Influence of voluntary standards and design modifications on trampoline injury in Victoria, Australia

PURPOSE: To examine the influence of the voluntary Australian trampoline standard (AS 4989-2006) and market-driven design modifications on relevant trampoline injuries. METHODS: Trend and intervention analysis on frequencies and proportions of hospital-treated trampoline-related injury in Victoria, Australia, extracted from the Victorian Emergency Minimum Dataset from 1 July 1999 to 30 June 2013. The injuries relevant to the AS were contact with spring and frame, and multiple-user injury. Falls from trampolines were relevant for netted trampolines, a market-driven modification. RESULTS: Frequency of all trampoline injuries increased by 11.4% (95% CI 10.0% to 11.7%) on average each year. Spring and frame, and fall injuries increased to a lesser extent (8.7%, 95% CI 6.9% to 9.8% and 7.3%, 95% CI 5.8% to 8.3%, respectively). Multiple-user injuries increased by 21.0% (95% CI 16.3% to 21.9%). As a proportion of all trampoline injuries, spring and frame injury and falls injury decreased, while multiple-user injuries increased. The intervention analysis showed no significant change in spring and frame injuries associated with the AS (p=0.17). A significant increase was found for multiple-user injuries (p=0.01), in particular for the 0-year to 4-year age group (p<0.0001), post 2007. CONCLUSIONS: There was little evidence for an effect of the voluntary standard on spring and frame injury and none for multiple-user injury. Netted trampolines appear to be associated with a decrease in falls from trampolines but an increase in injuries to multiple users. A mandated trampoline safety standard and a safety campaign including warnings about multiple users is recommended. Continued monitoring of injury data will be required.