Research Article - Journal of Molecular Oncology Research (2018) Volume 2, Issue 2
Association between modified wells score and D-dimer in malignant lymphoma patients.
Siprianus Ugroseno Yudho Bintoro*, Agung Prasetiy and Ami Ashariati
Departement of Internal Medicine, Faculty of Medicine–Dr. Soetomo General Hospital, Universitas Airlangga, Indonesia
- *Corresponding Author:
- Siprianus Ugroseno Yudho Bintoro
Departement of Internal Medicine
Faculty of Medicine–Dr. Soetomo General Hospital
Universitas Airlangga, Indonesia
E-mail: [email protected]
Accepted date: March 20, 2018
Citation: Bintoro S, Prasetiyo A, Ashariati A. Association between modified wells score and D-dimer in malignant lymphoma patients. J Mol Oncol Res. 2018;2(2):21-26.
Naive malignant lymphoma, Thrombosis, Modified wells score, D-dimer
Cancer patients are at high risk of venous thromboembolism, either new or recurrent [1,2]. Cancer patients with venous thromboembolism were more likely to experience recurrent four times compared with non-cancer patients . Patients with hematologic malignancies especially malignant lymphomas and multiple myeloma had relatively high rates of venous thromboembolism. Anticancer treatments such as chemotherapy, anti-angiogenic drugs, hormonal therapy, and surgery also increased the predisposition of venous thromboembolism .
The diagnosis of subclinical venous thrombosis is still a problem today. Some studies suggested that in malignant lymphoma patients who had symptoms of Deep Vein Thrombosis (DVT), only 25% of venous thrombosis could be detected with doppler ultrasonography .
Thrombosis in malignant lymphoma is a serious complication resulting the greatest mortality if it is not immediately known. In the United States, in 2007 more than 2 million people died each year caused by venous thrombosis. More than 90% of pulmonary embolism cases were derived from the release of thrombus in the popliteal, femoral and iliac veins. Data analysis from Danish Cancer Registries in 2000 reported that the 1-year life expectancy rate of malignant lymphoma patients with venous thromboembolism was 12% while those with no venous thromboembolism were 36% . In addition, venous thromboembolism has an economic impact because Doppler ultrasonography treatment of 110.000 per year in the United States resulted in the loss of 3 million working hours per year [7-11].
Venous thrombosis diagnosis in malignant lymphoma was still difficult because 50% cases showed no clinical symptoms . In a study that performed an autopsy in 83% of DVT cases, only 19% showed DVT symptoms and were recorded in the medical record. The formation of thrombus in the deep vein system could not be seen clinically due to the large capacity of vein system and the formation of collateral circulation around obstruction . Doppler ultrasonography was one of the diagnostic devices in enforcing thrombosis especially in large superficial and deep veins, whereas venous thrombosis in connective veins was undetectable. In addition, the sensitivity of Doppler ultrasonography would decrease to 73-75% if it was used to diagnose DVT in the distal or calf vein . Doppler ultrasonography could confirm DVT in only 67/177 patients (37.58%) and exclude DVT in only 62.14% of patients. Thus, it needed other non-invasive markers that could detect or predict the presence of venous thrombosis .
The new approach as a non-invasive thrombosis marker was Modified Wells (MW) Score and D-dimer . MW scores were originally developed by Phillip S Wells to stratify the pretest probability of DVT, consisting of 9 clinical symptom variables, DVT risk factors, and the presence of potential diagnostic alternatives. A sensitivity of MW score (78.4%), a specificity of 66.1%, with a positive predictive value of 52.3% and a negative predictive value of 86.6% . In line with the increasing D-dimers use, MW scores with D-dimers have been tried to evaluate the possibility of DVT. Venous thrombosis activates the coagulation and fibrinolytic systems thereby increasing serum fibrin split product levels. In the fibrinolysis process, the fibrin polymer is degraded by plasmin. One of the last products of its process is the D-dimer. Theoretically Ddimers can be used as a marker of venous thromboembolism . D-dimer examination has high sensitivity but not specific. The sensitivity of D-dimer is 73.9%, specificity is 66.1%, positive predictive value is 50.8% and negative predictive value is 84.2% . Therefore, we aimed to identify the relationship between MW scores and D-dimers in malignant lymphoma patients who had never received chemotherapy (naive).
