Gender differential secular trend in lifetime smoking prevalence among adolescents: an age-period-cohort analysis.

BACKGROUND: There has been a gender difference in adolescents' lifetime smoking prevalence trends over the last 10 years. This study aimed to explain the gender differential secular trend in adolescents' lifetime smoking prevalence using age-period-cohort (APC) analysis and suggests possible causes for this trend, including Korean tobacco control policies during the last 10 years. METHODS: We utilized the 2006-2017 Korea Youth Risk Behavior Web-based Survey enrolling grades 7 to 12. Using year of survey and year of entry into middle school, we classified 859,814 students who had ever smoked into 6 age groups, 12 periods, and 17 school admission cohorts. Using APC analysis with the intrinsic estimator method, the effects of age, period, and school admission cohort on lifetime smoking prevalence were analyzed according to gender. RESULTS: Overall, there was a similar tendency of all the three effects on lifetime smoking prevalence between genders: an increasing age effect with grade, negative period effect with survey period, and similar pattern of school admission cohort groups. However, compared to boys, girls experienced reduction in the increasing age effect in the 12th grade, consistent and steeper decreasing trend in the period effect from 2006 to 2016, and shorter and lower school admission cohort effect. CONCLUSIONS: Gender differential response to chronological changes in lifetime smoking prevalence was measured by the APC effect, which affected the gender differential secular trend in lifetime smoking prevalence. Therefore, considering the APC effect could help us understand the trend in smoking rates, as well as the contextual factors that affect it.

Characteristics and Incidence Trends for Pediatric Inflammatory Bowel Disease in Daegu-Kyungpook Province in Korea: a Multi-Center Study.

BACKGROUND: Inflammatory bowel disease (IBD) is a heterogeneous chronic disease of unknown etiology. Although it is an important disease that shows a rapid increase in pediatric population, there are no pediatric studies that represent a specific region in Korea. Therefore, we studied the epidemiological and phenotypic characteristics of pediatric IBD in Daegu-Kyungpook province, Korea. METHODS: We included 122 children with pediatric IBD initially diagnosed at one of four university hospitals in Daegu-Kyungpook province between July 2010 and June 2016. We investigated the incidence trends, and the clinical characteristics at diagnosis were compared by Paris classification. RESULTS: We included 122 children: 98 with Crohn's disease (CD) and 24 with ulcerative colitis (UC). The average age at diagnosis was 13.6 years for IBD. The incidence shows an increasing trend. CD showed a significant increase, whereas UC appears to be increasing slowly. In CD, there was a significant male predominance. For disease activity sites, the most common location was L3 (77.6%), indicating ileocolonic involvement as the major type. B1 (88.8%) was the most common disease behaviors type. Perianal disease was noted in 43 patients (43.9%) and weight loss in 60 (61.2%). In UC, E4 (58.4%) was the most common disease activity site, indicating pancolonic involvement as the major type. CONCLUSION: We found that the number of pediatric patients with IBD is increasing rapidly in Daegu-Kyungpook province in Korea. Our study also revealed that the characteristics of pediatric IBD in our province differ somewhat from those of pediatric IBD in Western countries.

Red meat and chicken consumption and its association with high blood pressure and obesity in South Korean children and adolescents: a cross-sectional analysis of KSHES, 2011-2015.

