OBJECTIVES: Inconsistent results are available regarding the association between low estimated glomerular filtration rate (eGFR) and lung cancer risk. We aimed to explore the risk of lung cancer according to eGFR category in the Korean population. METHODS: We included 358,293 adults who underwent health checkups between 2009 and 2010, utilizing data from the National Health Insurance Service-National Sample Cohort. Participants were categorized into 3 groups based on their baseline eGFR, as determined using the Chronic Kidney Disease Epidemiology Collaboration equation: group 1 (eGFR ≥90 mL/min/1.73 m2), group 2 (eGFR ≥60 to <90 mL/min/1.73 m2), and group 3 (eGFR <60 mL/min/1.73 m2). Incidences of lung cancer were identified using the corresponding codes from the International Classification of Diseases, 10th revision. Multivariate Cox proportional hazard models were employed to calculate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for lung cancer incidence up to 2019. RESULTS: In multivariate analysis, group 2 exhibited a 26% higher risk of developing lung cancer than group 1 (HR, 1.26; 95% CI, 1.19 to 1.35). Furthermore, group 3 demonstrated a 72% elevated risk of lung cancer relative to group 1 (HR, 1.72; 95% CI, 1.58 to 1.89). Among participants with dipstick proteinuria of 2+ or greater, group 3 faced a significantly higher risk of lung cancer than group 1 (HR, 2.93; 95% CI, 1.37 to 6.24). CONCLUSIONS Low eGFR was significantly associated with increased lung cancer risk within the Korean population. A particularly robust association was observed in individuals with severe proteinuria, emphasizing the need for further investigation.

Background: Despite high coverage (~98%) of universal varicella vaccination (UVV) in the Republic of Korea since 2005, reduction in the incidence rate of varicella is not obvious.The study aimed to evaluate the vaccine effectiveness (VE) of one-dose UVV by timeline and severity of the disease. Methods: All children born in Korea in 2011 were included for this retrospective cohort study that analyzed insurance claims data from 2011–2018 and the varicella vaccination records in the immunization registry. Adjusted hazard ratios by Cox proportional hazard models were used to estimate the VE through propensity score matching by the month of birth, sex, healthcare utilization rate, and region. Results: Of the total 421,070 newborns in the 2011 birth cohort, 13,360 were matched for age, sex, healthcare utilization rate, and region by the propensity score matching method. A total of 55,940 (13.29%) children were diagnosed with varicella, with the incidence rate 24.2 per 1000 person-year; 13.4% of vaccinated children and 10.4% of unvaccinated children. The VE of one-dose UVV against any varicella was 86.1% (95% confidence interval [CI], 81.4–89.5) during the first year after vaccination and 49.9% (95% CI, 43.3–55.7) during the 6-year followup period since vaccination, resulting in a 7.2% annual decrease of VE. The overall VE for severe varicella was 66.3%. The VE of two-dose compared to one-dose was 73.4% (95% CI, 72.2–74.6). Conclusion We found lower long-term VE in one-dose vaccination and waning of effectiveness over time. Longer follow ups of the vaccinated children as well as appropriately designed studies are needed to establish the optimal strategy in preventing varicella in Korea.

Background: Despite high coverage (~98%) of universal varicella vaccination (UVV) in the Republic of Korea since 2005, reduction in the incidence rate of varicella is not obvious.The study aimed to evaluate the vaccine effectiveness (VE) of one-dose UVV by timeline and severity of the disease. Methods: All children born in Korea in 2011 were included for this retrospective cohort study that analyzed insurance claims data from 2011–2018 and the varicella vaccination records in the immunization registry. Adjusted hazard ratios by Cox proportional hazard models were used to estimate the VE through propensity score matching by the month of birth, sex, healthcare utilization rate, and region. Results: Of the total 421,070 newborns in the 2011 birth cohort, 13,360 were matched for age, sex, healthcare utilization rate, and region by the propensity score matching method. A total of 55,940 (13.29%) children were diagnosed with varicella, with the incidence rate 24.2 per 1000 person-year; 13.4% of vaccinated children and 10.4% of unvaccinated children. The VE of one-dose UVV against any varicella was 86.1% (95% confidence interval [CI], 81.4–89.5) during the first year after vaccination and 49.9% (95% CI, 43.3–55.7) during the 6-year followup period since vaccination, resulting in a 7.2% annual decrease of VE. The overall VE for severe varicella was 66.3%. The VE of two-dose compared to one-dose was 73.4% (95% CI, 72.2–74.6). Conclusion We found lower long-term VE in one-dose vaccination and waning of effectiveness over time. Longer follow ups of the vaccinated children as well as appropriately designed studies are needed to establish the optimal strategy in preventing varicella in Korea.

