The Impact of Intervention Design on User Engagement in Digital Therapeutics Research: Factorial Experiment With a Mixed Methods Study.

BACKGROUND: User engagement is crucial for digital therapeutics (DTx) effectiveness; due to variations in the conceptualization of engagement and intervention design, assessment and retention of engagement remain challenging. OBJECTIVE: We investigated the influence of the perceived acceptability of experimental intervention components and satisfaction with core intervention components in DTx on user engagement, while also identifying potential barriers and facilitators to user engagement. METHODS: We conducted a mixed methods study with a 2 × 2 factorial design, involving 12 outpatients with atopic dermatitis. Participants were randomized into 4 experimental groups based on push notification ("basic" or "advanced") and human coach ("on" or "off") experimental intervention components. All participants engaged in self-monitoring and learning courses as core intervention components within an app-based intervention over 8 weeks. Data were collected through in-app behavioral data, physician- and self-reported questionnaires, and semistructured interviews assessed at baseline, 4 weeks, and 8 weeks. Descriptive statistics and thematic analysis were used to evaluate user engagement, perceived acceptability of experimental intervention components (ie, push notification and human coach), satisfaction with core intervention components (ie, self-monitoring and learning courses), and intervention effectiveness through clinical outcomes. RESULTS: The primary outcome indicated that group 4, provided with "advanced-level push notifications" and a "human coach," showed higher completion rates for self-monitoring forms and learning courses compared to the predetermined threshold of clinical significance. Qualitative data analysis revealed three key themes: (1) perceived acceptability of the experimental intervention components, (2) satisfaction with the core intervention components, and (3) suggestions for improvement in the overall intervention program. Regarding clinical outcomes, the Perceived Stress Scale and Dermatology Life Quality Index scores presented the highest improvement in group 4. CONCLUSIONS: These findings will help refine the intervention and inform the design of a subsequent randomized trial to test its effectiveness. Furthermore, this design may serve as a model for broadly examining and optimizing overall engagement in DTx and for future investigation into the complex relationship between engagement and clinical outcomes. TRIAL REGISTRATION: Clinical Research Information Service KCT0007675; http://tinyurl.com/2m8rjrmv.

Surgeon Experience Is the Most Important Predictor of Case Failure Rate for Anterior Odontoid Screw Fixation: A Large Database Study.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: Determine risk factors and failure rate of anterior odontoid screw fixation surgery. SUMMARY OF BACKGROUND DATA: Anterior odontoid screw fixation (AOSF) stabilizes type II dens fractures while preserving cervical motion. Despite having potential advantages, AOSF's failure rate and factors contributing to failure remain unknown. MATERIALS AND METHODS: We identified AOSF patients in the national claims database Pearldiver using CPT code 22318. Failure was defined as the requirement of supplementary posterior fusion surgery in the C1-C2 or occiput-C2 region after the AOSF. We considered potential predictors of failure including age, sex, Charlson Comorbidity Index (CCI), surgeon experience, history of osteoporosis, obesity, and tobacco use. Univariate comparison analysis and logistic regression were conducted to identify factors associated with the need for additional posterior surgery. RESULTS: For 2008 identified cases of AOSF, 249 cases (12.4%) required additional posterior fusion. Seventy-one of the 249 cases (28.5%) underwent revision surgery on the same day as the AOSF. Over 86% of revisions (215 cases) occurred within 200 days of the initial procedure. Posterior fusion rates are inversely correlated with surgeon experience, with the most experienced surgeons having a rate of 10.0%, followed by 11.5% for moderately experienced surgeons, and 15.0% for the least experienced surgeons. When comparing moderate and inexperienced surgeons to experienced surgeons, the odds ratios for posterior fusion were 1.18 (P>0.05) and 1.61 (P<0.006), respectively. Logistic regression revealed that both lesser experience (odds ratio=1.50) and osteoporosis (odds ratio=1.44) were the only factors significantly associated with failure (P<0.05). CONCLUSIONS: Our findings indicate a correlation between AOSF success and surgeon experience. While currently published results suggest higher success rates, most of this data originates from experienced surgeons and specialized centers, therefore, they may not accurately reflect the failure rate encountered in a more general practice setting. LEVEL OF EVIDENCE: Level III.

