Nicotine & Tobacco Research Advance Access published June 25, 2015 Nicotine & Tobacco Research, 2015, 1–4 doi:10.1093/ntr/ntv130 Brief report
Brief report
Mortality Attributable to Secondhand Smoke Exposure in Spain (2011) Downloaded from http://ntr.oxfordjournals.org/ at Orta Dogu Teknik University Library (ODTU) on February 9, 2016
Maria J. López PhD1,2,3, Mónica Pérez-Ríos PhD4,5, Anna Schiaffino MPH6, Esteve Fernández PhD6,7 Evaluation and Intervention Methods Service, Agència de Salut Pública de Barcelona, Barcelona, Spain; 2Biomedical Research Centre Network for Epidemiology and Public Health (CIBERESP), Madrid, Spain; 3Institute of Biomedical Research (IIB Sant Pau), Barcelona, Spain; 4Epidemiology Unit, Galician Directorate for Public Health, Galician Health Authority, Xunta de Galicia, Santiago de Compostela, Galicia, Spain; 5Department of Preventive Medicine and Public Health, School of Medicine, University of Santiago de Compostela, A Coruña, Spain; 6Tobacco Control Unit, Cancer Control and Prevention Programme, Institut Català d’Oncologia (ICO), Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat (Barcelona), Barcelona, Spain; 7Department of Clinical Sciences, School of Medicine, Universitat de Barcelona, L’Hospitalet del Llobregat (Barcelona), Barcelona, Spain 1
Corresponding Author: Maria J. López, PhD, Public Health Agency of Barcelona, Plaza Lesseps 1, Barcelona 08023, Spain. Telephone: 34-932027748; Fax: 34-932921443; E-mail: [email protected]
Abstract Introduction: The objective of this study was to assess the mortality attributable to secondhand smoke (SHS) exposure among never-smokers in Spain in 2011, after the implementation of the Spanish smoking law. Methods: Data on SHS exposure were obtained from a computer-assisted telephone survey carried out in a representative sample of the adult Spanish population. We included the two main diseases widely associated with SHS exposure: lung cancer and ischaemic heart disease. The relative risks for these diseases were selected from previously published meta-analyses.The number of deaths attributable to SHS was calculated by applying the population attributable fraction to mortality not attributable to active smoking in 2011. The analyses were stratified by sex, age and setting of exposure (home, workplace, and both combined). In addition, a sensitivity analysis was performed for distinct scenarios. Results: In 2011, a total of 586 deaths in men and 442 deaths in women would be attributable to SHS exposure. The total number of deaths from lung cancer attributable to SHS exposure would be 124, while the total number of deaths from ischaemic heart disease would be 904. The inclusion of ex-smokers or SHS exposure in leisure time in the study would considerably increase the total number of attributable deaths (by 20% and 130%, respectively). Conclusions: The total number of deaths attributable to SHS exposure at home and at work in Spain would be 1028 in 2011. Efforts are still needed to reduce the current prevalence of exposure—mainly due to exposure in nonregulated settings such as homes or cars and some outdoor spaces—and the associated morbidity and mortality.
Introduction Exposure to secondhand smoke (SHS) has numerous adverse effects on the health of children and adults. These adverse health effects include cancer, coronary heart disease, and respiratory symptoms, as well as other specific diseases affecting children.1
It is estimated that 40% of children worldwide, 33% of male nonsmokers, and 35% of female nonsmokers are exposed to SHS.2 Therefore, the burden in terms of morbidity and mortality might be substantial. SHS exposure was estimated to have caused 603 000 premature deaths and the loss of 10.9 million daily-adjusted life
© The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: [email protected].
