epiH :: Epidemiology and Health

COVID-19: Special Article Smoking, drinking, and physical activity among Korean adults before and during the COVID-19 pandemic: a special report of the 2020 Korea National Health and Nutrition Examination Survey

Sunhye Choi, Jinwook Bahk, Suyeon Park, Kyungwon Oh, et al. Epidemiol Health. 2022;44:e2022043.

COVID-19: Special Article Mental health of Korean adults before and during the COVID-19 pandemic: a special report of the 2020 Korea National Health and Nutrition Examination Survey

Hyunsuk Jeong, Suyeon Park, Jihee Kim, Kyungwon Oh, et al. Epidemiol Health. 2022;44:e2022042.

Abstract: OBJECTIVES:
This study aimed to describe trends in health behaviours between 2011 and 2020 and compare the changes in these behaviours between the 2020 COVID-19 pandemic and previous periods according to socio-demographic variables.
METHODS:
This study used data from the 2011 to 2020 Korea National Health and Nutrition Examination Survey. Current cigarette smoking, high-risk drinking, and inadequate physical activity levels were used as health behaviour indicators. The age-standardized prevalence, differences in prevalence between the periods, and the annual percentage change (APC) were calculated.
RESULTS:
Current cigarette smoking showed a decreasing trend (APC, -2.6), high-risk drinking remained unchanged, and inadequate physical activity levels increased (APC, 3.5) during 2011-2020. There were significant differences in high-risk drinking (3.1%p; 95% confidence interval [CI], 0.3 to 5.9) and inadequate physical activity levels (4.3%p; 95% CI, 0.4 to 8.1) between 2019 and 2020 in men. Among men, increased high-risk drinking was found in those aged 40-49 years, non-single households, urban residents, and the middle and highest income groups between 2019 and 2020. The low educational group and manual workers among men aged 30-59 years also showed an increased proportion of high-risk drinking. Inadequate physical activity levels also increased among men between 2019 and 2020 in those aged 30-39 years, non-single households, urban residents, and the upper-middle-income group.
CONCLUSIONS:
In the first year of the COVID-19 pandemic, Korean men’s high-risk drinking and inadequate physical activity levels increased. In addition to social efforts to reduce the spread of infectious diseases, active measures to positively change health behaviour are needed.

Abstract: OBJECTIVES:
Coronavirus disease 2019 (COVID-19) and the associated social distancing, limited freedom, and fear of an uncertain future are expected to have substantial mental health effects. We investigated mental health responses in the community during the first year of the COVID-19 pandemic in Korea.
METHODS:
We used 2016-2019 and 2020 data from the Korea National Health and Nutrition Examination Survey (KNHANES) to assess pre-pandemic and pandemic mental health status, respectively, in terms of perceived severe stress, depression, and suicidal plans. All analyses were gender-stratified. Pre-specified subgroup analyses were performed according to age, employment status, and household income.
RESULTS:
The percentage of Korean adults with suicidal plans increased significantly from 1.3%p (95% confidence interval [CI], 1.1 to 1.5) in 2016-2019 to 1.8%p (95% CI, 1.4 to 2.1) in 2020. Individuals in their 20s and 40s showed a marked increase in suicidal plans (1.2%p; 95% CI, 0.0 to 2.3 and 0.9%p; 95% CI, 0.0 to 1.8, respectively). In men, depression and perceived severe stress increased significantly from pre-COVID-19 to 2020. There was a 2.4%p (95% CI, 0.8 to 4.0) increase in depression among standard workers and a 2.9%p increase in depression in individuals in the second-highest quintile of household income from 2016 and 2018 to 2020.
CONCLUSIONS:
As COVID-19 continued, mental health issues such as suicidal plans, depression, and severe stress increased significantly in young men and people in the second-highest quintile of household income. Proactive community mental health efforts are needed to prevent increases in the suicide rate resulting from prolonged exposure to the COVID-19 pandemic.

COVID-19: Special Article Obesity, hypertension, diabetes mellitus, and hypercholesterolemia in Korean adults before and during the COVID-19 pandemic: a special report of the 2020 Korea National Health and Nutrition Examination Survey

Ga Bin Lee, Yoonjung Kim, Suyeon Park, Hyeon Chang Kim, et al. Epidemiol Health. 2022;44:e2022041.

COVID-19: Original Article Unemployment and COVID-19-related mortality: a historical cohort study of 50,000 COVID-19 patients in Fars, Iran

Alireza Mirahmadizadeh, Mohammad Taghi Badeleh Shamooshaki, Amineh Dadvar, Mohammad Javad Moradian, et al. Epidemiol Health. 2022;44:e2022032.

Abstract: OBJECTIVES:
We investigated trends in obesity, hypertension, diabetes, and hypercholesterolemia before and during the coronavirus disease 2019 (COVID-19) pandemic in the Korean adult population.
METHODS:
Data from 60,098 participants in the Korea National Health and Nutritional Examination Survey between 2011 and 2020 aged ≥19 were used. The age-standardized prevalence and annual percent changes (APCs) were calculated for obesity (body mass index ≥25 kg/m2), hypertension (systolic/diastolic blood pressure ≥140/90 mmHg or under treatment), diabetes (hemoglobin A1c ≥6.5%, fasting glucose ≥126 mg/dL, physician diagnosis, or under treatment), and hypercholesterolemia (total cholesterol ≥240 mg/dL or under treatment).
RESULTS:
Over the past decade (2011-2020), the age-standardized APCs (95% confidence intervals) for obesity, hypertension, diabetes and hypercholesterolemia were 3.0% (2.1 to 3.8), 0.1% (-1.3 to 1.5), 1.5% (-1.0 to 4.0) and 8.0% (5.7 to 10.3), respectively, in men; and -0.2% (-1.5 to 1.2), -0.5% (-1.9 to 0.9), -0.1% (-2.3 to 2.2) and 5.9% (3.9 to 8.0), respectively, in women. In 2020 compared to the previous 3 years (2017-2019), obesity, hypertension, diabetes, and hypercholesterolemia increased in men (6.0, 1.8, 1.9, and 2.8%p, respectively), but an increase was not apparent in women (2.5, -1.1, 0.8, and 0.7%p, respectively).
CONCLUSIONS:
An increase in major chronic diseases was observed in Korean adults, especially men, during the COVID-19 pandemic. In order to reduce the burden of cardiovascular and metabolic diseases in the future, effective intervention strategies need to be developed according to the characteristics of the target groups.

