Association of physical activity in 2009 with traffic safety in 2006 and change in traffic safety between 2006 and 2009 according to gender, age, and employment status, for 2009 respondentsa.

*The association is statistically significant by P≤0.05, two-sided.aThe analysis only includes neighborhoods with a minimum of 30 respondents per survey year.bOne unit change corresponds to an increase by 10% points in the proportion of residents reporting their neighbourhood to be safe.cOne unit change corresponds to an increase by 10% points in changes in levels of traffic safety between 2006 and 2009.dOdds ratios were calculated on zero versus at least 1 hour physically active per week.eReference group were respondents who reported zero hours of PA.fNumber of hours of PA, among those who reported being physically active for at least one hour per week.gActivity intensity ratio for those who reported being physically active for at least one hour per week.hControl variables include gender, age, employment status, education, and household income (when applicable).

*经双侧检验，当P≤0.05时，关联具有统计学显著性。
a 本分析仅纳入各调查年度受访者不少于30人的社区。
b 自变量每变动1个单位，对应自评社区安全的居民占比提升10个百分点。
c 自变量每变动1个单位，对应2006年至2009年间交通安全水平变化幅度提升10个百分点。
d 比值比基于"每周体育活动(physical activity, PA)时长为0小时"与"每周至少1小时体育活动"的对比计算得出。
e 参照组为自评每周体育活动时长为0小时的受访者。
f 仅纳入每周至少进行1小时体育活动的受访者，统计其体育活动时长。
g 针对每周至少进行1小时体育活动的受访者，计算其活动强度比。
h 控制变量包括性别、年龄、就业状况、教育程度及家庭收入（如适用）。