BACKGROUND: The impact of meat consumption on high blood pressure (HBP) and obesity in children and adolescents is a subject of debate. The aim of this study was thus to evaluate the association between meat consumption and both HBP and obesity in this group. METHODS: We performed a cross-sectional analysis using nationally representative samples of children and adolescents aged 9, 12, and 15 years old (n = 136,739) who were included in the Korea School Health Examination Survey (KSHES) for the 2011-2015 period. Multiple linear and logistic regression analysis was used to determine the factors influencing systolic blood pressure (SBP), diastolic blood pressure (DBP), and body mass index (BMI, kg/m2) levels, and to test the strength of these relationships. RESULTS: Adjusted for covariates, 6.3% of those subjects who consumed >5 servings of meat (including beef, pork, and chicken) per week were obese, compared with 9.1% of the subjects who consumed <1 serving of meat/wk (obesity adjusted odds ratio [OR]: 1.44; 95% confidence interval [CI]: 1.21-1.70; P ≤0.001). Those who consumed <1 serving of meat/wk had an HBP prevalence of 8.2%, compared with 7.2% for subjects who consumed >5 servings of meat/wk (systolic HBP adjusted OR: 1.30; 95% CI: 1.05-1.62; P ≤0.01, diastolic HBP adjusted OR: 1.25; 95% CI: 1.02-1.54; P <0.05). Obese subjects were estimated to have a higher SBP (ß = 7.497, P < 0.001) and DBP (ß = 4.123, P <0.001) than subjects who had no excess weight. Compared to subjects who consumed >5 servings of meat/wk, those who consumed <3 servings of meat/wk had a higher SBP (ß = 0.574, P <0.001) and DBP (ß = 0.376, P = 0.003) after adjusting for BMI. The intake of milk, fruit, and vegetables was not associated with either SBP or DBP (P >0.05). In contrast, BMI was significantly associated with milk, fruits, and vegetables (P <0.01). CONCLUSIONS: Among children and adolescents, a higher level of meat consumption was associated with lower SBP, DBP, and BMI, and greater height, suggesting that consuming an appropriate amount of meat is important for healthy growth at a young age.

Simplified Radiographic Damage Index for Affected Joints in Chronic Gouty Arthritis.

The aim of this study was to develop and validate a new radiographic damage scoring method (DAmagE index of GoUt; DAEGU) in chronic gout using plain radiography. Two independent observers scored foot x-rays from 15 patients with chronic gout according to the DAEGU method and the modified Sharp/van der Heijde (SvdH) method. The 10 metatarsophalangeal (MTP) and 2 interphalangeal (IP) joints of the first toes of both feet were scored to assess the degrees of erosion and joint space narrowing (JSN). The intraobserver and interobserver reliabilities were analyzed by calculating the intraclass correlation coefficient (ICC) and minimal detectable change (MDC). The correlation between the DAEGU and SvdH methods was analyzed by calculating the Spearman's rho correlation coefficients and Kappa coefficients. The DAEGU method was found to be highly reproducible (0.945-0.987 for the intraobserver and 0.993-0.996 for the interobserver ICC values). The erosion, JSN, and total scores exhibited strong positive correlations between the DAEGU and SvdH methods and also within each method (r = 0.860-0.969, P < 0.001 for all parameters). The DAEGU and SvdH methods were in very good agreement as determined by Kappa coefficient analysis [0.732 (0.387-1.000) for erosion and 1.000 (1.000-1.000) for JSN]. In conclusion, this study revealed that DAEGU method was a reliable and feasible tool in the assessment of radiographic damage in chronic gout. The DAEGU method may provide a more easy assessment of structural damage in chronic gout in the real clinical practice.

Interaction Effect between Weight Perception and Comorbidities on Weight Control Behavior in Overweight and Obese Adults: Is There a Sex Difference?

We investigated the interaction effect between body weight perception and chronic disease comorbidities on body weight control behavior in overweight/obese Korean adults. We analyzed data from 9,138 overweight/obese adults ≥20 yr of age from a nationally representative cross-sectional survey. Multiple logistic regression using an interaction model was performed to estimate the effect of chronic disease comorbidities on weight control behavior regarding weight perception. Adjusted odds ratios for weight control behavior tended to increase significantly with an increasing number of comorbidities in men regardless of weight perception (P<0.05 for trend), suggesting no interaction. Unlike women who perceived their weight accurately, women who under-perceived their weight did not show significant improvements in weight control behavior even with an increasing number of comorbidities. Thus, a significant interaction between weight perception and comorbidities was found only in women (P=0.031 for interaction). The effect of the relationship between accurate weight perception and chronic disease comorbidities on weight control behavior varied by sex. Improving awareness of body image is particularly necessary for overweight and obese women to prevent complications.

Incidence of metabolic syndrome and relative importance of five components as a predictor of metabolic syndrome: 5-year follow-up study in Korea.

