Age-adjusted D-dimer Cut-off Levels Research Articles

Diagnostic Strategies in Pulmonary Embolism

AbstractKey to the diagnosis of pulmonary embolism (PE) is a careful bedside evaluation. After this, there are three further diagnostic steps. In all patients, estimation of the clinical probability of PE is performed. The other two steps are measurement of D-dimer when indicated and chest imaging when indicated. The clinical probability of PE is estimated at low, moderate, or high. The prevalence of PE is less than 15% among patients with low clinical probability, 15 to 40% with moderate clinical probability, and >40% in patients with high clinical probability. Clinical gestalt has been found to be very useful in estimating probability of PE. However, clinical prediction rules, such as Wells criteria, the modified Geneva score, and the PE rule out criteria have been advocated as adjuncts. In patients with high clinical probability, the high prevalence of PE can lower the D-dimer negative predictive value, which could increase the risk of diagnostic failure. Consequently, patients with high probability for PE need to proceed directly to chest imaging, without prior measurement of D-dimer level. Key studies in determining which low to moderate probability patients require chest imaging are the Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism (ADJUST-PE), the Simplified diagnostic management of suspected pulmonary embolism (YEARS), and the Pulmonary Embolism Graduated D-Dimer trials. In patients with low clinical probability, PE can be excluded without imaging studies if D-dimer is less than 1,000 ng/mL. In patients in whom there is not a low likelihood for PE, this can be excluded without imaging studies if the D-dimer is below the age-adjusted threshold.

A study of modified Wells score for pulmonary embolism and age-adjusted D-dimer values in patients at risk for deep venous thrombosis.

Pulmonary embolism (PE) is the most severe complication of deep venous thrombosis (DVT). This study was designed to evaluate the usefulness of modified Wells score combined with age-adjusted D-dimer cut-off levels as a clinical pre-test probability assessment for predicting PE in patients 'at risk for DVT.' This was a cross-sectional study including 200 in-patients at risk for DVT. Patients were categorized as 'pulmonary embolism unlikely' or 'pulmonary embolism likely' using modified Wells score and underwent D-dimer testing. PE was considered excluded in patients classified as unlikely with normal D-dimer levels, whereas the rest of the patients underwent computed tomography pulmonary angiogram (CTPA). Out of 200 patients, 163 patients (81.50%) were 'pulmonary embolism unlikely,' whereas 37 patients (18.50%) were 'pulmonary embolism likely.' Of 163 patients categorized as 'pulmonary embolism unlikely,' 67 patients (41.5%) had normal D-dimer values and were excluded from CTPA. PE was detected in 24.2% of the patients who underwent CTPA. The combined strategy using modified Wells score and age-adjusted D-dimer cut-off value has 100% sensitivity and a negative predictive value and can be used to safely exclude PE in in-patients.

Role of an age-adjusted D-dimer cutoff level in the diagnosis algorithm of lower limb deep venous thrombosis in outpatients

ObjectiveOur 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. MethodsThis 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). ResultsThere 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. ConclusionsIn our series, the age-adjusted D-dimer cutoff level is not useful in the diagnostic algorithm of DVT.

Role of the Age-adjusted D-dimer Cut-off Level in the Diagnosis of Lower Limbs Dvt in Outpatients

Role of the Age-adjusted D-dimer Cut-off Level in the Diagnosis of Lower Limbs Dvt in Outpatients

Скрининговый тест выявления тромбоза глубоких вен и тромбоэмболии легочной артерии

