New framework to assess tracing and testing based on South Korea's response to COVID-19.

South Korea's remarkable success in controlling the spread of COVID-19 during the pre-Omicron period was based on extensive contact tracing and large-scale testing. Here we suggest a general criterion for tracing and testing based on South Korea's experience, and propose a new framework to assess tracing and testing. We reviewed papers on South Korea's response to COVID-19 to capture its concept of tracing and testing. South Korea expanded its testing capabilities to enable group tracing combined with preemptive testing, and to conduct open testing. According to our proposed model, COVID-19 cases are classified into 4 types: confirmed in quarantine, source known, source unknown, and unidentified. The proportion of the first two case types among confirmed cases is defined as "traced proportion", and used as the indicator of tracing and testing effectiveness. In conclusion, South Korea successfully suppressed COVID-19 transmission by maintaining a high traced proportion (> 60%) using group tracing in conjunction with preemptive testing as a complementary strategy to traditional contact tracing.

Patterns of cigarette, heated tobacco product, and nicotine vaping product use among Korean adults: Findings from the 2020 ITC Korea Survey.

INTRODUCTION: Non-combustible nicotine products (NCNPs), such as heated tobacco products (HTPs) and nicotine vaping products (NVPs) have gained a significant nicotine market share in South Korea. This descriptive study examined patterns of regular cigarette and NCNP use among South Korean adults. METHODS: Data were from the 2020 International Tobacco Control Korea Survey and included 4016 adults (aged ≥19 years) in the Republic of Korea who were regularly (at least weekly) using at least one NCNP (NVP/HTP, n=2117) and/or smoked cigarettes (n=3763) at the time of the survey. Weighted descriptive estimates were computed to assess respondents' nicotine product use among all respondents (exclusive, dual, or triple use). Thereafter, we identified sociodemographic characteristics associated with NCNP use (n=2117). RESULTS: Among Korean adults who were smoking cigarettes, 83.1% (95% CI: 81.6-84.6) did so exclusively, and 16.9% (95% CI: 15.4-18.4) smoked cigarettes and used NCNPs. Among those who used HTPs (n=1877), 14.9% (95% CI: 11.5-18.4) did so exclusively, 59.6% used HTPs and smoked cigarettes (95% CI: 55.4-63.1), 4.2% used HTPs and vaped (95% CI: 11.5-18.4), and 21.6% (95% CI: 18.9-24.2) used all three products. Of adults who used HTPs and smoked cigarettes, 86.6% smoked daily. Among those who vaped (n=865), 13.3% did so exclusively (95% CI: 9.4-17.1), 55.6% (95% CI: 49.6-61.5) vaped and smoked cigarettes, 5.1% (95% CI: 1.7-8.6) used HTPs and vaped, and 26.1% (95% CI: 22.1-30.1) used all three products. Of adults who vaped and smoked cigarettes, 82.4% (95% CI: 77.1-87.7) smoked daily. CONCLUSIONS: Cigarettes remain the most commonly used nicotine product in South Korea, and among adults using heated tobacco and/or vaping products, the majority were also smoking. Research is urgently needed to assess whether adults who are using an NCNP are doing so to quit, or rather to complement their cigarette smoking.

Association between accelerometer-derived physical activity and depression: a cross-sectional study using isotemporal substitution analysis.

