National trends in physical activity among adolescents in South Korea before and during the COVID‐19 pandemic, 2009−2021

With the ongoing COVID‐19 pandemic, several previous studies from different countries showed that physical activity (PA) decreased during the COVID‐19 outbreak. However, few studies have examined the recent tendency of PA in the adolescent population. Thus, we aimed to investigate the long‐term trend of PA in Korean youth and the prevalence changes between before and during the COVID‐19 pandemic. Data from Korea Youth Risk Behavior Web‐Based Survey (KYRBS) was collected for consecutive years between 2009 and 2021. The period was separated into prepandemic (2009−2019), early‐pandemic (2020), and mid‐pandemic (2021). Self‐reported amount of PA was categorized into four groups (insufficient, aerobic, muscle strengthening, and both physical activities) according to World Health Organization (WHO) PA guidelines. A total of 840 488 adolescents aged 12−18 who fully responded to the survey were selected (response rate: 95.2%). The 13‐year trends in the proportion of adolescents who reported aerobic and muscle‐strengthening activities met or exceeded 2020 WHO exercise guidelines for adolescents plateaued (11.9% from 2009 to 2011, 14.2% from 2018 to 2019, 14.4% from 2020, and 14.0% from 2021); however, the slope decreased during the pandemic (βdiff, −0.076; 95% confidence interval [CI], −0.123 to −0.029). Proportion of sufficient aerobic exercise among adolescents sharply decreased midst the pandemic (28.0% from 2009 to 2011, 29.4% from 2018 to 2019, and 23.8% from 2020; βdiff, −0.266; 95% CI, −0.306 to −0.226) but increased again in 2021 (26.0% from mid‐COVID 19; 95% CI, 25.4−26.7). Similar patterns were observed in Metabolic Equivalent Task (MET) score (MET‐min/week; 804.1 from 2018 to 2019, 720.9 from 2020, and 779.6 from 2021). The mean difference in MET score between pre‐COVID and post‐COVID was −55.4 MET‐min/week (95% CI, −70.5 to −40.3). Through a nationwide representative study, there was no significant difference with regard to the number of Korean adolescents who achieved the PA guidelines (pre and postpandemic); however, the prevalence of recommended levels of PA needs to increase more based on the trend before the COVID‐19 outbreak. The findings of this study suggest reinforcement of the importance of public health policies for Korean youths to be more physically active, especially during and after the pandemic.</p

Global incidence and prevalence of eosinophilic esophagitis, 1976–2022: a systematic review and meta-analysis

Background and AimsOwing to 2018 expanded diagnostic criteria for eosinophilic esophagitis (EoE) and thus a possible increase in diagnosis, previous studies on the global incidence and prevalence of EoE may need to be updated. We aimed to describe global, regional, and national trends in the incidence and prevalence of EoE from 1976 to 2022 and analyze their associations with geographic, demographic, and social factors through a systematic review.MethodsWe searched the PubMed/MEDLINE, Embase, CINAHL, Google Scholar, and Cochrane databases from their inception dates to December 20, 2022, for studies that reported the incidence or prevalence of EoE in the general population. We calculated the global incidence and prevalence of EoE using pooled estimates with 95% confidence intervals (CIs) and performed subgroup analysis based on age, sex, race, geographical area, World Bank income group, and diagnostic criteria of EoE.ResultsForty studies met the eligibility criteria, including over 288 million participants and 147,668 patients with EoE from 15 countries across the five continents. The global pooled incidence and prevalence of EoE were 5.31 cases per 100,000 inhabitant-years (95% CI, 3.98–6.63; number of studies, 27; sample population, 42,191,506) and 40.04 cases per 100,000 inhabitant-years (95% CI, 31.10–48.98; number of studies, 20; sample population, 30,467,177), respectively. The pooled incidence of EoE was higher in high-income countries (vs low- or middle-income countries), males, and North America (vs Europe and Asia). The global prevalence of EoE followed a similar pattern. The pooled prevalence of EoE gradually increased from 1976 to 2022 (1976–2001; 8.18; 95% CI, 3.67–12.69 vs 2017–2022; 74.42; 95% CI, 39.66–109.19 cases per 100,000 inhabitant-years).ConclusionsThe incidence and prevalence of EoE have increased substantially and vary widely across the world. Further research is needed to evaluate the incidence and prevalence of EoE in Asia, South America, and Africa.</p

Breastfeeding and impact on childhood hospital admissions: a nationwide birth cohort in South Korea

Benefits of breastfeeding for both the mother and the child are well established, but a comprehensive and robust study to investigate the protective effect of breastfeeding and attenuated time effect stratified by cause of morbidity are lacking. This study is based on the nationwide birth cohort in Korea that includes data on all infants born from 2009 to 2015. Of 1,608,540 children, the median follow-up period was 8.41 years (interquartile range, 6.76-10.06). When compared to children with fully formula feeding, the hospital admission rate was 12% lower in those with partially breastfeeding and 15% lower in those with exclusive breastfeeding. The apparent protective effect of breastfeeding was reduced with increasing age. Our study provides potential evidence of the beneficial association of breastfeeding on subsequent hospital admissions. The protective effect declined over time as the children grew older. Encouraging any breastfeeding for at least the first 6 months among infants is an important public health strategy to improve overall child health.</p

Estimated prevalence and trends in smoking among adolescents in South Korea, 2005–2021: a nationwide serial study

Background: Although smoking is classified as a risk factor for severe COVID-19 outcomes, there is a scarcity of studies on prevalence of smoking during the COVID-19 pandemic. Thus, this study aims to analyze the trends of prevalence of smoking in adolescents over the COVID-19 pandemic period. Methods: The present study used data from middle to high school adolescents between 2005 and 2021 who participated in the Korea Youth Risk Behavior Web-based Survey (KYRBS). We evaluated the smoking prevalence (ever or daily) by year groups and estimated the slope in smoking prevalence before and during the pandemic. Results: A total of 1,137,823 adolescents participated in the study [mean age, 15.04 years [95% confidence interval (CI) 15.03–15.06]; and male, 52.4% (95% CI 51.7–53.1)]. The prevalence of ever smokers was 27.7% (95% CI 27.3–28.1) between 2005 and 2008 but decreased to 9.8% (95% CI 9.3–10.3) in 2021. A consistent trend was found in daily smokers, as the estimates decreased from 5.4% (95% CI 5.2–5.6) between 2005 and 2008 to 2.3% (95% CI 2.1–2.5) in 2021. However, the downward slope in the overall prevalence of ever smokers and daily smokers became less pronounced in the COVID-19 pandemic period than in the pre-pandemic period. In the subgroup with substance use, the decreasing slope in daily smokers was significantly more pronounced during the pandemic than during the pre-pandemic period. Conclusions: The proportion of ever smokers and daily smokers showed a less pronounced decreasing trend during the pandemic. The findings of our study provide an overall understanding of the pandemic’s impact on smoking prevalence in adolescents. [MediaObject not available: see fulltext.