Trends in educational inequalities in smoking and physical activity in Canada: 1974-2005

Background: In Canada levels of smoking have decreased and levels of physical activity have increased over the last 20 years. However, little research has examined if educational inequalities in either of these important health determinants have changed. Methods: A secondary analysis of Canadian population-based surveys from 1974 through to 2005 was conducted. The prevalence of both smoking and physical activity across educational groups for both men and women, as well as relative and absolute measures of inequality was estimated. Results: Differences in both smoking and physical activity across educational groups in all surveys examined between 1974 and 2005 were found, with lower educational groups more likely to be heavy smokers and inactive in each survey. Both relative and absolute educational inequalities in smoking widened between 1974 and 2005 (relative concentration index (RCI) for smoking 10 plus cigarettes per day changed from -7.9 to -26.9 among men; and from -4.8 to -27.4 among women), with inequalities in physical activity narrowing between 1981 and 1996, then widening between 1996 and 2005 (RCI for inactivity -4.34 to -6.75 among men; -3.57 to -5.54 among women). In general, results among men and women did not differ substantially. Conclusions: It is unlikely that the widening educational inequalities in smoking and physical activity documented here reflect lower knowledge of the consequences of smoking and physical inactivity among lower educated groups. The results suggest more work needs to be done in both designing population health approaches that focus on equity and the creation of supportive environments that provide equal opportunities for behaviour change for all educational groups in Canada.