Prevalence, Correlates of and Perceptions Toward Cigarette Smoking Among Adolescents in South Korea

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1 Original Article Prevalence, Correlates of and Perceptions Toward Cigarette Smoking Among Adolescents in South Korea Emmanuel Rudatsikira, Adamson S. Muula 1 and Seter Siziya 2 Departments of Biostatistics and Epidemiology and Global Health, Loma Linda University, School of Public Health, Loma Linda, California; 1 Department of Community Health, University of Malawi, College of Medicine, Blantyre, Malawi, and 2 Department of Community Medicine, University of Zambia, School of Medicine, Lusaka, Zambia ABSTRACT Objective. To estimate the prevalence of current smoking, correlates of smoking and assess exposure to and perceptions towards smoking by gender. Methods. We used data from the South Korea Global Youth Tobacco Survey (GYTS). Frequencies of selected characteristics and their 95% confidence were obtained. Current cigarette smoking was defined as having smoked, even a single puff, within the last 30 days. Logistic regression analysis was conducted to assess the factors that were considered to be associated with current cigarette smoking in bivariate and multivariate analyses. Results. Of the 5615 respondents, 7.4% males and 5.0% females reported being current smokers (p = 0.003). Having smoked friends who was strongly associated with smoking after controlling for age, gender, parental smoking status, exposure to anti-smoking media messages, and perception of risks of smoking (OR=69.92; 95% CI [41.24, ] for most friends and OR=11.86; 95% CI [7.26, 19.36] for some friends). Male gender and having one or both smoking parents were associated with smoking (OR=1.43; 95% CI [1.09, 1.89] and OR=1.29; 95% CI [1.00-, 1.71] respectively). Exposure to antismoking media messages was negatively associated with smoking (OR=0.52; 95% CI [0.36, 0.77]. Conclusion. Prevalence of smoking among adolescents in South Korea is lower than in many other Asian countries. There is however, need to strengthen anti-tobacco messages especially among adolescents. [Indian J Pediatr 2009; 76 (5) : ] muula@yahoo.com Key words : Adolescents; Cigarettes; Smoking; Tobacco; South Korea Tobacco use is a leading cause of deaths among noncommunicable diseases globally. 1 In the past 20 years mortality from lung and other tobacco-related cancers in Korea has increased, having largely been preceded by increase in prevalence of smoking. 2-4 Many adults initiate smoking as adolescents, therefore prevention of cigarette smoking among adolescents is of paramount importance. While many of the adverse health effects of cigarette smoking are experienced later in the life of the smoker, adolescent smoking has also short term untoward implications. Adolescent smokers have high incidence Correspondence and Reprint requests : Dr. Adamson S. Muula, Department of Community Health, University of Malawi, College of Medicine, Private Bag 360, Chichiri, Blantyre 3, Malawi. [DOI /s ] [Received September 17, 2007; Accepted August 8, 2008] of asthma, 5 exacerbation of asthma 6 and wheezing. 7 Smoking in adolescents may also be a marker of other problem behaviors and unhealthy lifestyles. 8 Park et al have reported that smoking was associated with suicidal ideation among adolescents in Korea. 9,10 Shin et al have reported that snoring in class was associated with being a smoker among adolescents in Korea. 11 Elliot et al have reported that adolescent females who used anabolic steroids were also likely to smoke cigarette in the United States. 12 There is a growing literature on the prevalence of adolescent cigarette smoking in Korea. Many of the studies have reported mainly on demographic factors associated with being a smoker. Few studies have documented whether there are differences in the perceptions of smoking between boys and girls. The present study was carried out to assess the socio-demographic correlates of current smoking; compare exposure to tobacco-related Indian Journal of Pediatrics, Volume 76 May,

2 E. Rudatsikira et al messages/media by gender and compare perceptions towards cigarette smoking between boys and girls. METHODS Study design and participant recruitment This study is based on secondary analysis of data from the South Korean Global Youth Tobacco Survey conducted in The survey was school based. The school population was students that were registered with the Ministry of Education, South Korea. A total of 75 schools within grades 1 to 3 and classes having at least 40 students were selected. The first-stage of sampling consisted of all the schools which had the eligible grades. The schools were selected with probability proportional to their enrollment size. The second sampling stage consisted of systematic sampling (with a random start) of classes