OBJECTIVES: Depression is a significant public health concern, and physical activity has been identified as a non-pharmacological intervention. Understanding the dose-response relationship between physical activity and depression is crucial for designing effective exercise interventions and recommending physical activity to individuals with depression. The isotemporal substitution model is considered the gold standard for estimating the dose-response effects of physical activity. This study aims to investigate the dose-response association between depression and accelerometer-measured physical activity in the Korean population. DESIGN: Cross-sectional analysis. SETTING: A non-probability sample of the community population was drawn from the 2014 and 2016 Korean National Health and Nutrition Examination Survey. PARTICIPANTS: The study included 1543 adults aged 19-64 years who completed the Patient Health Questionnaire-9 (PHQ-9) and volunteered to wear an accelerometer. MAIN OUTCOME MEASURES: Physical activity was measured using a GT3X+ accelerometer for 7 consecutive days, and activity was categorised as sedentary behaviour (SB) or light, moderate or vigorous physical activity. Depression was assessed using the PHQ-9. RESULTS: Physical activity and SB were associated with depression. In the single-parameter model, moderate-vigorous physical activity (MVPA) showed a significant association with reduced odds of depression (OR: 0.817, 95% CI: 0.678 to 0.985). Substituting 30 min of SB with 30 min of MVPA (OR: 0.815, 95% CI: 0.669 to 0.992) was linked to a decrease in the odds of depression. Conversely, replacing 30 min of MVPA with 30 min of SB (OR: 1.227, 95% CI: 1.008 to 1.495) was associated with an increase in the odds of depression. CONCLUSIONS: This study provides evidence of an association between physical activity and depression in the Korean population, highlighting the importance of reducing SB and increasing MVPA to prevent and manage depression. Further research is needed to confirm causality and determine optimal levels of physical activity for preventing depression in different populations.

Evaluation of the Vestibulo-ocular Reflex Using the Video Head Impulse Test in Patients with Unilateral Chronic Otitis Media.

OBJECTIVES: To evaluate the vestibulo-ocular reflex (VOR) using the video head impulse test (vHIT) as a vestibular function assessment method in patients with unilateral chronic otitis media (COM). METHODS: Twenty-eight patients with unilateral COM scheduled for middle ear surgery, including 12 males and 16 females with a mean age of 54.5 years, successfully underwent preoperative vHIT. vHIT variables, including VOR gain, VOR gain asymmetry, and the incidence of corrective saccades, were compared between the ipsilesional and contralesional ears. RESULTS: Ten (35.7%) patients reported varying degrees of disequilibrium or lightheadedness. The VOR gain in the ipsilesional and contralesional ears were 1.01 ± 0.10 and 1.04 ± 0.11, 0.97 ± 0.12 and 0.94 ± 0.13, and 0.97 ± 0.13 and 1.04 ± 0.15 in the horizontal canal (HC), anterior canal (AC), and posterior canal (PC), respectively. The average VOR gains in the ipsilesional ears were within the predefined range of normal values; however, the gains in HC and PC significantly decreased compared with those in contralesional ears (p=0.038 in HC and p=0.015 in PC). The prevalence of corrective saccades, including overt and/or covert saccades, did not differ significantly between the two ears. CONCLUSION: This study assessed the pathophysiology of the inner ear affected by chronic middle ear infection by quantitatively comparing the VOR using vHIT. It demonstrated that vHIT can be a practical assessment of vestibular function in patients with COM.

National Smoking Cessation Services (NSCS) enrollment and their effect on long-term tobacco cessation in Korea: Results from a 1-year prospective follow-up of NSCS participants.

INTRODUCTION: The study aimed to identify predictors associated with long-term tobacco cessation at 12-month follow-up among users of the National Smoking Cessation Services (NSCS) in Korea. METHODS: To measure the long-term effect of NSCS delivery, the target sample size of 5167 adult smokers registered in the NSCS in 2018 was enrolled with proportional random sampling. A multiple logistic regression analysis (crude, adjusted) was performed to identify the changes in smoking status at the 12-month follow-up after the last NSCS enrollment and the potential factors associated with changes in smoking status. RESULTS: The response rate to reach the number of subjects targeted was 22.4%. A total of 41.2% of the tobacco users enrolled had successfully quit at baseline, and the 7-day point prevalence of tobacco cessation at the follow-up at 12 months, via a telephone survey, was 34.4%. Factors positively associated with cessation at the 12-month follow-up were longer experience with tobacco abstinence and additional quitting attempts with or without NSCS enrollment, although every additional quit attempt with NSCS use had a better outcome. In addition, having a successful quit outcome with NSCS use at the baseline and having more satisfaction with the service of professional counseling or incentives than others provided by NSCS, increased cessation at follow-up after adjustment of other factors considered. CONCLUSIONS: In addition to multiple quitting attempts, longer experience with tobacco abstinence, and additional enrollment in NSCS, the service experience, and satisfaction with the content that NSCS offered, might improve the lasting success of abstinence. These results might be considered to improve the contents and protocols of the NSCS for better outcomes.

