Study designs of evaluations included in the review
No inclusion criteria for the study design were specified. All included studies were retrospective.
Specific interventions included in the review
Studies assessing the usefulness of 12-lead ECG were eligible for inclusion. Where stated, cardiologists reported ECGs in the included studies.
Reference standard test against which the new test was compared
The included studies were required to use a clearly reported reference standard. The included studies used echocardiography as the reference standard.
Participants included in the review
Patients with suspected heart failure referred from primary care to open access echocardiography services were eligible for inclusion.
Outcomes assessed in the review
No inclusion criteria for the diagnostic outcome were specified. Sensitivity and specificity were calculated for each included study.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.