Kazuki Yamada, Toshifumi Ozaki, Yutaka Inaba.
Response/Recommendation: The clinical diagnosis of lower extremity deep venous thrombosis (DVT) is nonspecific and individual clinical findings are of limited value in diagnosing DVT.
Strength of Recommendation: Moderate.
Rationale: Patients with lower extremity DVT may show swelling, cramping, pulling discomfort, warmth, palpable cord, and prominent venous collaterals1,2. One meta-analysis estimated the likelihood ratio (LR) of individual clinical features of lower extremity DVT3. According to the results of this study, the LR (95% confidence interval [CI]) for each individual sign was as follows. Calf pain: 1.08 (0.96 – 1.20), calf swelling: 1.45 (1.25 – 1.69), difference in calf diameter: 1.80 (1.48 – 2.19), Homan’s sign: 1.40 (1.18 – 1.66), warmth: 1.29 (1.07 – 1.54), tenderness: 1.27 (1.11 – 1.45), erythema: 1.30 (1.02 – 1.67), edema: 1.35(1.05 – 1.74)3. The meta-analysis concluded that individual clinical features were of limited value in diagnosing DVT3.
However, structured clinical scoring systems may allow stratification of patients into groups according to their pretest probability of DVT. The most widely used and studied system is the Wells score4–7, which was developed and validated in the outpatient setting.
The classic Wells score is a 9 point score, giving one point for each clinical presentation (active cancer/paralysis, paresis or recent immobilization of the lower extremities / recently bedridden > 3 days and/or major surgery within 4 weeks / localized tenderness along the distribution of the deep system/thigh and calf swollen / calf swelling > 3 cm compared to the asymptomatic side / pitting edema / collateral superficial veins/history of DVT) and two negative points if an alternative diagnosis is possible. The Wells score allows patients to be categorized into high (≧ 3 points), moderate (1 – 2 points) and low (< 1 points) risk with a prevalence of DVT of 75%, 17% and 3%, respectively6. A dichotomized categorization (high- and -isk only) was also validated.
One meta-analysis elucidated that a high Wells score was associated with a markedly increased probability of DVT (LR, 5.2), whereas a low Wells score was associated with a markedly reduced probability of DVT (LR, 0.25)3.
One systematic review reported that the Wells score had median positive LR for patients with high pretest probability being 6.62 (range, 1.9 to 17.6)8. For those in the moderate pretest probability category, the median positive LR was 1 (range, 0 to 1.4)8. The positive LR for those in the low pretest probability was consistently below 18. These findings suggest that patients classified as having a high pretest probability of DVT have a high likelihood of the disease, those in the moderate pretest category have no increase in the likelihood of the disease, and those with low pretest probability have a low likelihood of having the disease8.
1. Piazza G, Seddighzadeh A, Goldhaber SZ. Double trouble for 2,609 hospitalized medical patients who developed deep vein thrombosis: prophylaxis omitted more often and pulmonary embolism more frequent. Chest. 2007;132(2):554-561. doi:10.1378/chest.07-0430
2. Chopard R, Albertsen IE, Piazza G. Diagnosis and Treatment of Lower Extremity Venous Thromboembolism: A Review. JAMA. 2020;324(17):1765-1776. doi:10.1001/jama.2020.17272
3. Goodacre S, Sutton AJ, Sampson FC. Meta-analysis: The value of clinical assessment in the diagnosis of deep venous thrombosis. Ann Intern Med. 2005;143(2):129-139. doi:10.7326/0003-4819-143-2-200507190-00012
4. Kafeza M, Shalhoub J, Salooja N, Bingham L, Spagou K, Davies AH. A systematic review of clinical prediction scores for deep vein thrombosis. Phlebology. 2017;32(8):516-531. doi:10.1177/0268355516678729
5. Wells PS, Hirsh J, Anderson DR, et al. Accuracy of clinical assessment of deep-vein thrombosis. Lancet. 1995;345(8961):1326-1330. doi:10.1016/s0140-6736(95)92535-x
6. Wells PS, Anderson DR, Bormanis J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997;350(9094):1795-1798. doi:10.1016/S0140-6736(97)08140-3
7. Wells PS, Anderson DR, Rodger M, et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003;349(13):1227-1235. doi:10.1056/NEJMoa023153
8. Tamariz LJ, Eng J, Segal JB, et al. Usefulness of clinical prediction rules for the diagnosis of venous thromboembolism: a systematic review. Am J Med. 2004;117(9):676-684. doi:10.1016/j.amjmed.2004.04.021