In the last decade the U.S. Centers for Disease Control and Prevention has issued revised guidelines to encourage health care providers to routinely offer HIV testing. 41 , 42 In practice, D-dimer measurement has been most comprehensively validated in (1) the exclusion of VTE in certain patient populations and (2) the diagnosis and monitoring of coagulation activation in disseminated intravascular coagulation (DIC).
Although it is true that individual symptoms and signs, such as pain, swelling, and limb tenderness, are notoriously inaccurate predictors of DVT, their cumulative use in conjunction with other parameters derived from the medical history provide the additional information to discriminate between those patients at high risk and those patients who are significantly less likely to have a thrombosis.
Firstly, to evaluate the diagnostic performances of the Liatest D-Dimer assay and the Asserachrom DDi (ELISA) assay, sensitivity, specificity, and negative and positive predictive values and their 95% confidence intervals (95% CI) were calculated according to standard methods for proportions ( 23 ).
D-Dimer concentrations also vary with duration of symptoms ( 77 ), use of anticoagulants ( 78 )( 79 ), and age of the patient ( 80 ). However, we were unable to explore the effect of clinical heterogeneity on test discrimination because few studies stratified their results by patient characteristics and none provided disaggregated patient-level data.
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. 9 In this study, PTP assessment was not documented in the majority of emergency department cases of suspected VTE.
The American College of Radiology (ACR) considers chest CTA to be the current standard of care for the detection of pulmonary embolism in these patients. Key differences between studies include differences between clinical prediction rules (CPRs), D‐dimer assays family nurse practitioner and thresholds used.