Study designs of evaluations included in the review
The authors did not report any inclusion criteria in relation to the study design.
Specific interventions included in the review
Studies that evaluated a turbidimetric latex D-dimer test for the diagnosis of PE were eligible for inclusion. The specific tests (with threshold for positive result in brackets) assessed in the included studies were Liatest (500 microg/L), MDA (500 microg/L), IL-test (200 microg/L), Plus (190 microg/L), Minutex (500 microg/L) and Tinaq (500 microg/L).
Reference standard test against which the new test was compared
The authors stated that, although a positive angiogram or autopsy is considered the reference standard for the diagnosis of PE, any of the following were considered acceptable reference standards: high probability ventilation-perfusion scan; computed tomography scan positive for PE; or positive lower extremity imaging study (ultrasound, impedance plethysmography, venogram, or computed tomography venogram). A negative angiogram is the reference standard for ruling out PE, but the following were considered acceptable reference standards: normal or very low probability ventilation-perfusion scan; or clinical follow-up documenting the absence of a thromboembolic event over at least 3 months. Studies that did not include one of the reference standards described above, or in which the reference standard was unclear, were excluded from the analysis.
Participants included in the review
The studies had to involve predominantly out-patient populations (at least 80%) presenting with symptoms and signs suspicious for PE to be included. Studies that reported on less than 80% out-patients were eligible for inclusion if data were available to calculated the sensitivity and specificity for the out-patient component of the study population. In the included studies, the mean age of the patients ranged from 44 to 66 years, the proportion of out-patients ranged from 80 to 100%, and the prevalence of PE ranged from 9 to 62%.
Outcomes assessed in the review
The authors did not report any inclusion criteria in relation to the outcomes. The primary outcomes reported in the review were the sensitivity and specificity.
How were decisions on the relevance of primary studies made?
Two reviewers independently reviewed abstracts identified through the searches. Any disagreements were resolved through discussion.