Table 1.

Inclusion and exclusion criteria

Study population	Patients of all age ages in the need for acute care (acutely ill or seriously injured somatic or psychiatric patients)
Intervention	Patient prioritizing by the use of a validated triage system in the pre-hospital setting; face-to-face or telephone triage-assessment
Comparison	Acutely ill or seriously injured patients who were assessed with a triage system different from that of the intervention, or who were not triaged at all in the same type of setting
Outcomes	Health outcomes (mortality, morbidity)
	Patient safety (for example undertriage)
	Patient satisfaction
	Job-satisfaction with the triage systems among health workers
	Resources use (for example overtriage)
	To what degree triage was completed (goal achievement)
	The quality of the information exchange between the different settings of the EMS (for example the quality of documentation)
Study design	Systematic review of high quality (see checklist, Additional file 2)
	Randomized controlled trial (RCT)
	Non-randomized controlled study (non-RCT)
	Controlled before-and-after study (CBA)
	Interrupted time series analysis (ITS)
Exclusion	Studies were excluded if triage assessment was done in the hospital setting only without including triage assessment in any of the pre-hospital settings, if the patients were not acutely ill or seriously injured, or if there was no use of a comparison for the evaluation of the effects of a triage system or an ITS design