OBJECTIVES: Since exposure to sexual content and early sexual initiation among adolescents have become serious social issues in Korea, an in-depth analysis of trends in the prevalence of sexual experience among Korean adolescents is necessary to project the trends and policies required for the next 10 years. The objective of this study was to identify the contributions of age, period, and birth cohort effects on the prevalence of sexual experience in Korean adolescents. METHODS: We analyzed age-specific, period-specific, and birth cohort–specific trends in the prevalence of sexual experience among 911,502 adolescents (469,593 boys, 51.5%; 441,909 girls, 48.5%) aged 12 years to 17 years from the 2006 to 2017 Korean Youth Risk Behavior Web-based Survey. Joinpoint regression analysis was conducted to examine significant changes in the prevalence of sexual experience and to find the optimal number and location of places where trends changed. RESULTS: The prevalence of sexual experience generally increased with age in all periods in both boys and girls. In boys, the prevalence of sexual experience increased in recent periods, especially in the age group of 12-13 years, while the prevalence of sexual experience decreased in the age group of 16-17 years. In girls, the age group of 12-13 years showed an increased prevalence of sexual experience in recent periods. However, the prevalence showed a decreasing trend in the age group of 16-17 years. CONCLUSIONS In boys and girls, sexual experience increased with age, although this tendency has slowed in recent cohorts. Therefore, early sex education is needed.

OBJECTIVES: Since exposure to sexual content and early sexual initiation among adolescents have become serious social issues in Korea, an in-depth analysis of trends in the prevalence of sexual experience among Korean adolescents is necessary to project the trends and policies required for the next 10 years. The objective of this study was to identify the contributions of age, period, and birth cohort effects on the prevalence of sexual experience in Korean adolescents. METHODS: We analyzed age-specific, period-specific, and birth cohort–specific trends in the prevalence of sexual experience among 911,502 adolescents (469,593 boys, 51.5%; 441,909 girls, 48.5%) aged 12 years to 17 years from the 2006 to 2017 Korean Youth Risk Behavior Web-based Survey. Joinpoint regression analysis was conducted to examine significant changes in the prevalence of sexual experience and to find the optimal number and location of places where trends changed. RESULTS: The prevalence of sexual experience generally increased with age in all periods in both boys and girls. In boys, the prevalence of sexual experience increased in recent periods, especially in the age group of 12-13 years, while the prevalence of sexual experience decreased in the age group of 16-17 years. In girls, the age group of 12-13 years showed an increased prevalence of sexual experience in recent periods. However, the prevalence showed a decreasing trend in the age group of 16-17 years. CONCLUSIONS In boys and girls, sexual experience increased with age, although this tendency has slowed in recent cohorts. Therefore, early sex education is needed.

OBJECTIVES: Previous studies have shown that marital status is associated with household composition and living arrangements, which partially explain observed differences in health status according to marital status. However, due to the rapid socioeconomic and demographic transformations of the last few decades, the distribution of marital status among middle-aged adults has become more diverse. Therefore, this study aimed to obtain up-to-date information on the associations between marital status and health and to investigate the implications of these findings for conventional explanations of the health effects of marriage. METHODS: The data for this study were obtained from the 2015 Korean Community Health Study. We compared 4 modifiable lifestyle behaviors—smoking, alcohol consumption, physical activity, and self-rated health status—as outcome variables in association with marital status in Korean middle-aged men (age 40-44) living in Seoul and other regions. RESULTS: Married men showed the lowest cigarette smoking prevalence and the highest subjective health status both before and after adjusting for education and income. The odds of engaging in vigorous physical activity did not show a major difference before and after adjustment for income and education. CONCLUSIONS: In married men, the prevalence of cigarette smoking was lowest and subjective health status was highest, similar to previous studies. However, the prevalence of engaging in physical activity was highest in divorced/widowed/separated men. The health behaviors and health status of Korean middle-aged adults should be more closely followed, since they are representative of demographic changes in the Korean population.
Adult ; Alcohol Drinking ; Diagnostic Self Evaluation ; Education ; Family Characteristics ; Health Behavior ; Humans ; Korea ; Life Style ; Male ; Marital Status ; Marriage ; Motor Activity ; Prevalence ; Residence Characteristics ; Seoul ; Smoking

