Measurement Properties and Determinants of the 6-Minute Walk Test in Patients with Lower Limb Lymphedema.

The aim of this study was to investigate the validity and reliability and identify determinants of the 6-minute walk test (6MWT) in patients with lower limb lymphedema (LLL). The study included 28 patients with LLL and 28 healthy subjects. To investigate the convergent validity and determinants of the 6MWT, patients were assessed using the following measurements: circumference measurement for lymphedema severity, hand-held dynamometry for muscle strength, time up and go for functional mobility, five-time sit-to-stand test for functional lower extremity strength, Lower Extremity Functional Scale for lower extremity functionality, Lymphedema Life Impact Scale for quality of life, and International Physical Activity Questionnaire-Short Form for physical activity level. The test-retest reliability of the 6MWT was assessed using intraclass correlation coefficients (ICCs). 6MWT, a test-retest reliability analysis was carried out with 28 patients within 3-7 days. The receiver operating characteristic (ROC) curve was employed to determine the cut-off point of 6MWT. The test-retest reliability of 6MWT was detected as excellent (ICC [95%] 0.93 [0.87-0.97]). Significant correlations were found between the 6MWT health-related and disease-specific parameters, indicating sufficient convergent validity ( ≥ 0.3). The ROC curve indicated a cut-off point of 504 meters (area under the curve [AUC] 0.712 [95%CI: 0.575-0.849]). Multiple linear regression analysis demonstrated that lymphedema severity, hip abduction muscle strength, and lower limb functionality were the predictors of 6MWT. The 6MWT has been shown to be a reliable and valid tool for assessing the functional capacity of patients with LLL.