Aim To present a systematic review on the validity of triage systems for paediatric emergency care.

Methods Search in MEDLINE, Cochrane Library, Latin American and Caribbean Health Sciences Literature (LILACS), Scientific Electronic Library Online (SciELO), Nursing Database Index (BDENF) and Spanish Health Sciences Bibliographic Index (IBECS) for articles in English, French, Portuguese or Spanish with no time limit. Validity studies of five-level triage systems for patients 0–18 years old were included. Two reviewers performed data extraction and quality assessment as recommended by PRISMA statement.

Results We found 25 studies on seven triage systems: Manchester Triage System (MTS); paediatric version of Canadian Triage and Acuity Scale (PedCTAS) and its adaptation for Taiwan (paediatric version of the Taiwan Triage and Acuity System); Emergency Severity Index version 4 (ESI v.4); Soterion Rapid Triage System and South African Triage Scale and its adaptation for Bostwana (Princess Marina Triage Scale). Only studies on the MTS used a reference standard for urgency, while all systems were evaluated using a proxy outcome for urgency such as admission. Over half of all studies were low quality. The MTS, PedCTAS and ESI v.4 presented the largest number of moderate and high quality studies. The three tools performed better in their countries or near them, showing a consistent association with hospitalisation and resource utilisation. Studies of all three tools found that patients at the lowest urgency levels were hospitalised, reflecting undertriage.

Conclusions There is some evidence to corroborate the validity of the MTS, PedCTAS and ESI v.4 for paediatric emergency care in their own countries or near them. Efforts to improve the sensitivity and to minimise the undertriage rates should continue. Cross-cultural adaptation is necessary when adopting these triage systems in other countries.