Open access Original research BMJ Open: first published as 10.1136/bmjopen-2019-034760 on 28 February 2020. Downloaded from Prevalence and determinants of current cigarette smoking and secondhand smoking among Greek adolescents: the Global Youth Tobacco Survey (GYTS) 2013 study George Rachiotis,1 Anastasia Barbouni,2 Athanasios Basagiannis,1 Antonis Katsioulis,1 Konstantinos Kostikas,1 Varvara Mouchtouri,1 Kyriakoula Merakou,2 Jenny Kremastinou,2 Christos S Hadjichristodoulou 1 To cite: Rachiotis G, ABSTRACT Strengths and limitations of this study Barbouni A, Basagiannis A, et al. Objectives Smoking prevalence in Greece is considered Prevalence and determinants high within the European Union and the collection of ► Nationwide, representative sample of Greek student of current cigarette smoking evidence on tobacco use among adolescents is of and secondhand smoking population aged 13–15 years old. vital importance in order to develop effective smoking among Greek adolescents: the ► Standardised methodology to ensure comparability prevention and cessation programmes. Global Youth Tobacco Survey across countries. Design Cross- sectional. (GYTS) 2013 study. BMJ Open ► The questionnaires were collected through inter- Setting Greece. 2020;10:e034760. doi:10.1136/ views resulting in satisfactory response rate. bmjopen-2019-034760 Primary and secondary outcome measures Global ► The main limitation of the study is related to the self- Youth Tobacco Survey (GYTS) is a national representative, Prepublication history for reported nature of the information collected. ► paper- and- pencil, cross- sectional, school- based study this paper is available online. To view these files, please visit of students at ages 13–15 years. The survey employed a the journal online (http:// dx. doi. multistage cluster sample design with schools selected hazard to human health. The WHO reported org/ 10. 1136/ bmjopen- 2019- proportional to enrolment size. Finally, 4618/5127 students that more than 8 million deaths per year are 034760). aged 13–15 years participated in the survey. The school attributed to tobacco smoking.1 It is well response rate was 98.1%, the student response rate was http://bmjopen.bmj.com/ Received 04 November 2019 90.1% and the overall response rate was 88.4%. known that the vast majority of current adult Revised 07 January 2020 Results The prevalence of current cigarette smoking smokers initiated smoking before the age of 2 Accepted 28 January 2020 was estimated at 10.1% (10.4% in GYTS 2005) and of 18 years. In this context, cigarette smoking— exposure to secondhand smoking in public places at the most prevalent form of tobacco use—has 67.4% (94.1% in GYTS 2005). The vast majority of the been described as a ‘pediatric epidemic’.3 adolescents (82.1%) supported the banning of smoking In addition, early initiation of smoking inside enclosed public places. Most of the current smokers is associated with increased likelihood of (90.8%) were not prevented/refused purchase because of chronic health conditions.4 In May 2003, the their age according to existing law. Multivariate analysis WHO adopted the Framework Convention on October 3, 2021 by guest. Protected copyright. showed that peer influence (OR=48.32; 95% CI 36.2 to on Tobacco Control (FCTC). The Global 64.48), pocket money (OR=2.63; 95% CI 1.28 to 3.41), © Author(s) (or their Tobacco Surveillance System (GTSS) was increasing age (OR=2.35; 95% CI 1.63 to 3.39) and low employer(s)) 2020. Re- use established in 1998 in order to establish permitted under CC BY-NC. No educational level of father (OR=2.82; 95% CI 1.7 to 4.68) commercial re- use. See rights were risk factors independently associated with current tobacco control surveillance and monitoring 5 and permissions. Published by cigarette smoking. programmes. Global Youth Tobacco Survey BMJ. Conclusions Despite the existence of strict laws (GYTS) is a component of GTSS, and was 1Department of Hygiene and related to tobacco control, exposure to secondhand developed in order to provide an interna- Epidemiology, University of smoking among Greek students remained high even tional protocol for standardised monitoring Thessaly Faculty of Medicine, when compared with GYTS in 2005. This is likely a and surveillance of tobacco use among adoles- Larissa, Greece result of weak enforcement, what is really missing is the 2Department of Public and cents. The GYTS is a joint project between enforcement of the related legislation. Administrative Hygiene, National WHO, US Centers for Disease Control and School of Public Health, Athens, Prevention (CDC) and the Canadian Public Greece Health Association. The first wave of GYTS Correspondence to INTRODUCTION was conducted in 140 countries and recently, Dr Christos S Hadjichristodoulou; Tobacco cigarette smoking is the dominant the CDC analysed