OBJECTIVES: Many studies have explored the relationship between short-term weather and its health effects (including pneumonia) based on mortality, although both morbidity and mortality pose a substantial burden. In this study, the authors aimed to describe the influence of meteorological factors on the number of emergency room (ER) visits due to pneumonia in Seoul, Korea. METHODS: Daily records of ER visits for pneumonia over a 6-year period (2009-2014) were collected from the National Emergency Department Information System. Corresponding meteorological data were obtained from the National Climate Data Service System. A generalized additive model was used to analyze the effects. The percent change in the relative risk of certain meteorological variables, including pneumonia temperature (defined as the change in average temperature from one day to the next), were estimated for specific age groups. RESULTS: A total of 217 776 ER visits for pneumonia were identified. The additional risk associated with a 1°C increase in pneumonia temperature above the threshold of 6°C was 1.89 (95% confidence interval [CI], 1.37 to 2.61). Average temperature and diurnal temperature range, representing within-day temperature variance, showed protective effects of 0.07 (95% CI, 0.92 to 0.93) and 0.04 (95% CI, 0.94 to 0.98), respectively. However, in the elderly (65+ years), the effect of pneumonia temperature was inconclusive, and the directionality of the effects of average temperature and diurnal temperature range differed. CONCLUSIONS: The term ‘pneumonia temperature’ is valid. Pneumonia temperature was associated with an increased risk of ER visits for pneumonia, while warm average temperatures and large diurnal temperature ranges showed protective effects.
Aged ; Climate ; Emergencies ; Emergency Service, Hospital ; Humans ; Information Systems ; Korea ; Meteorological Concepts ; Mortality ; Pneumonia ; Public Health ; Seoul ; Weather

OBJECTIVES: Estimating influenza-associated mortality is important since seasonal influenza affects persons of all ages, causing severe illness or death. This study aimed to estimate influenza-associated mortality, considering both periodic changes and age-specific mortality by influenza subtypes. METHODS: Using the Microdata Integrated Service from Statistics Korea, we collected weekly mortality data including cause of death. Laboratory surveillance data of respiratory viruses from 2009 to 2016 were obtained from the Korea Centers for Disease Control and Prevention. After adjusting for the annual age-specific population size, we used a negative binomial regression model by age group and influenza subtype. RESULTS: Overall, 1 859 890 deaths were observed and the average rate of influenza virus positivity was 14.7% (standard deviation [SD], 5.8), with the following subtype distribution: A(H1N1), 5.0% (SD, 5.8); A(H3N2), 4.4% (SD, 3.4); and B, 5.3% (SD, 3.7). As a result, among individuals under 65 years old, 6774 (0.51%) all-cause deaths, 2521 (3.05%) respiratory or circulatory deaths, and 1048 (18.23%) influenza or pneumonia deaths were estimated. Among those 65 years of age or older, 30 414 (2.27%) all-cause deaths, 16 411 (3.42%) respiratory or circulatory deaths, and 4906 (6.87%) influenza or pneumonia deaths were estimated. Influenza A(H3N2) virus was the major contributor to influenza-associated all-cause and respiratory or circulatory deaths in both age groups. However, influenza A(H1N1) virus–associated influenza or pneumonia deaths were more common in those under 65 years old. CONCLUSIONS: Influenza-associated mortality was substantial during this period, especially in the elderly. By subtype, influenza A(H3N2) virus made the largest contribution to influenza-associated mortality.
Aged ; Cause of Death ; Centers for Disease Control and Prevention (U.S.) ; Cost of Illness ; Humans ; Influenza, Human ; Korea ; Mortality ; Orthomyxoviridae ; Pneumonia ; Population Density ; Seasons