from each school that participated in the survey. All classes in the selected schools were included in the sampling. All students in the selected classes were eligible to participate in the survey regardless of their ages. The overall response rate was 87.7%, with 92.0% (69 of the 75 sampled schools) school response rate. The student response rate was 95.3% (5,940 of the 6,234 eligible sampled students participated). Questionnaire administration Questionnaires were completed anonymously in the classroom by the study participants within one class session. Students recorded their response directly on a computer scannable answer. Field researchers were trained in September 2004 in each of regions where they were instructed on standard procedure to assure comparability on data collection. The present study had approval from both the Ministry of Health and Ministry of Education. Letters from these ministries were sent to all the Principals of the 75 selected schools, inviting them to participate in the GYTS. All 75 schools agreed to participate. Data collection was carried out during October and November Ten trained enumerators were involved in administering the questionnaire. Data analysis Data analysis was performed using SUDAAN software (Research Triangle Institute, Research Triangle Park, North Carolina, United States of America). Current cigarette smoking (the main outcome) was defined as having smoked a cigarette, even a single puff, in the last 30 days preceding the survey. The predictor variables were obtained from the literature as factors that have been previously reported as being associated with adolescent smoking in other settings. These factors include: smoking in close friends; 13,14 gender 8 parental smoking 15 and exposure to tobacco related messages or advertisements. 16 A weighting factor was used in the analysis to reflect the 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: W = W1 * W2 * f1 * f2 *f3 *f4 where W1 = the inverse of the probability of selecting the school W2 = the inverse of the probability of selecting the classroom within the school fl = a school-level non response adjustment factor calculated by school size category (small, medium, large) f2= a class-level non response adjustment factor calculated for each school f3 = a student-level non response adjustment factor calculated by class f4 = a post stratification adjustment factor calculated by grade We obtained frequencies as estimation of prevalence. We conducted logistic regression analysis to estimate the association between relevant predictor variables and current cigarette smoking for both bivariate (unadjusted odds ratios) and multivariate (adjusted odds ratios) analyses. RESULTS Characteristics of study participants A total of 5,615 students participated in the study of whom 3,006 (51.2%) were females. The median age was 13 (Q 1 =11-12, Q 3 =14 ) years, range 11 to 17 years. Prevalence of smoking Of the 5,615 participants, 7.4% (95% CI [6.4, 8.6]) males and 5.0% (95% CI [4.2, 6.0]) females reported being current smokers (p = 0.003). Having smoking friends was very strongly associated with smoking after controlling for age, gender, parental smoking status, exposure to anti-smoking media messages, and perception of hazards caused by smoking. Participants, who had most of their friends as smokers, were more likely to smoke than those who had no smoking friends (OR=69.92; 95% [41.24, ]. Adolescents who had some friends as smokers were also likely to be smokers themselves (OR=11.86; 95% CI [7.26, 19.36]). Males were more likely to smoke than females (OR=1.43; 95% [1.09, 1.89]). Compared to subjects with non smoking parents, those whose parents smoked were 1.29 more likely to smoke (OR=1.29; 95% CI [1.00, 1.71]). 506 Indian Journal of Pediatrics, Volume 76 May, 2009

3 Prevalence Correlates of and Perceptions Towards Cigarette Smoking Among In-School Adolescents TABLE 1. Factors Associated with Current Smoking Among in-school Adolescents Characteristics Percent of Unadjusted odds ratios Adjusted odds ratios smokers [95% CI] [95% CI] Age (years) [0.59, 1.37] 1.03 [0.62, 1.72] [0.81, 1.58] 1.52 [0.91, 2.54] [0.77, 1.56] 1.32 [0.80, 2.19] [0.39, 7.44] 2.01 [0.20, 20.19] Gender Female Male [1.18, 1.93] 1.43 [1.09, 1.89] Parental smoking status None One or both parents smokers [1.24, 2.02] 1.29 [1.00, 1.71] Best friend smokers None Some [7.23, 16.93] [7.26, 19.36] Most or all [40.53, ] [41.24, ] Perception that smoking is harmful No Yes [0.36, 0.95] 1.06 [0.46, 2.43] Seen anti-smoking media messages No Yes [ ] 0.52 [ ] TABLE 2. Exposure to Tobacco Advertisements Among Adolescents Characteristics Number of Percent of total P participants [95% CI] value Seen cigarette brand name on TV in past 30 days All [94.9, 96.1] Males [93.9, 95.8] Females [95.7, 97.3] Seen tobacco adverts