Study designs of evaluations included in the review
The studies had to include at least 15 patients to be eligible.
Specific interventions included in the review
Studies evaluating history, physical examination, and routine diagnostic tests such as electrocardiography or plain chest radiography were eligible for inclusion. The included studies evaluated the following: clinical history; indicators in the physical examination, such as pulsus paradoxus above 10 mmHg, tachycardia or elevated jugular venous pressure; abnormalities in electrocardiography; and cardiomegaly on chest radiography.
Reference standard test against which the new test was compared
Studies that compared test results to pericardiocentesis with right heart catheterisation and echocardiography were eligible. The majority of the included studies used right heart catheterisation and pericardiocentesis as the reference standard.
Participants included in the review
Studies of patients with suspected cardiac tamponade were eligible; studies of patients with cardiac tamponade after cardiac surgery and studies dealing with other pericardial diseases were excluded. The majority of studies were of patients referred for pericardiocentesis.
Outcomes assessed in the review
The studies had to report data on the diagnosis of cardiac tamponade to be eligible. The review reported the sensitivity of the investigated indicators; for some outcomes the specificity and likelihood ratios (LRs) were also reported. The measurement methods used in the included studies varied, e.g. pulsus paradoxus was measured with an intra-arterial transducer or sphygmomanometer.
How were decisions on the relevance of primary studies made?
Two reviewers independently screened the studies.