Введение. Учитывая распространенность тромбозов, а каждый год в большинстве стран тромбоз глубоких вен (ТВГ) или тромбоэмболия легочной артерии (ТЭЛА) развивается у 80–120 человек на 100 тысяч населения, актуальным является использование скрининговых параметров гемостаза и оценка предрасположенности к тромбозам. Важным лабораторным маркером тромбоза и тромбоэмболии является Д-димер. Представляет интерес сравнение тестов различной чувствительности, имеющих признанное клиническое применение, для принятия решения о возможности их использования в ходе амбулаторного скрининга пациентов. Материалы и методы. Исследованы цитратные пробы крови 101 пациента (средний возраст — 41 ± 9,1 лет), среди которых были сформированы 3 группы: 69 человек, проходивших диспансерное обследование; 8 пациентов отделения интенсивной терапии; 24 пациента с подтвержденным сердечно-сосудистым заболеванием. Исследование содержания Д-димера в пробах цитратной плазмы выполняли одномоментно 2 методами: иммунотурбодиметрическим (ИТД) и иммунохемилюминесцентным (ИХЛ). Результаты. Получены результаты сравнения 2 методов исследования Д-димера. Коэффициент корреляции в разных группах пациентов составил 0,74–0,99 в зависимости от патологии, что свидетельствует о высокой степени соответствия результатов измерения Д-димера и возможности применения как метода ИТД, так и метода ИХЛ в скрининге пациентов с целью исключения ТВГ и ТЭЛА. Заключение. Проведенные исследования позволяют рассматривать метод ИХЛ для исследования содержания Д-димера на анализаторе Immulite 2000 XPi как скрининговый для амбулаторного догоспитального обследования пациентов. Introduction. Every year in most countries deep vein thrombosis (DVT) or pulmonary embolism (PE) develops in 80–120 people per 100 thousand population so screening of hemostatic parameters and assessment of predisposition to thrombosis is very actual problem. D-dimer is the important laboratory marker of thrombosis and thromboembolism. It is of interest to compare common clinical tests with diff erent sensitivities to determine whether they can be used during outpatient screening. Materials and methods. We examined citrate blood samples of 101 patients (mean age — 41 ± 9.1 years) who were divided into 3 groups: 69 persons passed the outpatient examination; 8 patients were in intensive care unit; 24 patients had confirmed cardiovascular disease. Measurement of D-dimer content in citrate plasma samples was carried out simultaneously by 2 methods: immunoturbodimetry (ITD) and immunochemiluminescence (IСL). Results. We obtained the results of D-dimer levels that were measured by 2 methods and calculated their relationships. The correlation coeffi cient in diff erent patient groups was 0.74–0.99 depending on their pathology. This fact shows a high degree of compliance of D-dimer results and the possibility of using both methods (ITD and IСL) in screening patients for excluding DVT and PE. Conclusion. Our researches allow to consider the IСL method for studying D-dimer content by Immulite 2000 XPi analyzer as a screening method for outpatient pre-hospital examination.

Age-Adjusted D-Dimer Cut-Off Levels to Rule-out Venous Thromboembolism in Patients with Non-High Pre-Test Probability. Clinical Performance and Cost-Effectiveness Analysis

