Steve Goodacre, MB, ChB, FFAEM, MSc, PhD; Alex J. Sutton, BSc, MSc, PhD; Fiona C. Sampson, BA, MSc
Disclaimer: The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the United Kingdom Department of Health.
Acknowledgments: The authors thank Vanja Dukic for her assistance with the meta-regression analysis and Angie Ryan for her help with the literature searches.
Grant Support: The United Kingdom Health Technology Assessment R&D Programme funded this project (reference no. 02/03/01).
Potential Financial Conflicts of Interest: None disclosed.
Requests for Single Reprints: Steve Goodacre, MB, ChB, FFAEM, MSc, PhD, Medical Care Research Unit, University of Sheffield, Regent Court, 30 Regent Street, Sheffield, S1 4DA, United Kingdom; e-mail, firstname.lastname@example.org.
Current Author Addresses: Dr. Goodacre and Ms. Sampson: Medical Care Research Unit, University of Sheffield, Regent Court, 30 Regent Street, Sheffield, S1 4DA, United Kingdom.
Dr. Sutton: Department of Health Sciences, University of Leicester, 22-28 Princess Road West, Leicester, LE1 6TP, United Kingdom.
Clinical assessment of suspected deep venous thrombosis (DVT) should be based on systematically evaluated evidence.
To determine whether clinical findings, risk scores, and physicians' empirical judgments affect the likelihood of detecting DVT on definitive testing.
MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, ACP Journal Club, and citation lists (1966 to January 2005).
Cohort studies published in English, French, Spanish, or Italian that compared clinical assessment with a reference standard.
The authors extracted standardized data, including setting, exclusions, population characteristics, reference standard, and results, and assessed quality against validated criteria.
The authors combined data by using random-effects meta-analysis and, if appropriate, used meta-regression to identify covariates that predicted diagnostic accuracy. Only malignancy (likelihood ratio [LR], 2.71), previous DVT (LR, 2.25), recent immobilization (LR, 1.98), difference in calf diameter (LR, 1.80), and recent surgery (LR, 1.76) were useful for ruling in DVT, while only absence of calf swelling (LR, 0.67) or difference in calf diameter (LR, 0.57) was useful for ruling out DVT. The Wells clinical score was more valuable than the individual characteristics; it stratified patients into groups with high (LR, 5.2), intermediate, and low (LR, 0.25) probability of DVT. The Wells score seemed able to stratify patients by risk only for proximal DVT, and it performed better in cohorts that were younger or excluded patients with previous thromboembolism.
Pooled estimates were subject to substantial heterogeneity. This may limit extrapolation between observers and settings. Only published studies were included, so findings may be subject to publication bias.
Individual clinical features are of limited value in diagnosing DVT. Overall assessment of clinical probability by using the Wells score is more useful.
Which clinical findings most affect the probability of deep venous thrombosis (DVT)?
This systematic review of 54 cohort studies found that previous DVT and malignant disease modestly increased the probability of DVT (positive likelihood ratios, 2.25 and 2.71), followed by recent immobilization, difference in calf diameter, and recent surgery (positive likelihood ratios, 1.75 to 1.98). Wells scores, based on 9 items, stratified patients' probability of proximal DVT much better than did individual findings, particularly in younger patients and in patients without previous DVT.
Estimating the probability of DVT is best accomplished by assessing and scoring multiple findings.
Flow diagram of studies considered for the review.
Table 1. Summaries of Characteristics of Cohorts Included in Each Meta-Analysis
Table 2. Likelihood Ratios for Each Reported Clinical Characteristic
Meta-analysis estimates of diagnostic value of clinical features of deep venous thrombosis (DVT).
Table 3. Results of Meta-Analysis of Wells Clinical Risk Score
Appendix Table 1. Characteristics of Cohorts Included in the Meta-Analysis
Post-test probability of deep venous thrombosis after high or low Wells scores as a function of pretest probability (population prevalence of deep venous thrombosis).
Performance of the Wells clinical risk score for detecting all episodes of deep venous thrombosis.
Appendix Table 2. Results of Summary Receiver-Operating Characteristic Curve Analysis Examining How Each Covariate Individually Influenced the Shape of the Curve
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Goodacre S, Sutton AJ, Sampson FC. Meta-Analysis: The Value of Clinical Assessment in the Diagnosis of Deep Venous Thrombosis. Ann Intern Med. ;143:129–139. doi: 10.7326/0003-4819-143-2-200507190-00012
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Published: Ann Intern Med. 2005;143(2):129-139.
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