Angiology and Vascular Surgery Unit, Bellvitge University Hospital, Hospitalet del Llobregat, Spain.
Angiology and Vascular Surgery Unit, Bellvitge University Hospital, Hospitalet del Llobregat, Spain.
J Vasc Surg Venous Lymphat Disord. 2020 Sep;8(5):734-740. doi: 10.1016/j.jvsv.2019.11.015. Epub 2020 Feb 14.
Our goal was to analyze the utility of the age-adjusted D-dimer cutoff value in patients with clinically suspected deep venous thrombosis (DVT) in an ambulatory care setting, including distal DVTs.
This was an observational cohort study of 606 outpatients older than 18 years presenting with low or moderate clinical suspicion of lower limb DVT (measured by Wells scale). D-dimer levels were obtained, and duplex ultrasound was performed (including femoropopliteal and below-knee veins). We calculated sensitivity, specificity, and positive and negative predictive D-dimer values and when to apply the age-adjusted D-dimer cutoff value (D-dimer threshold = age × 10 μg/L). We split patients older than 50 years into 10-year age groups. We constructed receiver operating characteristic curves of the D-dimer test for each group to find the best threshold (defined as the value of D-dimer that gives more specificity, maintaining the maximum possible sensitivity).
There were 249 men and 357 women with a mean age of 69.3 years; 41 patients were diagnosed with DVT. At a D-dimer threshold of 250 μg/L, sensitivity was 93%, specificity was 8%, positive predictive value was 7%, and negative predictive value was 94%. When the age-adjusted cutoff level was applied, global sensitivity was 76% and specificity 61%; positive predictive value was 12%, and negative predictive value was 97%. False-negative rate was 24%. We split patients older than 50 years into 10-year age groups: 50 to 60 years, 60 to 70 years, 70 to 80 years, and >80 years. The optimum thresholds were, respectively, 526 μg/L, 442.5 μg/L, 475 μg/L, and 549. μg/L.
In our series, the age-adjusted D-dimer cutoff level is not useful in the diagnostic algorithm of DVT.
我们的目标是分析在门诊环境中，包括远端深静脉血栓形成（DVT）患者中，临床疑似深静脉血栓形成（DVT）患者使用年龄校正 D-二聚体截断值的实用性。
这是一项观察性队列研究，纳入了 606 例年龄大于 18 岁、临床疑似下肢 DVT（通过 Wells 量表评估）的门诊患者。测量 D-二聚体水平，并进行双功超声检查（包括股腘静脉和膝下静脉）。我们计算了 D-二聚体的敏感性、特异性、阳性和阴性预测值，以及何时应用年龄校正的 D-二聚体截断值（D-二聚体阈值=年龄×10μg/L）。我们将年龄大于 50 岁的患者分为 10 岁年龄组。我们为每个组构建 D-二聚体检测的受试者工作特征曲线，以找到最佳阈值（定义为在保持最大可能敏感性的情况下，特异性更高的 D-二聚体值）。
249 例男性和 357 例女性，平均年龄为 69.3 岁；41 例患者诊断为 DVT。D-二聚体阈值为 250μg/L 时，敏感性为 93%，特异性为 8%，阳性预测值为 7%，阴性预测值为 94%。当应用年龄校正的截断值时，总敏感性为 76%，特异性为 61%；阳性预测值为 12%，阴性预测值为 97%。假阴性率为 24%。我们将年龄大于 50 岁的患者分为 10 岁年龄组：50-60 岁、60-70 岁、70-80 岁和>80 岁。最佳阈值分别为 526μg/L、442.5μg/L、475μg/L 和 549μg/L。
在我们的研究中，年龄校正的 D-二聚体截断值在 DVT 的诊断算法中并不适用。