The aim of this study was to describe the incidence of metabolic syndrome and to identify five components as metabolic syndrome predictors. The final study included 1,095 subjects enrolled in a rural part of Daegu Metropolitan City, Korea for a cohort study in 2003. Of these, 762 (69.6%) subjects had participated in the repeat survey. During the five-year follow-up, incidence density was significantly higher for women than for men (men, 30.0/1,000 person-years; women, 46.4/1,000 person-years). In both men and women, incidence of metabolic syndrome showed a significant increase with increasing number of metabolic syndrome components at baseline. Compared with individuals presenting none of components at baseline, relative risks were increased 1.22 (men; 95% CI, 0.43-3.51), 2.21 (women; 95% CI, 0.98-4.97) times more for individuals with one component of metabolic syndrome and 5.30 (men; 95% CI, 2.31-12.13), 5.53 (women; 95% CI, 2.78-11.01) times more for those who had two components. In multivariate analysis, the most powerful risk factor for metabolic syndrome was abdominal obesity in men and low HDL-cholesterol in women (adjusted relative risk, 3.28, 2.53, respectively). Consequently, finding a high risk group for metabolic syndrome according to gender and prevention of metabolic syndrome through lifestyle modification are essential.

Foreign body ingestion trends in children in the Daegu-Kyungpook Province, Korea before and during the COVID-19 period: a repeated cross-sectional study.

Background: During the coronavirus disease 2019 (COVID-19) period, children spent more time at home, which is where most foreign body ingestions (FBIs) in children occur. We compared the rate of FBI in children in the Daegu-Kyungpook Province during COVID-19 to the rate in the 2 years before the COVID-19 period. Methods: The period from January to December in the year 2020 was defined as the COVID-19 period, and the corresponding time period in 2018 and 2019 was defined as the pre-COVID-19 period. Medical records were analyzed retrospectively for pediatric patients aged 0-15 years who visited outpatient and emergency rooms at seven tertiary referral hospitals in Daegu-Kyungpook Province. Results: The annual occurrence rate of FBIs in patients visiting seven tertiary referral hospitals was not different during COVID-19 compared to that in the pre-COVID-19 period and the median age of these patients during the COVID-19 and pre-COVID-19 periods was similar. However, occurrence rates increased in the groups aged 0-3 and 4-6 years but decreased in the group aged 7-15 years during the COVID-19 period. The proportion of male patients as well as inpatients increased significantly during the COVID-19 period (both P=0.01). The proportion of foreign bodies located in the post-pyloric region increased during the COVID-19 period (P=0.02). The most common symptom, foreign body sensation in the neck, was similar in both groups. There was no significant difference in the foreign body removal method between the two groups. The occurrence rates of swallowing of toys, coins, magnets, button batteries, and superabsorbent polymers non-significantly increased; and the food ingestion rate decreased, while the non-food ingestion rate increased in all age groups during the COVID-19 period. Conclusions: The FBI rate in children did not differ during the COVID-19 period compared to that in the pre-COVID-19 period. The occurrence of FBI in boys, the number of foreign bodies located in the post-pyloric region, and the number of hospitalizations due to FBI increased during the COVID-19 period.

Associations of Polyp Characteristics in Children and Adolescents Presenting with Less Than Five Colorectal Polyps: A Full Colonoscopy Is Still Required.

Background/Aims: A full colonoscopy is currently required in children and adolescents with colorectal polyps, because of their potential of neoplastic transformation and complications such as intussusception. We aimed to analyze the associations of polyp characteristics in children and adolescents with colorectal polyps. Based on these findings, we also aimed to reevaluate the necessity of conducting a full colonoscopy. Methods: Pediatric patients <18 years of age who had undergone a colonoscopic polypectomy and those with <5 colorectal polyps were included in this multicenter, retrospective study. Baseline clinicodemographics, colonoscopic and histologic findings were investigated. Results: A total of 91 patients were included. Multivariate logistic regression analysis showed that polyp size was the only factor associated with the presence of any polyps located proximal to the splenic flexure (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28 to 4.28; p=0.007). Furthermore, polyp location proximal to the splenic flexure and sessile morphology were associated with the presence of any adenomatous polyp (OR, 8.51; 95% CI, 1.43 to 68.65; p=0.023; OR, 18.41; 95% CI, 3.45 to 173.81; p=0.002, respectively). Conclusions: In children and adolescents presenting with <5 colorectal polyps, polyp size and the presence of any adenomatous polyp were positively associated with polyp location proximal to the splenic flexure. This finding supports the necessity of a full colonoscopic exam in pediatric patients with colorectal polyps for the detection of polyps before the occurrence of complications such as intussusception or neoplastic transformation.

