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TC Online First, published on February 20, 2015 as 10.1136/tobaccocontrol-2014-051892 Research paper
Gender equality and smoking: a theory-driven approach to smoking gender differences in Spain Usama Bilal,1,2 Paula Beltrán,2,3 Esteve Fernández,4,5,6 Ana Navas-Acien,1,7 Francisco Bolumar,2,8,9 Manuel Franco1,2,10 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ tobaccocontrol-2014-051892). For numbered affiliations see end of article. Correspondence to Dr Manuel Franco, Social and Cardiovascular Epidemiology Research Group, School of Medicine, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain; [email protected] Received 11 July 2014 Revised 16 January 2015 Accepted 26 January 2015
ABSTRACT Background The intersection between gender and class can aid in understanding gender differences in smoking. Aim To analyse how changes in gender inequality relate to differences in smoking prevalence by gender, education and birth cohort in Spain over the past five decades (1960–2010). Methods The Gender Inequality Index (GII) was calculated in 5-year intervals from 1960 to 2010. GII ranges from 0 to 1 (1=highest inequality) and encompasses three dimensions: reproductive health, empowerment and labour market. Estimates of female and male smoking prevalence were reconstructed from representative National Health Surveys and stratified by birth cohort and level of education. We calculated female-to-male smoking ratios from 1960 to 2010 stratified by education and birth cohort. Results Gender inequality in Spain decreased from 0.65 to 0.09 over the past 50 years. This rapid decline was inversely correlated (r=−0.99) to a rising female-tomale smoking ratio. The youngest birth cohort of the study (born 1980–1990) and women with high education levels had similar smoking prevalences compared with men. Women with high levels of education were also the first to show a reduction in smoking prevalence, compared with less educated women. Conclusions Gender inequality fell significantly in Spain over the past 50 years. This process was accompanied by converging trends in smoking prevalence for men and women. Smoking prevalence patterns varied greatly by birth cohort and education levels. Countries in earlier stages of the tobacco epidemic should consider gender-sensitive tobacco control measures and policies.
INTRODUCTION
To cite: Bilal U, Beltrán P, Fernández E, et al. Tob Control Published Online First: [ please include Day Month Year] doi:10.1136/ tobaccocontrol-2014051892
Differences in smoking prevalence between men and women are one of the key elements in the four-stage model of the tobacco epidemic in developed countries.1 2 This model was described and reproduced in several Western countries showing similar patterns of smoking prevalence but with differences in the magnitude and timing of the epidemic by gender.2 Several theories have been proposed to explain the differential uptake of smoking by women and men.3 4 The theory of diffusion of innovations describes the time lapse between early adopters (highly educated men) and late adopters (highly educated women and less educated men, followed by less educated women), but fails to explain why women are consistently late adopters. Several
gender theory concepts apply to the study of the tobacco epidemic and may help inform a theorydriven approach to smoking differences.5 Recently, female empowerment has been shown to be correlated with an increased prevalence of smoking among women relative to men6 and may be one of the factors that—together with industry activity7— shape the population distribution of smoking. First, we approach the evaluation of smoking prevalence differences from a gender perspective that treats these differences as the result of social processes operating at an intrapersonal, interpersonal and society level.8 These processes relate to both socioeconomic and gender differentials, which are known to be strong determinants of smoking prevalence.9 Second, we acknowledge that smoking may be one of the pathways that embody unequal power structures.10 Last, and central to this study, lies the concept of intersectionality,11 or the interaction between inequality dimensions such as social class and gender. Since the population distribution of smoking is heavily influenced by social class and gender,9 we argue that it is of great relevance to include this concept in gender-based research on smoking. Recent analyses in Spain have shown gender and social class interactions in self-reported health.12 As tobacco control research, policy and practice regarding women remain a challenge worldwide,13 studying the tobacco smoking epidemic in Spain over the past 50 years from a gender perspective may prove useful to understanding the dynamics of the epidemic and the processes behind the adoption of health-related behaviours in a country that underwent rapid social, political and economic transformation in the second half of the 20th century.14 We developed this study in an attempt to better understand the cumulative influence of genderrelated social processes that could result in differential patterns of smoking for women and men. Our aim was to evaluate whether changes in gender inequality correlate with gender smoking ratio (GSR) patterns in Spain over the past 50 years. Special attention was paid to the variation of smoking patterns over five decades by social class and birth cohort. This study can provide valuable information for countries in earlier stages of the tobacco epidemic in order to predict future patterns of smoking associated with developments in gender equality and to better design tobacco control policies.
METHODS Study population Our population of interest was the entire noninstitutionalised Spanish population 16 years of age
Bilal U, et al. Tob Control 2015;0:1–6. doi:10.1136/tobaccocontrol-2014-051892
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://tobaccocontrol.bmj.com/ on July 2, 2015 - Published by group.bmj.com
Research paper or older for the period 1960–2010. Nationally representative data sources were used to estimate the Gender Inequality Index (GII, main exposure), and smoking prevalence by gender (GSR, main outcome).