OBJECTIVES: Although smoking is associated with both low socioeconomic status and blood cadmium (Cd) levels, the association between socioeconomic status and Cd levels remains unclear. Therefore, our study aimed to examine this association and to clarify whether smoking is a confounding or mediating variable in this relationship. METHODS: Data (n=7,734) were drawn from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008- 2011), including years that contained data on blood Cd and urinary cotinine levels. We investigated the associations of income, education, and occupation with blood Cd levels. Smoking was investigated by categorizing participants by smoking status (never, former, and current) and pack-years into quartiles. The weekly frequency of rice and barley intake was analyzed to gain insights into participants’ dietary patterns. Additionally, urinary cotinine levels were used to ensure the validity of the smoking variables. RESULTS: Participants earning a low income and with less formal education had higher blood Cd levels. After controlling for smoking, the association between income and Cd levels substantially weakened. Further controlling for education, the association between income and Cd levels disappeared. However, there was a strong negative association between education and Cd levels, even after controlling for smoking history, pack-years, and urinary cotinine levels. CONCLUSIONS: In cross-sectional data from the KNHANES, blood Cd levels were significantly higher among those with a low income and less formal education. Smoking history contributed to, but did not fully explain, these associations.
Cadmium ; Cotinine ; Education ; Hordeum ; Korea ; Negotiating ; Nutrition Surveys ; Occupations ; Smoke ; Smoking ; Social Class

OBJECTIVES: Previous studies have shown that marital status is associated with household composition and living arrangements, which partially explain observed differences in health status according to marital status. However, due to the rapid socioeconomic and demographic transformations of the last few decades, the distribution of marital status among middle-aged adults has become more diverse. Therefore, this study aimed to obtain up-to-date information on the associations between marital status and health and to investigate the implications of these findings for conventional explanations of the health effects of marriage.METHODS: The data for this study were obtained from the 2015 Korean Community Health Study. We compared 4 modifiable lifestyle behaviors—smoking, alcohol consumption, physical activity, and self-rated health status—as outcome variables in association with marital status in Korean middle-aged men (age 40-44) living in Seoul and other regions.RESULTS: Married men showed the lowest cigarette smoking prevalence and the highest subjective health status both before and after adjusting for education and income. The odds of engaging in vigorous physical activity did not show a major difference before and after adjustment for income and education.CONCLUSIONS: In married men, the prevalence of cigarette smoking was lowest and subjective health status was highest, similar to previous studies. However, the prevalence of engaging in physical activity was highest in divorced/widowed/separated men. The health behaviors and health status of Korean middle-aged adults should be more closely followed, since they are representative of demographic changes in the Korean population.
Adult ; Alcohol Drinking ; Diagnostic Self Evaluation ; Education ; Family Characteristics ; Health Behavior ; Humans ; Korea ; Life Style ; Male ; Marital Status ; Marriage ; Motor Activity ; Prevalence ; Residence Characteristics ; Seoul ; Smoking

OBJECTIVES: Although smoking is associated with both low socioeconomic status and blood cadmium (Cd) levels, the association between socioeconomic status and Cd levels remains unclear. Therefore, our study aimed to examine this association and to clarify whether smoking is a confounding or mediating variable in this relationship.METHODS: Data (n=7,734) were drawn from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008- 2011), including years that contained data on blood Cd and urinary cotinine levels. We investigated the associations of income, education, and occupation with blood Cd levels. Smoking was investigated by categorizing participants by smoking status (never, former, and current) and pack-years into quartiles. The weekly frequency of rice and barley intake was analyzed to gain insights into participants' dietary patterns. Additionally, urinary cotinine levels were used to ensure the validity of the smoking variables.RESULTS: Participants earning a low income and with less formal education had higher blood Cd levels. After controlling for smoking, the association between income and Cd levels substantially weakened. Further controlling for education, the association between income and Cd levels disappeared. However, there was a strong negative association between education and Cd levels, even after controlling for smoking history, pack-years, and urinary cotinine levels.CONCLUSIONS: In cross-sectional data from the KNHANES, blood Cd levels were significantly higher among those with a low income and less formal education. Smoking history contributed to, but did not fully explain, these associations.
Cadmium ; Cotinine ; Education ; Hordeum ; Korea ; Negotiating ; Nutrition Surveys ; Occupations ; Smoke ; Smoking ; Social Class