This study was cross-sectional with consecutive sampling technique in all patients with malignant lymphoma which fulfilled inclusion criteria of malign lymphoma patients who treated in the division of Haematology-Medical Oncology Department of Internal Medicine Dr. Soetomo General Hospital, Surabaya and willing to participate in the research. This research started from July 1st, 2014 to September 30th, 2014.
This research used independent variable that was D-dimer. D-dimers are thrombotic markers formed after thrombus formation and are the final product of cross-linked fibrin. D-dimer was done by taking left arm blood vein of subjects and was kept into a 2.7 ml plastic vacutainer containing sodium citrate with 0.109 M levels. Blood samples were then sent to private laboratories without special treatment. Centrifugation was done to obtain a supernatant. The supernatant was kept at a stable temperature of -20°C for a month. Normal reference value was less than 500 μg/l . The method used was ICT principle (Immuno-chromatography) which was the reaction between two monoclonal antibodies toward fibrin degradation product containing element of d-dimer structure [18,19].
Dependent variable in this research was MW score. MW score is a score for estimating thrombosis consisting of 9 detailed questions, those are active cancer (currently in therapy, within the last 6 months or palliative); paralysis or immobilization due to fixation of gyps of the lower leg; lying for 3 days or more, or major surgery within 12 weeks and requiring general or regional anaesthesia; local tenderness in the area of deep venous system; a whole swollen legs; calf swelling with a circumference of at least 3 cm larger than a healthy leg; Pitting edema limited to affected limbs; non-varicose collateral veins; previous DVT history; differential diagnosis leading to DVT .
Sample size was 35 patients with 30 LNH patients (85.7%) and 5 LH patients (14.3%), the age range of subjects was 17 to 68 years, with average age of 49 years. In this study, normal distributed variables were BMI, cholesterol and albumin. Meanwhile D-dimers, MW, GDA, TDS and TDD scores were not normally distributed. MW score median of LNH subjects was lower than LH subjects that was 1 vs. 2, D-dimer median of LNH subjects was lower than LH, that was 510 μg/l vs. 1400 μg/l. The details could be seen in table 1.
|S. No.||Characteristics||LNH, N=30||LH, N=5|
|Male||18 (60)||4 (80)|
|Female||12 (40)||1 (20)|
|<50 Years||11 (36.7)||5 (100)|
|≥50 Years||19 (63.3)||0|
|12 (40)||2 (40)|
|7 (23.3)||2 (40)|
|8 (26.7)||1 (20)|
|4||BMI Average (Standard Deviation)||21.27 (SD:1.69)||20.50 (SD:1.57)|
|5||Systolic Blood Pressure Median (Range) mmHg||110 (90-125)||110 (90-125)|
|6||Diastole Blood Pressure Median (Range) mmHg||72.5 (60-85)||75 (60-85)|
|7||Cholesterol Average (SD) mg/dl||133.60 (41.1)||146.20 (41.1)|
|8||Albumin Average (SD) g/dl||3.52(SD: 0.25)||3.49 (SD:0.29)9|
|9||Median of GDA(Range) g/dl||109(75-160)||96(80-110)|
|10||Median of MWS (Range)||1(1-4)||2(1-4)|
|11||Median of D-dimer (Range) μg/l||510(100-3700)||1400 (580-2100)|
Table 1: Subject Characteristics.
MW score result of the subjects
The result of MW score calculation was done by 2 observers, therefore the interclass correlation test was done between them (Table 2). The test results showed a strong and significant correlation (r=0.761). In table 3, it was known that most MW scores were less than 2 that was as many as 17/35 subjects or 56.7% in LNH. The percentage of MW score in LH was ≥ 2.
|Cronbach’s alpha||Cronbach’s alpha
Based on Standarized Items
Table 2: Interclass Test Result of MW Score.
|Variable||MW Score <2 (%)||LNH ≥ 2 (%)||MW Score <2 (%)||LH ≥ 2 (%)|
|Total Details||13 (43.3||1 (20)||4 (80)|
|I Stage||7 (23.3)||6 (20)||0||1 (20)|
|II Stage||4 (13.3)||3 (10)||1 (20)||1 (20)|
|III Stage||4 (13.3)||3 (10)||0||2 (40)|
|IV Stage||2 (6.7)||1 (3.33)||0||0|
Table 3: Calculation Result of MW Score.