BackgroundD-dimer levels below a well-defined cut-off level enable to safely rule out VTE in patients with a low or intermediate pre-test probability (PTP), as the test negative predictive value (NPV) was high. As ageing is associated with increased D-dimer levels, the question was raised of the usefulness of their measurement to rule out VTE in elderly patients. Various attempts were made in the recent years to address that issue, particularly the use of age-adjusted cut-off values calculated by multiplying the patient's age by 10, in patients aged over 50.Aim of that studyThe aim of the study was to validate such a strategy, and to evaluate its economic impact in unselected outpatients referred to the emergency departments of 5 French centres (2 university hospitals, and 3 general hospitals).Patients, Materials and MethodsAfter exclusion of those on anticoagulant treatment at the time of the diagnosis (n=23), a total of 1255 consecutive patients with a non-high PTP of VTE were included in the study. The same standardized procedure was used in the 5 centres, i.e. D-dimer measurement in patients with a non-high PTP, and imaging techniques (usually computed pulmonary angiography in case of suspected PE and Doppler ultrasonography in case of suspected DVT) only when D-dimer was above the cut-off level.D-dimer was evaluated using the same latex-based fully automated assay (HemosIL D-dimer HS500 assay, Instrumentation Laboratory). Test results were expressed in ng/mL fibrinogen equivalent units (FEU), and the traditional cut-off level for VTE exclusion was 500 ng/mL.ResultsVTE was diagnosed in 105 patients of the 1255 included patients (8.4%): 88 patients were diagnosed out of the 1082 patients referred for suspected PE and 27 out the 173 referred for suspected DVT. D-dimer levels were above 500 ng/mL in all patients with VTE and in 521 of the 1150 patients without VTE (45.3%). The test NPV was 100% as well as its sensitivity. If the overall test specificity was 54.7%, it significantly decreased in an age-dependent manner over 70 years, related to a high percentage of increased D-dimer levels in elderly patients, particularly in those above 80 years.Using age-adjusted cut-off levels, calculated by multiplying the patient's age by 10, induced a significantly improvement in test specificity, particularly in very old patients with an overall NPV=60.2% vs. 54.7% using the fixed cut-off value. The overall NPV remained high (99.9%), even if a 78 y-old female with a low PTP of PE would have been misdiagnosed as her D-dimer level (540 ng/mL) was above 500 ng/mL but below the age-adjusted cut-off value. Such an improvement in test performance was found both in patients with suspected PE and DVT (Table).As this increase in test specificity would have led to exclude VTE in a higher percentage of patients in the studied population, we evaluated the cost-effectiveness of that strategy, taking into account the local cost of D-dimer testing, angiography and Doppler US (16.20, 58.72, and 75.60 Euros respectively). In the case of suspected PE, the economic impact of the proposed diagnosis strategy was a decreased of 6.9% of total costs (45,023.4 vs. 48,356.4 Euros). In the case of DVT, the overall saving was 5.1% (9,909 vs. 10,438.2 Euros). If such an analysis was used in the US, where angiography and Doppler US were more expensive (648 and 226 US$ respectively), and D-dimer less costly (14 US$), the cost savings would have been even higher (-11.0% for PE, and -6.3% for DVT).ConclusionsThe use age-adjusted cut-off levels for D-dimer, in patients aged over 50 years old, leaded to a significant increase in the test specificity, but correlatively to slightly decreased NPV and sensitivity, as some patients with D-dimer levels above 500 ng/mL but below the age-adjusted cut-off value could be misdiagnosed. However such a strategy was found to be safe in our studied populations, as the NPV remained high (99.9%), and cost-effective. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Age-Adjusted Cutoff D-Dimer Level to Rule Out Acute Pulmonary Embolism: A Validation Cohort Study

BackgroundThe diagnosis of pulmonary embolism in the Emergency Room setting is challenging. Multiple patients have to undergo radiologic assessment with its inherent shortcomings. The D-dimer test with accepted cutoff level of 500 μg/L is associated with a high proportion of false-positive results. The present study aimed to validate the advantages of using an age-adjusted D-dimer cutoff level, compared with 500-μg/L value in the diagnosis of acute pulmonary embolism. MethodsThis study evaluated patients admitted to the Rambam Emergency Room between 2011 and 2014 with a suspected diagnosis of pulmonary embolism. Patient data, D-dimer plasma levels, and imaging results were collected. The study cohort was subdivided according to the D-dimer levels below and above 500 μg/L. The group with levels above 500 μg/L was further assessed using the newly suggested age-adjusted D-dimer cutoff level, defined as age multiplied by 10. ResultsFiles of 1241 patients were reviewed; 654 patients with low or intermediate risk for pulmonary embolism had a D-dimer level above 500 μg/L. Two hundred eight (208) patients had a D-dimer level above 500 μg/L but below the age-adjusted cutoff value; one of them was diagnosed with pulmonary embolism (0.48% [95% confidence interval 0%-2.6%]). Four hundred forty-six (446) patients had a D-dimer level above the age-adjusted cutoff value, and 28 of them were diagnosed with pulmonary embolism (6.28% [95% confidence interval 4.2%-8.9%]), representing a negative predictive value of 99.5% for the age-adjusted cutoff level. ConclusionsAn age-adjusted D-dimer cutoff level may be safely used to exclude pulmonary embolism in patients with a low or intermediate probability for acute pulmonary embolism, alleviating the need to perform unnecessary imaging evaluations.

