Statement of purpose Previous research has identified a variety of risk and protective factors for injuries in school-aged children, including age, sex, number of siblings, and child risk taking behaviors. The goal of the present study was to go beyond these known risk factors and investigate if and how siblings influence the frequency and severity of childhood injuries.

Methods/Approach Seventy-nine families with two school-aged children aged seven and ten years old on average were recruited from the community; 54% were female. Parents were 38 years old on average and self-identified as multiracial (8%), Indigenous (18%), and European-Canadian (75%); 92% were female. Parents reported on the frequency of minor and medically-attended child injuries within the past three months. They also reported on child risk-taking behavior and sibling supervision. Children reported on warmth and hostility in their sibling relationships.

Results Larger sibling spacing but not number of siblings was significantly associated with more minor injuries for younger siblings. Boys with older brothers experienced significantly more medically-attended injuries than boys or girls with older sisters. Greater risk taking was related to significantly more minor injuries for both younger and older siblings. Younger but not older sibling minor injuries were negatively related to sibling warmth and positively related to sibling hostility. Sibling supervision was not associated with injury frequency or severity, but was negatively related to warmth reported by both younger and older siblings.

Conclusions In addition to well-known demographic characteristics, siblings played an influential role in both elevating and mitigating injury risk for school-aged children, with older siblings having a greater influence on safety.

Significance Siblings are often not taken into account in injury research, their influence on child safety is understudied. The present study highlighted some of the important aspects of sibling influence that could inform future injury prevention programs.