This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows:
To investigate the ability of the D-dimer test to rule out a diagnosis of acute PE in patients managed in the hospital outpatient setting who have had a pre-test probability (PTP) for PE determined using a clinical prediction rule (CPR) but are not already established on anticoagulation at the time of recruitment to the study by estimating sensitivity and specificity.
To investigate the following as potential sources of heterogeneity: age, sex, previous VTE, prolonged immobilisation, and type of reference standard. However, we recognise that all of these listed items except type of reference standard are patient-specific rather than study-specific, and so study reports may lack the necessary level of detail to enable an informative analysis.