Department of Public Health, Aarhus University, Aarhus, Denmark.
Department of Clinical Medicine, Hammel Neurorehabilitation Centre and University Research Clinic, Aarhus University, Voldbyvej 15, 8450, Hammel, Denmark.
Acta Neurol Belg. 2022 Aug;122(4):893-901. doi: 10.1007/s13760-022-01991-4. Epub 2022 Jun 15.
The Six Spot Step Test has shown good psychometric properties in terms of validity and reliability in people with multiple sclerosis. Yet, the responsiveness and minimal important change are unknown. The objective was to investigate the responsiveness of the Six Spot Step Test against the perceived change of walking limitations and establish estimates for the minimal important change in people with multiple sclerosis.
The Six Spot Step Test was performed before and after four weeks of specialised multidisciplinary inpatient rehabilitation by 142 adults with mild to severe multiple sclerosis. Responsiveness was determined based on anchor- and distribution-based methods, using the Multiple Sclerosis Walking Scale-12 as external criterion. In a supplementary analysis, the Six-Minute Walking Test was used as an external criterion.
The correlation between the baseline (r = 0.56, p < 0.01) and discharge (r = 0.55, p < 0.01) Multiple Sclerosis Walking Scale-12 and Six Spot Step Test scores were acceptable. Furthermore, the change scores were weakly associated (r = 0.1, p = 0.27). This trend was similar for the Six-Minute Walking Test when used as anchor. The smallest detectable change was estimated to 1.7 seconds. An improvement in the Six Spot Step Test exceeding 2.1 (95% CI - 0.9 to 5.0) sec and 4.9 (95% CI 1.2-8.6) sec may be considered clinically important on a group level based on the Multiple Sclerosis Walking Scale-12 and the Six-Minute Walking Test, respectively.
In a sample of mild to severely disabled people with multiple sclerosis, the Six Spot Step Test showed fair responsiveness against a subjective and objective criterion, indicating a minimal important change between ≥ 2.1 and ≥ 4.9 seconds, respectively. However, a weak association between the change in the Six Spot Step Test and the subjective and objective external criterion calls for cautious interpretation. Hence, the results should be further verified against a valid external criterion.
六点步梯测试在多发性硬化症患者中表现出良好的效度和信度的心理测量特性。然而，其反应能力和最小临床重要变化尚不清楚。本研究旨在调查六点步梯测试在感知到的步行能力受限变化方面的反应能力，并确定多发性硬化症患者的最小临床重要变化估计值。
142 名轻度至重度多发性硬化症成人在四周的专业多学科住院康复前后进行了六点步梯测试。反应能力基于锚定和分布基础方法确定，使用多发性硬化症步行量表-12 作为外部标准。在补充分析中，使用六分钟步行测试作为外部标准。
基线（r=0.56，p<0.01）和出院时（r=0.55，p<0.01）多发性硬化症步行量表-12 和六点步梯测试得分之间的相关性是可以接受的。此外，变化得分的相关性较弱（r=0.1，p=0.27）。当使用六分钟步行测试作为锚定时，这种趋势相似。最小可检测变化估计为 1.7 秒。基于多发性硬化症步行量表-12 和六分钟步行测试，六点步梯测试的改善超过 2.1（95%CI -0.9 至 5.0）秒和 4.9（95%CI 1.2-8.6）秒可能被认为在群体水平上具有临床意义。
在轻度至重度残疾的多发性硬化症患者样本中，六点步梯测试对主观和客观标准显示出良好的反应能力，表明最小临床重要变化分别为≥2.1 和≥4.9 秒。然而，六点步梯测试的变化与主观和客观外部标准之间的弱相关性需要谨慎解释。因此，结果应进一步针对有效外部标准进行验证。