The relationship between poor sleep quality measured by the Pittsburgh Sleep Quality Index and smoking status according to sex and age: an analysis of the 2018 Korean Community Health Survey.

OBJECTIVES: Multiple studies have found that cigarette smokers are more likely to experience sleep disturbances than non-smokers. This study aimed to examine various associations between smoking and sleep quality according to sex and age, which have yet to be sufficiently examined in prior studies. METHODS: Data analysis was conducted using a nationally representative sample of 224,986 Korean adults who participated in the 2018 Korea Community Health Survey. Sleep quality, as the dependent variable, was measured using the Pittsburgh Sleep Quality Index (PSQI), with PSQI scores indicating either good (≤4 points) or poor (>5 points) sleep quality. Multiple logistic regression analysis was performed considering socio-demographic factors, health behaviors, comorbidities, and psychological factors as covariates. RESULTS: The overall weighted prevalence of poor sleep quality was 39.4% (95% confidence interval, 39.1 to 39.7). In the multivariate model that excluded psychological factors, poor sleep quality positively correlated to smoking for both sexes and all age groups except for male aged ≥65 years. However, in the full model that included psychological factors, statistically significant odds ratios (approximately 1.5) for poor sleep quality according to smoking status were only observed for female under 65 years of age. CONCLUSIONS: The relationship between poor sleep quality and smoking status differed according to sex and age. In order to improve the quality of sleep, it is necessary to intervene smoking cessation along with solving psychological problems, especially female in middle age and younger.

Harm Perception in Response to Pictorial Warning Labels Predict Higher Non-Smoking Intention among Korean Adolescents.

Because of recent controversy surrounding the use of excessively graphic pictorial warning labels (PWL) on cigarette packs in South Korea, it is necessary to provide evidence to evaluate their effectiveness as a tobacco control policy according to the harm perception they evoke. An analysis was performed using a nationally representative survey conducted six months after the introduction of PWLs in South Korea. Among 62,276 survey participants, 43,231 students from grades 7-12 who had seen a PWL in the past 30 days comprised the research sample. Non-smoking intention was evaluated according to the harm perception evoked by PWLs, which predicted higher non-smoking intention among adolescents. Non-smoking intention was particularly higher in daily smokers with harm perception (52.0%) than those who have never smoked and have no harm perception (40.1%). In the case of those who perceived harmfulness, non-smoking intention was formed in about 45% of daily smokers who had no experience of trying to quit in the last 12 months. Therefore, it is important to select PWLs that can arouse in adolescents sufficient harm perception of smoking.

Smoking Cessation Intention and Its Association with Advice to Quit from Significant Others and Medical Professionals.

Few studies have simultaneously considered the effects of significant others and medical professionals' advice to quit smoking on smoking cessation intention. The present study involved 3841 current adult Korean smokers, divided into four groups with an intention to quit within 1 month, within 6 months, someday, and without intention to quit. Multinomial multiple logistic regression analysis was conducted according to smoking cessation intention level, adjusted for potential confounders, including past smoking cessation attempts. Smokers who had been advised to quit smoking by both significant others and medical professionals, significant others only, and medical professionals only were 2.63 (95% confidence interval (CI): 1.62-4.29), 1.84 (95% CI: 1.17-2.89), and 1.44 (95% CI: 0.70-2.94) times more likely to intend to quit within 1 month, respectively, than those who were not advised to quit. The odds ratios of an intention to quit within 6 months were 2.91 (95% CI: 1.87-4.54), 2.49 (95% CI: 1.69-3.68), and 0.94 (95% CI: 0.44-2.05), respectively. To promote smokers' intention to quit, the role of significant others should be considered. Medical professionals' advice to quit smoking remains important, increasing the effects of significant others' advice.

Incidence and Prevalence Trends of Pediatric Inflammatory Bowel Disease in the Daegu-Kyungpook Province From 2017 to 2020.

