Wong et al. BMC Public Health 2011, 11:618 http://www.biomedcentral.com/1471-2458/11/618 Table 1 Descriptive statistics for elementary and second- ary school students (Continued) Regions Toronto 112 (21.6) North 57 (5.7) West 304 (43.9) East 613 (28.9) Catholic school (yes) 376 (38.9) Changing school in the last five 419 (43.5) years (yes) Moving home in the last five years 513 (48.5) (yes) 256 (16.6) 0.07 199 (6.6) 857 (43.6) 1167 (33.2) 935 (36.4) 0.80 752 (30.2) < 0.001 1031 (44.5) 0.24 transport. The overall prevalence of active school trans- port ranged from 38% in the morning to 47% in the afternoon among elementary school students. The cor- responding figures were 23% and 32% for secondary school students. The lowest prevalence of walking/bik- ing to and from school in elementary school students were 23% in Northern Ontario and 30% in Eastern Ontario, respectively, whereas the greatest proportions were 60% and 68% in Toronto, correspondingly. The prevalence of walking/biking to and from school in sec- ondary school students ranged from 20% and 24% in the North to 30% and 39% in Toronto, respectively. Among secondary students in the sample, 42.2% held a drivers license, considerable potential exists for secondary stu- dents to drive alone or with others either to or from school. Among elementary school students, more years of par- ental education (ORto= 0.83; 95% CI: 0.75-0.92 and ORfr= 0.86; 95% CI: 0.78-0.96), longer travel time (ORto16-30 m= 0.40; 95% CI: 0.20-0.80, ORto≥31 m= 0.11; 95% CI: 0.03-0.32, ORfr16-30 m= 0.45; 95% CI: 0.25-0.81, and ORfr≥31 m= 0.40, 95% CI: 0.19-0.85), and living in the North (ORto= 0.27; 95% CI: 0.10-0.70 and ORfr= 0.31; 95% CI: 0.10-0.98) were negatively correlated with walking/biking either to or from school whereas living in urban areas was positively correlated with walking/ biking either to or from school (ORto= 3.00; 95% CI: 1.29-6.98 and ORfr= 4.84; 95% CI: 2.05-11.42) (Table 3). Physical activity (ORto= 1.27; 95% CI: 0.95-1.71 and Table 2 Prevalence of active school transport in Ontario Page 5 of 12 ORfr= 0.90; 95% CI: 0.59-1.36) and weight status (ORto= 0.83; 95% CI: 0.60-1.33 and ORfr= 0.90; 95% CI: 0.59- 1.36) were not associated with walking/biking to or from school. Better perceived health and being involved in the school travel decision making process were only correlated positively with active school transport in the afternoon (ORph= 2.20; 95% CI: 1.23-3.92 and ORdecide= 1.73; 95% CI: 1.11-2.69, respectively). In contrast, the presence of a household car was negatively correlated with active school transport in the morning (ORto= 0.22; 95% CI: 0.08-0. 61). Table 4 shows the correlates of active school transport for secondary school students. Female students (ORto = 0.66; 95% CI: 0.49-0.89 and ORfr = 0.74; 95% CI: 0.55- 0.99) and those working part-time (ORto≥6 hr/wk = 0.65; 95% CI: 0.45-0.93 and ORfr≥6 hr/wk = 0.62; 95% CI: 0.44- 0.86) were less likely to actively commute to school in either the morning or afternoon. Living in an urban area (OR = 2.67; 95%CI: 1.22-5.82) and contributing to the school travel decision was positively correlated with walking/biking from school (OR = 1.52; 95%CI: 1.13- 2.04). Adolescents who walked/biked to school were more physically active (OR = 1.39; 95%CI: 1.01-1.90), had shorter travel times (OR16-30 min = 0.84; 95%CI: 0.59-1.19 and OR≥31 min = 0.23; 95%CI: 0.13-0.38), and had moved house in the past five years (OR = 1.33; 95% CI: 1.05-1.70). Self-reported weight status was not asso- ciated with either morning or afternoon school trips (ORto= 0.99; 95% CI: 0.74-1.33 and ORfr= 0.94; 95% CI: 0.70-1.27). In terms of mode shift, both elementary and second- ary school students who lived in urban areas (ORele= 3.58; 95%CI: 1.00-12.90 and ORsec= 3.24; 95%CI: 1.18- 8.85) and decided on their school travel mode (ORele= 2.43; 95%CI: 1.23-4.80 and ORsec= 2.42; 95%CI: 1.61- 3.63) were more likely to shift their travel mode from passive in the morning to active in the afternoon (Table 5). Among secondary school students, students with a shorter travel time to school were more likely to shift their mode from passive in the morning to active in the afternoon (OR16-30 m = 0.11; 95% CI: 0.03-0.40 and OR≥31 m = 0.07; 95% CI: 0.02-0.29). Only elementary Toronto North West East Total Secondary To school Walk/bike 69 (29.8) 46 (20.0) 170 (20.9) 234 (22.5) 519 (22.9) p = 0.18 Other 187 (70.2) 153 (80.0) 687 (79.1) 933 (77.5) 1960 (77.2) From school Walk/bike 91 (38.9) 53 (24.0) 265 (30.5) 350 (31.5) 759 (31.8) p = 0.27 Other 165 (61.1) 146 (76.0) 592 (69.5) 817 (68.5) 1720 (68.2) Elementary To school Walk/bike 65 (59.6) 11 (22.6) 127 (39.9) 142 (23.6) 345 (38.4) Other 47 (40.4) 46 (77.4) 177 (60.1) 471 (76.4) 741 (61.6) p == 0.03 From school Walk/bike 75 (68.4) 18 (34.4) 161 (49.9) 178 (29.7) 432 (47.2) Other 37 (31.6) 39 (65.6) 143 (50.1) 435 (70.3) 654 (52.8) p = 0.04