Cross-sectional data fromthe TRavel, Environment, and Kids project (TREK)
was used. The research methodology for TREK is described fully elsewhere
. In 2007, 36 government primary schools in Perth,
Western Australia were invited to participate; 25 participated (69.4% response
rate (RR)). In each school, one class from each grade (years 5, 6, 7)was randomly
selected until at least 30 children per gradewere recruited. In total, 1480 children
(57% RR) and 1314 of their parents (89% RR) participated. We analyzed
data for 727 (49%) children who had a family dog