1
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Methods Data on SHS exposure were obtained from a computer-assisted telephone survey carried out in a representative sample of the adult Spanish population (age ≥ 18 years). The sample size was 2500 after accepting a total margin of error of ±2% for a 95% confidence interval and p = q = .50. The sample was weighted by region population size, the size of the municipality of residence, sex, and age group. The sampling method included substitution to reach the total sample size needed. A substitute of the same sex and age-group was looked in the following randomly selected household. Substitutions accounted for 24.6% of the sample. The fieldwork was carried out in 2011. Participants were selected in two phases: in the first phase, homes were randomly chosen from a directory of fixed telephones, and in the second, a person from the home who would respond to the survey was selected, based on the sample strata. The final sample included 2504 valid interviews. SHS exposure at home was assessed by asking “Nowadays, how many people usually smoke at home (excluding outdoor spaces)?”. SHS exposure at work was assessed by asking “Is there anybody at your workplace who smokes close enough so that you can smell the tobacco smoke?” In this study, we included the two main diseases widely associated with SHS exposure: lung cancer and ischaemic heart disease. The relative risks (RR) for these diseases were selected from three published meta-analyses used in previous studies.12–14 In our study, observed mortality refers to deaths caused by lung cancer (ICD-10, C33–34) and ischaemic heart diseases (ICD-10, I20–I25) in persons older than 34 years. The mortality for these diseases in 2011 was obtained from the Spanish National Institute of Statistics.15 Mortality was stratified by sex and by age groups (35– 64 years and over 64 years), and the number of deaths attributable to active smoking for the same year were excluded. The number of deaths not attributable to active smoking was obtained by multiplying the total mortality by the complementary fraction of the population attributable fraction of active smoking (including smokers and ex-smokers), calculated for each of the selected diseases. This
calculation was done by stratifying by age and sex groups. The result of this multiplication provided the observed mortality not attributable to active smoking. The attributable mortality to SHS was calculated by applying the population attributable fraction to SHS to the mortality not attributable to active smoking in 2011 (attributable mortality = observed mortality × population attributable fraction), where population attributable fraction was obtained after applying the classic formula that takes into account the prevalence of the condition (SHS in this case) and the RR of the diseases considered for SHS exposure.16 We followed conservative criteria to avoid overestimating of the number of deaths attributable to SHS exposure. Therefore, we did not use data on the prevalence of SHS exposure during leisure time, nor did we include ex-smokers, and we only took into account lung cancer and ischaemic heart diseases. Moreover, we considered people exposed in more than one setting as having the same risk as people exposed in the setting with the higher risk. In addition to sex and age, the analyses were stratified by setting of exposure (only home, only workplace and both combined). Finally, we performed a sensitivity analysis. We assessed the number of attributable deaths: (1) among ex-smokers; (2) using additive risks for people exposed at home and at work; (3) using RR estimated with biomarkers17; (4) including deaths attributable to stroke; (5) including deaths attributable to daily exposure during leisure time; and (6) considering persons susceptible to the effects of SHS only if exposed a minimum of 1 hour per day.
Results The overall prevalence of smokers and ex-smokers was 20.7% and 30.6%, respectively. Among never-smokers (48.7%), 63% were women and the mean age was 48.9 years (SD = 19.2). According to Table 1, the total number of deaths from lung cancer attributable to SHS exposure would be 124 (52 deaths among adults aged 35–64 years and 72 deaths in adults older than 64 years). The total number of deaths from ischaemic heart disease attributable to SHS would be 904 (174 deaths among the population aged 35–64 years and 730 among people older than 64 years). A sensitivity analysis of mortality attributable to SHS is shown in Table 2. Assuming that ex-smokers are susceptible to the effects of SHS, the total number of deaths would increase by 20%. Using the RR of ischaemic heart disease derived from studies using biomarkers, the number of deaths would be 2711 (164% increase). Including stroke among the diseases associated with SHS in the analysis would raise the total number of deaths to 2964 (188% increase). Including persons exposed in leisure time would increase the number of deaths to 2365 (130% increase). If we chose only those people who reported exposure for a minimum of 1 hour per day, the total number of deaths would decrease by 38%.
Discussion The total number of deaths attributable to SHS exposure at home and at work in Spain would be 1028 in 2011, with a total of 586 deaths in men and 442 deaths in women. Overall, the mortality attributable to SHS is lower than that assessed in 2002.3 This decrease is mainly due to the prevalence of SHS exposure, which significantly decreased after the successful smoking bans in 2005 and 2010.11,18 According to the estimation assessed in 2002,3 the minimum number of deaths attributable to SHS was
Downloaded from http://ntr.oxfordjournals.org/ at Orta Dogu Teknik University Library (ODTU) on February 9, 2016
years in 2004. The largest number of estimated deaths attributable to SHS exposure in adults was caused by ischaemic heart disease.2 According to the only study carried out in Spain assessing the mortality attributable to SHS, SHS exposure at home and at work was responsible for a minimum of 1228 deaths from lung cancer and ischaemic heart disease in 2002.3 This estimation, however, was based on a range of prevalences assessed in regional surveys in Spain, since no surveys had assessed SHS exposure nationwide until then. Furthermore, that study was developed before the implementation of the Spanish smoking law in 2006, which prohibited smoking in indoor public places and workplaces, except for hospitality venues.4,5 In 2011, that prohibition was widened to hospitality venues.6 After the implementation of the law, numerous studies demonstrated a decrease in SHS exposure.7–10 This reduction was observed at workplaces, during leisure time, and even in some settings not regulated by the law. Overall, according to a study carried out in Barcelona, the self-reported exposure decreased from 75.7% (2004–2005) to 56.7% (2011–2012).11 Therefore, a long term decrease in the mortality attributable to SHS in Spain would be expected. The objective of this study was to assess the mortality attributable to SHS exposure among never-smokers in Spain in 2011 after the implementation of the Spanish smoking law.