Abstract: OBJECTIVES:
Previous studies have estimated the risk of death associated with unemployment in the coronavirus disease 2019 (COVID-19) pandemic, but no studies have examined unemployment before COVID-19 infection as a risk factor for COVID-19-related mortality. Thus, this study aimed to investigate COVID-19 mortality among this population.
METHODS:
Data on 50,038 people aged 25-59 years were collected from 38 agencies in Fars Province, Iran, from February 2020 to July 2021. Follow-up lasted from participants’ diagnosis with COVID-19 based on the results of a reverse transcription-polymerase chain reaction test to participants’ death or the end of the study period. The association between unemployment and COVID-19-related mortality was estimated using the Poisson regression method, and a sensitivity analysis was conducted to calculate the E-value.
RESULTS:
Unemployment was associated with a 2.41-fold (95% confidence interval [CI], 2.01 to 2.90) higher age-adjusted and sex-adjusted risk of COVID-19-related mortality. The adjusted Poisson regression analysis showed 8.82 (95% CI, 6.42 to 12.11), 2.84 (95% CI, 1.90 to 4.24), and 1.58 (95% CI, 1.24 to 2.01) times higher risks of COVID-19-related mortality among unemployed people aged 25-39 years, 40-49 years, and 50-59 years, respectively, than among their employed counterparts. Unemployment increased the risk of COVID-19 mortality by 3.31 (95% CI, 2.31 to 4.74) and 2.30 (95% CI, 1.86 to 2.84) times in female and male, respectively. The E-value was 3.43, reflecting the minimum strength of confounding required to shift the association between unemployment and COVID-19-related mortality toward the null.
CONCLUSIONS:
Unemployment prior to COVID-19 infection increased the risk of COVID-19-related mortality. COVID-19-related mortality disproportionately impacted unemployed women and younger unemployed people.

Perspective Measles susceptibility of marriage migrant women in Korea

Sooyeon Kim, Sun A Kim, Hanbich Hong, Seong Ryeong Choi, et al. Epidemiol Health. 2022;44:e2022031.

Original Article Recent trends in opioid prescriptions in Korea from 2002 to 2015 based on the Korean NHIS-NSC cohort

Joungyoun Kim, Sang-Jun Shin, Jihyun Yoon, Hyeong-Seop Kim, et al. Epidemiol Health. 2022;44:e2022029.

Abstract: International migrants could be considered a risk group susceptible to vaccine-preventable diseases. We conducted a measles seroprevalence study among 419 marriage migrant women living in Sinan-gun and Wando-gun, South Jeolla Province, located in the southwestern part of Korea. The overall seroimmunity was 92.8%. The seroimmunity varied considerably according to the country of origin and increased with age. Our current analysis could be valuable in the context of discussions concerning vaccination policies for immigrants in Korea.

Abstract: OBJECTIVES:
Opioids are prescribed to treat moderate to severe pain. We investigated recent trends in opioid (morphine, oxycodone, fentanyl, and hydromorphone) prescriptions using data from the Korean National Health Insurance Service-National Sample Cohort between 2002 and 2015.
METHODS:
The morphine milligram equivalent (MME) was calculated to standardize the relative potency of opioids. The number (cases) or amount (MME) of annual opioid prescriptions per 10,000 registrants was computed to analyze trends in opioid prescriptions after age standardization. Joinpoint regression analysis was conducted to calculate the annual percentage change and average annual percentage change (AAPC).
RESULTS:
The number (cases) of prescriptions per 10,000 registrants increased from 0.07 in 2002 to 41.23 in 2015 (AAPC, 76.0%; 95% confidence interval [CI], 61.6 to 91.7). The MME per 10,000 registrants increased from 15.06 in 2002 to 40,727.80 in 2015 (AAPC, 103.0%; 95% CI, 78.2 to 131.3). The highest AAPC of prescriptions and MME per 10,000 registrants were observed in the elderly (60-69 years) and in patients treated at general hospitals. Fentanyl prescriptions increased most rapidly among the 4 opioids.
CONCLUSIONS:
Consumption of opioids greatly increased in Korea over the 14-year study period.

Original Article Association between levels of physical activity and low handgrip strength: Korea National Health and Nutrition Examination Survey 2014-2019

Hyungsoon Ahn, Hwa Young Choi, Moran Ki Epidemiol Health. 2022;44:e2022027.

Original Article Differences in accuracy of height, weight, and body mass index between self-reported and measured using the 2018 Korea Community Health Survey data

Yoonsil Ko, Sunhye Choi, Jisoo Won, Yeon-Kyeng Lee, et al. Epidemiol Health. 2022;44:e2022024.

