Appropriateness of diagnostic strategies for evaluating suspected venous thromboembolism

Summary

It was the objective of this study to determine the proportion of patients who undergo an appropriate diagnostic work-up following a D-dimer test performed to evaluate suspected pulmonary embolism (PE) or deep vein thrombosis (DVT). We performed a retrospective cohort study at a tertiary care hospital. We included patients if they underwent D-dimer testing between 2002 and 2005, if the D-dimer was performed for evaluation of VTE, and if the D-dimer test was successful. We classified: the patients’ clinical probability of DVT or PE according to theWells models,the imaging results,and the appropriateness of the testing algorithm. Of 1,000 randomly selected patients, 863 met our study criteria. Seven hundred nineteen patients (83%) had testing during an emergency department visit, while 144 were tested as inpatients (17%). Physicians performed the D-dimer test to evaluate DVT and PE in 238 (28%) and 625 (72%) patients, respectively. Overall, the testing strategy was appropriate in 69% (95% confidence interval [CI]: 66%–72%) of cases. The testing strategy was more likely to be appropriate for emergency department versus inpatients (75% vs. 39%, p < 0.05) and for DVT versus PE patients (84% vs. 63%, p < 0.05). Of all inappropriately tested patients, under-utilization of diagnostic imaging was more common than over-utilization (90% vs. 10%, p < 0.05). VTE was confirmed in 37 of 138 ‘DVT patients’ and 35 of 625 ‘PE patients’ (16% [95% CI: 11%–21%] and 6% [95% CI: 4%–8%], respectively). In conclusion, physicians often fail to use diagnostic testing strategies for VTE correctly following a D-dimer test.

Keywords

Diagnostic tests - venous thromboembolism - D-dimer test

• References

• 1 White RH. The epidemiology of venous thromboembolism. Circulation 2003; 107 (23) (Suppl. 01) I4-8.
• 2 Giuntini C, Di Ricco G, Marini C. et al. Pulmonary embolism: epidemiology. Chest 1995; 107 (Suppl. 01) 3S-9S.
• 3 Paterson DI, Schwartzman K. Strategies incorporating spiral CT for the diagnosis of acute pulmonary embolism: a cost-effectiveness analysis. Chest 2001; 119: 1791-1800.
• 4 Perrier A, Nendaz MR, Sarasin FP. et al. Cost-effectiveness analysis of diagnostic strategies for suspected pulmonary embolism including helical computed tomography.[ see comment]. Am J Resp Crit Care Med 2003; 167: 39-44.
• 5 Wells PS, Anderson DR, Rodger M. et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer. Thromb Haemost 2000; 83: 416-420.
• 6 Wells PS, Anderson DR, Rodger M. et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. New Engl J Med 2003; 349: 1227-1235.
• 7 Wells PS, Anderson DR, Rodger M. et al. Excluding pulmonary embolism at the bedside without diagnostic imaging: management of patients with suspected pulmonary embolism presenting to the emergency department by using a simple clinical model and d-dimer. Ann Intern Med 2001; 135: 98-107.
• 8 Hirsh J, Lee AY. How we diagnose and treat deep vein thrombosis. Blood 2002; 99: 3102-3110.
• 9 Fedullo PF, Tapson VF. Clinical practice. The evaluation of suspected pulmonary embolism. New Engl J Med 2003; 349: 1247-1256.
• 10 Wells PS, Owen C, Doucette S. et al. Does this patient have deep vein thrombosis?. J Am Med Assoc 2006; 295: 199-207.
• 11 Writing Group for the Christopher Study Investigators. Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. J Am Med Assoc 2006; 295: 172-179.
• 12 Newcombe RG. Two-sided confidence intervals for the single proportion: comparison of seven methods. Stat Med 1998; 17: 857-872.
• 13 Tillie-Leblond I, Marquette CH, Perez T. et al. Pulmonary embolism in patients with unexplained exacerbation of chronic obstructive pulmonary disease: Prevalence and risk factors. Ann Intern Med 2006; 144: 390-396.
• 14 Roy PM, Meyer G, Vielle B. et al. Appropriateness of diagnostic management and outcomes of suspected pulmonary embolism . Ann Intern Med 2006; 144: 157-164.
• 15 Wolf SJ, McCubbin TR, Feldhaus KM. et al. Prospective validation of Wells Criteria in the evaluation of patients with suspected pulmonary embolism. Ann Emerg Med 2004; 44: 503-510.
• 16 Shields GP, Turnipseed S, Panacek EA. et al. Validation of the Canadian clinical probability model for acute venous thrombosis. Acad Emerg Med 2002; 9: 561-566.
• 17 Kline JA, Webb WB, Jones AE. et al. Impact of a rapid rule-out protocol for pulmonary embolism on the rate of screening, missed cases, and pulmonary vascular imaging in an urban US emergency department. Ann Emerg Med 2004; 44: 490-502.
• 18 Kline JA, Runyon MS, Webb WB. et al. Prospective study of the diagnostic accuracy of the Simplify D-dimer assay for pulmonary embolism in emergency department patients. Chest 2006; 129: 1417-1423.
• 19 van der Putten RF, Glatz JF, Hermens WT. Plasma markers of activated hemostasis in the early diagnosis of acute coronary syndromes. Clinica Chimica Acta 2006; 371: 37-54.