Reliability and validity of the 6-minute pegboard and ring test for functional exercise capacity in patients with breast cancer

Background: Chronic pain, sensory disturbances, and lymphedema are frequent after breast cancer, leading to arm dysfunction. There is a need for objective performance-based clinical exercise tests for the upper extremity in patients with breast cancer. Objective: The aim of this study was to evaluate the validity and reliability of the 6-minute pegboard and ring test (6PBRT) in breast cancer survivors. Methods: Forty-eight women with breast cancer (mean age = 55.40 ± 10.40 years) were included. All patients performed 6PBRT on the first day and one week later to investigate the test-retest reliability of the 6PBRT, and intraclass correlation coefficients (ICC) were calculated. The peak workload (W_peak) and oxygen consumption level (VO_2peak) during the arm ergometer test were used as outcomes for the criterion validity of the 6PBRT. Results: The 6PBRT showed good test–retest reliability with an ICC_1,2 value of 0.871 [95% confidence interval (CI) 0.769–0.928]. The first 6PBRT score was very strongly correlated with the second test score (r = 0.866, p <.001). The 6PBRT score was significantly correlated with VO_2peak (r = 0.634, p <.001), and W_peak (r = 0.546, p <.001). While the 6PBRT score had less effect on VO_2peak, the determination of VO_2peak in the model was very good (R² = 0.832). Conclusion: The 6PBRT has good test-retest reliability and is a valid test in individuals with breast cancer. These findings suggest that 6PBRT is a practical, useful, valid and reliable assessment tool for determining functional arm exercise capacity in patients with breast cancer.