Conclusion
Positive DD has a higher correlation with PE diagnosis than the clinical
prediction score. DD assay, whether positive or negative, is therefore
an invaluable test in assessment of patients with suspected PE and can
help determine the need for tomographic imaging. The absolute DD is more
useful than the age-adjusted value.
What’s known (What’s already known about the topic)
- Tomographic imaging to establish a diagnosis of PE is expensive
- Clinical prediction scores are used widely to assist in assessing
individuals suspected of having PE
- The major utility of D-dimer is for excluding PE owing to its high
negative predictive value
What’s new (What does this article add)
- This is the first study to compare the correlation between D-dimer and
PE diagnosis with the correlation between a clinical prediction score
and PE diagnosis
- This is the first study to account for patients who didn’t have
imaging after initial clinical assessment
- The utility of absolute and age-adjusted D-dimer levels were compared
in terms of correlation with PE diagnosis
Introduction
Pulmonary embolism (PE) is associated with high mortality and
morbidity1 and creates a high financial and efficiency
burden on the healthcare system2. Diagnostic imaging
with tomographic techniques – such as computed tomography pulmonary
angiography (CTPA) or ventilation-perfusion (V/Q) scan with single
emission computed tomography (SPECT) is expensive3.
Early diagnosis has been shown to reduce mortality2.
Thus, the use of clinical decision aids and blood tests may help reduce
the resource and economic burdens on our health
system.4 The high negative predictive value of D-dimer
assays has been most useful for excluding the diagnosis of
PE4-6, particularly for patients in the Emergency
Department (ED)7, 8. However, many did not undergo
imaging investigations and this needs to be taken into account. Our aim
was to compare the ability of a positive DD level (both absolute and
age-adjusted) to predict a positive result for PE on imaging and compare
it with a conventional clinical risk score – to better justify use of
expensive tomographic imaging.
Methods