Surgical interventions performed for children before the introduction of the surgical safety checklist in Ontario, from October 2008 to September 2009.

Surgical interventions performed for children after the introduction of the surgical safety checklist in Ontario, from October 2010 to September 2011.

An Ontario hospital-wide introduction of a surgical safety checklist based on the WHO guidelines, as mandated by the Ontario Ministry of Health

Composite outcome, complications included were death (all-causes), acute renal failure, cardiac arrest, complications of implants or grafts, decubitus ulcer, deep vein thrombosis, disruption of wound, electrolyte or acid-base abnormality, hemorrhage or hematoma, pulmonary embolism, pulmonary collapse or pneumonia, surgical site infection, sepsis, shock, stroke, and vascular graft failure

Number of Emergency Room visits

Unplanned return to the operating room