Comparing the Diagnostic Performance of 2 Clinical Decision Rules to Rule Out Deep Vein Thrombosis in Primary Care Patients

Eit Frits van der Velde; Diane B. Toll; Arina J. ten Cate-Hoek; Ruud Oudega; Henri E. J. H. Stoffers; Patrick M. Bossuyt; Harry R. Büller; Martin H. Prins; Arno W. Hoes; Karel G. M. Moons; Henk C. P. M. van Weert

doi:10.1370/afm.1198

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Comments to: Comparing the diagnostic performance of 2 clinical decision rules to rule out deep vein thrombosis in primary care patients
Melanie Tan MD

Published on: 04 February 2011
Does skilling eqalises the outcome of the tests?
Hendrik J Nijhuis

Published on: 26 January 2011
A model for both conduct and reporting
Lee A. Green

Published on: 19 January 2011

Published on: (4 February 2011)
Page navigation anchor for Comments to: Comparing the diagnostic performance of 2 clinical decision rules to rule out deep vein thrombosis in primary care patients
Comments to: Comparing the diagnostic performance of 2 clinical decision rules to rule out deep vein thrombosis in primary care patients
Melanie Tan MD, Leiden, The Netherlands
Other Contributors:
In their prospective study, van der Velde and colleagues found comparable safety for the Wells rule and primary care rule in patients with a clinically suspected deep vein thrombosis (DVT) in the primary care setting, with the primary care rule slightly reducing (55 vs. 51%) the need for referral for compression ultrasonography (CUS).1 Although this study may be valuable for the diagnostic management of DVT in primary ca...
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In their prospective study, van der Velde and colleagues found comparable safety for the Wells rule and primary care rule in patients with a clinically suspected deep vein thrombosis (DVT) in the primary care setting, with the primary care rule slightly reducing (55 vs. 51%) the need for referral for compression ultrasonography (CUS).1 Although this study may be valuable for the diagnostic management of DVT in primary care, the results of the study deserve some comments.
First,with the Wells rule 373 patients (37%) were classified in the high-risk group and with the primary care rule 152 patients (15%). In (inter)national guidelines it is recommended to perform a repeated CUS after one week in the high risk group patients with a positive D-dimer test in both primary and secondary care setting. In the study by van der Velde et al no information has been given about this high risk group of patients. It would be interesting to know whether a difference in the Wells and primary care rule exists between the proportion of patients qualifying for a repeated CUS after one week. Likewise the 3-month follow -up of patients in the high-risk group with a negative D-dimer test result in both clinical decision rules would be of interest.
Furthermore another interesting observation would be the interobserver agreement of both clinical decision rules. The primary care rule consists of mainly objective items and the Wells rule includes the subjective item of “alternative diagnosis at least likely as DVT”. Hypothetically the primary care rule would therefore have a higher interobserver agreement.
Finally, a formal comparison between the Wells rule and primary care in specific subpopulations (e.g. older patients) with a suspected DVT in primary care is still to be investigated.
1. van der Velde EF, Toll DB, Ten Cate-Hoek AJ, Oudega R, Stoffers HE, Bossuyt PM, Büller HR, Prins MH, Hoes AW, Moons KG, van Weert HC. Comparing the diagnostic performance of 2 clinical decision rules to rule out deep vein thrombosis in primary care patients. Ann Fam Med. 2011;9(1):31-36.
Competing interests: None declared
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Competing Interests: None declared.
Published on: (26 January 2011)
Page navigation anchor for Does skilling eqalises the outcome of the tests?
Does skilling eqalises the outcome of the tests?
Hendrik J Nijhuis, Nederland
The primary care rule fits better than the Wels rule because of the little experience fysicians have in primary care and perhaps therefore are uncertain of the presence of an alternative diagnosis.The need of a D- dimertest to increase the accuracy of the diagnosis is with a slight difference obvious in both rules. But if the fysicians are better skilled and the statistic range is less than P=2 perhaps the concordance be...
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The primary care rule fits better than the Wels rule because of the little experience fysicians have in primary care and perhaps therefore are uncertain of the presence of an alternative diagnosis.The need of a D- dimertest to increase the accuracy of the diagnosis is with a slight difference obvious in both rules. But if the fysicians are better skilled and the statistic range is less than P=2 perhaps the concordance between the two rules equalizes without using the D-dimertest.In that case the need of a D-dimertest afterwards will probably decrease.
Competing interests: None declared
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Competing Interests: None declared.
Published on: (19 January 2011)
Page navigation anchor for A model for both conduct and reporting
A model for both conduct and reporting
Lee A. Green, Ann Arbor, Michigan, USA
This study was a joy to read. The authors studied a problem of importance in family medicine, in a way that is usable in family medicine. They found a highly statistically significant difference in the performance of the two estimators, but a difference that was quite small in absolute terms - and they reported it as a small difference. With spin- doctoring and overhyping of clinically trivial effects so prevalent in the m...
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This study was a joy to read. The authors studied a problem of importance in family medicine, in a way that is usable in family medicine. They found a highly statistically significant difference in the performance of the two estimators, but a difference that was quite small in absolute terms - and they reported it as a small difference. With spin- doctoring and overhyping of clinically trivial effects so prevalent in the medical literature, it does the heart good to see a genuinely useful study carried out in primary care and report its results modestly and accurately.
Competing interests: None declared
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Competing Interests: None declared.