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Table 1. Population Attributable Fraction (PAF) and Deaths Attributable to Secondhand Smoke (SHS) Exposure Among Never-Smokers, Spain, 2011 Relative risk
PAF
0.094 0.09
1.30 1.30
0.031 0.021
575 307
18 6
0.081 0.049
1.21 1.21
0.031 0.019
575 307
18 6
0.017 0.004
1.30 1.30
0.007 0.002
575 307
4 0
0.1 0.098
1.34 1.24
0.033 0.023
1390 1120
46 26
0.094 0.09
1.34 1.24
0.027 0.026
2143 425
59 11
0.081 0.049
1.39 1.39
0.017 0.010
2143 425
36 4
0.017 0.004
1.39 1.39
0.005 0.001
2143 425
11 1
0.1 0.098
1.30 1.30
0.029 0.029
13 540 13 581
394 388 1028
Total deaths among nonsmokers
Deaths attributable to SHS
Exposed at home = 1 or more people usually smoke inside the home; exposed at work = a workpartner usually smoke close enough so that you can smell the SHS.
a
Table 2. Sensitivity Analyses of Mortality Attributable to Secondhand Smoke (SHS) Under Different Assumptions, Spain, 2011 Study assumptions Ex-smokers not susceptible to effects of SHS When someone is exposed in both settings there is no additive risk RR of ischaemic heart disease is RR = 1.30/1.21 (home/work) There is not enough evidence on stroke Exposed in leisure time not susceptible to effects of SHS Susceptible to effects of SHS if exposed
Alternative assumptions Ex-smokers susceptible to effects of SHSa When someone is exposed in both settings the RR is additive RR of ischaemic heart disease estimated with biomarkers RR = 1.89 RR of stroke = 2.10 for men and 1.66 for women Daily exposed in leisure time are susceptible to effects of SHS Susceptible to effects of SHS only if exposed a minimum of 1 hour per day
Effect on number of deaths (percentage variation regarding the study assumptions) 1284 (+19.94) 1039 (+1.06) 2711 (+163.72) 2964 (+188.32) 2365 (+130.06) 634 (−38.33)
RR = relative risk. a Following a conservative criterion, we excluded those ex-smokers susceptible to dying because of smoking from the observed mortality.
1228 while the maximum was 3237 (there was a range since at that time no national estimates were available of the prevalence of SHS exposure). In our current study, the total number of deaths (1028) is lower than the minimum estimated in 2002. However, although the decrease in the prevalence of exposure has been substantial, we did not observe a major decrease in the total number of deaths attributable to SHS (a decrease of 16.3% compared with the minimum assessed in 2002). Among other factors, this finding is due to the fact
that active smoking has also decreased, leading to an increase in the mortality not attributable to active smoking and therefore susceptible to being attributable to passive smoking. Furthermore, it is important to note that the real impact of the current decrease of SHS prevalence on mortality from some causes, such as lung cancer, will need a much longer term monitoring period to become observable. Our study has some limitations, such as the use of non-country-specific RR and the use of prevalences of exposure based
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Lung cancer 35–64 years Home only Men Women Work only Men Women Home and work Men Women >64 years Home Men Women Ischaemic heart disease 35–64 years Home only Men Women Work only Men Women Home and work Men Women >64 years Home Men Women Total
Prevalence of never-smokers exposed to SHSa
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3. López MJ, Pérez-Ríos M, Schiaffino A, et al. Mortality attributable to passive smoking in Spain, 2002. Tob Control. 2007;16(6):373–377. 4. Ministerio de Sanidad y Consumo. Ley 28/2005, de 26 de diciembre, de medidas sanitarias frente al tabaquismo y reguladora de la venta, el suministro, el consumo y la publicidad de los productos del tabaco. 2005. www. msc.es/novedades/docs/disposicionesGenerales.pdf. Accessed November 3, 2013. 5. Fernández E. Spain: going smoke free. Tob Control. 2006;15(2):79–80. 6. Ministerio de Sanidad y Consumo. Ley 42/2010, de 30 de diciembre, por la que se modifica la Ley 28/2005, de 26 de diciembre, de medidas sanitarias frente al tabaquismo y reguladora de la venta, el suministro, el consumo y la publicidad de los productos del tabaco. 2010. www.boe.es/ boe/dias/2010/12/31/pdfs/BOE-A-2010–20138.pdf. Accessed November 3, 2013. 7. López MJ, Fernández E, Pérez-Rios M, et al. Impact of the 2011 Spanish smoking ban in hospitality venues: indoor secondhand smoke exposure and influence of outdoor smoking. Nicotine Tob Res. 2013;15(5):992– 996. doi:10.1093/ntr/nts218. 8. López MJ, Nebot M, Schiaffino A, et al. Two-year impact of the Spanish smoking law on exposure to secondhand smoke: evidence of the failure of the ‘Spanish model’. Tob Control. 2012;21(4):407–411. doi:10.1136/ tc.2010.042275. 9. Nebot M, Lopez MJ, Ariza C, et al. Impact of the Spanish smoking law on exposure to secondhand smoke in offices and hospitality venues: before-and-after study. Environ Health Perspect. 2009;117(3):344e7. doi:10.1289/ehp.11845. 10. Fernandez E, Fu M, Pascual JA, et al. Impact of the Spanish smoking law on exposure to secondhand smoke and respiratory health in hospitality workers: a cohort study. PLoS One. 2009;4(1):e4244. doi:10.1371/journal.pone.0004244. 11. Sureda X, Martínez-Sánchez JM, Fu M, et al. Impact of the Spanish
