Validity and clinical utility of the simplified Wells rule for assessing clinical probability for the exclusion of pulmonary embolism

The recently introduced simplified Wells rule for the exclusion of pulmonary embolism (PE) assigns only one point to the seven variables of the original Wells rule. This study was performed to independently validate the simplified Wells rule for the exclusion of PE. We retrospectively calculated the prevalence of PE in the "unlikely" probability categories of the original Wells (cut-off < or =4) and the simplified Wells rule (cut-off < or =1) in 922 consecutive patients with clinically suspected PE from a multicenter cohort study. We compared the three-month incidence of venous thromboembolism (VTE) in patients with an unlikely probability and a normal D-dimer test using both scores, and the proportion of patients with this combination (clinical utility). The proportion of patients categorized as PE "unlikely" was similar using the original (78%) and the simplified (70%) Wells rule. The prevalence of PE was 13% (95% confidence interval [CI], 11-16%) and 12% (95%CI, 9.7-15%) for the original Wells and simplified Wells "unlikely" categories, respectively. None of the patients with PE "unlikely" and a normal D-dimer test experienced VTE during three-month follow-up. The proportions of patients in whom further tests could safely be withheld based on PE "unlikely" and a normal D-dimer test was 28% (95%CI, 25-31%) using the original and 26% (95%CI, 24-29%) using the simplified Wells rule. In this external retrospective validation study, the simplified Wells rule appeared to be safe and clinically useful, although prospective validation remains necessary. Simplification of the Wells rule may enhance the applicability.

[1]  V. Gerdes,et al.  The importance of clinical probability assessment in interpreting a normal d-dimer in patients with suspected pulmonary embolism. , 2008, Chest.

[2]  Patrick M Bossuyt,et al.  Further validation and simplification of the Wells clinical decision rule in pulmonary embolism , 2007, Thrombosis and Haemostasis.

[3]  R. C. Marshall,et al.  Current Diagnosis of Venous Thromboembolism in Primary Care: A Clinical Practice Guideline from the American Academy of Family Physicians and the American College of Physicians* , 2007, Annals of Internal Medicine.

[4]  H R Büller,et al.  Diagnostic accuracy of D‐dimer test for exclusion of venous thromboembolism: a systematic review , 2007, Journal of thrombosis and haemostasis : JTH.

[5]  R. W. Niessen,et al.  Simple and safe exclusion of pulmonary embolism in outpatients using quantitative D-dimer and Wells’ simplified decision rule , 2006, Thrombosis and Haemostasis.

[6]  G. Gal,et al.  Clinical probability assessment of pulmonary embolism by the Wells’ score: is the easiest the best? , 2006, Journal of thrombosis and haemostasis : JTH.

[7]  Arnaud Perrier,et al.  Prediction of Pulmonary Embolism in the Emergency Department: The Revised Geneva Score , 2006, Annals of Internal Medicine.

[8]  Pieter W Kamphuisen,et al.  Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. , 2006, JAMA.

[9]  M. Prins,et al.  Management studies using a combination of D‐dimer test result and clinical probability to rule out venous thromboembolism: a systematic review , 2005, Journal of thrombosis and haemostasis : JTH.

[10]  A. Turpie.  Multidetector-row computed tomography in suspected pulmonary embolism. , 2005, The New England journal of medicine.

[11]  J. Cornuz,et al.  Diagnosing pulmonary embolism in outpatients with clinical assessment, D-dimer measurement, venous ultrasound, and helical computed tomography: a multicenter management study. , 2004, The American journal of medicine.

[12]  B. Hunt,et al.  A clinical probability assessment and D-dimer measurement should be the initial step in the investigation of suspected venous thromboembolism. , 2003, Chest.

[13]  A. Fennerty,et al.  British Thoracic Society guidelines for the management of suspected acute pulmonary embolism , 2003, Thorax.

[14]  T. Perneger,et al.  Comparison of two clinical prediction rules and implicit assessment among patients with suspected pulmonary embolism. , 2002, The American journal of medicine.

[15]  J. Kline,et al.  Criteria for the safe use of D-dimer testing in emergency department patients with suspected pulmonary embolism: a multicenter US study. , 2002, Annals of emergency medicine.

[16]  G. Kovacs,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 , 2001, Annals of Internal Medicine.

[17]  T. Perneger,et al.  Assessing clinical probability of pulmonary embolism in the emergency ward: a simple score. , 2001, Archives of internal medicine.

[18]  G H Guyatt,et al.  Users' guides to the medical literature: XXII: how to use articles about clinical decision rules. Evidence-Based Medicine Working Group. , 2000, JAMA.

[19]  M Gent,et al.  Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism: Increasing the Models Utility with the SimpliRED D-dimer , 2000, Thrombosis and Haemostasis.

[20]  M. Pistolesi,et al.  Accuracy of clinical assessment in the diagnosis of pulmonary embolism. , 1999, American journal of respiratory and critical care medicine.

[21]  J. Hirsh,et al.  Sensitivity and Specificity of a Rapid Whole-Blood Assay for D-Dimer in the Diagnosis of Pulmonary Embolism , 1998, Annals of Internal Medicine.