Public support for tobacco endgame policies in South Korea: Findings from the 2020 International Tobacco Control Korea Survey.

BACKGROUND: Strong public support can increase the likelihood of adopting tobacco control policies. We assessed support for six commercial tobacco endgame policies in South Korea: limiting the nicotine in cigarettes, banning all additives in cigarettes, restricting the number of places where cigarettes are sold, and banning the manufacture and sales of cigarettes (unconditionally, with the provision of cessation support and with alternative tobacco products available). METHODS: Data were obtained from 4740 adults who completed the 2020 International Tobacco Control Korea Survey. Participants were categorised based on their nicotine use: (1) did not use any products, (2) vaped and/or used heated tobacco products (HTPs) but did not smoke cigarettes, (3) smoked cigarettes only and (4) smoked cigarettes and vaped and/or used HTPs. Attitudes towards the policies were classified as supportive, undecided or opposed. Weighted multinomial logistic regression models assessed support levels according to nicotine use. RESULTS: Support was highest for limiting the nicotine content in cigarettes (68.4%; 95% CI 64.6% to 72.3%) and restricting the number of retailers (68.1%; 95% CI 64.5% to 71.7%), and lowest for banning cigarette sales if alternative products are made available (45.0%; 95% CI 40.9% to 49.1%). People who did not use any products were most likely to support endgame policies, except for banning cigarette sales with alternatives available. The proportion of undecided participants exceeded 10% (range 13%-25%) for all policies. CONCLUSION: There is a strong public support for tobacco endgame policies in South Korea. Further research should prioritise the development of strategies to ensure the effective implementation of highly supported policies.

Decrease in household secondhand smoking among Korean adolescents associated with smoke-free policies: grade-period-cohort and interrupted time series analyses.

OBJECTIVES: Smoke-free areas have expanded and related campaigns have been implemented since 1995 in Korea. As a result, household secondhand smoke (SHS) exposure has decreased over the past 15 years. We assessed the cohort effect, the effect of a 2008 campaign on household SHS exposure, and the impact of a complete smoking ban in public places along with increased penalties, as implemented in December 2011. METHODS: Nationally representative cross-sectional 15-wave survey data of Korean adolescents were used. The 810,516 participants were classified into 6 grade groups, 15 period groups, and 20 middle school admission cohorts. An age-period-cohort analysis, conducted with the intrinsic estimator method, was used to assess the cohort effect of household SHS exposure, and interrupted-time series analyses were conducted to evaluate the effects of the smoke-free policy and the campaign. RESULTS: For cohorts who entered middle school from 2002 to 2008, the risk of household SHS exposure decreased among both boys and girls. Immediately after implementation of the smoke-free policy, the prevalence of household SHS exposure by period decreased significantly for boys (coefficient, -8.96; p<0.05) and non-significantly for girls (coefficient, -6.99; p=0.07). After the campaign, there was a significant decrease in household SHS exposure by cohort among boys, both immediately and post-intervention (coefficient, -4.84; p=0.03; coefficient, -1.22; p=0.02, respectively). CONCLUSIONS: A school-admission-cohort effect was found on household SHS exposure among adolescents, which was associated with the smoke-free policy and the campaign. Anti-smoking interventions should be implemented consistently and simultaneously.

Factors influencing psychological concerns about COVID-19 in South Korea: direct and indirect damage during the early stages of pandemic.