Funding This work was supported by the Ministry of Health, Instituto de Salud Carlos III-Subdirección General de Evaluación y Fomento de la Investigación, PN I+D+I 2008–2011, co-funded by the European Regional Development Fund (FEDER), grant number FIS PI10/00400.
smoke-free legislation on adult, non-smoker exposure to secondhand smoke: cross-sectional surveys before (2004) and after (2012) legislation. PLoS One. 2014;9(2):e89430. doi:10.1371/journal.pone.0089430. 12. Hackshaw AK, Law MR, Wald NJ. The accumulated evidence on lung cancer and environmental tobacco smoke. BMJ. 1997;315(7114):980–988. 13. Steenland K. Risk assessment for heart disease and workplace ETS exposure among nonsmokers. Environ Health Perspect. 1999;107(suppl
Declaration of Interests None declared.
6):859–863. 14. Wells AJ. Heart disease from passive smoking in the workplace. J Am Coll Cardiol. 1998;31(1):1–9. 15. Instituto Nacional de Estadística. www.ine.es/inebase/. 2012. Accessed
References 1. US Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2006. www.surgeongeneral.gov/library/reports/secondhandsmoke/fullreport.pdf. Accessed February 14, 2015. 2. Oberg M, Jaakkola MS, Woodward A, et al. Worldwide burden of disease from exposure to second-hand smoke: a retrospective analysis of data from 192 countries. Lancet. 2011;377(9760):139–146. doi:10.1016/ S0140-6736(10)61388-8.
September 8, 2013. 16. Walter SD. The estimation and interpretation of attributable risk in Health research. Biometrics. 1976;32(4):829–849. 17. Whincup PH, Gilg JA, Emberson JR, et al. Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement. BMJ. 2004;329(7459):200–205. 18. Lushchenkova O, Fernández E, López MJ, et al. [Secondhand smoke exposure in Spanish adult non-smokers following the introduction of an antismoking law]. Rev Esp Cardiol. 2008;61(7):687–694. 19. López MJ, Fernández E, Gorini G, et al. Exposure to secondhand smoke in terraces and other outdoor areas of hospitality venues in eight European countries. PLoS One. 2012;7(8):e42130. doi:10.1371/journal. pone.0042130.
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on reported data that might be affected by an information bias. However, country-specific risks or nonreported prevalences of exposure at the national level are not available, and the use of these data allow for comparison with other studies using the same methodology. Regarding the question assessing SHS exposure at home (“how many people usually smoke at home”), it might underestimate the real exposure due to socially desirable responses. However, we decided to use this question since it follows a conservative criterion and allows for comparison with previous studies. Finally, we would like to notice that ischaemic heart diseases and lung cancer have different latency periods. Therefore, the mortality assessed will appear at different moments in time, what should be taken into account in the interpretation of the results obtained in this study. This is the first attributable mortality study carried out after the implementation of the 2010 Spanish smoking law. It is also the first attributable mortality study in Spain based on prevalence data from a national survey carried out in a representative sample. Finally, this study allows assessment of the effect of SHS exposure on mortality under different assumptions such as the inclusion of ex-smokers and SHS exposure in leisure time, which would considerably increase the number of attributable deaths. In conclusion, SHS exposure decreased after the implementation of the tobacco control law in Spain, and therefore the population attributable fraction seems to be also decreasing. However, longer follow-up is required to observe larger effects on mortality. Efforts are still needed to reduce the current prevalence of exposure—mainly due to exposure in nonregulated places such as homes or cars and some outdoor spaces19—and the associated morbidity and mortality.