in newspapers/magazines in past 30 days All [49.4, 52.2] Males [46.3, 50.4] Females [50.7, 54.8] Has item with cigarette brand logo All [7.1, 8.7] Males [7.0, 9.3] Females [6.6, 8.9] Exposure to anti-smoking media messages were negatively associated with smoking (OR=0.52; [0.36, 0.77] (Table 1). Table 2 indicates the participants were exposed to tobacco advertisement through newspapers/ magazine (50.8%), and TV (95.5%). Altogether 7.8% respondents reported having an item with cigarette brand logo on it. Compared to females, males had lower estimates of exposure to cigarette advertisement on TV and in the newspapers/magazines (p=0.040 and p=0.020) respectively). Table 3 indicates that the vast majority (95.6%) of the respondents felt that smoking is harmful. About 1 in 3 respondents (30.5 %) thought that male smokers had more friends while 17.3% thought so for females. Furthermore, 14.6% of the participants felt that boys who smoke are attractive and 5.8% felt the same for girls who smoke. DISCUSSION The present study found prevalence of current cigarette smoking of 7.4% and 5.0% among boys and girls, with median age of 12 Yr in South Korea. Kim has reported prevalence of current cigarette smoking of 26% among in-school adolescents in grades 7 th to 12 th in Korea. 17 We found just as had been reported by Kim (2005) that males were more likely to be smokers than females. 17 In 1995, Juon et al reported that among 7 th and 11 th graders in 1995, overall prevalence of current cigarette smoking was 8.5% (15.4% and 1.3% among males and female's respectively). 18 The prevalence of current smoking we found is similar to that estimated for Kampala (Uganda) and Lilongwe (Malawi) where prevalence was 5.6% and 6.2% respectively. 19 In the present study female's estimate is higher than that estimated by Juon et al in However, the Juon et al study was over a decade ago and so the estimates may no longer be relevant at the present time. Kyrlesi et al reported an overall prevalence among Greek in-school adolescents of 10.2%. 20 Boys were also more likely to be smokers compared to girls. The male predominance in smoking habit may be a reflection of socio-cultural acceptability of smoking among male Koreans, and this has been reported in many other settings. 21 The present study found that increasing age, having a parent or closest friend as smoker were positively associated with being a smoker. On the other hand, Indian Journal of Pediatrics, Volume 76 May,

4 E. Rudatsikira et al TABLE 3. Attitudes Towards Tobacco Smoking Distributed by Gender Characteristics Number of Percent of total P participants [95% CI] value Felt that boys who smoke have more friends All [28.6, 32.5] <0.001 Males [21.3, 26.3] Females [34.3, 40.6] Felt that girls who smoke had more friends All Males [15.3, 19.5] Females [15.3, 19.8] Felt that boys who smoke are attractive All [13.4, 15.9] Males [11.0, 14.5] Females [14.0, 17.6] Felt that girls who smoke are attractive All [5.0, 6.6] Males [5.2, 7.5] Females [3.5, 5.5] Felt that tobacco smoking is harmful to health All [95.0, 96.2] Males [93.5, 95.4] Females [96.6, 97.9] Note that totals do not add up to total sample size as some responses were missing adolescents who reported having been exposed to antismoking messages were less likely to have been smokers. Perception that smoking was harmful to health was negatively associated with being a smoker in bivariate analysis. However, after controlling for potential confounders, there was no association between the variables. The association between parental smoking or peer smoking and adolescent smoking has been described elsewhere. 14,15,22 The relation between having a friend who smokes and adolescent s own smoking could be because an adolescent smoker is likely to choose other smokers as friends or that having a friend who smoke, could influence an adolescent into picking up the habit. However, due to the cross sectional nature of the current study, it is not possible to determine which of the two mechanisms is more likely. We do however believe that both of these explanations may be operational in this study setting. The present study found that at least 95.5% of both males and females reported having seen tobacco brand names on television in the past 30 days. About half of the study participants reported seeing tobacco-related advertisements in magazines in past 30 days and 7.8% reported having an item with tobacco brand logo. Compared to male study participants, females were more likely to have seen pro-tobacco related advertisements in the media. Males were more likely to own an item with a tobacco brand logo. Although the present study found statistical differences between males and females with regard to the above characteristics, we also recognize that the actual differences are small. That adolescents in South Korea have high exposure to pro-tobacco advertisements on television and magazines, should be cause for concern. Andreeva et al have reported a higher likelihood of smoking initiation among adolescents who had been exposed to pro-tobacco media in magazines in Ukraine. 