PURPOSE: The flipped classroom has been suggested as a method for efficient teaching in medical education. However, its feasibility and effectiveness in the educational environment are often overlooked. The authors redesigned an epidemiology course applying the flipped classroom method under a traditional curriculum consisting of heavily scheduled classroom hours and explored its feasibility and effectiveness. METHODS: In the fall semester of 2017, we flipped the ‘practice of epidemiology’ course for third-year medical students at Korea University College of Medicine. We provided online lectures and assigned readings as pre-class materials, and substituted group discussions and communicative activities for traditional lectures. We conducted pre- and post-course surveys to review students' perceptions. We also analyzed the pre-test results and final exam scores for quantitative comparison. RESULTS: Ninety-seven students out of 120 completed the course. Most students made use of the online lectures, but not the reading materials. Lack of time was the most frequently cited reason for under-preparedness. We observed improvements in preparedness, participation, and effectiveness at the end of the course, while changes in satisfaction were unclear. Students' perceptions of course relevance and difficulty were predictive of pre-test outcomes, but the effects of preparedness and length of materials were insignificant. The authors found no evidence of differing test scores before and after the course. CONCLUSION This study supports the feasibility of the flipped classroom model even under a traditional, heavily scheduled medical curriculum. To encourage self-directed learning and achieve better learning outcomes, restructuring pre-existing curricular components should also be considered in parallel with new instructional methods.

PURPOSE: The flipped classroom has been suggested as a method for efficient teaching in medical education. However, its feasibility and effectiveness in the educational environment are often overlooked. The authors redesigned an epidemiology course applying the flipped classroom method under a traditional curriculum consisting of heavily scheduled classroom hours and explored its feasibility and effectiveness. METHODS: In the fall semester of 2017, we flipped the ‘practice of epidemiology’ course for third-year medical students at Korea University College of Medicine. We provided online lectures and assigned readings as pre-class materials, and substituted group discussions and communicative activities for traditional lectures. We conducted pre- and post-course surveys to review students' perceptions. We also analyzed the pre-test results and final exam scores for quantitative comparison. RESULTS: Ninety-seven students out of 120 completed the course. Most students made use of the online lectures, but not the reading materials. Lack of time was the most frequently cited reason for under-preparedness. We observed improvements in preparedness, participation, and effectiveness at the end of the course, while changes in satisfaction were unclear. Students' perceptions of course relevance and difficulty were predictive of pre-test outcomes, but the effects of preparedness and length of materials were insignificant. The authors found no evidence of differing test scores before and after the course. CONCLUSION: This study supports the feasibility of the flipped classroom model even under a traditional, heavily scheduled medical curriculum. To encourage self-directed learning and achieve better learning outcomes, restructuring pre-existing curricular components should also be considered in parallel with new instructional methods.
Curriculum ; Education, Medical ; Epidemiology ; Humans ; Korea ; Learning ; Lectures ; Methods ; Preventive Medicine ; Reading ; Students, Medical

OBJECTIVES: Many studies have explored the relationship between short-term weather and its health effects (including pneumonia) based on mortality, although both morbidity and mortality pose a substantial burden. In this study, the authors aimed to describe the influence of meteorological factors on the number of emergency room (ER) visits due to pneumonia in Seoul, Korea. METHODS: Daily records of ER visits for pneumonia over a 6-year period (2009-2014) were collected from the National Emergency Department Information System. Corresponding meteorological data were obtained from the National Climate Data Service System. A generalized additive model was used to analyze the effects. The percent change in the relative risk of certain meteorological variables, including pneumonia temperature (defined as the change in average temperature from one day to the next), were estimated for specific age groups. RESULTS: A total of 217 776 ER visits for pneumonia were identified. The additional risk associated with a 1°C increase in pneumonia temperature above the threshold of 6°C was 1.89 (95% confidence interval [CI], 1.37 to 2.61). Average temperature and diurnal temperature range, representing within-day temperature variance, showed protective effects of 0.07 (95% CI, 0.92 to 0.93) and 0.04 (95% CI, 0.94 to 0.98), respectively. However, in the elderly (65+ years), the effect of pneumonia temperature was inconclusive, and the directionality of the effects of average temperature and diurnal temperature range differed. CONCLUSIONS The term ‘pneumonia temperature’ is valid. Pneumonia temperature was associated with an increased risk of ER visits for pneumonia, while warm average temperatures and large diurnal temperature ranges showed protective effects.