Brief report
Mortality Attributable to Secondhand Smoke Exposure in Spain (2011) Downloaded from http://ntr.oxfordjournals.org/ at Orta Dogu Teknik University Library (ODTU) on February 9, 2016
Maria J. López PhD1,2,3, Mónica Pérez-Ríos PhD4,5, Anna Schiaffino MPH6, Esteve Fernández PhD6,7 Evaluation and Intervention Methods Service, Agència de Salut Pública de Barcelona, Barcelona, Spain; 2Biomedical Research Centre Network for Epidemiology and Public Health (CIBERESP), Madrid, Spain; 3Institute of Biomedical Research (IIB Sant Pau), Barcelona, Spain; 4Epidemiology Unit, Galician Directorate for Public Health, Galician Health Authority, Xunta de Galicia, Santiago de Compostela, Galicia, Spain; 5Department of Preventive Medicine and Public Health, School of Medicine, University of Santiago de Compostela, A Coruña, Spain; 6Tobacco Control Unit, Cancer Control and Prevention Programme, Institut Català d’Oncologia (ICO), Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat (Barcelona), Barcelona, Spain; 7Department of Clinical Sciences, School of Medicine, Universitat de Barcelona, L’Hospitalet del Llobregat (Barcelona), Barcelona, Spain 1
Corresponding Author: Maria J. López, PhD, Public Health Agency of Barcelona, Plaza Lesseps 1, Barcelona 08023, Spain. Telephone: 34-932027748; Fax: 34-932921443; E-mail: [email protected]
Abstract Introduction: The objective of this study was to assess the mortality attributable to secondhand smoke (SHS) exposure among never-smokers in Spain in 2011, after the implementation of the Spanish smoking law. Methods: Data on SHS exposure were obtained from a computer-assisted telephone survey carried out in a representative sample of the adult Spanish population. We included the two main diseases widely associated with SHS exposure: lung cancer and ischaemic heart disease. The relative risks for these diseases were selected from previously published meta-analyses.The number of deaths attributable to SHS was calculated by applying the population attributable fraction to mortality not attributable to active smoking in 2011. The analyses were stratified by sex, age and setting of exposure (home, workplace, and both combined). In addition, a sensitivity analysis was performed for distinct scenarios. Results: In 2011, a total of 586 deaths in men and 442 deaths in women would be attributable to SHS exposure. The total number of deaths from lung cancer attributable to SHS exposure would be 124, while the total number of deaths from ischaemic heart disease would be 904. The inclusion of ex-smokers or SHS exposure in leisure time in the study would considerably increase the total number of attributable deaths (by 20% and 130%, respectively). Conclusions: The total number of deaths attributable to SHS exposure at home and at work in Spain would be 1028 in 2011. Efforts are still needed to reduce the current prevalence of exposure—mainly due to exposure in nonregulated settings such as homes or cars and some outdoor spaces—and the associated morbidity and mortality.
Introduction Exposure to secondhand smoke (SHS) has numerous adverse effects on the health of children and adults. These adverse health effects include cancer, coronary heart disease, and respiratory symptoms, as well as other specific diseases affecting children.1
It is estimated that 40% of children worldwide, 33% of male nonsmokers, and 35% of female nonsmokers are exposed to SHS.2 Therefore, the burden in terms of morbidity and mortality might be substantial. SHS exposure was estimated to have caused 603 000 premature deaths and the loss of 10.9 million daily-adjusted life
© The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: [email protected].
