Methods: A total of 86 of the 136 schools with hazardous play
equipment had the equipment removed and replaced with
safer equipment within the study period (intervention schools).
Playground injury rates before and after equipment replacement
were compared in intervention schools. A database of
incident reports from the Ontario School Board Insurance Exchange
was used to identify injury events. There were 225
schools whose equipment did not require replacement (nonintervention
schools); these schools served as a natural control
group for background injury rates during the study period. Injury
rates per 1000 students per month, relative risks (RRs) and
95% confidence intervals (CIs) were calculated, adjusting for
clustering within schools.