PO-29 - Age-adjusted D-dimer cutoff level increases the number of cancer patients in who pulmonary embolism can be safely excluded without CT-PA imaging: The ADJUST-PE cancer substudy

Patients with cancer frequently present with suspected pulmonary embolism (PE). The D-dimer test is less useful to rule out PE in cancer patients due to a lower specificity, whereas the safety of the combination of a clinical decision rule (CDR) and D-dimer test to rule out PE in these patients is unclear. In the general population, use of an age-adjusted cutoff for D-dimer in combination with a CDR has been shown to improve specificity in the diagnosis of PE. We prospectively analysed the safety and efficacy of the age-adjusted D-dimer (defined as age×10 in patients >50 years) combined with CDR for the exclusion of PE in patients with cancer. We conducted a multicenter multinational prospective management outcome study in 19 centers in Belgium, France, The Netherlands and Switzerland, the ADJUST-PE study, to validate an age-adjusted D-dimer cut-off in patients with suspected PE. The performance of the age-adjusted D-dimer cut-off and CDR was compared between patients with and without cancer. The primary outcome was the rate of adjudicated thromboembolic events during three-month follow-up. Of the 3,324 patients with suspected PE, 429 (12.9%) patients had cancer. Cancer patients were older and more often had surgery or immobilisation. The prevalence of PE was 108/429 (25.2%) in cancer patients and 522/2894 (18%) in patients without cancer, p<0.001. Among cancer patients with an unlikely CDR, 27/274 (9.9%) had a D-Dimer <500 μg/L as compared with 19.7% using the age-adjusted D-dimer cut-off; in patients without cancer, these rates were 30.1% and 41.9%, respectively. The percentage of cancer patients in whom PE could be excluded based on CDR and age-adjusted D-dimer doubled from 6.3% to 12.6%. None of these cancer patients had a venous thromboembolic event during three-month follow-up, thus the failure rate was 0.0% (95% CI 0.0-6.9%). Compared with the usual cut-off, the age-adjusted D-dimer cut-off doubles the proportion of patients with cancer in whom PE can be safely excluded by CDR and D-dimer without need for CTPA imaging.

Diagnosis and management of acute pulmonary embolism. ESC guidelines 2014

Acute pulmonary embolism (PE) still represents a challenge regarding a rapid diagnosis and a risk-adapted therapy. In the 2014 guidelines of the European Society of Cardiology (ESC) on the diagnosis and management of acute PE, several new recommendations have been issued based on new study data. Some established scores for risk stratification were developed further and there is now good evidence for the use of age-adjusted D-dimer cut-off levels. For the risk stratification in patients without clinical features of shock, the utilization of the pulmonary embolism severity index (PESI) and simplified PESI (sPESI) scores is recommended. In patients with intermediate risk, right ventricular morphology and function can be evaluated by computer tomography or echocardiography and biomarkers facilitate further risk stratification. For the treatment of patients with venous thromboembolism with or without PE, the non-vitamin K-dependent oral anticoagulants (NOACs) are a safe alternative to the standard anticoagulation regimen with heparin and vitamin K antagonists. Systemic thrombolytic therapy should be restricted to patients with high risk or intermediate high risk with hemodynamic instability. Finally, new recommendations for the diagnosis and therapy of patients with chronic thromboembolic pulmonary hypertension (CTEPH), with cancer or during pregnancy are given.

Clinical usefulness and safety of an age-adjusted D-dimer cutoff levels to exclude pulmonary embolism: a retrospective analysis.