Abstract: OBJECTIVES:
This study aimed to investigate the association between levels of physical activity (PA) and low handgrip strength in Korean adults.
METHODS:
Our cross-sectional study design included 24,109 Korean adults older than 19 years of age who participated in the Korea National Health and Nutrition Examination Survey 2014–2019. Low handgrip strength is described as hand strength less than the cut-off value of the 20th percentile of handgrip strength from a healthy population in each gender and age group. PA was categorized into three levels (inactive, active, and highly active) according to the World Health Organization’s global recommendations on PA for health. Multivariable logistic regression analysis was used to examine the association between levels of PA and low handgrip strength.
RESULTS:
Odds ratios (ORs) for low handgrip strength were significantly higher in middle-aged women who were active (adjusted odds ratio [aOR], 1.40; 95% confidence interval [CI], 1.15 to 1.69) and inactive (aOR, 1.47; 95% CI, 1.23 to 1.76) than in those highly active in walking exercise. Most of older people had significantly higher ORs for low handgrip strength in active compared to highly active in the context of aerobic, muscle strengthening, and walking exercise.
CONCLUSIONS:
Walking exercise was associated with a lower risk of sarcopenia in middle-aged women and older individuals. However, further studies are necessary to confirm the causal relationship between levels of PA and low handgrip strength.

Abstract: OBJECTIVES:
This study aimed to determine an effective survey method for the accurate calculation of obesity prevalence by comparing the self-reported and measured height, weight, and body mass index (BMI) using the 2018 Korea Community Healthy Survey (CHS) data.
METHODS:
Raw data from the 2018 CHS were used to analyze the differences, correlation, and agreement between self-reported and measured height, weight, and BMI.
RESULTS:
The self-reported height was over-reported than the measured height (0.59 cm greater for men and 0.71 cm greater for women), while the self-reported weight was under-reported than the measured weight (0.55 kg less for men and 0.67 kg less for women). Subsequently, the self-reported BMI was under-estimated (0.35 kg/m² lower for men and 0.49 kg/m² lower for women) compared with the measured BMI. The kappa statistic and agreement between measured and self-reported values per BMI category (underweight, normal, overweight, and obesity) were 0.82 and 79.6%, respectively.
CONCLUSIONS:
The prevalence of obesity should be calculated using the measured values provided in the CHS in order to promote local health projects based on accurate evidence.

Original Article Secular trends and related factors in leisure-time sedentary behavior among Koreans: an analysis of data from the 2011-2017 Korea Community Health Survey

Hyun-Ju Seo, Min-Jung Choi, Soon-Ki Ahn Epidemiol Health. 2022;44:e2022023.

Original Article 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

Jun Hyun Hwang, Soon-Woo Park Epidemiol Health. 2022;44:e2022022.

Abstract: OBJECTIVES:
Sedentary behavior has gradually increased and has become a public health problem. Therefore, this study investigated trends in weekday leisure-time sedentary behaviors, as well as characteristic socio-demographic and lifestyle correlates in Korean adults.
METHODS:
We analyzed data from 914,946 adults aged ≥19 years who participated in the Korea Community Health Survey (2011, 2013, 2015, and 2017). Leisure-time sedentary behavior was categorized as a binary variable (<4 and ≥4 hr/day). Multivariable regression analysis was used to model the prevalence of sedentary behavior and estimate odds ratios.
RESULTS:
The prevalence of leisure-time sedentary behavior decreased from 15.2% to 14.4% in men and from 16.6% to 16.0% in women between 2011 and 2017, respectively. However, a significant increase was observed in subjects with an education lower than high school in both genders (β coefficient=0.12 for men and 0.08 for women, p for trend <0.001). Women in the lowest household income level (β coefficient=0.08, p for trend=0.001) and with poor subjective health status (β coefficient=0.05, p for trend=0.013) showed an increasing trend. Other factors associated with sedentary behavior were age, education level, body mass index, household income, walking activity, perceived stress level, and subjective health status in both genders.
CONCLUSIONS:
Identifying the secular trends and correlates of sedentary behavior by gender and associated factors will provide empirical evidence for developing public health campaigns and promotion programs to reduce sedentary behavior in Koreans.

Abstract: 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.

Data Profile The Korea National Health and Nutrition Examination Survey data linked Cause of Death data

Sungha Yun, Kyungwon Oh Epidemiol Health. 2022;44:e2022021.

COVID 19: Original Article The general public’s perspectives on telemedicine during the COVID-19 pandemic in Korea: analysis of a nationwide survey

EunKyo Kang, Hyejin Lee, Ki Jeong Hong, Jieun Yun, et al. Epidemiol Health. 2022;44:e2022020.

Abstract: The Korea National Health and Nutrition Examination Survey (KNHANES) is a national health survey that is conducted annually to assess the health and and health-related behaviors of Korean population. To utilize KNHANES data to studies of mortality risk factors, the Korea Disease Control and Prevention Agency (KDCA) constructed a database linking KNHANES data to cause-of-death statistics in Statistics Korea, made available to researchers since 2020. The KNHANES data were linked to the Cause of Death Statistics based on resident registration numbers for subjects aged 19 years or older who agreed to link the data. The linkage rate between 2007-2015 National Health and Nutrition Examination Survey and 2007-2019 Cause of Death Statistics was 97.1%. In the linked dataset, the total death rate was 6.6%, of which neoplasms accounted for the highest death rate (32.1%), followed by circulatory system disease (22.7%) and respiratory system disease (11.5%). The linked dataset was made available through the Research Data Center of the KDCA after a review of the research proposal, and will be made available after periodical updates.

