Bottom Line:
Current smoking decreased and quitting increased with increasing SES.Current prevention and cessation policies have not been successful in improving the situation for all areas and groups.Future efforts to reduce smoking uptake and increase cessation in Canada will need consideration of socioeconomic and geographic factors to be successful.

Affiliation: Harvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, United States of America. djcorsi@hsph.harvard.edu

ABSTRACT

Objective: To describe the socioeconomic and geographic distribution of smoking behaviour in Canada among 19,383 individuals (51% women) aged 15-85 years.

Methods: Current smoking and quitting were modeled using standard and multilevel logistic regression. Markers of socioeconomic status (SES) were education and occupation. Geography was defined by Canadian Provinces.

Results: The adjusted prevalence of current smoking was 20.2% (95% confidence interval [CI]: 18.8-21.7) and 63.7% (95% CI: 61.1-66.3) of ever smokers had quit. Current smoking decreased and quitting increased with increasing SES. The adjusted prevalence of current smoking was 32.8% (95% CI: 28.4-37.5) among the least educated compared to 11.0% (95% CI: 8.9-13.4) for the highest educated. Among the least educated, 53.0% (95% CI: 46.8-59.2) had quit, rising to 68.7% (95% CI: 62.7-74.1) for the most educated. There was substantial variation in current smoking and quitting at the provincial level; current smoking varied from 17.9% in British Columbia to 26.1% in Nova Scotia, and quitting varied from 57.4% in Nova Scotia to 67.8% in Prince Edward Island. Nationally, increasing education and occupation level were inversely associated with current smoking (odds ratio [OR] 0.64, 95% CI: 0.60-0.68 for education; OR 0.82, 95% CI: 0.77-0.87 for occupation) and positively associated with quitting (OR 1.27, 95% CI: 1.16-1.40 for education; OR 1.20, 95% CI: 1.12-1.27 for occupation). These associations were consistent in direction across provinces although with some variability in magnitude.

Conclusion: Our findings indicate that socioeconomic inequalities in smoking have persisted in Canada; current smoking was less likely and quitting was more likely among the better off groups and in certain provinces. Current prevention and cessation policies have not been successful in improving the situation for all areas and groups. Future efforts to reduce smoking uptake and increase cessation in Canada will need consideration of socioeconomic and geographic factors to be successful.

pone-0057646-g005: Odds ratios for current smoking for a one-category increase in the level of education and occupation across Canadian provinces.BC British Columbia; PEI Prince Edward Island.

Mentions:
In order to assess consistency in the SES-current smoking and SES-quitting relationships across provinces, we estimated random-intercept, random slope multilevel models (Equation 2). In these models, the SES-current smoking and SES-quitting relationships were allowed to vary across provinces for education and occupation. The overall odds ratio for current smoking in Canada for a one-category increase in education was 0.64 (95% CI: 0.60–0.68) (Figure 5A) and 0.82 (95% CI: 0.77–0.87) for a one-category increase in occupation (Figure 5B). The direction of these relationships were consistent and statistically significant (p<0.05) in all provinces for both education and occupation. The magnitude of the association was greater than the national average in the provinces of British Columbia, Alberta, and Saskatchewan for the education relationship and in the provinces of Nova Scotia, British Columbia, Alberta, Newfoundland, and Ontario for the occupation relationship. In general, the magnitude of the SES-current smoking relationship was stronger for education compared to occupation. The associations between education and quitting and occupation and quitting were positive across all provinces, and statistically significant in 8/10 provinces for education (Figure 6A) and 9/10 provinces for occupation (Figure 6B). The overall odds ratio for quitting with each successive increase in the level of education was 1.27 (95% CI: 1.16–1.40) and 1.20 (95% CI: 1.12–1.27) for each successive increase in level of occupation. The education-quitting relationship was stronger than the national average in Saskatchewan, Alberta, Newfoundland, and was highest in British Columbia (OR 1.56, 95% CI: 1.29–1.88). The occupation-quitting relationship was stronger than the national average in Ontario, British Columbia, and Prince Edward Island. Associations were shallower than the national average in Quebec, Nova Scotia, Manitoba, and New Brunswick for both education and occupation; in Ontario and Prince Edward Island for education; and in Alberta for occupation.

pone-0057646-g005: Odds ratios for current smoking for a one-category increase in the level of education and occupation across Canadian provinces.BC British Columbia; PEI Prince Edward Island.

