Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea
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https://doi.org/10.4046/trd.2019.0011 ORIGINAL ARTICLE ISSN: 1738-3536(Print)/2005-6184(Online) • Tuberc Respir Dis 2020;83:71-80 Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea Do Sun Kwon, M.D.1 , Tae Hee Kim, M.D.1, Min Kwang Byun, M.D., Ph.D.1, Hyung Jung Kim, M.D., Ph.D.1, Hye Sun Lee, Ph.D.2, Hye Jung Park, M.D., Ph.D.1 and Korean Smoking Cessation Study Group 1Department of Internal Medicine, Gangnam Severance Hospital, Seoul, 2Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea Background: In January 2015, South Korea’s government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers. Methods: We analyzed data collected by the 2013–2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio. Results: Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4). Conclusion: This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea. Keywords: Cigarette Price; South Korea; Smoking; Policy Introduction Address for correspondence: Hye Jung Park, M.D., Ph.D. Consistent with the global trend and based on inflation, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei South Korea has gradually increased its cigarette tax by 10%– University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 06273, 1 Korea 30% in an attempt to reduce the smoking rate . However, even Phone: 82-2-2019-3302, Fax: 82-2-3463-3882 with these increases, the price of cigarettes in South Korea was E-mail: [email protected] still low, and the prevalence of smoking was high compared Received: Feb. 11, 2019 to other Organisation for Economic Co-operation and Devel- Revised: Jun. 10, 2019 opment countries2. Moreover, the price of cigarettes in South Accepted: Aug. 30, 2019 Korea had not increased in 10 years from 2004 to 20143. From Published online: Nov. 7, 2019 2008 to 2011, the smoking rate among male South Koreans cc It is identical to the Creative Commons Attribution Non-Commercial did not vary very much, reduce from 47.7% to 47.3%, slightly License (http://creativecommons.org/licenses/by-nc/4.0/). decreased to 43.7% in 2012, and to 42.1% in 20134. In January 2015, the government abruptly increased the cigarette tax, Copyright © 2020 and the retail price of cigarettes increased by 80% compared The Korean Academy of Tuberculosis and Respiratory Diseases. to the previous year (Figure 1A). In addition, smoke-free areas 71 DS Kwon et al. Quit Decrease No change ABIncrease C 5,000 2% 8% 12 * (%) (won) 10 4,000 rate 8 cigarette 3,000 of 32% cessation 6 2,000 pack 58% 4 smoking one of 1,000 2 Recent Cost 0 0 1990 1995 2000 2005 2010 2015 2013 2014 2015 Year Figure 1. Effects of abrupt cigarette price increase on recent smoking cessation rate in Korea. (A) The price change for one pack of cigarettes from 1989 to 2015 in Korea. (B) Habit changes after cigarette price increase. (C) Changes in recent smoking cessation rates before (2013–2014) and after (2015) cigarette price increase. *p<0.05 signifies changes in recent smoking cessation rates according to year. were expanded from public places to indoor areas, including procedures to provide a sample representative of the South worksites, restaurants, coffee shops, and bars. Although previ- Korean general population, with stratification and multiple ous studies have examined the effects of national policy on stages of cluster selection using age, sex, residence type, edu- smoking prevalence5, there has been no study on the signifi- cation level, and other variables. We followed the guidelines cant effects of the recent policy, which increased the price of for reporting sample weight (sampling weights) and stratifica- cigarettes by 80% in January 2015, on smoking cessation. tion as indicated by the KCDC; this information is available on The South Korea National Health and Nutrition Examina- the KNHANES website (http://knhanes.cdc.go.kr). tion Survey (KNHANES) is a large-scale annual survey con- Among 20,482 subjects surveyed in 2013–2015, a total of ducted systemically by the South Korea Centers for Disease 15,203 subjects ≥19 years of age responded to the health sur- Control and Prevention (KCDC). The data in the KNHANES vey, including a questionnaire concerning smoking habits. represents the entire general population of South Korea6. The Using regression analysis, 3,086 subjects who were current KNHANES survey includes various questionnaires that