BACKGROUND: COVID-19 pandemic has led to psychological concerns, the distribution of which across populations may differ depending on whether pandemic-related damage is direct or indirect. This study aims to investigate concerns associated with direct and indirect damage according to population characteristics, and identify relatively vulnerable groups that are particularly affected by concerns. METHOD: This cross-sectional study used data from the 2020 Korea Community Health Survey, which collected data based on a complex sampling design. A total of 208,106 responses from individuals aged ≥ 19 were collected via in-person interviews. The items related to COVID-19 concerns were measured by Likert scales ranging from 1 to 5 and categorized into two types: direct concerns, which pertained to infection or death, and indirect concerns, which pertained to criticism, vulnerability, and economic damage, through factor analysis. We compared the means and effect size of direct concerns, indirect concerns, and overall concerns using weighted mean, ANOVA, and multiple regression analysis. RESULTS: Exploratory and confirmatory factor analyses supported a two-factor structure for psychological concerns about COVID-19 (CFI = 0.99, TLI = 0.97, SRMR = 0.02, RMSEA = 0.06), which were divided into direct and indirect concerns. Mean scores were 3.62 for direct concerns and 4.07 for indirect concerns. Direct concerns were higher in females (B = .26); the elderly (B = .15); those diagnosed with hypertension or diabetes (B = .04; B = .06); those with few assistants during quarantine (B = .15); and those whose neighbors responded inappropriately to COVID-19 (B = .07). Indirect concerns were lower among the elderly (B = -.04), and higher among young; married (B = .25); pink- or blue-collar workers (B = .08; B = .06); and those who felt that the city responded inappropriately to COVID-19 (B = .02). CONCLUSION: The prevalence of concerns regarding direct and indirect damage caused by the COVID-19 pandemic differed according to population characteristics. Some factors had a marked influence on direct and indirect concerns. Our findings could inform psychological interventions and policies for future pandemics. Customized interventions are needed to prevent negative psychological concerns and improve mental health.

Associations of meteorological factors and dynamics of scrub typhus incidence in South Korea: A nationwide time-series study.

Scrub typhus, also known as Tsutsugamushi disease, is a climate-sensitive vector-borne disease that poses a growing public health threat. However, studies on the association between scrub typhus epidemics and meteorological factors in South Korea need to be complemented. Therefore, we aimed to analyze the association among ambient temperature, precipitation, and the incidence of scrub typhus in South Korea. First, we obtained data on the weekly number of scrub typhus cases and concurrent meteorological variables at the city-county level (Si-Gun) in South Korea between 2001 and 2019. Subsequently, a two-stage meta-regression analysis was conducted. In the first stage, we conducted time-series regression analyses using a distributed lag nonlinear model (DLNM) to investigate the association between temperature, precipitation, and scrub typhus incidence at each location. In the second stage, we employed a multivariate meta-regression model to combine the association estimates from all municipalities, considering regional indicators, such as mite species distribution, Normalized Difference Vegetation Index (NDVI), and urban-rural classification. Weekly mean temperature and weekly total precipitation exhibited a reversed U-shaped nonlinear association with the incidence of scrub typhus. The overall cumulative association with scrub typhus incidence peaked at 18.7 C° (with RRs of 9.73, 95% CI: 5.54-17.10) of ambient temperature (reference 9.7 C°) and 162.0 mm (with RRs of 1.87, 95% CI: 1.02-3.83) of precipitation (reference 2.8 mm), respectively. These findings suggest that meteorological factors contribute to scrub typhus epidemics by interacting with vectors, reservoir hosts, and human behaviors. This information serves as a reference for future public health policies and epidemiological research aimed at controlling scrub typhus infections.

Mitophagy Decreases in the Peripheral Vestibular System of Aged C57BL/6J Mice.