Abstract: OBJECTIVES:
We investigated the awareness, experience, approval, intention to use, and the desired type of telemedicine among Korean general public.
METHODS:
From November to December 2020, we conducted an online self-reported survey on awareness, experience, approval, and intent to use telemedicine services among Korean residents aged 20 years or older. A total of 2,097 participants completed the survey.
RESULTS:
Of the 2,097 participants, 1,558 (74.3%) were aware of, 1,198 (57.1%) approved of, and 1,474 (70.3%) had the intention to use telemedicine. Participants from regions other than the Seoul metropolitan area and Daegu–Gyeongbuk Province (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.02 to 1.63), households with a monthly household income of US$6,000 or more (aOR, 1.44; 95% CI, 1.01 to 2.08), participants who had a college/university or associate’s degree (aOR, 1.35. 95% CI, 1.04 to 1.75) or a master’s degree or above (aOR, 1.73; 95% CI, 1.20 to 2.50), and housewives (aOR, 1.30; 95% CI, 1.03 to 1.64) had higher odds of approval. Elderly participants, those with a chronic disease (aOR, 1.26; 95% CI, 1.04 to 1.54), those who had experienced delays of healthcare services (aOR, 1.94; 95% CI, 1.27 to 2.96), and those who had experience with telemedicine (aOR, 4.28; 95% CI, 1.69 to 10.82) were more likely to intend to use telemedicine services. Regarding types of telemedicine, teleconsultation between doctors showed the highest approval rate (73.1%).
CONCLUSIONS:
In the context of the coronavirus disease 2019 pandemic, more than 70% of participants had already used or intended to use telemedicine at some point. Groups with a substantial need for telemedicine were more in favor of telemedicine.

Original Article Dairy product consumption and type 2 diabetes among Korean adults: a prospective cohort study based on the Health Examinees (HEXA) study

Jiaqi Zhang, Kyungjoon Lim, Sangah Shin Epidemiol Health. 2022;44:e2022019.

COVID 19: Original Article Depression, anxiety, and stress in Korean general population during the COVID-19 pandemic

Hooyeon Lee, Dongwoo Choi, Jung Jae Lee Epidemiol Health. 2022;44:e2022018.

Abstract: OBJECTIVES:
It has been suggested that the consumption of dairy products helps lower the prevalence of type 2 diabetes (T2D). We investigated the association between the consumption of dairy products and T2D events in middle-aged Korean adults.
METHODS:
We followed up 53,288 participants (16,895 male and 36,393 female) in the Health Examinees (HEXA) study. The consumption of dairy products was assessed using the self-administered food frequency questionnaire, and T2D was defined according to the 2015 treatment guidelines of the Korean Diabetes Association. Hazard ratios (HRs) and 95% confidence intervals (CIs) between the consumption of dairy products and the risk of T2D were calculated using Cox proportional hazards models after adjusting for potential confounders. Spline regression was used to better represent the association between the consumption of dairy products and the risk of T2D.
RESULTS:
Among male, those with higher consumption of dairy products had a significantly lower risk of T2D than those who consumed essentially no dairy products (HR, 0.73; 95% CI, 0.58 to 0.91). In particular, consumption of yogurt (HR, 0.75; 95% CI, 0.60 to 0.93; p_trend=0.035) and cheese (HR, 0.66; 95% CI, 0.49 to 0.89; p_trend=0.005) was negatively associated with the incidence of T2D in male. In female, daily consumption of 1 serving of yogurt decreased the risk of T2D by 11%.
CONCLUSIONS:
The association between the consumption of dairy products and the risk of T2D differed by sex and dairy product type. Further prospective studies are needed to confirm these associations.

Abstract: OBJECTIVES:
The aim of this study was to investigate the prevalence and risk factors of poor mental health in the general Korean population during the coronavirus disease 2019 (COVID-19) pandemic.
METHODS:
This cross-sectional, population-based, online survey-based study was conducted from November 5 to 20, 2020 and included adults aged 20-49 years in Chungnam Province, Korea. A total of 549 adults were included.
RESULTS:
In total, 18.8% of the participants had symptoms of depression, 10.6% had symptoms of anxiety, and 5.1% had a high level of perceived stress during the COVID-19 pandemic. Higher levels of stress (odds ratio [OR], 3.13; 95% confidence interval [CI], 1.13 to 8.67), anxiety (OR, 2.33; 95% CI, 1.09 to 4.49), and depression (OR, 3.00; 95% CI, 1.64 to 5.50) were found among never married, widowed, divorced, and separated people than among married/cohabiting/partnered participants. Participants who felt increased stress at home during the COVID-19 outbreak reported more depression (OR, 2.45; 95% CI, 1.49 to 4.05) and anxiety (OR, 2.42; 95% CI, 1.31 to 4.50). Women had higher risks of anxiety (OR, 1.97; 95% CI, 1.09 to 3.58) and stress (OR, 6.40; 95% CI, 2.30 to 17.85) than men. Participants with the highest household income were less likely to report symptoms of stress than those with the lowest household income (OR, 0.24; 95% CI, 0.06 to 0.96).
CONCLUSIONS:
The participants in this study exhibited poor mental health index scores, suggesting that some people are at risk for mental health problems during the COVID-19 pandemic. Being married was independently and significantly associated with a lower likelihood of depression, anxiety, and stress.

Original Article Elder abuse/mistreatment and associated covariates in India: results from the Longitudinal Aging Study in India wave 1, 2017-2018

Thennavan Sathya, Yesuvadian Selvamani, Rangasamy Nagarajan Epidemiol Health. 2022;44:e2022017.