Age-adjusted D-dimer (AADD) appears to increase the proportion of patients in whom pulmonary embolism (PE) can safely be excluded compared with conventional D-dimer (CDD), according to a limited number of studies. The aim if this study was to assess whether the use of an AADD might safely increase the clinical usefulness of CDD for the diagnosis of PE in our setting. Three hundred and sixty two consecutive outpatients with clinically suspected PE in whom plasma samples were obtained to measure D-dimer were included in this post hoc analysis of a previous study. CDD cutoff value was 500 ng/mL and AADD was calculated as (patient's age × 10) ng/mL in patients aged >50. Sensitivity, specificity, clinical usefulness (i.e., proportion of true-negative tests among all patients with suspected PE), and the proportion of false negatives were calculated for both AADD and CDD among patients with low-to-moderate clinical probability of PE according to Well's criteria. PE was confirmed in 98 patients (27%). Among 331 patients with low-to-moderate clinical probability of PE, sensitivity and clinical usefulness were 100 and 27.8% for CDD, respectively, and 100 and 36.5% for AADD, respectively. In 29 patients aged >50 with CDD >500 ng/mL, AADD showed values under its normal cutoff point, without false negatives for the diagnosis of PE (0%, 95% CI 0-11%). AADD increases clinical usefulness notably with respect to that of CDD in patients with clinical suspected PE without losing sensitivity in our cohort. The use of AADD apparently does not reduce the safety of CDD for the exclusion of PE.

Highlights of the American Society of Hematology Meeting 2013: hemostaseology

Venous thromboembolism is associated with substantial morbidity and mortality. Furthermore, the subsequently indicated anticoagulation treatment puts the patient at risk of possible bleeding complications. Therefore, improving treatment strategies as well as diagnostic approaches can optimize patient care. During the 55th Annual Meeting 2013 of the American Society of Hematology the Choosing Wisely® campaign was presented. An expert committee recommends against the test for thrombophilia after venous thromboembolism occurring in the setting of major transient risk factors to avoid over treatment in these patients. Other presentations focused on the use of the direct oral anticoagulants in patients with cancer-associated thromboembolism. However, specific studies comparing direct oral anticoagulants with the state-of the art treatment with low molecular heparins in cancer-associated thromboembolism are still missing. Finally, age-adjusted cut-off levels can increase the specificity of D-Dimer in older patients. Consequently, using clinical probability assessment in the combination with age-adjusted D-dimer cut-off levels may be associated with a larger number of patients in whom pulmonary embolism can be ruled out.

In suspected PE, an age-adjusted D-dimer cutpoint improved ability to exclude PE.

ACP Journal Club15 July 2014In suspected PE, an age-adjusted D-dimer cutpoint improved ability to exclude PEEddy Lang, MDEddy Lang, MDUniversity of Calgary, Calgary, Alberta, Canada (E.L.)Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-161-2-201407150-02013 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Source CitationRighini M, Van Es J, Den Exter PL, et al. Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism: the ADJUST-PE study. JAMA. 2014;311:1117-24. https://pubmed.ncbi.nlm.nih.gov/24643601Clinical Impact RatingsEmergency Med: Hospitalists: Hematology: Critical Care: References1 Torres-Macho J, Mancebo-Plaza AB, Crespo-Giménez A, et al. Clinical features of patients inappropriately undiagnosed of pulmonary embolism. Am J Emerg Med. 2013;31:1646-50. [PMID: 24060320] Google Scholar2 Huckins DS, Price LL, Gilley K. Utilization and yield of chest computed tomographic angiography associated with low positive D-dimer levels. J Emerg Med. 2012;43:211-20. [PMID: 21764536] Google Scholar3 Pasha SM, Klok FA, Snoep JD, et al. Safety of excluding acute pulmonary embolism based on an unlikely clinical probability by the Wells rule and normal D-dimer concentration: a meta-analysis. Thromb Res. 2010;125:e123-7. [PMID: 19942258] Google Scholar4 Linkins LA, Bates SM, Lang E, et al. Selective D-dimer testing for diagnosis of a first suspected episode of deep venous thrombosis: a randomized trial. Ann Intern Med. 2013;158:93-100. [PMID: 23318311] Google Scholar5 Schouten HJ, Geersing GJ, Koek HL, et al. Diagnostic accuracy of conventional or age adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis. BMJ. 2013;346:f2492. [PMID: 23645857] Google Scholar Author, Article, and Disclosure InformationAuthors: Eddy Lang, MDAffiliations: University of Calgary, Calgary, Alberta, Canada (E.L.)This article was published at Annals.org on 1 July 2014. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byTromboembolismo pulmonar en pacientes con COVID-19: estudio de prevalencia en un hospital terciarioPulmonary embolisms in patients with COVID-19: A prevalence study in a tertiary hospital 15 July 2014Volume 161, Issue 2Page: JC13KeywordsD-dimerDeep vein thrombosisPatientsProspective studiesPulmonary embolismResearch fundingSpecificityThromboembolismThrombosisVenous thromboembolism ePublished: 15 July 2014 Issue Published: 15 July 2014 Copyright & PermissionsCopyright © 2014 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...