Based on detailed MW scores, paresis was found in 2/35 subjects (5.7%), immobilization in 4/35 subjects (11.4%), swollen extremities in 2/35 subjects (5.79%), tenderness in 1/35 subjects (2.9%), swelling in 1/35 subjects (2.9%), and calves swelling in 1/35 subjects (2.9%) (Table 4).
|Clinical Characteristic||Percentage (%)|
|Active cancer (currently in therapy, within the last 6 months or
|Paralysis or immobilization due to fixation of gyps of the lower
|Lying for 3 days or more, or major surgery within 12 weeks
and requiring general or regional anaesthesia
|Local tenderness in the area of deep venous system||1 (2.9)|
|Whole swollen legs||1 (2.9)|
|Calf swelling with a circumference of at least 3 cm larger than a
|Pitting oedema limited to affected limbs||2 (5.7)|
|Non-varicose collateral veins||0|
|Previous DVT history||0|
|Differential diagnosis leading to DVT||0|
|Simplified probability score:|
|Does not support DVT||<2|
Table 4: MW Score Result of Subjects.
D-dimer level result of subjects
D-dimer examination of subjects was performed using semi quantitative immuno-chromatographic methods. Cut off point of D-dimer level was 500 μg/l. The distribution of both groups based on D-dimer results as followed. (Table 5) The highest level of D-dimer in LNH was ≥ 500 μg/l, those were 16/30 subjects (53.3%) and the highest level of D-dimer in LH ≥ 500 μg/l, those were 5/5 subjects (100%).
|D-dimer LNH||D-dimer LH|
|<500 µg/l (%)||≥ 500 µg/l (%)||<500 μg/l (%)||≥ 500 µg/l (%)|
|Total Stage:||14 (46.7)||16 (53.3)||-||5 (100)|
|8 (26.7)||4 (133)||-||1 (20)|
|3 (10)||5 (16.7)||-||1 (20)|
|2 (6.7)||5 (16.7)||-||3 (60)|
|1 (3.3)||2 (6.7)||-|
Table 5: D-dimer level Calculation Result of Subjects.
Correlation analysis of MW score and D-dimer level of subjects
Based on table 6, the magnitude of Spearman correlation coefficient on LNH was 0.46 with p=0.001. In LH, p=0.215 and Spearman's correlation was 0.671. In table 6 showed that there was a correlation between MW Score and D-dimer level of LNH subjects. In LH subjects, there was no correlation between MW Score and D-dimer level of LH subjects (p >0.05, Table 6).
|Correlation||Spearman 0.462||Spearman 0.671|
|P value (2 tails)||0.001||0.215|
Table 6: Analysis Result of Correlation between MW Score and Ddimer Level.
In this study, the number of LNH subjects was more than LH subjects. LNH subjects were 30 patients (85.7%) and LH subjects were 5 patients (14.3%). LNH subjects was male dominated (51.4%). This result was consistent with the Shankland study that reported the incidence of LNH in males was 67.7%. The result of this study was also similar to the study in Pakistan that the incidence of LNH in men was more than women, those were 5.3/100.00 vs. 4.1/100.000 [20,21]. The results of this study were in accordance with the research of Birmann and Hoffbrand who mentioned that in LH the ratio of men was more compared to women that were 1.4:1 . Most of LNH subjects >50 years old were more comparing to <50 years (63.3% vs. 36.7%). Most of LH patients <50 years was less than patients >50 years (100% vs. 0%). This result was similar to a study by Thomas et al., who reported that most of LH patients was <50 years .
In this study, the median MW score of LH subjects was higher than LNH subjects. This was due to several variables such as embolization that was the most variable (11.4%), paresis found in 2 patients (5.7%), swollen on the extremity in 1 patient (2.9%). These results were different from Mozafar in Iran who found that swelling was the most variable (108/177.61%), paresis was found in 20/177 (11%), immobilized in 24/177 (13.5%) patients . Different results were also presented by Geersing who reported that tenderness was the most variable (51%), followed by edema of 47%, paresis of 6.1%; immobilization of 11.1%.