BACKGROUND/AIM: Mitophagy is a cardinal process for maintaining healthy and functional mitochondria. A decline in mitophagy has been associated with age-related pathologies. We aimed to investigate mitophagy changes in age-related balance problems using an animal model. MATERIALS AND METHODS: C57BL/6J mice were divided into young (1 month old) and aged (12 months old) groups. Balance performance, mitochondrial DNA integrity, ATP content, mitophagic process, and mitophagy-related genes and proteins were investigated in both groups. RESULTS: Balance and motor performance were reduced in the aged group. Mitochondrial DNA integrity and ATP content, and mRNA levels of PINK1, Parkin, BNIP3, AMBRA1, MUL1, NIX, Bcl2-L-13, Atg3, Atg5, Atg12, and Atg13 in the vestibule were significantly lower in aged mice compared with those in young mice. The protein levels of PINK1, Parkin, BNIP3, LC3B, and OXPHOS subunits were significantly decreased in the aged vestibule. Mitophagosome and mitophagolysosome counts and the immunohistochemical expression of Parkin and BNIP3 were also decreased in the saccule, utricle, and crista ampullaris in the aged group. CONCLUSION: A general decrease in mitophagy with aging might be attributed to a decrease in cellular function in the aged vestibule during the development of age-related balance problems.

Working hours, social engagement, and depressive symptoms: an extended work-life balance for older adults.

BACKGROUND: In recent years, researchers have been examining the impact of work-life balance (WLB) on mental health, considering it as a potential risk factor. However, it remains unclear whether the traditional understanding of WLB applies to older adults who worked for fewer hours before full retirement and whose children are likely to be independent adults. Therefore, this study aims to propose a modified form of WLB specifically for older adults. Within this context, we hypothesize that an optimum balance between working hours and social engagement protects against depressive symptoms among older adults. METHOD: We conducted an analysis using data on 5,751 Korean adults older than 55 years from the Korean Longitudinal Study of Aging 2016. Multivariate logistic regression analysis was used to evaluate the relationships among working hours, social engagement, and depressive symptoms. RESULTS: Older adults who worked fewer than 35 h per week were less likely to experience depressive symptoms than were non-working older adults and those working 35 h or more per week. Additionally, older adults with a high level of informal social participation, thus occurring almost every day or two to three times per week, were less likely to experience depressive symptoms than were those with a low level of such participation (once a month or less). Furthermore, depressive symptoms were less frequent among those who worked fewer than 35 h per week and engaged in a high level of informal social participation compared to non-working older individuals and those with a low level of informal social participation. CONCLUSIONS: Maintaining an optimal number of working hours and degree of social engagement are necessary to minimize the risk of depressive symptoms in older adults. Based on these findings, we suggest that fulfillment for work and life and their balance are important for older adults and propose work-life fulfillment balance.

Corrigendum: Modeling the future of tobacco control: Using SimSmoke to explore the feasibility of the tobacco endgame in Korea.

[This corrects the article DOI: 10.18332/tid/174127.].

Physical Activity Pattern of Adults With Metabolic Syndrome Risk Factors: Time-Series Cluster Analysis.

Background: Physical activity plays a crucial role in maintaining a healthy lifestyle, and wrist-worn wearables, such as smartwatches and smart bands, have become popular tools for measuring activity levels in daily life. However, studies on physical activity using wearable devices have limitations; for example, these studies often rely on a single device model or use improper clustering methods to analyze the wearable data that are extracted from wearable devices. Objective: This study aimed to identify methods suitable for analyzing wearable data and determining daily physical activity patterns. This study also explored the association between these physical activity patterns and health risk factors. Methods: People aged >30 years who had metabolic syndrome risk factors and were using their own wrist-worn devices were included in this study. We collected personal health data through a web-based survey and measured physical activity levels using wrist-worn wearables over the course of 1 week. The Time-Series Anytime Density Peak (TADPole) clustering method, which is a novel time-series method proposed recently, was used to identify the physical activity patterns of study participants. Additionally, we defined physical activity pattern groups based on the similarity of physical activity patterns between weekdays and weekends. We used the χ2 or Fisher exact test for categorical variables and the 2-tailed t test for numerical variables to find significant differences between physical activity pattern groups. Logistic regression models were used to analyze the relationship between activity patterns and health risk factors. Results: A total of 47 participants were included in the analysis, generating a total of 329 person-days of data. We identified 2 different types of physical activity patterns (early bird pattern and night owl pattern) for weekdays and weekends. The physical activity levels of early birds were less than that of night owls on both weekdays and weekends. Additionally, participants were categorized into stable and shifting groups based on the similarity of physical activity patterns between weekdays and weekends. The physical activity pattern groups showed significant differences depending on age (P=.004) and daily energy expenditure (P<.001 for weekdays; P=.003 for weekends). Logistic regression analysis revealed a significant association between older age (≥40 y) and shifting physical activity patterns (odds ratio 8.68, 95% CI 1.95-48.85; P=.007). Conclusions: This study overcomes the limitations of previous studies by using various models of wrist-worn wearables and a novel time-series clustering method. Our findings suggested that age significantly influenced physical activity patterns. It also suggests a potential role of the TADPole clustering method in the analysis of large and multidimensional data, such as wearable data.

