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D-dimer test for excluding the diagnosis of pulmonary embolism

Overview of attention for article published in Cochrane database of systematic reviews, August 2016
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  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (85th percentile)
  • Above-average Attention Score compared to outputs of the same age and source (57th percentile)

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17 tweeters
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1 Facebook page

Citations

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34 Dimensions

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172 Mendeley
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Title
D-dimer test for excluding the diagnosis of pulmonary embolism
Published in
Cochrane database of systematic reviews, August 2016
DOI 10.1002/14651858.cd010864.pub2
Pubmed ID
Authors

Fay Crawford, Alina Andras, Karen Welch, Karen Sheares, David Keeling, Francesca M Chappell

Abstract

Pulmonary embolism (PE) can occur when a thrombus (blood clot) travels through the veins and lodges in the arteries of the lungs, producing an obstruction. People who are thought to be at risk include those with cancer, people who have had a recent surgical procedure or have experienced long periods of immobilisation and women who are pregnant. The clinical presentation can vary, but unexplained respiratory symptoms such as difficulty breathing, chest pain and an increased respiratory rate are common.D-dimers are fragments of protein released into the circulation when a blood clot breaks down as a result of normal body processes or with use of prescribed fibrinolytic medication. The D-dimer test is a laboratory assay currently used to rule out the presence of high D-dimer plasma levels and, by association, venous thromboembolism (VTE). D-dimer tests are rapid, simple and inexpensive and can prevent the high costs associated with expensive diagnostic tests. To investigate the ability of the D-dimer test to rule out a diagnosis of acute PE in patients treated in hospital outpatient and accident and emergency (A&E) settings who have had a pre-test probability (PTP) of PE determined according to a clinical prediction rule (CPR), by estimating the accuracy of the test according to estimates of sensitivity and specificity. The review focuses on those patients who are not already established on anticoagulation at the time of study recruitment. We searched 13 databases from conception until December 2013. We cross-checked the reference lists of relevant studies. Two review authors independently applied exclusion criteria to full papers and resolved disagreements by discussion.We included cross-sectional studies of D-dimer in which ventilation/perfusion (V/Q) scintigraphy, computerised tomography pulmonary angiography (CTPA), selective pulmonary angiography and magnetic resonance pulmonary angiography (MRPA) were used as the reference standard.• Participants: Adults who were managed in hospital outpatient and A&E settings and were suspected of acute PE were eligible for inclusion in the review if they had received a pre-test probability score based on a CPR.• Index tests: quantitative, semi quantitative and qualitative D-dimer tests.• Target condition: acute symptomatic PE.• Reference standards: We included studies that used pulmonary angiography, V/Q scintigraphy, CTPA and MRPA as reference standard tests. Two review authors independently extracted data and assessed quality using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). We resolved disagreements by discussion. Review authors extracted patient-level data when available to populate 2 × 2 contingency tables (true-positives (TPs), true-negatives (TNs), false-positives (FPs) and false-negatives (FNs)). We included four studies in the review (n = 1585 patients). None of the studies were at high risk of bias in any of the QUADAS-2 domains, but some uncertainty surrounded the validity of studies in some domains for which the risk of bias was uncertain. D-dimer assays demonstrated high sensitivity in all four studies, but with high levels of false-positive results, especially among those over the age of 65 years. Estimates of sensitivity ranged from 80% to 100%, and estimates of specificity from 23% to 63%. A negative D-dimer test is valuable in ruling out PE in patients who present to the A&E setting with a low PTP. Evidence from one study suggests that this test may have less utility in older populations, but no empirical evidence was available to support an increase in the diagnostic threshold of interpretation of D-dimer results for those over the age of 65 years.

Twitter Demographics

The data shown below were collected from the profiles of 17 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 172 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 172 100%

Demographic breakdown

Readers by professional status Count As %
Unspecified 2 1%
Student > Postgraduate 1 <1%
Student > Doctoral Student 1 <1%
Student > Bachelor 1 <1%
Unknown 167 97%
Readers by discipline Count As %
Medicine and Dentistry 3 2%
Immunology and Microbiology 1 <1%
Unspecified 1 <1%
Unknown 167 97%

Attention Score in Context

This research output has an Altmetric Attention Score of 11. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 17 April 2019.
All research outputs
#1,354,815
of 13,232,126 outputs
Outputs from Cochrane database of systematic reviews
#3,917
of 10,531 outputs
Outputs of similar age
#37,198
of 263,466 outputs
Outputs of similar age from Cochrane database of systematic reviews
#67
of 158 outputs
Altmetric has tracked 13,232,126 research outputs across all sources so far. Compared to these this one has done well and is in the 89th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 10,531 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 20.7. This one has gotten more attention than average, scoring higher than 62% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 263,466 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 85% of its contemporaries.
We're also able to compare this research output to 158 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 57% of its contemporaries.