Real-life characteristics of asthma inhaler device use in South Korea

Background and Aims: Historically, dry powder inhalers (DPIs) were considered to provide better airway distribution, easier identification of empty devices, and easier handling when compared to pressurized metered dose inhalers (pMDIs). Prior research into the major handling errors with inhaler device use has shown that errors result in comparable impairment of asthma control in both DPIs and pMDIs. Our own research has demonstrated that patients who are prescribed similar types of preventer inhaler devices to their reliever have better asthma control. Patients prescribed pMDI inhaled corticosteroid/long acting beta agonist relievers could benefit from switching from a DPI to a pMDI. The Health Insurance Review and Assessment (HIRA) database provides coverage of medical claims for over 50 million people in Korea and offers the opportunity to study asthma control on a national basis. The aim of this study was to provide a review of the possibilities of the Korean HIRA database in preparation for a study to investigate the effect on asthma control when patients switch inhaler types. Methods: Methodology from previous literature describing the HIRA database was analysed. We focused on the identification of asthma patients, their clinical characteristics (e.g. exacerbations, comorbidities), real-life medication switching behaviour, healthcare resource use (including medication) and associated costs. Results: Patient medical history could be constructed from primary and secondary diagnosis associated with individual database entries. Asthma exacerbations could be proxied by a prescription of acute oral corticosteroids, hospital admission or emergency room attendance associated with a diagnosis of asthma, lower respiratory infection or respiratory failure. Patients could be considered switch patients if they received a prescription of a pMDI after prescription of ≥2 DPI inhalers. Additional variables that were available included medication and hospitalisation cost. Conclusions: The HIRA database will allow studies analysing switch success of inhaler types in terms of persistence, asthma control and healthcare resource utilisation

Ethnic and sex differences in the distributions of body mass index and waist circumference among adults: a binationally representative study in South Korea and the United States

OBJECTIVE: The ethnic and sex differences in the distributions of body mass index (BMI) and waist circumference (WC) among adults are largely unknown. Therefore, we aimed to investigate the percentiles of BMI and WC in groups divided according to age, sex, and ethnicity. PATIENTS AND METHODS: We conducted a population-based binational study of adults aged ≥20 years based on data from two sources: US National Health and Nutrition Examination Survey (2015 to 2020) and Korea National Health and Nutrition Examination Survey (2016 to 2019). RESULTS: Weight, height, and WC were measured in 13,144 American adults and 30,191 Korean adults. Overall, BMI increased at younger ages and decreased at older ages, which indicates a reversed U-shaped relationship, and differed in terms of age, sex, and ethnicity. Women in the other Hispanic, non-Hispanic white, non-Hispanic black, and “other ethnic groups” showed a common BMI peak at ages 50-54 years. The patterns of WC distribution were similar to those of BMI distribution. CONCLUSIONS: In this binational representative study, we found varied distributions of ethnic and sex differences in BMI and WC. Considering the differences in these distributions may help improve individual and personalized treatment strategies

Modelling of bubble-mediated gas transfer : fundamental principles and a laboratory test

gas transfer; wave breaking, air-sea interaction; sea surfaceInternational audienceThe air–water exchange of gases can be substantially enhanced by wave breaking and specifically by bubble-mediated transfer. A feature of bubble-mediated transfer is the additional pressure on bubbles resulting from the hydrostatic forces on a submerged bubble and from surface tension and curvature. This peculiarity results in asymmetry of bubble-mediated gas transfer and equilibrium supersaturations of dissolved gases in a bubbly ocean. A second peculiarity is the finite capacity of bubbles, so that the composition of a bubble may change during the exchange. The result is that gas transfer mediated by bubbles is characterized by an altered dependence on the molecular properties of the dissolved gas compared to direct transfer across the main air–water interface. A related phenomenon for bubble plumes with a high void fraction (air volume to total volume ratio) is that the composition of the dissolved gas within the interstitial water of a plume may alter during the exchange process and only mix into the full water reservoir later. Three asymptotes are identified for gas exchange mediated by high-void-fraction bubble plumes and a semi-empirical parameterization of bubble-mediated gas transfer is devised on the basis of these asymptotes, which describes the dependence of the overall transfer velocity on plume properties and molecular properties of the gas. These models are confronted with data from laboratory experiments. The experiments use artificial aeration with the gas source switched during each run. Measurements of the bubble distribution enable calculation of the theoretical transfer of the gases. A parameterization fits the theoretical transfer satisfactorily. Gas measurements are used to test if the actual transfer of gases is similar to the theoretical transfer. The experimental method enables separation of bubble-mediated transfer from transfer directly across the main air–water interface. The agreement between gas and bubble-derived values of transfer velocity is sufficient to generally validate the theory, but is imprecise. The results suggest that the interstitial water plays a significant role in limiting gas transfer–in particular, limiting transfer of helium–despite the fact that typical void fractions were low (< 0.1%). It should be possible to predict gas transfer velocities in the field by simulating oceanic bubble plumes sufficient to constrain that part of the transfer, but targets of 10% or 20% may be beyond reach especially for the most poorly soluble gases (for which the bubble-mediated mechanism is particularly important). These simulations require accurate bubble distributions, void fractions and a good description of the entire plume dynamics. Such simulations are particularly important for interpreting dual tracer and nitrogen/oxygen experiments in stormy conditions, where the relative transfer of different gases is a non-trivial problem

