Wells Philip S, Anderson David R, Rodger Marc, Forgie Melissa, Kearon Clive, Dreyer Jonathan, Kovacs George, Mitchell Michael, Lewandowski Bernard, Kovacs Michael J
Department of Medicine, Ottawa Hospital, University of Ottawa, Ottawa, Ont, Canada.
N Engl J Med. 2003 Sep 25;349(13):1227-35. doi: 10.1056/NEJMoa023153.
Several diagnostic strategies using ultrasound imaging, measurement of D-dimer, and assessment of clinical probability of disease have proved safe in patients with suspected deep-vein thrombosis, but they have not been compared in randomized trials.
Outpatients presenting with suspected lower-extremity deep-vein thrombosis were potentially eligible. Using a clinical model, physicians evaluated the patients and categorized them as likely or unlikely to have deep-vein thrombosis. The patients were then randomly assigned to undergo ultrasound imaging alone (control group) or to undergo D-dimer testing (D-dimer group) followed by ultrasound imaging unless the D-dimer test was negative and the patient was considered clinically unlikely to have deep-vein thrombosis, in which case ultrasound imaging was not performed.
Five hundred thirty patients were randomly assigned to the control group, and 566 to the D-dimer group. The overall prevalence of deep-vein thrombosis or pulmonary embolism was 15.7 percent. Among patients for whom deep-vein thrombosis had been ruled out by the initial diagnostic strategy, there were two confirmed venous thromboembolic events in the D-dimer group (0.4 percent; 95 percent confidence interval, 0.05 to 1.5 percent) and six events in the control group (1.4 percent; 95 percent confidence interval, 0.5 to 2.9 percent; P=0.16) during three months of follow-up. The use of D-dimer testing resulted in a significant reduction in the use of ultrasonography, from a mean of 1.34 tests per patient in the control group to 0.78 in the D-dimer group (P=0.008). Two hundred eighteen patients (39 percent) in the D-dimer group did not require ultrasound imaging.
Deep-vein thrombosis can be ruled out in a patient who is judged clinically unlikely to have deep-vein thrombosis and who has a negative D-dimer test. Ultrasound testing can be safely omitted in such patients.
几种使用超声成像、D - 二聚体测量以及疾病临床可能性评估的诊断策略已被证明对疑似深静脉血栓形成的患者是安全的，但它们尚未在随机试验中进行比较。
出现疑似下肢深静脉血栓形成的门诊患者可能符合条件。使用临床模型，医生对患者进行评估并将他们分类为深静脉血栓形成可能性大或不大。然后将患者随机分配为仅接受超声成像（对照组）或接受D - 二聚体检测（D - 二聚体组），随后进行超声成像，除非D - 二聚体检测为阴性且患者被认为临床上深静脉血栓形成可能性不大，在这种情况下不进行超声成像。
530例患者被随机分配到对照组，566例被分配到D - 二聚体组。深静脉血栓形成或肺栓塞的总体患病率为15.7%。在通过初始诊断策略排除深静脉血栓形成的患者中，在三个月的随访期间，D - 二聚体组有2例确诊的静脉血栓栓塞事件（0.4%；95%置信区间，0.05至1.5%），对照组有6例事件（1.4%；95%置信区间，0.5至2.9%；P = 0.16）。使用D - 二聚体检测导致超声检查的使用显著减少，从对照组每位患者平均1.34次检查降至D - 二聚体组的0.78次（P = 0.008）。D - 二聚体组中有218例患者（39%）不需要超声成像。
对于临床判断深静脉血栓形成可能性不大且D - 二聚体检测为阴性的患者，可以排除深静脉血栓形成。在此类患者中可以安全地省略超声检查。