COVID 19: Perspective Neglecting the neglected during the COVID-19 pandemic: the case of leptospirosis in Sri Lanka

Janith Warnasekara, Suneth Agampodi Epidemiol Health. 2022;44:e2022015.

Abstract: OBJECTIVES:
Elder abuse has significant adverse consequences for the overall health and well-being of the elderly, including premature mortality. Using cross-sectional data, we assessed the prevalence of elder abuse in India, its variation across states, and associated factors.
METHODS:
Nationally representative data from the first wave of the Longitudinal Aging Study in India were analyzed. Bivariate and multivariate analyses were used to study the prevalence, state variations, and associated factors of elder abuse.
RESULTS:
Overall, 5.2% of elderly adults (≥60 years) had experienced abuse in the year prior to the survey and 3% had experienced abuse within their own household. Verbal abuse or disrespect was the most common form of abuse. Considerable variation was observed in the prevalence of elder abuse across states and union territories, with the highest prevalence observed in Bihar (11.6%) and Karnataka (10.1%). In regression analysis, education level emerged as a protective factor against elder abuse, particularly among women. Older adults who lived alone, had functional limitations, had multiple morbidities, and had been hospitalized in the past year were more likely to experience abuse. Older adults who experienced abuse were 2 times more likely to experience depressive symptoms.
CONCLUSIONS:
Cross-state variation in the prevalence of elder abuse and subgroup differences suggest that state-specific interventions and essential monitoring of older adults with functional limitations, chronic diseases, and recent hospitalization can further reduce the prevalence and consequences of elder abuse in India.

Abstract: The coronavirus disease 2019 (COVID-19) pandemic has disrupted global health systems and affected the transmission dynamics as well as the surveillance of other infectious diseases. This study described the probable effect of the COVID-19 pandemic on the surveillance and control of leptospirosis in Sri Lanka. With 8,579 reported cases and more than 800 estimated deaths, the Sri Lankan public health surveillance system documented the largest outbreak of leptospirosis in Sri Lankan history in 2020. This was the worst infectious disease outbreak Sri Lanka experienced in 2020, but it was neglected, primarily due to the COVID-19 pandemic.

COVID 19: Original Article Socioeconomic inequality in compliance with precautions and health behavior changes during the COVID-19 outbreak: an analysis of the Korean Community Health Survey 2020

Ga Bin Lee, Sun Jae Jung, Yang Yiyi, Jea Won Yang, et al. Epidemiol Health. 2022;44:e2022013.

Original Article Independent predictors of depressive symptoms and social isolation on 2-year all-cause mortality among the Korean elderly in a population-based cohort study: gender differences

Hyunsuk Jeong, Hyeon Woo Yim, Beom-Woo Nam Epidemiol Health. 2022;44:e2022012.

Abstract: OBJECTIVES:
This study examined socioeconomic inequalities in compliance with precautions and health behavior changes during the coronavirus disease 2019 (COVID-19) outbreak using a representative Korean sample.
METHODS:
This exploratory study utilized around 210,000 participants aged ≥25 years in the Korean Community Health Survey 2020. Socioeconomic status was measured with educational attainment and household income. Outcomes included non-compliance with 8 precaution measures and deterioration in 6 health behaviors. The relative inequality index (RII) was calculated to quantify the degree of inequality by education and income level. RII values >1.0 indicate that deprived people have a higher frequency of health problems, and RII values <1.0 conversely indicate a higher frequency of health problems in more advantaged groups.
RESULTS:
People with lower education or income levels tended to have higher rates of non-compliance with COVID-19 safety precautions (RII range, 1.20 to 3.05). Lower education and income levels were associated with an increased smoking amount (RII=2.10 and 1.67, respectively) and sleep duration changes (RII=1.21 and 1.36, respectively). On the contrary, higher education and income levels were associated with decreased physical activity (RII=0.59 and 0.77, respectively) and increased delivery food consumption (RII=0.27 and 0.37, respectively). However, increased alcohol drinking was associated with lower education and income levels in younger men (RII=1.73 and 1.31, respectively), but with higher levels in younger women (RII=0.73 and 0.68, respectively).
CONCLUSIONS:
Our findings suggest the need to develop customized strategies, considering the characteristics of the target population, to decrease the burden and impact of the COVID-19 outbreak.

Abstract: OBJECTIVES:
This study examined whether depressive symptoms and social isolation were independent predictors of 2-year all-cause mortality among the elderly using data from a population-based cohort study.
METHODS:
In total, 1,033 participants (320 men and 713 women) older than 60 years of age participated in this study. Depressive symptoms, social isolation status, and socio-demographic and health-related covariates were assessed at baseline. The primary outcome measure was 2-year all-cause mortality. Data were collected through in-person interviews by trained interviewers. The GENMOD procedure was used to calculate relative risks (RRs).
RESULTS:
Of the 1,033 participants, 102 (40 men and 62 women) died within the follow-up period of 2 years. During the 2-year follow-up period, 17.8% of depressed men and 12.3% of depressed women died, and 29.8% of socially isolated men and 14.9% of socially isolated women died. Social isolation was an independent predictor of mortality in elderly men (adjusted relative risk [aRR], 4.6, 95% confidence interval [CI], 2.0 to 10.2), while depressive symptoms were an independent predictor of mortality in elderly women (aRR, 2.0; 95% CI, 1.2 to 3.6) when controlling for potential confounding factors. However, the depressive symptoms detected using the geriatric depression scale were not associated with mortality in men, and social isolation was not associated with mortality in women.
CONCLUSIONS:
The effects of depressive symptoms and social isolation on 2-year all-cause mortality within an elderly population differed according to gender. Gender-specific community-based interventions must be developed to potentially reduce 2-year all-cause mortality among the elderly.