Background and Aim: There is paucity of data regarding the epidemiology of pediatric IBD in Asia compared to that of Western countries. We aimed to investigate the incidence and prevalence trends of pediatric inflammatory bowel disease (IBD) in the Daegu-Kyungpook province of South Korea from 2017 to 2020. Methods: This study was a multicenter, retrospective study conducted in eight IBD referral centers located in the Daegu-Kyungpook province. Children and adolescents of ≤18 years who were initially diagnosed with IBD between 2017 and 2020 were included. The annual number of children and adolescents newly diagnosed with IBD and the annual resident population of children and adolescents ≤18 years of age in the Daegu-Kyungpook province were investigated to calculate the annual incidence and prevalence in the region. Results: A total 304 children and adolescents that had been diagnosed with IBD were included in this study. Among these patients, 71.4% had been diagnosed with Crohn's disease (CD), and 28.6% with ulcerative colitis (UC). The population based annual incidences of IBD from 2017 to 2020 were each 7.24, 6.82, 10.27, and 13.33 per 100,000, respectively (P for trend <0.001), 4.48, 5.26, 7.39, and 9.8 per 100,000, respectively, for CD (P for trend <0.001), and 2.76, 1.56, 2.88, and 3.53 per 100,000, respectively, for UC (P for trend = 0.174). Conclusion: Pediatric IBD, especially CD has significantly increased recently in the Daegu-Kyungpook province. Epidemiology studies from other regions of Asia are required to better elucidate this trend of increase in Asia.

The occurrence of infection-related systemic diseases in Korean children and adolescents has decreased after the spread of the COVID-19 pandemic: a multicenter retrospective study.

BACKGROUND: The occurrences of infection-related systematic diseases, such as Henoch-Schönlein Purpura (HSP), intussusception, and mucocutaneous lymph node syndrome (MCLS) may have decreased, similarly to the decreased occurrence of infectious diseases following the Coronavirus disease 2019 (COVID-19) pandemic. We aimed to investigate whether there was a change in the occurrence of these diseases in South Korea after the spread of the COVID-19 pandemic. METHODS: In this multicenter, retrospective study conducted in 16 medical centers in South Korea patients diagnosed with HSP, intussusception, and MCLS at the age of <18 years between January 2016 and December 2020 were included. New occurrences of these three diseases were investigated monthly and annually, while to compare between the pre- and post-COVID-19 era cases, new occurrences between 2017-2019 and 2020 were compared. Additionally, the total annual occurrence rate was calculated by dividing each center's occurrence into the annual population per 100,000 of the population <18 years in each region that the center covers. RESULTS: A total 6,857 patients were included in this study. From 2017 to 2020, the number of patients diagnosed with HSP, intussusception, MCLS at the age of <18 years were 1,301, 1,693, and 3,863 patients, respectively. The average number of patients during the three years before the COVID-19 pandemic were each 379.7, 505.3, and 1,112.0 for HSP, intussusception, MCLS, respectively, which each decreased by 57.3%, 65.0%, 52.6% to 162, 177, 527 in 2020, respectively. Furthermore, the total annual occurrence rate showed a significant decrease in 2020 compared to 2017 to 2019 in all three diseases (2017-2020; HSP: 11.85, 12.96, 10.52, and 5.48; intussusception: 13.94, 16.97, 16.31, and 5.98; MCLS: 33.89, 35.11, 34.69, and 17.82, respectively). CONCLUSIONS: We revealed that the occurrence of HSP, intussusception, and MCLS, which are representative of infection-related systemic diseases in the pediatric population, decreased significantly after the spread of the COVID-19 pandemic.

Low-dose persistent organic pollutants increased telomere length in peripheral leukocytes of healthy Koreans.