From table 7 it was known that this study reported different results with the study by Kearon, Bates, Mozafar, Geersing and Owaidah. The most variables were immobilization whereas in other studies the most variables were tenderness, total swelling of one leg, calf swelling and pitting edema. Based on Geersing's study, the risk of DVT increased in line with the MW score. Thus theorytically, LH subjects who was at risk of DVT was 26.6% meanwhile in LNH was 19%. According to study, in patients with an MW score <2 and D-dimer <500 μg/l, DVT could be excluded .
|Clinical Characteristic||Study Result (%)||Kearon (%)||Bates (%)||Mozafar (%)||Geersing (%)||Owaidah (%)|
|Active cancer (currently in therapy, within the last 6 months or palliative)||35 (100)||47 (11)||50 (9.1)||38 (40.1)||65 (56)||43 (76)|
|Paralysis or immobilization due to fixation of gyps of the lower leg||2 (5.7)||12 (2.8)||12 (2.2)||11||6.1||3|
|Lying for 3 days or more, or major surgery within 12 weeks and requiring general or regional anesthesia||4 (11.4)||25 (5.8)||39 (7.1)||13.5||11.1||7|
|Local tenderness in the area of deep venous system||1 (2.9)||203 (47.3)||176 (32)||6||9||26.2|
|Whole swollen legs||1(2.9)||30 (7.0)||83 (15.1)||61||47||78.5|
|Calf swelling with a circumference of at least 3 cm larger than a healthy leg||1(2.9)||96(22.4)||114 (20.7)||15||20||32|
|Pitting edema limited to affected limbs||2 (5.7)||87(20.3)||251(45.6)||43||31||23|
|Non-varicose collateral veins||0||33(7.7)||28 (5.1)||4||3.7||4.1|
|Previous DVT history||0|
|Previous DVT history||0||176 (41)||245 (44.6)||2.1||3||3.8|
Table 7: MW Score Rersult of Subjects and other Studies.
D-dimer is a thrombosis marker that increases rapidly in blood circulation in line with thrombosis process. Righini reported that D-dimer examination could be applied to patients under the age of 79 years. In LH subjects, D-dimer median was 1400 μg/l with a range of 580-2100 μg/l. Meanwhile LNH D-dimer median was lower than LH which was 510 μg/l with a range of 100-3700 μg/l. D-dimer levels are influenced by several factors, how many thrombus formed before followed by fibrinolysis response, thrombus age, blood clot position, and heparin use. D-dimer level decreased to normal after a month since the formation of venous thrombus . Thus, the lower levels of D-dimer in LNH could also be assumed that within a month to 42 days after blood sampling there was no venous thrombus formation or had already formed venous but had experienced spontaneous resolution. In this study, all LH patients (5/5.100%) were under 50 years old but had D-dimer levels >500 μg/l. Meanwhile in LNH, patients under 50 years old were 6/30 patients (20%) having D-dimer levels <500 μg/l and 5/30 patients (16.6%) having D-dimer levels ≥ 500 μg/l. In patients >50 years old, 11/30 patients (36.6%) had a D-dimer level of ≥ 500 μg/l, and 8/30 patients (26.6%) had D-dimer levels <500 μg/l. D-dimer levels were also affected by age .
In this study, MW scores and D-dimer levels in LH were higher than LNH. It is similar to other studies that the incidence of venous thrombosis in LH was more frequently than low grade LNH (7.2% vs. 5.8%)  and a higher incidence of venous thromboembolism in LNH compared to LH (51/641; 8%) vs. LH (3/45; 6.7%) . Thus it was known that in prospective design, the incidence of venous thrombosis in LH was higher whereas in retrospective design studies the incidence of venous thrombosis in LNH patients was higher than in LH patients .
LH was at greater risk of venous thrombosis compared to LNH marked with MW scores and higher D-dimer levels. In LH subjects there was a patient having an MW <2 but D-dimer >500 μg/l. Meanwhile 4 other subjects had MW score ≥ 2 with D-dimer ≥ 500 μg/l. Increased MW scores indicated by LH subjects showed a risk of thrombosis. This result also conformed the study by Lacombe et al., that reported the incidence of distal vein thrombosis in the low risk group (MW score <2) was 0.6%. The study by Engelberger et al., mentioned the prevalence of venous thrombosis in low risk group was 7-8%, whereas in high risk group was 36-37% .
