Study designs of evaluations included in the review
Studies had to use a control/comparison group. Studies compared trauma outcomes across trauma centres/ systems(geographic analysis), within a trauma centre/system (temporal analysis) or contrasted regional outcomes to a national criterion standard. Study designs used were panel review, comparison to a national criterion injury register or population based studies. Studies providing case reports, literature reviews or information based on expert opinion were excluded.
Panel review studies use an expert panel to review the medical records of injured patients who die to reach a conclusion regarding whether the patient could have survived given optimal treatment. The outcomes are often designated as 'preventable' or 'non-preventable'. The second type of study design uses a large criterion injury registry to generate predicted survival or mortality rates, which are then compared with observed survival or mortality. A commonly used 'national' trauma database is the MTOS. Studies in the final study design category rely on large existing databases to evaluate the outcomes of entire populations in a region or state. These studies often use hospital claims data to evaluate outcomes.
Specific interventions included in the review
Formal trauma centres and trauma systems incorporating any of the following: enhanced emergency medical services training and triage, advances in hospital procedures and training, organisation of coordinated in-hospital trauma care teams. Trauma systems were designed to "facilitate and coordinate a multidisciplinary system response to severely injured patients from the time of injury through the provision of definitive care". Studies were limited to those looking at trauma systems in the US and Canada.
Participants included in the review
Adults and children, in rural and urban areas.
Outcomes assessed in the review
Deaths, survival or death/injury ratio.
How were decisions on the relevance of primary studies made?
Abstracts were read independently by two reviewers. Conflict was resolved by open discussion.