1
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Methods Data on SHS exposure were obtained from a computer-assisted telephone survey carried out in a representative sample of the adult Spanish population (age ≥ 18 years). The sample size was 2500 after accepting a total margin of error of ±2% for a 95% confidence interval and p = q = .50. The sample was weighted by region population size, the size of the municipality of residence, sex, and age group. The sampling method included substitution to reach the total sample size needed. A substitute of the same sex and age-group was looked in the following randomly selected household. Substitutions accounted for 24.6% of the sample. The fieldwork was carried out in 2011. Participants were selected in two phases: in the first phase, homes were randomly chosen from a directory of fixed telephones, and in the second, a person from the home who would respond to the survey was selected, based on the sample strata. The final sample included 2504 valid interviews. SHS exposure at home was assessed by asking “Nowadays, how many people usually smoke at home (excluding outdoor spaces)?”. SHS exposure at work was assessed by asking “Is there anybody at your workplace who smokes close enough so that you can smell the tobacco smoke?” In this study, we included the two main diseases widely associated with SHS exposure: lung cancer and ischaemic heart disease. The relative risks (RR) for these diseases were selected from three published meta-analyses used in previous studies.12–14 In our study, observed mortality refers to deaths caused by lung cancer (ICD-10, C33–34) and ischaemic heart diseases (ICD-10, I20–I25) in persons older than 34 years. The mortality for these diseases in 2011 was obtained from the Spanish National Institute of Statistics.15 Mortality was stratified by sex and by age groups (35– 64 years and over 64 years), and the number of deaths attributable to active smoking for the same year were excluded. The number of deaths not attributable to active smoking was obtained by multiplying the total mortality by the complementary fraction of the population attributable fraction of active smoking (including smokers and ex-smokers), calculated for each of the selected diseases. This
calculation was done by stratifying by age and sex groups. The result of this multiplication provided the observed mortality not attributable to active smoking. The attributable mortality to SHS was calculated by applying the population attributable fraction to SHS to the mortality not attributable to active smoking in 2011 (attributable mortality = observed mortality × population attributable fraction), where population attributable fraction was obtained after applying the classic formula that takes into account the prevalence of the condition (SHS in this case) and the RR of the diseases considered for SHS exposure.16 We followed conservative criteria to avoid overestimating of the number of deaths attributable to SHS exposure. Therefore, we did not use data on the prevalence of SHS exposure during leisure time, nor did we include ex-smokers, and we only took into account lung cancer and ischaemic heart diseases. Moreover, we considered people exposed in more than one setting as having the same risk as people exposed in the setting with the higher risk. In addition to sex and age, the analyses were stratified by setting of exposure (only home, only workplace and both combined). Finally, we performed a sensitivity analysis. We assessed the number of attributable deaths: (1) among ex-smokers; (2) using additive risks for people exposed at home and at work; (3) using RR estimated with biomarkers17; (4) including deaths attributable to stroke; (5) including deaths attributable to daily exposure during leisure time; and (6) considering persons susceptible to the effects of SHS only if exposed a minimum of 1 hour per day.
Results The overall prevalence of smokers and ex-smokers was 20.7% and 30.6%, respectively. Among never-smokers (48.7%), 63% were women and the mean age was 48.9 years (SD = 19.2). According to Table 1, the total number of deaths from lung cancer attributable to SHS exposure would be 124 (52 deaths among adults aged 35–64 years and 72 deaths in adults older than 64 years). The total number of deaths from ischaemic heart disease attributable to SHS would be 904 (174 deaths among the population aged 35–64 years and 730 among people older than 64 years). A sensitivity analysis of mortality attributable to SHS is shown in Table 2. Assuming that ex-smokers are susceptible to the effects of SHS, the total number of deaths would increase by 20%. Using the RR of ischaemic heart disease derived from studies using biomarkers, the number of deaths would be 2711 (164% increase). Including stroke among the diseases associated with SHS in the analysis would raise the total number of deaths to 2964 (188% increase). Including persons exposed in leisure time would increase the number of deaths to 2365 (130% increase). If we chose only those people who reported exposure for a minimum of 1 hour per day, the total number of deaths would decrease by 38%.
Discussion The total number of deaths attributable to SHS exposure at home and at work in Spain would be 1028 in 2011, with a total of 586 deaths in men and 442 deaths in women. Overall, the mortality attributable to SHS is lower than that assessed in 2002.3 This decrease is mainly due to the prevalence of SHS exposure, which significantly decreased after the successful smoking bans in 2005 and 2010.11,18 According to the estimation assessed in 2002,3 the minimum number of deaths attributable to SHS was
Downloaded from http://ntr.oxfordjournals.org/ at Orta Dogu Teknik University Library (ODTU) on February 9, 2016
years in 2004. The largest number of estimated deaths attributable to SHS exposure in adults was caused by ischaemic heart disease.2 According to the only study carried out in Spain assessing the mortality attributable to SHS, SHS exposure at home and at work was responsible for a minimum of 1228 deaths from lung cancer and ischaemic heart disease in 2002.3 This estimation, however, was based on a range of prevalences assessed in regional surveys in Spain, since no surveys had assessed SHS exposure nationwide until then. Furthermore, that study was developed before the implementation of the Spanish smoking law in 2006, which prohibited smoking in indoor public places and workplaces, except for hospitality venues.4,5 In 2011, that prohibition was widened to hospitality venues.6 After the implementation of the law, numerous studies demonstrated a decrease in SHS exposure.7–10 This reduction was observed at workplaces, during leisure time, and even in some settings not regulated by the law. Overall, according to a study carried out in Barcelona, the self-reported exposure decreased from 75.7% (2004–2005) to 56.7% (2011–2012).11 Therefore, a long term decrease in the mortality attributable to SHS in Spain would be expected. The objective of this study was to assess the mortality attributable to SHS exposure among never-smokers in Spain in 2011 after the implementation of the Spanish smoking law.
