Minimal important difference of the 6-minute walk test after allogenic hematopoietic stem cell transplantation

Abstract

Purpose

The 6-min walk test (6MWT) of allogenic hematopoietic stem cell transplantation (allo-HSCT) recipients has been gaining attention; however, minimal differences have not been reported. This study aimed to determine the minimal important difference (MID) in the 6MWT among hospitalized patients with allo-HSCT.

Materials and methods

The MID of the 6MWT was calculated using three different methodologies based on an anchor-based method; basic anchor-based methods, linear regression analysis, and receiver operating characteristic (ROC) curve analysis. The decrease in the score of Question 2 of the European Organization for Research and Treatment of Cancer Quality of life questionnaire core-30 was included as an anchor question for calculating the MID. Both actual and percentage changes in 6MWT values from baseline and at discharge were used in the MID calculations. In the actual and percentage change of the 6MWT, the one with the larger the area under the curve in the ROC curve was recommended as the MID.

Results

Among the three methods using actual values, the largest MID of the 6MWT was −37.5 m (sensitivity: 54%, specificity: 88%).

Conclusion

More careful follow-up after discharge is necessary for allo-HSCT patients who show a reduction of 37.5 m or more in the acute illness phase.

IMPLICATIONS FOR REHABILITATION

• Advancements in allogeneic hematopoietic stem cell transplantation have improved the survival rates of individuals with malignant hematological disorders, and efforts should now be focused on enhancing their physical function and quality of life.

• There is a problem that the physical performance of the patients is reduced by the side effects of treatment.

• More careful follow-up after discharge is necessary for allo-HSCT patients who show a reduction of 37.5 m or more in the acute illness phase.

Keywords:

• Allogeneic hematopoietic stem cell transplantation
• 6-minute walk test
• the European organization for research and treatment of cancer quality of life questionnaire core-30
• minimal important difference
• exercise tolerance

Disclosure statement

The authors declare that they have no conflict of interest.

Data availability statement

The datasets generation during and/or analysed during the current study can be accessed from the corresponding author on reasonable request.

Additional information

Funding

This work was supported by the under Grant: The Management Expenses Grants of Kyoto University from the Ministry of Education, Culture, Sports, Science, and Technology, Japan (to T. Kondo).