COVID 19: Brief Communication Trends in gastrointestinal infections before and during non-pharmaceutical interventions in Korea in comparison with the United States

Soyeoun Kim, Jinhyun Kim, Bo Youl Choi, Boyoung Park Epidemiol Health. 2022;44:e2022011.

Original Article Increasing trends in mortality and costs of infectious diseases in Korea: trends in mortality and costs of infectious diseases

Dahye Baik, Byung-Woo Kim, Moran Ki Epidemiol Health. 2022;44:e2022010.

Abstract: OBJECTIVES:
This study examined how trends in the weekly frequencies of gastrointestinal infectious diseases changed before and during the coronavirus disease 2019 (COVID-19) pandemic in Korea, and compared them with the trends in the United States.
METHODS:
We compared the weekly frequencies of gastrointestinal infectious diseases (16 bacterial and 6 viral diseases) in Korea during weeks 5-52 before and after COVID-19. In addition, the weekly frequencies of 5 gastrointestinal infectious diseases in the United States (data from the Centers for Disease Control and Prevention) that overlapped with those in Korea were compared.
RESULTS:
The mean weekly number of total cases of gastrointestinal infectious diseases in Korea showed a significant decrease (from 522 before COVID-19 to 245 after COVID-19, p<0.01). Only bacterial gastrointestinal infectious diseases caused by Campylobacter increased significantly; other bacterial gastrointestinal infectious diseases showed either a decrease or no change. The incidence of all other viral diseases decreased. In the United States, the weekly numbers of Salmonella, Campylobacter, typhoid, shigellosis, and hepatitis A virus cases sharply decreased after the COVID-19 outbreak. The weekly case numbers of all viral diseases markedly decreased in both countries; however, bacterial gastrointestinal infectious diseases showed a different pattern.
CONCLUSIONS:
The incidence of gastrointestinal infectious diseases decreased after the COVID-19 outbreak. In contrast, Campylobacter infections showed an increasing trend in Korea, but a decreasing trend in the United States. Further studies are needed to elucidate the different trends in bacterial and viral infectious diseases before and after non-pharmaceutical interventions and between different countries.

Abstract: OBJECTIVES:
In an era when the average life expectancy and overall mortality rate have improved, Korea remains at risk for infectious disease outbreaks that place substantial burdens on the healthcare system. This study investigated trends in mortality and the economic burden of infectious diseases.
METHODS:
Healthcare data from the Health Insurance Review and Assessment Service (2009-2019) and the Korean Statistics Information Service (1997-2019) were used. We selected 10 infectious disease groups (intestinal infections, tuberculosis, vaccine- preventable diseases, sepsis, viral hepatitis, HIV-related diseases, central nervous system infections, rheumatic heart diseases, respiratory tract infections, and arthropod-borne viral diseases).
RESULTS:
The age-standardized mortality rate for infectious diseases increased from 27.2 per 100,000 population in 1997 to 37.1 per 100,000 population in 2019 and has had an upward trend since 2004. During this same period, significant increases were seen in respiratory tract infections and among elderly persons, especially those aged ≥85 years. The costs for infectious diseases increased from 4.126 billion US dollar (USD) in 2009 to 6.612 billion USD in 2019, with respiratory tract infections accounting for 3.699 billion USD (69%). The annual cost per patient for visits for medical care due to infectious diseases increased from 131 USD in 2009 to 204 USD in 2019.
CONCLUSIONS:
Mortality among elderly persons and those with respiratory tract infections increased during the study period. The economic burden of infectious diseases has consistently increased, especially for respiratory tract infections. It is therefore essential to establish effective management policies that considers specific infectious diseases and patient groups.

Original Article The predictive value of resting heart rate in identifying undiagnosed diabetes in Korean adults: Korea National Health and Nutrition Examination Survey

Dong-Hyuk Park, Wonhee Cho, Yong-Ho Lee, Sun Ha Jee, et al. Epidemiol Health. 2022;44:e2022009.

Systematic Review Quantifying the duration of the preclinical detectable phase in cancer screening: a systematic review

Sandra M. E. Geurts, Anne M. W. M. Aarts, André L. M. Verbeek, Tony H. H. Chen, et al. Epidemiol Health. 2022;44:e2022008.

Abstract: OBJECTIVES:
The purpose of this study was (1) to examine whether the addition of resting heart rate (RHR) to the existing undiagnosed diabetes mellitus (UnDM) prediction model would improve predictability, and (2) to develop and validate UnDM prediction models by using only easily assessable variables such as gender, RHR, age, and waist circumference (WC).
METHODS:
Korea National Health and Nutrition Examination Survey (KNHANES) 2010, 2012, 2014, 2016 data were used to develop the model (model building set, n=19,675), while the data from 2011, 2013, 2015, 2017 were used to validate the model (validation set, n=19,917). UnDM was defined as a fasting glucose level ≥126 mg/dL or glycated hemoglobin ≥6.5%; however, doctors have not diagnosed it. Statistical package for the social sciences logistic regression analysis was used to determine the predictors of UnDM.
RESULTS:
RHR, age, and WC were associated with UnDM. When RHR was added to the existing model, sensitivity was reduced (86 vs. 73%), specificity was increased (49 vs. 65%), and a higher Youden index (35 vs. 38) was expressed. When only gender, RHR, age, and WC were used in the model, a sensitivity, specificity, and Youden index of 70%, 67%, and 37, respectively, were observed.
CONCLUSIONS:
Adding RHR to the existing UnDM prediction model improved specificity and the Youden index. Furthermore, when the prediction model only used gender, RHR, age, and WC, the outcomes were not inferior to those of the existing prediction model.