Mentions:
In order to assess consistency in the SES-current smoking and SES-quitting relationships across provinces, we estimated random-intercept, random slope multilevel models (Equation 2). In these models, the SES-current smoking and SES-quitting relationships were allowed to vary across provinces for education and occupation. The overall odds ratio for current smoking in Canada for a one-category increase in education was 0.64 (95% CI: 0.60–0.68) (Figure 5A) and 0.82 (95% CI: 0.77–0.87) for a one-category increase in occupation (Figure 5B). The direction of these relationships were consistent and statistically significant (p<0.05) in all provinces for both education and occupation. The magnitude of the association was greater than the national average in the provinces of British Columbia, Alberta, and Saskatchewan for the education relationship and in the provinces of Nova Scotia, British Columbia, Alberta, Newfoundland, and Ontario for the occupation relationship. In general, the magnitude of the SES-current smoking relationship was stronger for education compared to occupation. The associations between education and quitting and occupation and quitting were positive across all provinces, and statistically significant in 8/10 provinces for education (Figure 6A) and 9/10 provinces for occupation (Figure 6B). The overall odds ratio for quitting with each successive increase in the level of education was 1.27 (95% CI: 1.16–1.40) and 1.20 (95% CI: 1.12–1.27) for each successive increase in level of occupation. The education-quitting relationship was stronger than the national average in Saskatchewan, Alberta, Newfoundland, and was highest in British Columbia (OR 1.56, 95% CI: 1.29–1.88). The occupation-quitting relationship was stronger than the national average in Ontario, British Columbia, and Prince Edward Island. Associations were shallower than the national average in Quebec, Nova Scotia, Manitoba, and New Brunswick for both education and occupation; in Ontario and Prince Edward Island for education; and in Alberta for occupation.

Bottom Line:
Current smoking decreased and quitting increased with increasing SES.Current prevention and cessation policies have not been successful in improving the situation for all areas and groups.Future efforts to reduce smoking uptake and increase cessation in Canada will need consideration of socioeconomic and geographic factors to be successful.

Affiliation:
Harvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, United States of America. djcorsi@hsph.harvard.edu

ABSTRACT

Objective: To describe the socioeconomic and geographic distribution of smoking behaviour in Canada among 19,383 individuals (51% women) aged 15-85 years.

Methods: Current smoking and quitting were modeled using standard and multilevel logistic regression. Markers of socioeconomic status (SES) were education and occupation. Geography was defined by Canadian Provinces.

Results: The adjusted prevalence of current smoking was 20.2% (95% confidence interval [CI]: 18.8-21.7) and 63.7% (95% CI: 61.1-66.3) of ever smokers had quit. Current smoking decreased and quitting increased with increasing SES. The adjusted prevalence of current smoking was 32.8% (95% CI: 28.4-37.5) among the least educated compared to 11.0% (95% CI: 8.9-13.4) for the highest educated. Among the least educated, 53.0% (95% CI: 46.8-59.2) had quit, rising to 68.7% (95% CI: 62.7-74.1) for the most educated. There was substantial variation in current smoking and quitting at the provincial level; current smoking varied from 17.9% in British Columbia to 26.1% in Nova Scotia, and quitting varied from 57.4% in Nova Scotia to 67.8% in Prince Edward Island. Nationally, increasing education and occupation level were inversely associated with current smoking (odds ratio [OR] 0.64, 95% CI: 0.60-0.68 for education; OR 0.82, 95% CI: 0.77-0.87 for occupation) and positively associated with quitting (OR 1.27, 95% CI: 1.16-1.40 for education; OR 1.20, 95% CI: 1.12-1.27 for occupation). These associations were consistent in direction across provinces although with some variability in magnitude.

Conclusion: Our findings indicate that socioeconomic inequalities in smoking have persisted in Canada; current smoking was less likely and quitting was more likely among the better off groups and in certain provinces. Current prevention and cessation policies have not been successful in improving the situation for all areas and groups. Future efforts to reduce smoking uptake and increase cessation in Canada will need consideration of socioeconomic and geographic factors to be successful.