Study	Reason for exclusion
Asai 1985	Intervention included dipyridamole as well as prednisolone as the difference between the groups. Effect of steroids therefore not ascertainable. Furthermore primary outcome— arterial changes — poorly defined
Hashino 2001	Steroids only used if children were non‐responders to 2 treatments with IVIG. These IVIG non‐responsive children were then divided into groups allocated to receiving steroid (9 children) and those who received another dose of IVIG (8 children). This caused a significant delay in the administration of any steroids Due to the steroid treatment group being classed as non‐responders to IVIG, and the delay in receiving treatment, this study was not included as it is not comparable to any of the other studies used in this review
ISRCTN74427627	Study outcome data not available despite attempts to contact author
Jibiki 2005	Outcome not as per inclusion criteria of the review. Investigators assessed the laboratory mechanism of action of IVIG and steroid therapy in KD
Kato 1979	Study outcome data not available despite attempts to contact author. Available outcome information does not provide objective data but categorises into aneurysm vs no aneurysm with inadequate detail on exact approach
Kusakawa 1983	Study outcome data not available despite attempts to contact author. Available outcome information does not provide objective data but categorises into aneurysm versus no aneurysm with inadequate detail on exact approach
Miura 2008	Outcome not as per inclusion criteria. Investigators assessed the laboratory mechanism of action of IVIG and steroid therapy in KD
Nakamura 1985	Outcome not as per inclusion criteria of the review. The outcome of this study was regarding platelet laboratory processes, which was not an outcome measure of this review
Nonaka 1995	Study outcome data not available despite attempts to contact author. Available outcome information does not provide objective data but categorises into aneurysm vs no aneurysm with inadequate detail on exact approach
Ogata 2009	Outcome not as per inclusion criteria of the review. Investigators assessed the molecular mechanism of action of IVIG and steroid therapy in KD
Sekine 2012	Outcome not as per inclusion criteria of the review. The outcome of this study was oxidative stress, which was not an outcome measure of this review
Seto 1983	Inadequate information on methodology for validation, specifically no evidence of randomisation
Xu 2002	Interventions included immunoglobulin versus steroids, meaning steroids were not the only differential factor between the groups and therefore their effect cannot be clearly defined. Inadequate information on methodology, specifically around randomisation, despite contacting authors
Yuan 2000	Outcome not as per inclusion criteria of the review. Study does not clearly define coronary aneurysm or how this was measured

IVIG: intravenous immunoglobulin