GYTS data from the second xhatzi@ med. uth. gr form of tobacco use and a major preventable wave of GYTS with 61 participating countries Rachiotis G, et al. BMJ Open 2020;10:e034760. doi:10.1136/bmjopen-2019-034760 1 Open access BMJ Open: first published as 10.1136/bmjopen-2019-034760 on 28 February 2020. Downloaded from Questionnaire Table 1 Point prevalence of selected variables in 2005 and 2013 (Global Youth Tobacco Survey, Greece) The questionnaire used included the following sections: use of tobacco products, exposure to SHS, smoking 2013 2005 cessation, advertisements in the media for and against Variable % (95% CI) % (95% CI) smoking, availability and access to tobacco products and Current use of any tobacco 16.0 16.2 knowledge of the harmful effects of tobacco use. Current product (13.9 to 18.3) (14.3 to 18.4) tobacco smoking was defined as answering ≥1 day to the Current cigarette smokers 10.1 10.4 question: ‘During the past 30 days, on how many days did (8.3 to 12.2) (8.8 to 12.4) you smoke cigarettes?’ We used three questions to assess Exposure to secondhand smoke secondhand exposure at home: (1) ‘During the past 7 At home 70.0 89.8 days, on how many days of those has anyone smoked inside (67.7 to 72.2) (88.3 to 91.1) your home, in your presence?’ (2) ‘How often do you see In public places 67.4 94.1 your father (stepfather or mother’s partner) smoking (65.2 to 69.6) (93.2 to 94.9) in your home?’ (3) ‘How often do you see your mother In favour of banning smoking 82.1 84.8 (stepmother or father’s partner) smoking in your home?’ inside enclosed public places (79.7 to 84.2) (82.7 to 86.6) Participants who gave positive responses to at least one of Percentage of current cigarette 90.8 95.0 the questions mentioned above were considered to have smokers who bought cigarettes (85.2 to 94.4) (89.5 to 97.7) been exposed to SHS at home. We also used one question and were not prevented/refused to assess secondhand exposure in public enclosed places: purchase because of their age* ‘During the past 7 days, on how many days has anyone *From a store, shop, and so on. smoked in your presence, inside any enclosed public place, other than your home (school, shops, restaurants, shopping malls, movie theaters)?’ Those who responded 6–8 ‘0 days’ were considered to have not been exposed to SHS across the six WHO regions for the period 2012–2015. in public places. Participants who responded ‘1–7 days’ Greece is a major tobacco- producing country within were considered to have been exposed to SHS in public the European Union and the collection of evidence on places. tobacco use among adolescents is of vital importance in order to develop effective smoking prevention and cessa- Sampling tion programmes.9 The first GYTS in Greece has been The survey employed a multistage (geographical) cluster conducted in 2005. The results of this study showed that sample design with schools selected proportional to the prevalence of current tobacco use was 16.2% while enrolment size. The sampling technique included two the prevalence of exposure to secondhand smoke (SHS) geographical strata: the Attica region and the rest of varied from 88% at home to 93.4% in public places.10 Greece. The primary sampling units were 30 high schools http://bmjopen.bmj.com/ In addition, further analysis indicated that current and from each stratum. The selection of classes within the schools was based on a simple random sampling method. secondhand smoking were influenced by several variables The final sampling units consisted of all students in related to individual/social context.11 12 The aim of the the selected classes. All students in the selected classes present study which uses data from the 2013 Greece GYTS attending school on the day of the survey were eligible to was to report on the prevalence and determinants of participate in the study. Parents were notified by a letter current and secondhand smoking among Greek adoles- and students gave verbal consent to participate in the cents and compare the results of the present study to study. on October 3, 2021 by guest. Protected copyright. those of the first GYTS study conducted in 2005. Lastly, we examined the level of exposure to secondhand smoking Statistical analysis and sales of tobacco products to minors in relation to the A weighting factor was used in the analysis to reflect the articles 8 and 16 of FCTC.13 likelihood of sampling each student and to reduce bias by compensating for differing patterns of non- response. The weight used for estimation is given by the following formula: METHODS W = W1 W2 f1 f2 f3 f4 ∗ ∗ ∗ ∗ ∗ GYTS is a national representative, paper-and- pencil, where W1 is the inverse of the probability of selecting cross- sectional, school- based study of students at ages the school; W2 is the inverse of the probability of selecting 13–15 years.