Trubey, R, Huang, C, Lugg-Widger, F, Hood, K, Allen, D, Edwards, D, Lacy, D, Lloyd, A, Mann, M, Mason, B, Oliver, A, Roland, D, Sefton, G, Skone, R, Thomas-Jones, E, Tume, LN, Powell, C, "Validity and effectiveness of paediatric early warning systems and track and trigger tools for identifying and reducing clinical deterioration in hospitalised children: a systematic review", BMJ Open, 2019