Association between depression, anemia and physical activity using isotemporal substitution analysis.

BACKGROUND: Depression is a leading cause of disability and mortality, with estimated number of deaths exceeding 2.2 million worldwide. We examined depression in relation to anemia and physical activity, both of which have an impact on depression mechanisms. METHODS: This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey, including 18,622 participants. Depression was measured by The Patient Health Questionnaire-9, and physical activity was assessed by the Global Physical Activity Questionnaire. Anemia was defined by World Health Organization criteria for blood hemoglobin levels. Isotemporal substitution model for physical activity was used to assess the effect of replacing sedentary behavior to each intensity level of physical activity. Logistic regression was applied to estimate the association on depression. RESULTS: Replacing sedentary behavior with moderate or vigorous physical activity was associated with a lower risk of depression in the anemic (OR: 0.875, 95% CI: 0.782-0.978) and non-anemic groups (OR: 0.943, 95% CI: 0.919-0.967). Depression risk was significantly reduced by replacing walking with moderate to vigorous physical activity in both anemic (OR: 0.877, 95% CI: 0.784-0.982) and non-anemic groups (OR: 0.951, 95% CI: 0.927-0.976). CONCLUSIONS: Moderate to vigorous physical activity had a protective association against depression in both anemic and non-anemic groups. Anemic patients are recommended to perform physical activity for any duration acceptable to them to prevent depression.

Modeling the future of tobacco control: Using SimSmoke to explore the feasibility of the tobacco endgame in Korea.

INTRODUCTION: We used a simulation model to assess the feasibility of reaching the tobacco endgame target (reducing the smoking prevalence to below 5% by 2050) and explored potential implementation strategies. METHODS: The impact of strengthened tobacco-control policies on smoking prevalence was analyzed using Korea SimSmoke, a discrete-time Markov process. We considered the effects of various scenarios from 2023 and predictions were conducted until 2050. To confirm the stability of the results, deterministic and probabilistic sensitivity analyses were carried out by increasing and decreasing parameter estimates. RESULTS: The implementation of tobacco-control policies in accordance with the WHO MPOWER (Μonitor tobacco use and prevention policies; Protect people from tobacco smoke; Offer help to quit tobacco smoking; Warn of the dangers of tobacco; Enforce bans on tobacco advertising, promotion, and sponsorship; Raise taxes on tobacco) measures were insufficient to achieve the tobacco endgame objective of 5% by 2050. The overall predicted smoking prevalence in 2050 is 4.7% if all policies are fully implemented in accordance with the FCTC guidelines together with a complete ban on the sale of cigarettes to people born after 2003 and annual 10% increases in price. Sensitivity analyses using the varying policy effect assumptions demonstrated the robustness of the simulation results. CONCLUSIONS: For a substantive reduction in smoking prevalence, it is essential to strongly implement the MPOWER strategy. Beyond this foundational step, the eradication of smoking requires a paradigm shift in the perception of conventional tobacco-control policies, including a tobacco-free generation strategy and radical increases in the price of tobacco products.

Implication of findings from a two-wave survey on embitterment in South Korea for strategies to promote mental health of the general public.