LUMINY: an overview

Experiments were undertaken in the Large Air Sea Interaction Simulation Tunnel of IRPHE-IOA, Laboratoire de LUMINY, in Marseille, France, aimed at improving our understanding of the effects of breaking waves on gas transfer, and providing parameterisations for the transfer velocities. Detailed studies were made of breaking wave phenomena, bubbles and turbulence in water and air, and exchange rates of gases with a variety of physical properties (CO2, CH4, N2O, DMS, CH3Br, 4He and SF6). A simple scaling of air-water transfer velocities with friction velocity and Schmidt number breaks down at high wind speeds. A solubility-dependent enhancement of transfer velocity by bubbles can explain only part of the behaviour. An "interfacial resistance" model can explain much of the outstanding behaviour at high wind speeds. Bubble-mediated transfer, surface disruption by turbulence and surfacing bubbles, and interfacial resistance, are all identified as significant to air-sea gas exchange at high wind and sea states

National trends in suicide-related behaviors among youths between 2005-2020, including COVID-19: a Korean representative survey of one million adolescents

OBJECTIVE: It is difficult to conclude that COVID-19 is associated with a decrease in the suicide attempts rate by comparing only a short-term period. Therefore, it is necessary to examine attempted suicide rates through a trend analysis over a longer period. This study aimed to investigate an estimated long-term trend regarding the prevalence of suicide-related behaviors among adolescents in South Korea from 2005 to 2020, including COVID-19. SUBJECTS AND METHODS: We sourced data from a national representative survey (Korea Youth Risk Behavior Survey) and analyzed one million Korean adolescents aged 13 to 18 years (n=1,057,885) from 2005 to 2020. The 16-year trends regarding the prevalence of sadness or despair and suicidal ideation and attempt and the trend changes before and during COVID-19. RESULTS: Data of 1,057,885 Korean adolescents was analyzed (weighted mean age, 15.03 years; males, 52.5%; females, 47.5%). Although the 16-year trend in the prevalence of sadness or despair and suicide ideation and attempt consistently decreased (prevalence of sadness or despair between 2005-2008, 38.0% with 95% confidence interval [CI], 37.7 to 38.4 vs. prevalence in 2020, 25.0% [24.5 to 25.6]; suicide ideation between 2005-2008, 21.9% [21.6 to 22.1] vs. prevalence in 2020, 10.7% [10.3 to 11.1]; and suicide attempt between 2005-2008, 5.0% [4.9 to 5.2] vs. prevalence in 2020, 1.9% [1.8 to 2.0]), the downward slope decreased during COVID-19 (βdiff in sadness, 0.215 with 95% CI 0.206 to 0.224; βdiff in suicidal ideation, 0.245 [0.234 to 0.256]; and βdiff in suicide attempt, 0.219 [0.201 to 0.237]) compared with pre-pandemic period. CONCLUSIONS: This study found that the observed risk of suicide-related behaviors during the pandemic was higher than expected through long-term trend analysis of the prevalence of sadness/despair and suicidal ideation and attempts among South Korean adolescents. We need a profound epidemiologic study of the change in mental health due to the pandemic’s impact and the establishment of prevention strategies for suicide ideation and attempt