Determinants of active commuting.

In this issue of Preventive Medicine Bringolf-Isler et al. (Bringolf-Isler et al., 2008) report on factors associated with active commuting to school in more than 1000 children aged 6–14 years in a German-speaking, a French-speaking, and a bilingual area in Switzerland. This study design naturally allows for separating cultural from other determinants of selftransportation. Switzerland may be a small country with a socio-economically homogenous population but it nevertheless has different language regions with subtle differences in culture. Active commuting to school of children is still the rule in Switzerland (on average 78% in this study), which is high compared to some other countries, and probably reflects a high perceived safety by parents of the way to school (63% of parents judged the way to school sufficiently safe). But, as in other countries, childhood obesity is on the rise in Switzerland and there are indications that active commuting to school is decreasing. A better understanding of the factors related to active commuting is needed to keep the high prevalence of active transportation to school. Using a geographical information system (GIS) the authors identified distance to school and density of major traffic hurdles as important factors. They also found that belonging to the French-speaking population is related to less active modes of commuting as compared to the German-speaking population. The authors recommend that, in order to keep active commuting levels high, the route to school should remain relatively short and safe. They also underline the importance of taking cultural differences into account, as exemplified by the differences found between Germanand French-speaking sub-populations, even though the origin of the cultural effect remains poorly understood (Stamm and Lamprecht, 2005). Limiting factors of the study are its crosssectional design precluding conclusions on causality and the lack of objective measures of physical activity levels (the study used parental questionnaires).