Construct validity and reliability of the 2-minute step test in patients with lumbar spinal stenosis.

Aim: This study aimed to investigate the validity and reliability of the 2-Minute Step Test (2MST) in patients with lumbar spinal stenosis (LSS).

Method: This cross-sectional study involved 55 volunteers, aged 18-80, diagnosed with lumbar spinal stenosis. The participants were assessed using the 2MST, the 2-Minute Walk Test (2MWT), the 6-Minute Walk Test (6MWT), the Visual Analogue Scale (VAS), and the Oswestry Disability Index (ODI). To evaluate the reliability of the 2MST, test-retest reliability was determined by administering the 2MST again after a 7-day interval. The reliability analysis included the intraclass correlation coefficient (ICC) with a 95% confidence interval (CI), standard error of measurement (SEM), and minimum detectable change at the 95% confidence level (MDC₉₅). For concurrent validity, the correlations of the 2MST with the 2MWT, 6MWT, and ODI were assessed.

Results: The 2MST exhibited excellent test-retest reliability (ICC = 0.94, SEM = 5.56, MDC₉₅=15.41) in LSS patients. Additionally, the 2MST showed significant correlations with the 2MWT (r = 0.842, p < 0.001), 6MWT (r = 0.819, p < 0.001), and ODI score (r = -0.722, p < 0.001).

Conclusion: This study demonstrated that the 2MST is a valid and reliable tool for assessing exercise capacity in individuals with LSS.

Clinicaltrials.gov id: NCT06060821.