Increased levels of D-dimer above 500 μg/l found in LH subjects showed the high risk and recurrence of venous thrombosis. D-dimer levels increased up to 100 times under acute venous thrombosis . D-dimer tests had high sensitivity, and normal results could be used to rule out venous thrombosis . In this study, D-dimer levels were not comparable with BMI. BMI in LNH was higher than in LH. The association of body weight with risk of venous thrombosis had been demonstrated by experts including research in Austria with a sample of 1107, studies in Sweden with a sample size of 855, and a study in Italy with a sample size of 15.180 patients [31-33]. In this study, although MW scores and D-dimer levels were high but the incidence of venous thrombosis was low, it was caused by the highest MW score variables that was immobilization as listed in Table 7.
Theoretically, it was assumed that the risk of venous thromboembolism was higher in LH than in LNH. In a study with splenectomy experimental animal samples given B cells via infusion, it was shown that B cells played a role in the resolution of thrombus but this process continued that caused unstable venous thrombus and triggered venous thrombosis at other sites and increased the risk of recurrent thrombosis . In addition, Reed Stenberg cells also produced TNF-α which further inhibited the formation of thrombomodulin and inhibited C protein, which led to the formation of venous thrombosis .
Demographic factors including ethnicity, age and gender also affected venous thrombosis. The highest incidence of venous thrombosis was in blacks and the lowest was in Asian. In addition, the risk of venous thrombosis increased in line with age up to 90 times from <15 years to >80 years due to endothelial dysfunction . This study was different from other study in which the high D-dimer level was found in younger subject. Patients with high blood glucose levels due to diabetes mellitus and hyperglycaemia were at greater risk of venous thrombosis . D-dimer result was also affected by the method used. Patients with MW score <2 were recommended to use ELISA and immunoturbinometry while patients with MW score ≥ 2 were recommended to use SimpliRED method due to its sensitivity (88%) .
There was a moderate positive correlation between MW scores and D-dimer levels in naive LNH patients.
- Wada H, Sase T, Yamaguchi M. Hypercoagulant states in malignant lymphoma. Exp Oncol. 2005; 27:179–85.
- Shelke AR. Cancer associated thrombosis: an update. Drug Discov Today Dis Mech. 2011; 8:e39-e45.
- Prandoni P, Lensing A, Piccioli A, et al. Recurrent venous thromboembolism and bleeding complications during anticoagulant treatment in patients with cancer and venous thrombosis. Blood. 2002; 100:3484-8.
- Blom JW, Doggen C, Osanto S, et al. Malignancies, prothrombotic mutations, and the risk of venous thrombosis. JAMA. 2005; 293:715-22.
- Rahiminejad M, Rastogi A, Prabudeshai S, et al. Evaluating the use of a negative d-dimer and Modified Low Wells Score in excluding above knee Deep Venous Thrombosis in an outpatient population, assessing need for diagnostic ultrasound. ISRN Radiol. 2014; 2014:1-6.
- Sorensen HT, Mellemkjaer L, Olsen JH, et al. Prognosis of cancers associated with venous thromboembolism. N Engl J Med. 2000; 343:1846–1850.
- Winter P. The pathogenesis of venous thromboembolism in cancer: emerging links with tumour biology. Hematol Oncol. 2006; 24:126–33.
- Bakta. Thrombosis dan umur lanjut. Jurnal Penyakit Dalam. 2007; 8:18-161.
- Sousou T, Khorana A. New insight into cancer-associated thrombosis. Arterioscler Thromb Vasc Biol. 2009; 29:316-20.
- Justad J. Deep Vein Thrombosis (DVT). Best Pract Guidel 2. 2010:1-3.
- Geersing GJ, Zuithoff NP, Kearon C, et al. Exclusion of deep vein thrombosis using the Wells rule in clinically important subgroups:individual patient data meta-analysis. Br Med J. 2014; 348:g1340.
- Zierler B. Ultrasonography and diagnosis of venous thromboembolism. Circulation 109. 2004; S1-S9.
- Oguzkurt L. ltrasonographic anatomy of the lower extremity superficial veins. Diagn Interv Radiol. 2012;18:423–30.
- Segal JB, Eng J, Tamariz LJ, et al. Review of the evidence on diagnosis of deep venous thrombosis and pulmonary embolism. Annu Family Med. 2007; 5:63-7.
- Ay C, Dunkler D, Marosi C, et al. Prediction of venous thromboembolism in cancer patients. Blood. 2011; 116:5377-92.
- Zhu L, Wang JG, Liu M, et al. Value of combined wells score and D-dimer test on diagnosing patients with deep venous thrombosis. Xonghua Xin Xue Guan Bing Za Zhi. 2009; 37:818-22.