con- smokers and who had smoked more than 100 cigarettes in tain demographics and clinical manifestations. In addition, their lifetime or who had stopped smoking within the past six detailed questionnaires concerning smoking habits are in- months were examined to detect the significant factors for cluded, especially in the 2013–2015 surveys. Thus, KNHANES recent smoking cessation. Recent smoking cessation was de- data will be useful for confirming any significant changes in fined as having stopped smoking within the past six months: the smoking habits of South Korean smokers before and after they answered, “I smoked cigarettes in the past but do not the implementation of the new policy. smoke now” to a question asking “Current smoking status,” The goal of this study was to determine the effects of the in- and gave a variable period less than 6 months to a question novative policy including the increase in tobacco prices and asking “Non-smoking period.” The recent smoking cessation expansion of smoke-free areas on cigarette smoking cessa- rate (%) was calculated as follows: subjects with recent smok- tion among South Korean smokers, and which sub-groups of ing cessation×100 (%)/total enrolled subjects (current smoker smokers more readily responded to the new policy. and ever smoker including subjects with recent smoking cessation). This retrospective study was approved by the In- stitutional Review Board (IRB) of Yongin Severance Hospital Materials and Methods (No. 3-2017-0020). The requirement of informed consent was waived considering the retrospective nature of this study. 1. Participants 2. Definition of variables We used data from the KNHANES, a national survey per- formed in 2013–2015. The survey used complex probability All data were collected by self-reported questionnaires, 72 www.e-trd.org National cigarette price increase policy in Korea including diabetes status, hypertension status, marital sta- variables from before and after the policy change were ana- tus, education level, residence type, and household income. lyzed by chi-square tests and t-tests, respectively. Univariate Household income was determined based on each subject’s and multivariate logistic regression analyses were conducted self-reported monthly household income in South Korea. to identify factors associated with recent smoking cessation. Income level was categorized into four quartiles. Body mass The interaction odds ratio (OR) value refers to the relative index (BMI; measured as body weight divided by the square size of the OR value after the increase of cigarette tax in prepa- of the body weight, and expressed in units of kg/m2) was mea- ration for a before-tax change. This was used to determine if sured by the healthcare provider. there were significant differences in the critical factors; that is, if the interaction OR value is greater than 1, it is a positive ef- 3. Statistical analysis fect that relatively increases the smoking cessation rate, and if it is smaller than 1, it has a negative effect that has a relatively We used KNHANES stratification variables and sampling lower smoking cessation rate. weights. Differences in categorized variables and continuous Table 1. Clinical characteristics of total enrolled subjects before and after policy change Variable Before increase policy (2013–2014) After increase policy (2015) p-value Male sex, n (%) 5,068 (49.6) 2,487 (49.9) 0.836 Age, yr 0.806 19–29 1,982 (19.4) 951 (19.1) 30–39 1,992 (19.5) 927 (18.6) 40–49 2,125 (20.8) 1,026 (20.6) 50–59 1,982 (19.4) 981 (19.7) ≥60 2,135 (20.9) 1,096 (22.0) Height, cm 164.2±0.1 164.3±0.2 0.195 Weight, kg 64.7±0.1 64.0±0.2 0.170 BMI, kg/m2 23.9±0.1 23.7±0.1 0.296 Diabetes 950 (9.3) 428 (8.6) 0.303 Hypertension 2,482 (24.3) 1,290 (25.9) 0.140 Married 7,918 (77.5) 1,513 (76.3) 0.343 Education level 0.247 Below elementary 1,716 (16.8) 797 (16.1) Middle school 939 (9.2) 433 (8.7) High school 3,218 (31.5) 1,869 (37.5) Above university 3,606 (35.3) 1,883 (37.8) Type of residence 0.694 General type 5,251 (51.4) 2,467 (49.5) Apartment 4,965 (48.6) 2,516 (50.5) Household income 0.551 Lowest quartile (Q1) 1,532 (15.0) 757 (15.2) Low–middle quartile (Q2) 2,615 (25.6) 1,156 (23.2) High–middle quartile (Q3) 2,983 (29.2) 1,500 (30.1) Highest quartile (Q4) 3,085 (30.2) 1,569 (31.5) Enrolled number 10,219 (100) 4,984 (100) Representing number 23,879,830 12,071,069 Values are presented as percentage or mean±SD unless otherwise indicated.