Abstract: OBJECTIVES:
The aim of this study was to provide an overview of published mathematical estimation approaches to quantify the duration of the preclinical detectable phase (PCDP) using data from cancer screening programs.
METHODS:
A systematic search of PubMed and Embase was conducted for original studies presenting mathematical approaches using screening data. The studies were categorized by mathematical approach, data source, and assumptions made. Furthermore, estimates of the duration of the PCDP of breast and colorectal cancer were reported per study population.
RESULTS:
From 689 publications, 34 estimation methods were included. Five distinct types of mathematical estimation approaches were identified: prevalence-to-incidence ratio (n=8), maximum likelihood estimation (n=16), expectation-maximization algorithm (n=1), regression of observed on expected (n=6) and Bayesian Markov-chain Monte Carlo estimation (n=5). Fourteen studies used data from both screened and unscreened populations, whereas 19 studies included only information from a screened population. Estimates of the duration of the PCDP varied between 2 years and 7 years for breast cancer in the Health Insurance Plan study (annual mammography and clinical breast examinations in women aged 40-64 years) and 2 years and 5 years for colorectal cancer in the Calvados study (a guaiac fecal occult blood test in men and women aged 45-74 years).
CONCLUSIONS:
Different types of mathematical approaches lead to different estimates of the PCDP duration. We advise researchers to use the method that matches the data available, and to use multiple methods for estimation when possible, since no method is perfect.

Original Article Impact of water fluoridation on dental caries decline across racial and income subgroups of Brazilian adolescents

Rafael Aiello Bomfim, Paulo Frazão Epidemiol Health. 2022;44:e2022007.

COVID 19: Original Article Evidence of the importance of contact tracing in fighting COVID-19

Okyu Kwon Epidemiol Health. 2022;44:e2022006.

Abstract: OBJECTIVES:
The aim of this study was to assess the impact of community water fluoridation (CWF) on differences in dental caries decline across racial and socioeconomic subgroups of Brazilian adolescents.
METHODS:
Two nationwide Brazilian population-based oral health surveys were used (Brazilian Oral Health Survey 2003 and 2010). In total, 7,198 adolescents from 15 years to 19 years old living in 50 cities investigated in both surveys were included. The mean numbers of untreated decayed teeth (DT) according to racial (Whites vs. Browns/Blacks) and socioeconomic subgroups (at or above the minimum wage per capita vs. under) were analysed. Difference-in-differences negative binomial regressions were adjusted by schooling, age, and sex. Decayed, missing, and filled teeth and DT prevalence, calculated as a categorical variable, were used in sensitivity analyses.
RESULTS:
The adjusted difference of reduction in DT was similar across socioeconomic subgroups (β=-0.05; 95% confidence interval [CI], -0.45 to 0.35) and favoured, but not to a significant degree, Whites (β=-0.34; 95% CI, -0.74 to 0.04) compared to Brown/Blacks in fluoridated areas. In non-fluoridated areas, significant differences were observed in the mean number of DT, favouring the higher socioeconomic subgroup (β=-0.26; 95% CI, -0.53 to -0.01) and Whites (β=-0.40; 95% CI, -0.69 to -0.11) in relation to their counterparts. The sensitivity analyses confirmed the findings.
CONCLUSIONS:
The similar reduction in DT across income subgroups suggests that CWF has had a beneficial effect on tackling income inequalities in dental caries within a 7-year timeframe.

Abstract: OBJECTIVES:
We analyzed data to determine whether there are distinguishing characteristics depending on the success or failure of control for coronavirus disease 2019 (COVID-19) by country in the trend of the daily number of confirmed cases and the number of tests.
METHODS:
We obtained the number of confirmed cases and tests per day for almost every country in the world from Our World in Data. The Pearson correlation between the two time series was calculated according to the time delay to analyze the relationship between the number of tests and the number of cases with a lag.
RESULTS:
For each country, we obtained the time lag that makes the maximum correlation between the number of confirmed cases and the number of tests for COVID-19. It can be seen that countries whose time lag making maximum correlation lies in a special section between about 15 days and 20 days are generally been successful in controlling COVID-19. That section looks like a trench on the battlefield.
CONCLUSIONS:
We have seen the possibility that the success in mitigating COVID-19 can be expressed as a simple indicator of the time lag of the correlation between confirmed cases and tests. This time lag indicator is presumably reflected by efforts to actively trace the infected persons.

Original Article Association of participation in the Northern Finland Birth Cohort 1986 with mental disorders and suicidal behaviour

Martta Kerkelä, Mika Gissler, Juha Veijola Epidemiol Health. 2022;44:e2022005.

COVID 19: Original Article Does having various types of fear related to COVID-19 disrupt individuals’ daily life?: Findings from a nationwide survey in Korea

Woorim Kim, Yeong Jun Ju, Soon Young Lee Epidemiol Health. 2022;44:e2022004.