GII and components The GII15 reflects the loss in potential human development due to inequality between female and male achievements in three dimensions: reproductive health, measured by (1) maternal mortality ratio (maternal deaths per 100 000 live births) and (2) adolescent fertility rate (number of births per 1000 women aged 15–19); empowerment measured by (3) female and male population with at least secondary education ( percentage of female and male population ages 25 and older that had attained a secondary or higher level of education) and (4) shares of parliamentary seats held by each gender (ratio of seats held by a respective gender in the lower house of parliament); and labour market measured by (5) labour force participation rates ( percentage of female and male working-age population (ages 15–64) that actively engaged in the labour market). Each dimension and its components were obtained in 5-year intervals for the years 1960–2010. All data were obtained from the National Institute of Statistics (INE), except for the share of female and male parliamentary seats, which was obtained from the National Parliament’s historical archives (only the lower house of parliament was considered). Census data on secondary education and labour force participation were available only in 10-year intervals from 1960 to 1990. Values for 1965, 1975 and 1985 were imputed as the mean of the adjacent values. The GII value was computed for each selected year following the guidelines of the 2011 Human Development Report Technical Notes.15 The GII ranges from 0 to 1, with values closer to 0 indicating lower gender inequality (higher gender equality).
Smoking prevalence Data were obtained from the National Health Interview Survey (Encuesta Nacional de Salud) conducted in Spain in 2011 (n=21 007). The smoking prevalence rate for each calendar year from 1960 to 2010 was reconstructed using a method described previously.16 This method has been validated for estimating smoking prevalence trends.16 Birth year and highest level of education attained (defined as no formal education, primary education (less than high school), secondary education (high school), or tertiary education (college) or above completed) were obtained for each respondent in the surveys. A female-to-male GSR was obtained by dividing women’s smoking prevalence by men’s smoking prevalence. Values for the GSR below 1 indicate a higher prevalence of smoking among men, and values above 1 mean a higher smoking prevalence among women.
Statistical analysis We performed a log-log linear regression to estimate the per cent change in GSR by per cent change in GII. Moreover, we also checked if this association between GSR and GII varied by birth cohort or education attainment. For this, we fitted a linear model with generalised estimating equations (GEE with exchangeable correlation structures) with the natural logarithm of GSR as the dependent variable and the natural logarithm of GII, dummy variables for education and cohort and their interaction with GII as independent variables. We then checked if the association of GSR with GII was different across groups ( p value for statistical significance
TC Online First, published on February 20, 2015 as 10.1136/tobaccocontrol-2014-051892 Research paper
Gender equality and smoking: a theory-driven approach to smoking gender differences in Spain Usama Bilal,1,2 Paula Beltrán,2,3 Esteve Fernández,4,5,6 Ana Navas-Acien,1,7 Francisco Bolumar,2,8,9 Manuel Franco1,2,10 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ tobaccocontrol-2014-051892). For numbered affiliations see end of article. Correspondence to Dr Manuel Franco, Social and Cardiovascular Epidemiology Research Group, School of Medicine, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain; [email protected] Received 11 July 2014 Revised 16 January 2015 Accepted 26 January 2015
ABSTRACT Background The intersection between gender and class can aid in understanding gender differences in smoking. Aim To analyse how changes in gender inequality relate to differences in smoking prevalence by gender, education and birth cohort in Spain over the past five decades (1960–2010). Methods The Gender Inequality Index (GII) was calculated in 5-year intervals from 1960 to 2010. GII ranges from 0 to 1 (1=highest inequality) and encompasses three dimensions: reproductive health, empowerment and labour market. Estimates of female and male smoking prevalence were reconstructed from representative National Health Surveys and stratified by birth cohort and level of education. We calculated female-to-male smoking ratios from 1960 to 2010 stratified by education and birth cohort. Results Gender inequality in Spain decreased from 0.65 to 0.09 over the past 50 years. This rapid decline was inversely correlated (r=−0.99) to a rising female-tomale smoking ratio. The youngest birth cohort of the study (born 1980–1990) and women with high education levels had similar smoking prevalences compared with men. Women with high levels of education were also the first to show a reduction in smoking prevalence, compared with less educated women. Conclusions Gender inequality fell significantly in Spain over the past 50 years. This process was accompanied by converging trends in smoking prevalence for men and women. Smoking prevalence patterns varied greatly by birth cohort and education levels. Countries in earlier stages of the tobacco epidemic should consider gender-sensitive tobacco control measures and policies.
