The Association of Smoking Status with Education, Income, Marital Status, BMI and Physical Activity in Norway. An Analysis from 1974 to 2003. The Smoking and Cancer Project.

Abstract

Introduction: Cigarette smoking is still responsible for a significant loss of life in many countries; Despite decades of research about smoking health consequences and informational campaigns, cigarette use continues to be a part of Norwegian society and culture; Differences in smoking status prevalence for men and women, continue to be associated to inequalities in Socio-economic status (SES) and demographic characteristics such as marital status and life style. Objectives: The purpose of this thesis was to examine by gender the smoking status prevalence, its associations and changes in distribution according to selected Socio- economic and lifestyle characteristics, in a Norwegian population of 634,819 men and women, using a four group time period based on calendar years from 1974 to 2003. Methods: This cross sectional study analyzed data from 634,819 Norwegian men and women that participated in the 40 years study, the three counties study and the Cohort of Norway Study, from 1974 to 2003. A univariate descriptive analysis was done to examine the male and female studied population by smoking status with education, income, BMI, marital status and physical activity as variables of interest. The effect of each variable was examined controlling on the other variables and age at inclusion. A multivariable logistic regression analysis with 95% (CIs) was performed to determine current and former smoker’s odds, by levels of education, income, BMI, physical activity and marital status. All models were stratified by gender, smoking status and date of inclusion in four calendar periods [(1974-1980)(1981-1987)(1988-1995)(1996-2003)]. Conclusions: From the initial studied period (1974- 1980) to the final (1996- 2003), the prevalence of male and female current smokers decreased significantly.

From the initial studied period (1974- 1980) to the final (1996- 2003) there was an increase in the proportion of males and females current smokers in the following categories: - Higher level of education. - Higher income levels - Divorced/ widowed category. - BMI levels (+30kg/m2). - Higher levels of Physical activity

In both, first (1974- 1980) and last studied period (1996- 2003) smoking was associated with SES and marital status. Lower levels of education and being divorced/widowed increased the likelihood of smoking for males and females in this study. In the same periods, lifestyle choices were also associated with smoking. Males and females in the upper levels of BMI and physical activity were less likely to smoke. As for income levels and single marital status, these predictors showed contrasting associations with male and female current smokers in the first and last studied period.