Influence of C‐reactive protein levels and age on the value of D‐dimer in diagnosing pulmonary embolism

Recently, the number of performed CT-angiographies to diagnose pulmonary embolism (PE) rised markedly, while the incidence of PE hardly increased. This low yield of CT-angiography leads to more patients exposed to radiation and higher costs. The diagnostic value of age, C-reactive protein (CRP) and D-dimer in PE was investigated. Additionally an age-adjusted D-dimer cutoff level [age-adjusted cutoff=age/100mg/L] was compared with the conventional cutoff level in diagnosing PE for patients ≥50yr. This observational study (2004-2007) included all consecutive patients suspected for PE presenting on the emergency department with a performed CT-angiography after measuring CRP and D-dimer levels. Of 4609 patients suspected for PE, 1164 patients underwent CT-angiography of whom 309 (26.5%) had PE. Correlation between CRP and D-dimer was 0.42 (P<0.001). D-dimer and age correlated positively (rs =0.33, P<0.001), but only in patients >50yr and independent of PE. Multivariate regression analysis showed significant contribution of age, D-dimer and age-adjusted D-dimer for diagnosing PE, but not for CRP. Using an age-adjusted D-dimer cutoff value increased specificity from 37% to 50%, whereas sensitivity declined from 96% to 90%. Applying this age-adjusted cutoff level in patients ≥70yr, specificity increased from 18% to 40%, while sensitivity decreased from 96% to 88%. In the prediction of PE, age and D-dimer levels are relevant, while CRP level is not. Using an age-adjusted D-dimer cutoff in older patients remarkably improves the specificity of D-dimer testing with a minor decline in sensitivity. This may increase the yield of CT-angiography in diagnosing PE.

D-DIMER CUT-OFF ADJUSTED TO AGE PERFORMS BETTER FOR EXCLUSION OF PULMONARY EMBOLISM IN PATIENTS OVER 75 YEARS

Introduction: A D-dimer (DD) test improves the diagnosis of PE (PE) when combined with clinical scores. However, as DD levels increase physiologically with age, this testing has less specificity in older patients. Douma et al. (1). proposed the use of an age adjusted DD cut-off to increase the specificity of this test.Methods: We performed chart reviews of patients, older than 75 years, hospitalized for suspicion of PE in 2010-2011 (n = 165). PE was assessed with either pulmonary scintigraphy (PS, n = 64) and/or pulmonary computed tomography (PC, n = 101). We compared the specificity, sensitivity and false negatives rates of an age adjusted DD cut-off level (“ADC“ = (patient’s age × 0.01) μg/ml) with those of the conventional cut off level (“CDC”= 0.5 μg/ml).Results: PE was confirmed in 45 cases. In the 120 patients with no PE (negative PS or PC), 7 cases had CDC below cut-off levels, while 28 cases had an ADC below cut-off level. The use of the ADC thus increased the specificity (ADC: 23% vs CDC: 6%, p = 0.0001), and this was obtained without significant loss of sensitivity (ADC: 96% vs CDC: 98%, ns). Patients were clinically assessed with the revised Geneva scores. In the negative PE group, the number of patients classified with low, moderate or high clinical probability of PE were 31, 81 and 8, respectively. The percentage of patients with DD values below cut-off values was 4%, 0.8% and 0.8%, respectively using the CDC and 9%, 12% and 2.5% using the ADC.Conclusions: In this age group, the specificity of ADC was found superior to that of the CDC. The clinical use of the ADC might be associated with less useless diagnosis procedures, without significant increase in rate of diagnosis failure.