Goudman Lisa, Molenberghs Geert, Duarte Rui V, Moens Maarten
Department of Neurosurgery, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium.
STIMULUS Research Group (reSearch and TeachIng neuroModULation Uz bruSsel), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium.
J Clin Med. 2021 Oct 24;10(21):4897. doi: 10.3390/jcm10214897.
New waveforms have changed the field of Spinal Cord Stimulation (SCS) to optimize therapy outcomes, among which is High-Dose SCS (HD-SCS). Missing observations are often encountered when conducting clinical trials in this field. In this study, different approaches with varying assumptions were constructed to evaluate how conclusions may be influenced by these assumptions. The aim is to perform a tipping point sensitivity analysis to evaluate the influence of missing data on the overall conclusion regarding the effectiveness of HD-SCS on disability. Data from the Discover study were used, in which 185 patients with Failed Back Surgery Syndrome were included. Disability was evaluated before SCS and after 1, 3 and 12 months of HD-SCS. During the second, third and fourth visit, data from 130, 114 and 90 patients were available, respectively. HD-SCS resulted in a significant decrease in disability scores based on the analysis of observed data and with multiple imputations. The tipping point sensitivity analysis revealed that the shift parameter was 17. Thus, the conclusion concerning the time effect under a "missing at random" mechanism is robust when the shift parameter for the disability score is 17. From a clinical point of view, a shift of 17 points on disability is not very plausible. Therefore we tend to consider the conclusions drawn under "missing at random" as being robust.
新的波形改变了脊髓刺激（SCS）领域以优化治疗效果，其中包括高剂量脊髓刺激（HD-SCS）。在该领域进行临床试验时经常会遇到缺失观测值的情况。在本研究中，构建了具有不同假设的不同方法，以评估这些假设可能如何影响结论。目的是进行临界点敏感性分析，以评估缺失数据对关于HD-SCS对残疾有效性的总体结论的影响。使用了来自Discover研究的数据，其中纳入了185例腰椎手术失败综合征患者。在进行脊髓刺激之前以及HD-SCS治疗1、3和12个月后对残疾情况进行评估。在第二次、第三次和第四次随访时，分别有130、114和90例患者的数据可用。基于观察数据的分析和多次插补，HD-SCS导致残疾评分显著降低。临界点敏感性分析表明，偏移参数为17。因此，当残疾评分的偏移参数为17时，在“随机缺失”机制下关于时间效应的结论是稳健的。从临床角度来看，残疾评分偏移17分不太合理。因此，我们倾向于认为在“随机缺失”情况下得出的结论是稳健的。
