When considered from a provincial perspective, quantification of surgical procedures undertaken by different hospitals and healthcare networks is necessary for informing resource allocation and modelling of healthcare services. The investigators hypothesized that i) non-physiologically complex surgical procedures would account for most (>1/2) of pediatric surgical procedures performed at both pediatric specialist hospitals and the other hospitals performing pediatric surgery, ii) surgical discharges for non-physiologically complex surgical procedures would account for most (>1/2) in-hospital bed nights among pediatric surgical admissions at both pediatric specialist hospitals and the other hospitals performing pediatric surgery, and iii) the relative distributions of non-physiologically complex surgical procedures, but not physiologically complex procedures, would be at least moderately similar between pediatric specialist hospitals and the other hospitals performing pediatric surgery. To test these 3 hypotheses, the specific objectives of this study were to estimate i) the proportion (primary outcome) of non-physiologically complex pediatric surgical procedures, and ii) the similarity and diversity (secondary outcomes) of non-physiologically and physiologically complex surgical procedures between the pediatric specialist hospitals and the other hospitals performing pediatric surgery in Ontario, Canada.