OBJECTIVES: Previous studies have shown that marital status is associated with household composition and living arrangements, which partially explain observed differences in health status according to marital status. However, due to the rapid socioeconomic and demographic transformations of the last few decades, the distribution of marital status among middle-aged adults has become more diverse. Therefore, this study aimed to obtain up-to-date information on the associations between marital status and health and to investigate the implications of these findings for conventional explanations of the health effects of marriage. METHODS: The data for this study were obtained from the 2015 Korean Community Health Study. We compared 4 modifiable lifestyle behaviors—smoking, alcohol consumption, physical activity, and self-rated health status—as outcome variables in association with marital status in Korean middle-aged men (age 40-44) living in Seoul and other regions. RESULTS: Married men showed the lowest cigarette smoking prevalence and the highest subjective health status both before and after adjusting for education and income. The odds of engaging in vigorous physical activity did not show a major difference before and after adjustment for income and education. CONCLUSIONS In married men, the prevalence of cigarette smoking was lowest and subjective health status was highest, similar to previous studies. However, the prevalence of engaging in physical activity was highest in divorced/widowed/separated men. The health behaviors and health status of Korean middle-aged adults should be more closely followed, since they are representative of demographic changes in the Korean population.

OBJECTIVES: Although smoking is associated with both low socioeconomic status and blood cadmium (Cd) levels, the association between socioeconomic status and Cd levels remains unclear. Therefore, our study aimed to examine this association and to clarify whether smoking is a confounding or mediating variable in this relationship. METHODS: Data (n=7,734) were drawn from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008- 2011), including years that contained data on blood Cd and urinary cotinine levels. We investigated the associations of income, education, and occupation with blood Cd levels. Smoking was investigated by categorizing participants by smoking status (never, former, and current) and pack-years into quartiles. The weekly frequency of rice and barley intake was analyzed to gain insights into participants' dietary patterns. Additionally, urinary cotinine levels were used to ensure the validity of the smoking variables. RESULTS: Participants earning a low income and with less formal education had higher blood Cd levels. After controlling for smoking, the association between income and Cd levels substantially weakened. Further controlling for education, the association between income and Cd levels disappeared. However, there was a strong negative association between education and Cd levels, even after controlling for smoking history, pack-years, and urinary cotinine levels. CONCLUSIONS In cross-sectional data from the KNHANES, blood Cd levels were significantly higher among those with a low income and less formal education. Smoking history contributed to, but did not fully explain, these associations.

Eighty-five Korean kidney transplant recipients who received three doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine were tested with anti-receptor binding domain (RBD) antibody and neutralizing antibody. High anti-RBD antibody (≥ 100 U/mL) and neutralizing antibody responses (≥ 30%) were detected in 51/85 (60.0%) patients.When we divided the patients with the time from transplantation to vaccination (< 1, 1–2.4, 2.5–4.9, and ≥ 5-year), anti-RBD antibody titers were 3.2 U/mL, 27.8 U/mL, 370.2 U/mL, and 5,094.2 U/mL (P < 0.001) and anti-neutralizing antibody levels were 2.2%, 11.6%, 45.6%, and 93.0% (P < 0.001), respectively. Multivariate analysis revealed increased antibody responses when the time from transplantation to vaccination was five years or longer (odds ratio, 12.0; confidence interval, 2.7–52.8). Korean kidney transplant recipients had suboptimal antibody responses after the third dose of SARS-CoV-2 vaccine. A shorter time from transplantation to vaccination was a risk factor for a low antibody response.

Postpartum hemorrhage (PPH) is a major cause of maternal mortality and the risk factors for PPH differ among studies. In this large-scale study, we investigated whether the anesthetic method used was associated with PPH after cesarean section. Methods: We extracted data on cesarean sections performed between January 2008 and June 2013 from the National Health Insurance Service database. The anesthetic methods were categorized into general, spinal and epidural anesthesia. To compare the likelihood of PPH among deliveries using different anesthetic methods, crude and adjusted odds ratios (ORs) and 95% confidence intervals were calculated using logistic regression analysis. Results: Data from 330,324 cesarean sections were analyzed, and 21,636 cases of PPH were identified. Univariate analysis showed that general and epidural anesthesia increased the risk of PPH compared to spinal anesthesia. The OR for PPH was highest for morbidly adherent placenta, followed by placenta previa, placental abruption, and hypertension. When other clinical covariates were controlled for, general and epidural anesthesia still remained significant risk factors for PPH compared to spinal anesthesia. Conclusions: This study showed that general and epidural anesthesia elevated the risk of PPH compared to spinal anesthesia during cesarean section. Since we could not consider the potential bias of group differences in indications, more in-depth clinical trials are needed to validate our findings. Obstetric factors such as placental abnormalities had high odds ratios and thus are more important than the choice of anesthetic method, which should be based on the patient’s clinical condition and institutional resources.