16 The finding that pro-tobacco media is associated with smoking adolescents has been reported in many other setting. 23 When we assessed perceptions or attitudes toward smoking, girls were also more likely to believe that smoking is harmful to health than boys. Studies from elsewhere have documented that adolescents who have positive perception of smoking are likely to be smokers. 24 Primack et al have reported that students perceptions of smoking among the successful/elite and disapproval by parents/peers were independently associated with susceptibility to future smoking in the United States. 25 Park has reported that school-based anti-smoking programs in Korea have had limited impact towards adolescent smoking. 9 Park suggests that there is need to change the focus of school-based intervention programs from mere knowledge development to a skill training approach. The author also suggests an interactive delivery method be implemented to have better effects on smoking prevention. Kim et al have reported an experimental study on cessation program of adolescents smoking as being efficacious in preventing adolescent smoking. 26 Current smoking status was determined by biomarkers in this study consisted of 9 sessions with content on enhancement of self-efficacy, stress management, correction of distorted thoughts, consciousness raising, and assertiveness training. Limitation of the study The current study shares limitations with all other studies conducted within the GYTS. Many of these limitations have been reported elsewhere. 8,20,27,28 The GYTS recruited in-school students and therefore excluded adolescents who were not enrolled in school. To the extent that in-school adolescents differed from out of school adolescents in the smoking habits. In the present study findings may not be applicable to all adolescents in Korea. However, school enrolment in Korea is high such that out of school children are a small minority. The GYTS collects data only from students who are present on the day of the survey. No follow-up of absent of truant students is done. There is data to suggest that truant adolescents are likely to be smokers and also to engage in other unhealthy lifestyle. To the extent that this may be the case also in Korea, the present study findings may be under-estimates. The data on current smoking status was obtained through 508 Indian Journal of Pediatrics, Volume 76 May, 2009

5 Prevalence Correlates of and Perceptions Towards Cigarette Smoking Among In-School Adolescents self reports. Adolescents may not have reported accurately their own history of smoking either due to failure to recall or intentionally. Adolescents who are not regular smokers for instance may fail to remember whether they had smoked within the past 30 days. Although there are these concerns, evidence from the United States using a similar data collection methodology as the GYTS found a high level of reliability of the data collection method. 29 The findings from the GYTS are also limited by the fact that current smoking status was not verified through assessment of tobacco-related biomarkers such as exhaled carbon monoxide and blood, saliva or urine cotinine CONCLUSION The present study has estimated the prevalence of current cigarette smoking among in-school adolescents in Korea, which is lower than in many other Asian countries. There is need to intensify adolescent targeted public health interventions programs as prevalence of smoking appears to be a major health concern in Korea. Acknowledgements We are grateful to the Centers for Disease Prevention and Control (Atlanta, Georgia, United States of America) and the World Health Organisation, Geneva, Switzerland for making the dataset available to us for analysis. The CDC and WHO had no part in the analysis, or decision to publish the findings from the study. Contributions: ER, conducted data analysis, Participated in the interpretation of the findings and drafting of the manuscript. ASM, participated in the interpretation of the findings and drafting of the manuscript. SS, participated in the data interpretation of the findings and drafting of the manuscript. Conflict of Interest: None Role of Funding Source: None REFERENCES 1. Ezzati M, AD Lopez AD, Rodgers A, Vander Hoorn S, Murray CJL and the Comparative Risk Assessment Collaborating Group, Selected major risk factors and global and regional burden of disease. Lancet 2002; 360: Bae JM, Lee MS, Shin MH, Kim DH, Li ZM, Ahn YO. Cigarette smoking and risk of lung cancer in Korean men: the Seoul Male