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Table 1. Population Attributable Fraction (PAF) and Deaths Attributable to Secondhand Smoke (SHS) Exposure Among Never-Smokers, Spain, 2011 Relative risk
PAF
0.094 0.09
1.30 1.30
0.031 0.021
575 307
18 6
0.081 0.049
1.21 1.21
0.031 0.019
575 307
18 6
0.017 0.004
1.30 1.30
0.007 0.002
575 307
4 0
0.1 0.098
1.34 1.24
0.033 0.023
1390 1120
46 26
0.094 0.09
1.34 1.24
0.027 0.026
2143 425
59 11
0.081 0.049
1.39 1.39
0.017 0.010
2143 425
36 4
0.017 0.004
1.39 1.39
0.005 0.001
2143 425
11 1
0.1 0.098
1.30 1.30
0.029 0.029
13 540 13 581
394 388 1028
Total deaths among nonsmokers
Deaths attributable to SHS
Exposed at home = 1 or more people usually smoke inside the home; exposed at work = a workpartner usually smoke close enough so that you can smell the SHS.
a
Table 2. Sensitivity Analyses of Mortality Attributable to Secondhand Smoke (SHS) Under Different Assumptions, Spain, 2011 Study assumptions Ex-smokers not susceptible to effects of SHS When someone is exposed in both settings there is no additive risk RR of ischaemic heart disease is RR = 1.30/1.21 (home/work) There is not enough evidence on stroke Exposed in leisure time not susceptible to effects of SHS Susceptible to effects of SHS if exposed
Alternative assumptions Ex-smokers susceptible to effects of SHSa When someone is exposed in both settings the RR is additive RR of ischaemic heart disease estimated with biomarkers RR = 1.89 RR of stroke = 2.10 for men and 1.66 for women Daily exposed in leisure time are susceptible to effects of SHS Susceptible to effects of SHS only if exposed a minimum of 1 hour per day
Effect on number of deaths (percentage variation regarding the study assumptions) 1284 (+19.94) 1039 (+1.06) 2711 (+163.72) 2964 (+188.32) 2365 (+130.06) 634 (−38.33)
RR = relative risk. a Following a conservative criterion, we excluded those ex-smokers susceptible to dying because of smoking from the observed mortality.
1228 while the maximum was 3237 (there was a range since at that time no national estimates were available of the prevalence of SHS exposure). In our current study, the total number of deaths (1028) is lower than the minimum estimated in 2002. However, although the decrease in the prevalence of exposure has been substantial, we did not observe a major decrease in the total number of deaths attributable to SHS (a decrease of 16.3% compared with the minimum assessed in 2002). Among other factors, this finding is due to the fact
that active smoking has also decreased, leading to an increase in the mortality not attributable to active smoking and therefore susceptible to being attributable to passive smoking. Furthermore, it is important to note that the real impact of the current decrease of SHS prevalence on mortality from some causes, such as lung cancer, will need a much longer term monitoring period to become observable. Our study has some limitations, such as the use of non-country-specific RR and the use of prevalences of exposure based
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Lung cancer 35–64 years Home only Men Women Work only Men Women Home and work Men Women >64 years Home Men Women Ischaemic heart disease 35–64 years Home only Men Women Work only Men Women Home and work Men Women >64 years Home Men Women Total
Prevalence of never-smokers exposed to SHSa
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3. López MJ, Pérez-Ríos M, Schiaffino A, et al. Mortality attributable to passive smoking in Spain, 2002. Tob Control. 2007;16(6):373–377. 4. Ministerio de Sanidad y Consumo. Ley 28/2005, de 26 de diciembre, de medidas sanitarias frente al tabaquismo y reguladora de la venta, el suministro, el consumo y la publicidad de los productos del tabaco. 2005. www. msc.es/novedades/docs/disposicionesGenerales.pdf. Accessed November 3, 2013. 5. Fernández E. Spain: going smoke free. Tob Control. 2006;15(2):79–80. 6. Ministerio de Sanidad y Consumo. Ley 42/2010, de 30 de diciembre, por la que se modifica la Ley 28/2005, de 26 de diciembre, de medidas sanitarias frente al tabaquismo y reguladora de la venta, el suministro, el consumo y la publicidad de los productos del tabaco. 2010. www.boe.es/ boe/dias/2010/12/31/pdfs/BOE-A-2010–20138.pdf. Accessed November 3, 2013. 7. López MJ, Fernández E, Pérez-Rios M, et al. Impact of the 2011 Spanish smoking ban in hospitality venues: indoor secondhand smoke exposure and influence of outdoor smoking. Nicotine Tob Res. 2013;15(5):992– 996. doi:10.1093/ntr/nts218. 8. López MJ, Nebot M, Schiaffino A, et al. Two-year impact of the Spanish smoking law on exposure to secondhand smoke: evidence of the failure of the ‘Spanish model’. Tob Control. 2012;21(4):407–411. doi:10.1136/ tc.2010.042275. 9. Nebot M, Lopez MJ, Ariza C, et al. Impact of the Spanish smoking law on exposure to secondhand smoke in offices and hospitality venues: before-and-after study. Environ Health Perspect. 2009;117(3):344e7. doi:10.1289/ehp.11845. 10. Fernandez E, Fu M, Pascual JA, et al. Impact of the Spanish smoking law on exposure to secondhand smoke and respiratory health in hospitality workers: a cohort study. PLoS One. 2009;4(1):e4244. doi:10.1371/journal.pone.0004244. 11. Sureda X, Martínez-Sánchez JM, Fu M, et al. Impact of the Spanish
Funding This work was supported by the Ministry of Health, Instituto de Salud Carlos III-Subdirección General de Evaluación y Fomento de la Investigación, PN I+D+I 2008–2011, co-funded by the European Regional Development Fund (FEDER), grant number FIS PI10/00400.
