Evaluation of D-dimer in the diagnosis of suspected XXXX .

@entity1 @entity1150 @entity1031 @entity1151
BACKGROUND: Several diagnostic strategies using ultrasound imaging, measurement of D-dimer, and assessment of clinical probability of disease have proved safe in @entity1 with suspected @entity1150 , but they have not been compared in randomized trials. METHODS: Outpatients presenting with suspected @entity1150 were potentially eligible. Using a clinical model, physicians evaluated the @entity1 and categorized them as likely or unlikely to have @entity1150 . The @entity1 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 @entity1 was considered clinically unlikely to have @entity1150 , in which case ultrasound imaging was not performed. RESULTS: Five hundred thirty @entity1 were randomly assigned to the control group, and 566 to the D-dimer group. The overall prevalence of @entity1150 or @entity1151 was 15.7 percent. Among @entity1 for whom @entity1150 had been ruled out by the initial diagnostic strategy, there were two confirmed venous @entity1031 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 @entity1 in the control group to 0.78 in the D-dimer group (P=0.008). Two hundred eighteen @entity1 (39 percent) in the D-dimer group did not require ultrasound imaging. CONCLUSIONS: @entity1150 can be ruled out in a @entity1 who is judged clinically unlikely to have @entity1150 and who has a negative D-dimer test. Ultrasound testing can be safely omitted in such @entity1 .