Cancer Cohort Study. J Korean Med Sci 2007; 22: Choi Y, Kim Y, Hong YC, Park SK, Yoo KY. Temporal changes of lung cancer mortality in Korea. J Korean Med Sci 2007; 22: Lee H, Yoon SJ, Ahn HS. Measuring the burden of major cancers due to smoking in Korea. Cancer Sci 2006; 97: Frank P, Morris J, Hazell M, Linehan M, Frank T. Smoking, respiratory symptoms and likely asthma in young people: evidence from postal questionnaire surveys in the Wythenshawe Community Asthma Project (WYCAP). BMC Pulm Med 2006; 6: Annesi-Maesano I, Oryszczyn MP, Raherison C, Kopferschmitt C, Pauli G, Taytard A et al. Increased prevalence of asthma and allied diseases among active adolescent tobacco smokers after controlling for passive smoking exposure. A cause for concern? Clin Exp Allergy 2004; 34: Miedinger D, Chhajed PN, Karli C, Lupi GA, Leuppi JD. Respiratory symptoms and smoking behaviour in Swiss conscripts. Swiss Med Wkly 2006; 136: Rudatsikira E, Abdo A, Muula AS. Prevalence and determinants of adolescent tobacco smoking in Addis Ababa, Ethiopia. BMC Public Health 2007; 7: Park E. School-based smoking prevention programs for adolescents in South Korea: a systematic review. Health Educ Res 2006; 21: Park HS, Koo HY, Schepp KG. Predictors of suicidal ideation for adolescents by gender. Taehan Kanho Hakhoe Chi 2005; 35: Shin C, Joo S, Kim J, Kim T. Prevalence and correlates of habitual snoring in high school students. Chest 2003; 124: Elliot DL, Cheong J, Moe EL, Goldberg L. Cross-sectional study of female students reporting anabolic steroid use. Arch Pediatr Adolesc Med 2007; 161 : Lee E, Tak Y. Peer and parental influences on adolescent smoking. Taehan Kanho Hakhoe Chi 2005; 35 : Scragg R, Laugesen M. Influence of smoking by family and best friend on adolescent tobacco smoking: results from the 2002 New Zealand national survey of year 10 students. Aust N Z J Public Health 2007; 31: Otten R, Engels RC, van de Ven MO, Bricker JB. Parental smoking and adolescent smoking stages: the role of parents current and former smoking, and family structure. J Behav Med 2007; 30: Andreeva TI, Krasovsky KS, Semenova DS. Correlates of smoking initiation among young adults in Ukraine: a crosssectional study. BMC Public Health 2007; 7: Kim YH. Korean adolescents smoking behavior and its correlation with psychological variables. Addict Behav 2005; 30: Juon HS, Shin Y, Nam JJ. Cigarette smoking among Korean adolescents: prevalence and correlates. Adolescence 1995; 30: Muula AS, Mpabulungi L. Cigarette smoking prevalence among school-going adolescents in two African capital cities: Kampala Uganda and Lilongwe Malawi. Afr Health Sci 2007; 7: Kyrlesi A, Soteriades ES, Warren CW, Kremastinou J, Papastergiou P, Jones NR et al. Tobacco use among students aged years in Greece: the GYTS project. BMC Public Health 2007;7: Ando M, Asakura T, Ando S, Simons-Morton BG. Psychosocial factors associated with smoking and drinking among Japanese early adolescent boys and girls: Crosssectional study. Biopsychosoc Med 2007 J4; 1: Livaudais JC, Napoles-Springer A, Stewart S, Kaplan CP. Understanding Latino adolescent risk behaviors: parental and peer influences. Ethn Dis 2007; 17 : Lovato C, Linn G, Stead LF, Best A. Impact of tobacco advertising and promotion on increasing adolescent smoking behaviours. Cochrane Database Syst Rev 2003; CD Castrucci BC, Gerlach KK, Kaufman NJ, Orleans CT. The association among adolescents tobacco use, their beliefs and attitudes, and friends and parents opinions of Indian Journal of Pediatrics, Volume 76 May,

6 E. Rudatsikira et al smoking. Matern Child Health J 2002; 6: Primack BA, Switzer GE, Dalton MA. Improving measurement of normative beliefs involving smoking among adolescents. Arch Pediatr Adolesc Med 2007; 161: Kim S, Nam KA, Seo M, Lee HH. Effectiveness of a smoking cessation program for adolescents. Taehan Kanho Hakhoe Chi 2004; 34: Centers for Disease Control and Prevention (CDC). Tobacco use among students aged years Kurdistan Region, Iraq, MMWR Morb Mortal Wkly Rep : Global Youth Tobacco Survey Collaborative Group. Tobacco use among youth: a cross country comparison. Tob Control 2002;11: Brener ND, Kann L, McManus T, Kinchen SA, Sundberg EC, Ross JG. Reliability of the 1999 youth risk behavior survey questionnaire. J Adolesc Health 2002; 31: Hung J, Lin CH, Wang JD, Chann CC. Exhaled carbon monoxide level as an indicator of cigarette consumption in a workplace cessation program in Taiwan. J Formos Med Assoc 2006; 105: Jenkins RA, Counts RW. Personal exposure to environmental tobacco smoke: salivary cotinine, airborne nicotine, and nonsmoker misclassification. J Expo Anal Environ Epidemiol 1999, 9: Low EC, Ong MC, Tan M. Breath carbon monoxide as an indication of smoking habit in the military setting. Singapore Med J 2004; 45 : Indian Journal of Pediatrics, Volume 76 May, 2009