INTRODUCTION
To cite: Bilal U, Beltrán P, Fernández E, et al. Tob Control Published Online First: [ please include Day Month Year] doi:10.1136/ tobaccocontrol-2014051892
Differences in smoking prevalence between men and women are one of the key elements in the four-stage model of the tobacco epidemic in developed countries.1 2 This model was described and reproduced in several Western countries showing similar patterns of smoking prevalence but with differences in the magnitude and timing of the epidemic by gender.2 Several theories have been proposed to explain the differential uptake of smoking by women and men.3 4 The theory of diffusion of innovations describes the time lapse between early adopters (highly educated men) and late adopters (highly educated women and less educated men, followed by less educated women), but fails to explain why women are consistently late adopters. Several
gender theory concepts apply to the study of the tobacco epidemic and may help inform a theorydriven approach to smoking differences.5 Recently, female empowerment has been shown to be correlated with an increased prevalence of smoking among women relative to men6 and may be one of the factors that—together with industry activity7— shape the population distribution of smoking. First, we approach the evaluation of smoking prevalence differences from a gender perspective that treats these differences as the result of social processes operating at an intrapersonal, interpersonal and society level.8 These processes relate to both socioeconomic and gender differentials, which are known to be strong determinants of smoking prevalence.9 Second, we acknowledge that smoking may be one of the pathways that embody unequal power structures.10 Last, and central to this study, lies the concept of intersectionality,11 or the interaction between inequality dimensions such as social class and gender. Since the population distribution of smoking is heavily influenced by social class and gender,9 we argue that it is of great relevance to include this concept in gender-based research on smoking. Recent analyses in Spain have shown gender and social class interactions in self-reported health.12 As tobacco control research, policy and practice regarding women remain a challenge worldwide,13 studying the tobacco smoking epidemic in Spain over the past 50 years from a gender perspective may prove useful to understanding the dynamics of the epidemic and the processes behind the adoption of health-related behaviours in a country that underwent rapid social, political and economic transformation in the second half of the 20th century.14 We developed this study in an attempt to better understand the cumulative influence of genderrelated social processes that could result in differential patterns of smoking for women and men. Our aim was to evaluate whether changes in gender inequality correlate with gender smoking ratio (GSR) patterns in Spain over the past 50 years. Special attention was paid to the variation of smoking patterns over five decades by social class and birth cohort. This study can provide valuable information for countries in earlier stages of the tobacco epidemic in order to predict future patterns of smoking associated with developments in gender equality and to better design tobacco control policies.
METHODS Study population Our population of interest was the entire noninstitutionalised Spanish population 16 years of age
Bilal U, et al. Tob Control 2015;0:1–6. doi:10.1136/tobaccocontrol-2014-051892
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://tobaccocontrol.bmj.com/ on July 2, 2015 - Published by group.bmj.com
Research paper or older for the period 1960–2010. Nationally representative data sources were used to estimate the Gender Inequality Index (GII, main exposure), and smoking prevalence by gender (GSR, main outcome).
GII and components The GII15 reflects the loss in potential human development due to inequality between female and male achievements in three dimensions: reproductive health, measured by (1) maternal mortality ratio (maternal deaths per 100 000 live births) and (2) adolescent fertility rate (number of births per 1000 women aged 15–19); empowerment measured by (3) female and male population with at least secondary education ( percentage of female and male population ages 25 and older that had attained a secondary or higher level of education) and (4) shares of parliamentary seats held by each gender (ratio of seats held by a respective gender in the lower house of parliament); and labour market measured by (5) labour force participation rates ( percentage of female and male working-age population (ages 15–64) that actively engaged in the labour market). Each dimension and its components were obtained in 5-year intervals for the years 1960–2010. All data were obtained from the National Institute of Statistics (INE), except for the share of female and male parliamentary seats, which was obtained from the National Parliament’s historical archives (only the lower house of parliament was considered). Census data on secondary education and labour force participation were available only in 10-year intervals from 1960 to 1990. Values for 1965, 1975 and 1985 were imputed as the mean of the adjacent values. The GII value was computed for each selected year following the guidelines of the 2011 Human Development Report Technical Notes.15 The GII ranges from 0 to 1, with values closer to 0 indicating lower gender inequality (higher gender equality).
Smoking prevalence Data were obtained from the National Health Interview Survey (Encuesta Nacional de Salud) conducted in Spain in 2011 (n=21 007). The smoking prevalence rate for each calendar year from 1960 to 2010 was reconstructed using a method described previously.16 This method has been validated for estimating smoking prevalence trends.16 Birth year and highest level of education attained (defined as no formal education, primary education (less than high school), secondary education (high school), or tertiary education (college) or above completed) were obtained for each respondent in the surveys. A female-to-male GSR was obtained by dividing women’s smoking prevalence by men’s smoking prevalence. Values for the GSR below 1 indicate a higher prevalence of smoking among men, and values above 1 mean a higher smoking prevalence among women.
Statistical analysis We performed a log-log linear regression to estimate the per cent change in GSR by per cent change in GII. Moreover, we also checked if this association between GSR and GII varied by birth cohort or education attainment. For this, we fitted a linear model with generalised estimating equations (GEE with exchangeable correlation structures) with the natural logarithm of GSR as the dependent variable and the natural logarithm of GII, dummy variables for education and cohort and their interaction with GII as independent variables. We then checked if the association of GSR with GII was different across groups ( p value for statistical significance