OBJECTIVE: To examine the prevalence of embitterment by following individuals over time and to statistically evaluate how factors known as correlates of embitterment affect different groups with or without changes in embitterment over time. METHOD: Responses for the posttraumatic embitterment disorder (PTED) self-rating Scale were collected from the same 1,153 adults who participated in a follow-up survey delivered 14 months apart. Suggested cutoff points were applied to identify changes in embitterment and four groups were identified. For each group, the relative impacts of factors that affect changes in or maintenance of embitterment, such as negative life events (NLEs), belief in a just world (BJW), social support, relative deprivation, and resilience, were statistically analyzed. RESULTS: The average PTED scores were relatively high for both surveys (M = 1.73 and 1.58, respectively). "Persistent" or "increased" in embitterment was seen for 47.3% of the participants. In particular, 15.3% (Wave 1) and 12.1% (Wave 2) of participants experienced clinically relevant levels of embitterment. NLEs, BJW, relative deprivation, and resilience showed significant associations with the risk of persistence or deterioration of embitterment. CONCLUSIONS: Our study highlights embitterment as a dynamic emotion that can either be aggravated or moderated over time. Embitterment can be elicited by joint effects of multiple social and interactional factors including known embitterment correlates, and relative deprivation is confirmed as a possible core elicitor of embitterment in the context of comparative justice. These findings imply that additional longitudinal research and development of practices for mental health prevention in general populations are needed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Use of geographically weighted regression models to inform retail endgame strategies in South Korea: application to cigarette and ENDS prevalence.

BACKGROUND: Reducing tobacco retailer availability is a key tobacco endgame policy. The development and evaluation of retail-based policies require spatial methodologies. We modelled the prevalence of adult cigarette and electronic nicotine delivery system (ENDS) use according to tobacco retailer density, considering geographical variations. METHODS: Registration data for tobacco retail businesses, a population-representative survey of South Koreans aged ≥19 years, and population and land area data were used. We merged the datasets according to geographical units. Ordinary least squares (OLS) and geographically weighted regression (GWR) analyses were conducted to model cigarette and ENDS use prevalence, respectively. FINDINGS: Tobacco retailer density was associated with increased cigarette use prevalence in the OLS model (ß=2.19, p=0.02). A 1.9-fold difference by region was identified for the coefficient, indicating an association with tobacco retailer density (minimum 1.39, maximum 2.65), in the GWR analysis. No significant association was present between tobacco retailer density and ENDS prevalence in either the OLS (ß=0.24, p=0.37) or the GWR model (minimum 0.20, maximum 0.28). CONCLUSION: Our results suggest the importance of using spatial methods to develop and evaluate retail-based endgame policies. The establishment of tobacco retailer databases by the introduction of licensing is necessary to develop and evaluate the effectiveness of tobacco retailer regulations.

Perceptions of harmfulness of heated tobacco and nicotine vaping products compared to cigarettes, and the association of advertising exposure on harm perceptions among adults who smoke in South Korea: Cross-sectional findings from the 2020 ITC Korea Survey.

INTRODUCTION: Heated tobacco products (HTPs) and nicotine vaping products (NVPs) both are legal consumer products in the Republic of Korea. Little is known about perceptions of harmfulness of HTPs and NVPs relative to cigarettes in South Korea among adults who smoke, and how exposure to marketing may be associated with harmfulness perceptions. METHODS: This study used data from the 2020 International Tobacco Control (ITC) Korea Survey, and included 3713 adult (aged 19 years) cigarette smokers who were: 1) exclusive smokers (n=1845); 2) dual HTP + cigarette consumers (n=1130); 3) dual NVP + cigarette consumers (n=224); and 4) triple consumers (all three products, n=514). Weighted multinomial regression models were conducted to estimate smokers' perceptions of harmfulness of HTPs and NVPs compared to cigarettes, NVPs to HTPs, and self-reported exposure to HTP/NVP advertising. Analyses compared the perceptions of harmfulness between the four different consumer groups, and tested whether exposure to HTP/NVP advertising was associated with perceptions of lower relative harm. RESULTS: Among all respondents, 27.5% believe that HTPs are less harmful than cigarettes and 23.4% believe that NVPs are less harmful than cigarettes. Exclusive cigarettes smokers were significantly less likely to perceive that HTPs and NVPs are less harmful than cigarettes compared to dual HTP + cigarette consumers, dual NVP + cigarette consumers, and triple consumers (all p<0.001). Half of respondents perceive NVPs as equally harmful as HTPs (14.1% perceive NVPs as more harmful than HTPs). Exposure to HTP/NVP advertising was associated with perceiving these products as less harmful than cigarettes. CONCLUSIONS: About one-quarter of Korean cigarette smokers perceive HTPs and NVPs as less harmful than cigarettes. Further investigation is required to understand how harm perceptions and HTP/NVP advertising are related to changes in product use, such as switching between products, using multiple products, or discontinuing all product use.

