Reliability of graded cycling test with talk test and 30-s chair-stand test in men with prostate cancer on androgen deprivation therapy

PURPOSE: To investigate the absolute and relative reliability of the "graded cycling test with talk test" (GCT-TT) and the "30-second chair-stand test" (30s-CST) in men with prostate cancer receiving androgen deprivation therapy (ADT).

METHODS: Men with prostate cancer on ADT were included in this test-retest study. GCT-TT and 30s-CST were performed twice with 1 hour between test sessions. All tests were conducted by two experienced physiotherapists and all patients were familiar with the tests. Only intra-tester reliability was investigated as the test and retest of each participant were performed by the same physiotherapist. Intraclass correlation coefficient (ICC2.1), standard error of measurement (SEM and SEM95), and smallest real difference (SRD) were calculated.

RESULTS: Sixty men were included with a mean age of 70.8 ± 6.6 (mean ± SD) years. All performed 30s-CST twice without any problems. Two participants were excluded from the analysis of the GCT-TT results. Relative reliability for 30s-CST (ICC2.1) was 0.97 [95% CI: 0.94-0.98] with low measurement error: SEM95, 1.9 repetitions, and SRD, 2.6 repetitions. The corresponding results for GCT-TT were ICC2.1, 0.90 [95% CI: 0.84-0.94]; SEM95, 19.9 W; and SRD, 28.2 W.

CONCLUSIONS: The reliability of 30s-CST and GCT-TT is substantial for men with prostate cancer receiving ADT. Overall, an average 30s-CST improvement of 1.9 repetitions on a group level and three repetitions for individual patients are considered real improvements. A GCT-TT improvement exceeding 19.9 W represents a real improvement for a group of patients. Individual patients need to improve two steps (30 W).