OBJECTIVES: Estimating influenza-associated mortality is important since seasonal influenza affects persons of all ages, causing severe illness or death. This study aimed to estimate influenza-associated mortality, considering both periodic changes and age-specific mortality by influenza subtypes. METHODS: Using the Microdata Integrated Service from Statistics Korea, we collected weekly mortality data including cause of death. Laboratory surveillance data of respiratory viruses from 2009 to 2016 were obtained from the Korea Centers for Disease Control and Prevention. After adjusting for the annual age-specific population size, we used a negative binomial regression model by age group and influenza subtype. RESULTS: Overall, 1 859 890 deaths were observed and the average rate of influenza virus positivity was 14.7% (standard deviation [SD], 5.8), with the following subtype distribution: A(H1N1), 5.0% (SD, 5.8); A(H3N2), 4.4% (SD, 3.4); and B, 5.3% (SD, 3.7). As a result, among individuals under 65 years old, 6774 (0.51%) all-cause deaths, 2521 (3.05%) respiratory or circulatory deaths, and 1048 (18.23%) influenza or pneumonia deaths were estimated. Among those 65 years of age or older, 30 414 (2.27%) all-cause deaths, 16 411 (3.42%) respiratory or circulatory deaths, and 4906 (6.87%) influenza or pneumonia deaths were estimated. Influenza A(H3N2) virus was the major contributor to influenza-associated all-cause and respiratory or circulatory deaths in both age groups. However, influenza A(H1N1) virus–associated influenza or pneumonia deaths were more common in those under 65 years old. CONCLUSIONS Influenza-associated mortality was substantial during this period, especially in the elderly. By subtype, influenza A(H3N2) virus made the largest contribution to influenza-associated mortality.

BACKGROUND: Although pedobarographic measurement is increasingly used for clinical and research purposes, relatively few published studies have investigated normative data. This study examined pedobarographic findings in young healthy adults with regard to sex-related differences and correlations among measurement indices. METHODS: Twenty young healthy adults (mean age, 22.4 years; standard deviation, 1.2 years; and 10 males and 10 females) were included. Weight bearing anteroposterior (AP) and lateral foot radiographs were taken, and dynamic pedobarographic data during treadmill walking and maximum ankle dorsiflexion were obtained. AP talo-first metatarsal angle, naviculocuboid overlap, lateral talo-first metatarsal angle, and plantar soft tissue thickness were measured on foot radiographs. Pedobarographic data including peak pressure and pressure-time integral were measured on five plantar segments: medial forefoot (MFF), lateral forefoot (LFF), medial midfoot (MMF), lateral midfoot (LMF), and heel. RESULTS: Male and female subjects significantly differed in body mass index (BMI, p < 0.001), AP talo-first metatarsal angle (p = 0.018), soft tissue thickness under the metatarsal head (p = 0.040) and calcaneal tuberosity (p < 0.001), maximum dorsiflexion during stance phase (p = 0.041), peak pressure on the MFF (p = 0.005) and LFF (p = 0.004), and pressure-time integral on the MFF (p = 0.018) and heel (p = 0.001). BMI was significantly correlated with soft tissue thickness under the metatarsal head (r = 0.521, p = 0.018) and calcaneal tuberosity (r = 0.585, p = 0.007), peak pressure on the MFF (r = 0.601, p = 0.005) and LFF (r = 0.487, p = 0.029), pressure-time integral on the heel (r = 0.552, p = 0.012), and total pressure-time integral (r = 0.755, p < 0.001). Maximum dorsiflexion demonstrated significant negative correlations with pressure-time integral on the MFF (r = −0.595, p = 0.007) and total pressure-time integral (r = −0.492, p = 0.032). Pressure-time integral varus/valgus index was significantly correlated with pressuretime integral forefoot/heel index (r = 0.472, p = 0.036). CONCLUSIONS: Sex-related differences in pedobarographic examination were observed, which could provide useful information in setting appropriate treatment goals and obtaining appropriate control data. The effects of subtalar motion in distributing plantar pressure should be investigated in a future study.
Adult* ; Ankle ; Body Mass Index ; Female ; Foot ; Head ; Heel ; Humans ; Male ; Metatarsal Bones ; Sex Characteristics* ; Walking ; Weight-Bearing