smoke-free legislation on adult, non-smoker exposure to secondhand smoke: cross-sectional surveys before (2004) and after (2012) legislation. PLoS One. 2014;9(2):e89430. doi:10.1371/journal.pone.0089430. 12. Hackshaw AK, Law MR, Wald NJ. The accumulated evidence on lung cancer and environmental tobacco smoke. BMJ. 1997;315(7114):980–988. 13. Steenland K. Risk assessment for heart disease and workplace ETS exposure among nonsmokers. Environ Health Perspect. 1999;107(suppl
Declaration of Interests None declared.
6):859–863. 14. Wells AJ. Heart disease from passive smoking in the workplace. J Am Coll Cardiol. 1998;31(1):1–9. 15. Instituto Nacional de Estadística. www.ine.es/inebase/. 2012. Accessed
References 1. US Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2006. www.surgeongeneral.gov/library/reports/secondhandsmoke/fullreport.pdf. Accessed February 14, 2015. 2. Oberg M, Jaakkola MS, Woodward A, et al. Worldwide burden of disease from exposure to second-hand smoke: a retrospective analysis of data from 192 countries. Lancet. 2011;377(9760):139–146. doi:10.1016/ S0140-6736(10)61388-8.
September 8, 2013. 16. Walter SD. The estimation and interpretation of attributable risk in Health research. Biometrics. 1976;32(4):829–849. 17. Whincup PH, Gilg JA, Emberson JR, et al. Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement. BMJ. 2004;329(7459):200–205. 18. Lushchenkova O, Fernández E, López MJ, et al. [Secondhand smoke exposure in Spanish adult non-smokers following the introduction of an antismoking law]. Rev Esp Cardiol. 2008;61(7):687–694. 19. López MJ, Fernández E, Gorini G, et al. Exposure to secondhand smoke in terraces and other outdoor areas of hospitality venues in eight European countries. PLoS One. 2012;7(8):e42130. doi:10.1371/journal. pone.0042130.
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on reported data that might be affected by an information bias. However, country-specific risks or nonreported prevalences of exposure at the national level are not available, and the use of these data allow for comparison with other studies using the same methodology. Regarding the question assessing SHS exposure at home (“how many people usually smoke at home”), it might underestimate the real exposure due to socially desirable responses. However, we decided to use this question since it follows a conservative criterion and allows for comparison with previous studies. Finally, we would like to notice that ischaemic heart diseases and lung cancer have different latency periods. Therefore, the mortality assessed will appear at different moments in time, what should be taken into account in the interpretation of the results obtained in this study. This is the first attributable mortality study carried out after the implementation of the 2010 Spanish smoking law. It is also the first attributable mortality study in Spain based on prevalence data from a national survey carried out in a representative sample. Finally, this study allows assessment of the effect of SHS exposure on mortality under different assumptions such as the inclusion of ex-smokers and SHS exposure in leisure time, which would considerably increase the number of attributable deaths. In conclusion, SHS exposure decreased after the implementation of the tobacco control law in Spain, and therefore the population attributable fraction seems to be also decreasing. However, longer follow-up is required to observe larger effects on mortality. Efforts are still needed to reduce the current prevalence of exposure—mainly due to exposure in nonregulated places such as homes or cars and some outdoor spaces19—and the associated morbidity and mortality.