Although shortened telomeres have been found in many cancers, elongated telomere length has been observed as an early response after low-dose treatment with various chemical carcinogens in vitro and animal experiments, suggesting low-dose exposure to carcinogenic chemicals may function as a tumour promoter at the very early stage of carcinogenesis in humans. This cross-sectional study was performed to examine whether low-dose exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that mainly bioaccumulate in adipose tissue, is associated with telomere length of peripheral blood leukocytes in apparently healthy persons. Telomere length was measured using quantitative polymerase chain reaction method in 84 apparently healthy Koreans. Among various POPs, serum concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs) and polybrominated diphenylethers were measured. Most OC pesticides and PCBs were positively and significantly associated with telomere length with correlation coefficients from about +0.25 to +0.35. The strongest associations were observed with p,p'-dichlorodiphenyldichloroethylene, PCB99, PCB153, PCB180, PCB183 and PCB187. When we examined adjusted means of telomere length by quintiles of POPs, the steeper increases of telomere length tended to be observed within relatively lower ranges of POPs. Besides serum concentrations of POPs, none of the other variables studied, including age, were associated with telomere length in this study. We found that telomere length was increasing across low doses of exposure to POPs in which the majority of study subjects were found, suggesting that low-dose POPs may act as a tumour promoter in carcinogenesis in humans.

Association between Intention to Quit Cigarette Smoking and Use of Heated Tobacco Products: Application of Smoking Intensity Perspective on Heated Tobacco Product Users.

Tobacco companies have designed sophisticated marketing strategies for heated tobacco products (HTPs), and many smokers are exposed to advertisements purporting that HTPs can replace combustible cigarettes. The present study evaluates the relationship between poly-use of tobacco products and intention to quit cigarette smoking in association with smoking intensity, a meaningful indication of one's interest in quitting cigarette smoking. A total of 36,397 current cigarette smokers who participated in the 2019 Korea Community Health Survey were evaluated. A multivariable logistic regression model was designed. Additionally, smoking-intensity-stratified analyses were conducted. A total of 4.7% of the participants reported planning to quit cigarette smoking within one month. Current dual users of combustible cigarettes and HTPs presented no significantly increased likelihood of intention to quit cigarette smoking regardless of cigarette-smoking intensity. By contrast, light and heavy daily smokers who accompanied e-cigarette use presented significant adjusted odds ratios (aORs) of 1.81 (95% confidence interval (CI): 1.04-3.14) and 1.97 (95% CI: 1.14-3.42), respectively. Occasional and daily smokers who reported using both HTPs and e-cigarettes presented no significance. The results of the present study suggested that a complete replacement of combustible cigarettes with HTPs was unlikely.

Influence of School-Based Smoking Prevention Education on Reducing Gap in Exposure to Anti-Tobacco Media Message among Korean Adolescents.

Korean adolescents at high risk for smoking are less exposed to anti-tobacco media messages. This study examines whether school-based smoking prevention education is related to media exposure and whether it can contribute to reducing the gap in exposure to anti-tobacco media messages between smoking vulnerable and non-vulnerable groups. A nationally representative dataset, the 2018 Korea youth risk behavior web-based survey, comprising 59,410 students from grades 7-12, was analyzed. Logistic regression models were designed to evaluate the association between school-based smoking prevention education and media messages exposure. Within-group differences in exposure levels based on sociodemographic characteristics were compared depending on participation or nonparticipation in school-based smoking prevention education. Experience of smoking prevention education within a year was significantly associated with exposure to anti-tobacco media messages. Among Korean adolescents who participated in smoking prevention education compared to those who did not, the media messages exposure rate was more than 20% higher, and the exposure gap within the subgroups by sociodemographic characteristics was narrower. Participation in school-based smoking prevention education was significantly related to media messages exposure. This relationship can be used to improve the overall media messages exposure rate and to reduce the differences in exposure rate based on sociodemographic traits.

Cigarette or E-Cigarette Use as Strong Risk Factors for Heated Tobacco Product Use among Korean Adolescents.

Heated tobacco products (HTPs) were first introduced in Korea in June 2017. This study examined the prevalence of current HTP use among Korean adolescents and its association with conventional cigarette (CC) or electronic cigarette (EC) use. The study analyzed nationally representative data (the 2019 Korea Youth Risk Behavior Web-based Survey) from a sample of 57,303 Korean students from grades 7-12. Multinomial logistic regression models were designed to evaluate the association between EC or CC use and HTP use. A total of 2.6% of respondents were current HTP users and 95.9% of them were dual or triple users of CC or EC. The likelihood of HTP use was higher among current CC or EC users and highest among dual users. When the association between each tobacco product and current HTP use was analyzed, the dual use tendency of HTPs and other products steadily increased with the increase of CC or EC smoking frequency. Adolescents who use ECs and/or CCs are likely to use HTPs. Thus, HTPs could be a new public health concern for adolescents in terms of dual or triple use patterns of CC or EC.