Abstract: OBJECTIVES:
In prospective follow-up studies, participants are normally contacted during the follow-up period. Even though the idea is not to intervene, the studies conducted during follow-up may affect the target population. Our hypotheses were that participation in the prospective Northern Finland Birth Cohort 1986 study (NFBC 1986) increased the use of mental health services and reduced suicidal behaviour due to participation in follow-up studies.
METHODS:
The NFBC 1986 study covered people with an expected date of birth between July 1985 and June 1986 in northern Finland (n=9,396). The participants of the NFBC 1986 were followed since the antenatal period with follow-ups including clinical examinations. The comparison cohort comprised people born in the same area in 1987 (n=8,959), who were not contacted. Registry data on psychiatric treatment, suicide attempts, and suicides were available. Crude risk ratios (RRs) and adjusted (for marital status and education) Mantel-Haenszel RRs were reported.
RESULTS:
No increase in mental disorders were found in NFBC 1986 compared to comparison cohort. In the crude RR analysis of female participants, a lower risk for suicide attempts was found (RR, 0.67; 95% confidence interval, 0.49 to 0.92; p=0.011).
CONCLUSIONS:
The results did not support our first hypothesis regarding the increased use of mental health services in the NFBC 1986 cohort. However, our second hypothesis gained some support as female participants of the NFBC 1986 had a lower risk of suicide attempts, although it was not due to a higher number of participants receiving psychiatric treatment.

Abstract: OBJECTIVES:
Unexpected changes in daily routines caused by the coronavirus disease 2019 (COVID-19) pandemic may affect psychological health. This study investigated the association between various types of COVID-19-related fear and the subjective level of disturbance in daily activities experienced by individuals.
METHODS:
This cross-sectional study used the Korea Community Health Survey conducted from August through November 2020. COVID-19-related fear included fear of infection, death, public criticism, family members getting infected, and economic loss. The subjective level of disruption in daily activities was measured using a 0-100 numeric rating scale developed by the Korea Disease Control and Prevention Agency. Multivariable linear regression was used to analyze the associations between the independent and dependent variables. A subgroup analysis was performed based on income level.
RESULTS:
Participants who reported fear of infection (β=-3.37, p<0.001), death (β=-0.33, p=0.030), public criticism (β=-1.63, p<0.001), a family member getting infected (β=-1.03, p<0.001), and economic loss (β=-3.52, p<0.001) experienced more disturbances in daily activities. The magnitude of this association was most significant in the lowest-income group.
CONCLUSIONS:
Individuals reporting COVID-19-related fear experienced higher levels of subjective disruption in daily activities.

Epidemiologic investigation An outbreak of hepatitis A associated with salted clams in Busan, Korea

Hyunjin Son, Miyoung Lee, Youngduck Eun, Wonseo Park, et al. Epidemiol Health. 2022;44:e2022003.

Original Article Age-specific effects of ozone on pneumonia in Korean children and adolescents: a nationwide time-series study

Kyoung-Nam Kim, Youn-Hee Lim, Sanghyuk Bae, In Gyu Song, et al. Epidemiol Health. 2022;44:e2022002.

Abstract: OBJECTIVES:
In July 2019, there were multiple reports on patients with hepatitis A among the visitors of a restaurant in Busan. The current study presents the results of an epidemiological investigation and outlines the supplementary measures that would help with hepatitis A control.
METHODS:
A cohort study was conducted for all 2,865 customers who visited restaurant A from June to July. Using a standardized questionnaire, participants reported the presence of hepatitis A symptoms and whether they had consumed any of 19 food items. As for participants who had visited public health centers, their specimens were collected.
RESULTS:
From the study cohort, 155 participants (5.4%) had confirmed hepatitis A. The epidemic curve was unimodal, and the median number of days from the restaurant visit to symptom onset was 31 days. A genotype analysis indicated that 89 of 90 tested patients had hepatitis A virus (HAV) genotype 1A. The results of a multivariate logistic regression analysis indicated that the ingestion of salted clams increased the risk of hepatitis A by 68.12 times (95% confidence interval [CI], 9.22 to 510.87). In an unopened package of salted clams found and secured through traceback investigation, HAV genotype 1A was detected.
CONCLUSIONS:
To prevent people from ingesting uncooked clams, there needs to be more efforts to publicize the dangers of uncooked clams; the food sampling test standards for salted clams should also be expanded. Furthermore, a laboratory surveillance system based on molecular genetics should be established to detect outbreaks earlier.

Abstract: OBJECTIVES:
The aim of this study was to estimate the age-specific effects of 8-hour maximum ozone levels on pneumonia in children and adolescents.
METHODS:
We performed quasi-Poisson regression analyses for individuals of 0-4 years, 5-9 years, 10-14 years, and 15-19 years of age using nationwide time-series data from the Korea (2011-2015). We constructed distributed lag linear models employing a generalized difference-in-differences method and controlling for other air pollutants.
RESULTS:
A 10.0-parts per billion increase in 8-hour maximum ozone levels was associated with a higher risk of hospital admissions due to pneumonia at 0-4 (relative risk [RR], 1.02; 95% confidence interval [CI], 1.01 to 1.03) and 5-9 years of age (RR, 1.06; 95% CI, 1.04 to 1.08), but not at 10-14 (RR, 1.01; 95% CI, 0.98 to 1.04) or 15-19 years of age (RR, 1.01; 95% CI, 0.97 to 1.06). The association between ozone and hospital admissions due to pneumonia was stronger in cool seasons (from November to April) than in warm seasons (from May to October), but was similar between boys and girls.
CONCLUSIONS:
Short-term exposure to ozone was associated with a higher risk of pneumonia at 0-4 years and 5-9 years of age, but not at 10-14 years or 15-19 years of age. Our findings can help identify vulnerable periods, determine the target populations for public health interventions, and establish air pollution standards.

Editorial Happy New Year 2022 from Epidemiology and Health (epiH)

Hyeon Chang Kim Epidemiol Health. 2022;44:e2022001.

Abstract

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