- Wells PS, Owen C, Doucette S, et al. Does this patient have deep vein thrombosis? JAMA. 2006; 295:199-207.
- Nomura H, Wada H, Mizuno T, et al. Negative predictive value of d-dimer for diagnosis of venous thromboembolism. Int J Psychol Hematol. 2008; 87:250–5.
- Gardiner C, Pennaneac’h C, Walford C, et al. An evaluation of rapid d-dimer assays for the exclusion of deep vein thrombosis. Br J Haematol. 2004; 128:842– 8.
- Bhurgri Y, Pervez S, Bhurgri A, et al. Increasing incidence of Non-Hodgkin's lymphoma in Karachi. Asian Pac J Cancer Prev. 2005; 6:364-9.
- Shankland KR, Armitage JO, Hancock BW. Non-Hodgkin lymphoma. Lancet 380. 2012:848–57.
- Hjalgrim H, Askling J, Rostgaard K, et al. Characteristics of Hodgkin’s Lymphoma after infectious mononucleosis. N Engl J Med. 2003; 349:1324-32.
- Shenoy P, Maggioncakda A, Malik N and Flowers CR. Incidence patterns and outcomes for hodgkin lymphoma patients in the United States. Adv Hematol. 2011; 725219.
- Mozafar M SM, Lotfollahzadeh S. Application of wells criteria, in combination with serum d-dimer to rule out deep vein thrombosis in lower extremities. Scimetr. 2011;2(1):1-11.
- Sie P. The value of laboratory tests in the diagnosis of venous thromboembolism. Haematologica. 1995; 80:57-60.
- Hamblin AD, Cairns K, Keeling DM. The use of age-dependent d-dimer cut-off values to exclude deep vein thrombosis. Reply to “Using an age-dependent D-dimer cut-off value increases the number of older patients in whom deep vein thrombosis can be safely excluded”. Haematologica. 2012; 97(10):1507-13.
- Mohren M, Markmann I, Ullrich JK, et al. Increased risk of thromboembolism in patients with malignant lymphoma: a single-centre analysis. Br J Cancer. 2005;92:1349 – 51.
- Park LC, Woo SY, Kim S, et al. Incidence, risk factors and clinical features of venous thromboembolism in newly diagnosed lymphoma patients: results from a prospective cohort study with Asian population. Thromb Resp. 2012; 130:e6-12.
- Engelberger RP, Aujesky D, Calanca L, et al. Comparison of the diagnostic performance of the original and modified Wells score in inpatients and outpatients with suspected deep vein thrombosis. Thromb Respir. 2011; 127:535-9.
- Brill-Edwards P, Lee A. D-Dimer Testing in the Diagnosis of Acute Venous Thromboembolism. Thromb Haemost. 1999; 82:688-94.
- Minno G, Mannucci PM, Tufano A, et al. First ambulatory screening on thromboembolism (fast) study group. The first ambulatory screening on thromboembolism: a multicentre, cross-sectional, observational study on risk factors for venous thromboembolism. J Thromb Haemost. 2005; 3:1459-66.
- Romualdi E, Squizzato A, Ageno W. Abdominal obesity and the risk of recurrent deep vein thrombosis. Thromb Respir. 2007; 119:687-90.
- Eichinger S, Hron G, Bialonczyk C, et al. Overweight, obesity and the risk of recurrent venous thromboembolism. Arch Intern Med. 2008; 168:1678-83.
- Frey MK, Winter MP, Alimohammadi A, et al. Resolution of venous thrombus is depending on B-lymphocytes. Eur Respir J. 2012; 40.
- Jundt F, Anagnostopoulos I, Bommert K, et al. Hodgkin/Reed-Sternberg cells induce fibroblasts to secrete eotaxin, a potent chemoattractant for T cells and eosinophils. Blood. 1999; 94:2065-71.
- Montagnana M, Favaloro EJ, Franchini M, et al. The role of ethnicity, age and gender in venous thromboembolism. J Thromb Thrombolysis. 2010; 29:489-96.
- Hermanides J. Venous thrombosis is associated with hyperglycemia at diagnosis:a case control study. J Thromb Haemost. 2009; 7:945-9.
- Fancher TL, White RH, Kravitz RL. Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review. Br Med J. 2004; 329:21-824.