Tinnitus characteristics in patients with idiopathic sudden sensorineural hearing loss and acute tinnitus.

Objective: Tinnitus is a common symptom of idiopathic sudden sensorineural hearing loss (ISSHL). This study aimed to investigate the characteristics and outcomes of acute tinnitus in patients with ISSHL. Methods: A total of 59 patients with ISSHL and acute tinnitus were enrolled. All patients underwent audiological assessment, tinnitus matching for loudness and frequency, and steroid treatment for sudden hearing loss. Tinnitus-related distress was assessed using the tinnitus handicap inventory (THI) questionnaire. The outcomes of hearing recovery and tinnitus remission were investigated retrospectively. Results: The loudness and pitch of acute tinnitus were 63.2 ± 22.4 dB HL and 2010.63 ± 2368.99 Hz, respectively. Complete and partial recovery rates of acute tinnitus in ISSHL patients were 32.2% and 39% according to the THI scores. The group with complete recovery of hearing showed significantly greater improvement in tinnitus distress than the group with no improvement in hearing. The loudness and pitch of tinnitus did not correlate with tinnitus remission. Conclusion: Hearing recovery is more important for tinnitus remission than the psychoacoustic characteristics of acute tinnitus. Timely identification and proper treatment of hearing loss are important to improve tinnitus remission in patients with ISSHL. Level of Evidence: Level 4.

Characteristics of fatal occupational injuries in migrant workers in South Korea: A machine learning study.

Objective: Analysis of occupational injuries is essential for developing preventive strategies. However, few studies have evaluated severe occupational injuries in migrant workers from the perspective of gender. Therefore, using a new analytical method, this study was performed to identify gender-specific characteristics associated with fatal occupational injuries among migrant workers; the interactions between these factors, were also analyzed. In addition, we compared the utility of explainable artificial intelligence (XAI) using SHapley Additive exPlanations (SHAP) with logistic regression (LR) and discuss caveats regarding its use. Materials and methods: We analyzed national statistics for occupational injuries among migrant workers (n = 67,576) in South Korea between January 1, 2007, and September 30, 2018. We applied an extreme gradient boosting model and developed SHAP and LR models for comparison. Results: We found clear gender differences in fatal occupational injuries among migrant workers, with males in the same occupation having a higher risk of death than females. These gender differences suggest the need for gender-specific occupational injury prevention interventions for migrant workers to reduce the mortality rate. Occupation was a significant predictor of death among female migrant workers only, with care jobs having the highest fatality risk. The occupational fatality risk of female workers would not have been identified without the performance of detailed job-specific analyses stratified by gender. The major advantages of SHAP identified in the present study were the automatic identification and analysis of interactions, ability to determine the relative contributions of each feature, and high overall performance. The major caveat when using SHAP is that causality cannot be established. Conclusion: Detailed job-specific analyses stratified by gender, and interventions considering the gender of migrant workers, are necessary to reduce occupational fatality rates. The XAI approach should be considered as a complementary analytical method for epidemiological studies, as it overcomes the limitations of traditional statistical analyses.