTs, determining the MCID as the cut-off from the area under the receiver operating characteristic (AUROC) curve (anchor-based determination). The MCID was also determined from (1) the effect size and (2) the difference in standard error (SEM) of the results of the first and second 6MWT (distribution-based determination). Results The MCIDs in the during-chemotherapy group was 66.5 and 41.5 m and those in the after-treatment group to be 41.4 and 40.5 m (SEM and effect size based respectively). Conclusions The MCID in the treadmill 6MWT distance could be used to interpret changes in the physical health status of women with breast cancer.

Automated summary

The purpose of this study was to determine the minimal clinically important difference (MCID) in the treadmill 6-minute walk test (6MWT) among women with breast cancer. The results showed that MCID could be used to interpret changes in the physical health status of these women.