Nordanstig J, Pettersson M, Morgan M, Falkenberg M, Kumlien C
Department of Vascular Surgery and Institute of Medicine, Department of Molecular and Clinical Medicine, Sahlgrenska University Hospital and Academy, Gothenburg University, Gothenburg, Sweden.
Health and Care Sciences, Gothenburg University, Gothenburg, Sweden.
Eur J Vasc Endovasc Surg. 2017 Sep;54(3):340-347. doi: 10.1016/j.ejvs.2017.06.022. Epub 2017 Jul 25.
Patient reported outcomes are increasingly used to assess outcomes after peripheral arterial disease (PAD) interventions. VascuQoL-6 (VQ-6) is a PAD specific health-related quality of life (HRQoL) instrument for routine clinical practice and clinical research. This study assessed the minimum important difference for the VQ-6 and determined thresholds for the minimum important difference and substantial clinical benefit following PAD revascularisation.
This was a population-based observational cohort study. VQ-6 data from the Swedvasc Registry (January 2014 to September 2016) was analysed for revascularised PAD patients. The minimum important difference was determined using a combination of a distribution based and an anchor-based method, while receiver operating characteristic curve analysis (ROC) was used to determine optimal thresholds for a substantial clinical benefit following revascularisation.
A total of 3194 revascularised PAD patients with complete VQ-6 baseline recordings (intermittent claudication (IC) n = 1622 and critical limb ischaemia (CLI) n = 1572) were studied, of which 2996 had complete VQ-6 recordings 30 days and 1092 a year after the vascular intervention. The minimum important difference 1 year after revascularisation for IC patients ranged from 1.7 to 2.2 scale steps, depending on the method of analysis. Among CLI patients, the minimum important difference after 1 year was 1.9 scale steps. ROC analyses demonstrated that the VQ-6 discriminative properties for a substantial clinical benefit was excellent for IC patients (area under curve (AUC) 0.87, sensitivity 0.81, specificity 0.76) and acceptable in CLI (AUC 0.736, sensitivity 0.63, specificity 0.72). An optimal VQ-6 threshold for a substantial clinical benefit was determined at 3.5 scale steps among IC patients and 4.5 in CLI patients.
The suggested thresholds for minimum important difference and substantial clinical benefit could be used when evaluating VQ-6 outcomes following different interventions in PAD and in the design of clinical trials.
患者报告的结局越来越多地用于评估外周动脉疾病（PAD）干预后的结局。VascuQoL-6（VQ-6）是一种用于常规临床实践和临床研究的特定于PAD的健康相关生活质量（HRQoL）工具。本研究评估了VQ-6的最小重要差异，并确定了PAD血运重建后最小重要差异和显著临床获益的阈值。
这是一项基于人群的观察性队列研究。分析了瑞典血管登记处（2014年1月至2016年9月）中接受血运重建的PAD患者的VQ-6数据。使用基于分布和基于锚定的方法相结合来确定最小重要差异，同时使用受试者操作特征曲线分析（ROC）来确定血运重建后显著临床获益的最佳阈值。
共研究了3194例有完整VQ-6基线记录的血运重建PAD患者（间歇性跛行（IC）患者1622例，严重肢体缺血（CLI）患者1572例），其中2996例在血管干预后30天有完整的VQ-6记录，1092例在1年后有完整记录。根据分析方法的不同，IC患者血运重建1年后的最小重要差异为1.7至2.2个量表步长。在CLI患者中，1年后的最小重要差异为1.9个量表步长。ROC分析表明，VQ-6对IC患者显著临床获益的判别性能极佳（曲线下面积（AUC）为0.87，敏感性为0.81，特异性为0.76），在CLI患者中可接受（AUC为0.736，敏感性为0.63，特异性为0.72）。确定IC患者显著临床获益的最佳VQ-6阈值为3.5个量表步长，CLI患者为4.5个量表步长。
在评估PAD不同干预后的VQ-6结局以及设计临床试验时，可使用建议的最小重要差异和显著临床获益阈值。
