Study designs of evaluations included in the review
The authors did not specify any inclusion criteria in relation to the study design, except that at least 50 patients should be included in the study. The included studies seemed to be retrospective and prospective diagnostic cohort studies.
Specific interventions included in the review
Studies of plain skull radiographs for determining the presence of an ICH were eligible for inclusion. The authors stated that in studies where no plain skull radiography was performed, computed tomography (CT) data were used.
Reference standard test against which the new test was compared
The authors did not explicitly state in their inclusion criteria the reference test against which the skull fracture radiograph should be compared. However, it was implied that the reference test was confirmation of ICH by a CT scan, angiography or neurosurgical findings. If CT was not performed, the authors considered an uneventful recovery as a sign of the absence of ICH.
Participants included in the review
Studies of people with MHI were eligible for inclusion. MHI was defined as trauma to the head with a Glasgow Coma Scale score of 13 to 15 on initial presentation. Studies with only paediatric or geriatric patients were excluded. If the data permitted, patients with multiple traumas and patients referred from other centres were excluded.
Outcomes assessed in the review
Numbers of true-positive, false-positive, true-negative and false- negative observations were derived from the data collected in the included studies. The authors did not specify any inclusion criteria in relation to the outcomes.
How were decisions on the relevance of primary studies made?
Articles were primarily selected on the basis of the title and the abstract, then the full text of about 200 articles was retrieved and the inclusion criteria were applied. The authors did not state how many reviewers performed the selection.