Heated tobacco products: Cigarette complements, not substitutes.

BACKGROUND: In Korea, the sale of the first heated tobacco product (HTP), IQOS®, commenced in June 2017. This study evaluates the rates of HTP use and examines HTP users' smoking patterns of various tobacco products. METHODS: The study analyzed the 2018 Korea Community Health Survey data of a Korean provincial division, which includes 11 cities and 14 counties. Of 21,100 participants, the proportion of current HTP users was calculated and their smoking patterns, in regard to cigarette use, were examined. A multinomial logistic regression model was used to evaluate the related factors of HTP use. RESULTS: The proportion of current HTP users (HTP use within the past 30 days) was 2.13% of the study population. Of these current HTP users, 96.25% were dual users of cigarettes. The adjusted odds ratio (AOR) for current HTP use increased proportionately with frequency and amount of cigarette consumption with statistical significance. The AOR values showed a quadratic curve, descending after the peak value for moderate daily smokers (10-19 cigarettes/day) (Ptrend<0.001, Pquadratic<0.001). Current cigarette smokers who also used HTPs were not associated with an intention to quit cigarette smoking within a month. CONCLUSIONS: Given the smoking pattern of HTP users in terms of mutual use with cigarettes, HTPs might not be an alternative to cigarettes as tobacco companies claim.

Underestimation of Self-Reported Smoking Prevalence in Korean Adolescents: Evidence from Gold Standard by Combined Method.

The objective of this study was to evaluate the validity of self-reported smoking prevalence in Korean adolescents by using an improved gold standard by a combined method. Using a stratified sampling method, we selected 13 schools from among 397 high schools that participated in the 2015 Korean Youth Health Risk Behavior Web-Based Survey (KYRBS). A second survey (repeated self-reporting questionnaire and urinary cotinine test) was conducted on 1058 students who completed the KYRBS. The gold standard of current smoker was defined as those either self-reporting as a smoker in the second survey or having a urinary cotinine concentration ≥50 ng/mL. The current smoking prevalence in the first survey (KYRBS) was 7.9% (boys 16.5% and girls 1.8%), which was lower than the results based on gold standard (11.3% total, boys 21.9% and girls 3.7%). The sensitivity and specificity of self-reported smoking status was 62.5% and 99.0%, respectively. In particular, the sensitivity of girls (43.5%) was lower than that of boys (67.0%). The self-reported smoking prevalence in Korean adolescents was underestimated, particularly among girls. Careful attention should be paid to interpreting adolescents' smoking prevalence, and supplementary surveys or periodic validity tests need to be considered in Asian countries.

Is there differential responsiveness to a future cigarette price increase depending on adolescents' source of cigarette access?

We examined whether the responsiveness to an increase in cigarettes price differed by adolescents' cigarette acquisition source. We analyzed data on 6134 youth smokers (grades 7-12) from a cross-sectional survey in Korea with national representativeness. The respondents were classified into one of the following according to their source of cigarette acquisition: commercial-source group, social-source group, and others. Multiple logistic regressions were performed to estimate the effects of an increase in cigarette price on the intention to quit smoking on the basis of the cigarette acquisition source. Of the 6134 youth smokers, 36.0% acquired cigarettes from social sources, compared to the 49.6% who purchased cigarettes directly from commercial sources. In response to a future cigarette price increase, regardless of an individual's smoking level, there was no statistically significant difference in the odds ratio for the intention to stop smoking in association with cigarette acquisition sources. The social-source group had nonsignificant, but consistently positive, odds ratios (1.07-1.30) as compared to that of the commercial-source group. Our findings indicate that the cigarette acquisition source does not affect the responsiveness to an increase in cigarette price. Therefore, a cigarette price policy is a comprehensive strategy to reduce smoking among youth smokers, regardless of their source.