Quantifying Risk Factors for Slipped Capital Femoral Epiphysis and Postslip Osteonecrosis.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a disorder of the proximal femoral physis occurring in late childhood and adolescence. Previously postulated risk factors include obesity and endocrinopathies. The purpose of this investigation was to identify risk factors for developing SCFE, as well as postslip osteonecrosis (ON), among the United States pediatric population. METHODS: A national database investigation was performed using PearlDiver Technologies, Inc., queried for SCFE and ON using International Classification of Disease codes (2010 to 2020). Regression analyses to determine the risk of developing a SCFE, and ON after a patient has already been diagnosed with a SCFE ("postslip"). Propensity matching between SCFE and control groups generated a pseudo-randomization model to compare the relative risk. RESULTS: There were 11,465 patients with SCFE available in the database, matched with 134,680 controls. After matching, vitamin D deficiency, obesity, hypothyroidism, and growth hormone use were risk factors for developing SCFE [relative risk ranges from 1.42 (95% CI: 1.21-1.39, vitamin D deficiency) to 3.45 (95% CI: 3.33-3.57, obesity)]. ON risk factors were vitamin D deficiency [1.65 (1.26-2.14)] and hypothyroidism [1.49 (1.10-2.07)]. CONCLUSIONS: This United States national database study quantified risk factors of developing an SCFE and postslip ON. Obesity is the most significant risk factor for the development of a slip, but not ON. Growth hormone use, hypothyroidism, and vitamin D deficiency are also risk factors for SCFE development, whereas only the latter two were associated with ON. These findings demonstrate the public health implications of obesity and comorbid conditions in pediatric hip pathology. LEVEL OF EVIDENCE: Level III.

The Potential of Campanula takesimana Callus Extract to Enhance Skin Barrier Function.

Atopic dermatitis (AD) is a prevalent inflammatory skin disease characterized by epidermal barrier dysfunction and Th2-skewed inflammation. Campanula takesimana (C. takesimana), a Korean endemic plant grown on Ulleng Island, has long been associated with a traditional alternative medicine for asthma, tonsillitis, and sore throat. In this study, we reported the effect of C. takesimana callus extract on upregulating epidermal barrier-related proteins dysregulated by Th2 cytokines. C. takesimana callus extract induced the expression of skin barrier proteins, such as filaggrin, claudin-1, and zonula occludens-1, in both human primary keratinocytes and Th2-induced AD-like skin-equivalent models. Additionally, RNA sequencing analysis demonstrated that C. takesimana callus extract partially restored Th2 cytokine-induced dysregulation of the epidermal development and lipid metabolic pathways. Considering the advantages of callus as a sustainable eco-friendly source of bioactive substances, and its effect on skin barrier proteins and lipid metabolic pathways, C. takesimana callus extracts can possibly be utilized to improve the integrity of the skin barrier.

Impact of State Laws on Dispensing Opioid Prescriptions Following Posterior Lumbar Interbody Fusion Procedures: A Retrospective Large National Database Study.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: This study aimed to examine the effect of state legislation on prescribing behavior after a commonly performed spinal procedure, posterior lumbar interbody fusion (PLIF). METHODS: Two cohorts of patients from the Pearl Diver Database were created based on patients who underwent PLIF surgery in 2014-15 and 2018-19. We compared opioid prescription rates and morphine-milli-equivalent (MME) between states with and without prescription legislation. RESULTS: We analyzed 50 958 PLIF patients from 2014-15 and 46 751 patients from 2018-19. Among them, 38 states passed opioid prescription laws in 2016-2017, while 12 states did not. The percentage of patients receiving opioid prescriptions within 365 days post-surgery remained similar in both time periods (49% in 2014-15 and 48% in 2018-2019). This trend was consistent across states with and without prescription legislation (50% vs 48% in 2014-2015, and similar in 2018-19). Opioid prescription quantity significantly decreased in all states between 2014-15 and 2018-19. In states with legislation, average MME dropped from 9198 ± 21 002 to 4932 ± 13 213 (46.4% decrease), and in states without legislation, it decreased from 9175 ± 21 032 to 4994 ± 11 687 (45.6% decrease). However, these differences were not statistically significant (P = .7985). CONCLUSION: From 2014 to 2018, there was a significant decrease in the number of opioids prescribed after PLIF. However, this decrease occurred irrespective of state legislation on prescribing practices being passed. We believe the reduction in opioids prescribed was due to increased awareness surrounding the dangers of opioids among physicians.

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.

Global Incidence and Prevalence of Eosinophilic Esophagitis, 1976-2022: A Systematic Review and Meta-analysis.

BACKGROUND AND AIMS: Owing 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. METHODS: We 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. RESULTS: Forty 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). CONCLUSIONS: The 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.

Reaming the intramedullary canal during tibial nailing does not affect in vivo intramuscular pH of the anterior tibialis.

Many investigations have evaluated local and systemic consequences of intramedullary (IM) reaming and suggest that reaming may cause, or exacerbate, injury to the soft tissues adjacent to fractures. To date, no study has examined the effect on local muscular physiology as measured by intramuscular pH (IpH). Here, we observe in vivo IpH during IM reaming for tibia fractures. Methods: Adults with acute tibia shaft fractures (level 1, academic, 2019-2021) were offered enrollment in an observational cohort. During IM nailing, a sterile, validated IpH probe was placed into the anterior tibialis (<5 cm from fracture, continuous sampling, independent research team). IpH before, during, and after reaming was averaged and compared through repeated measures ANOVA. As the appropriate period to analyze IpH during reaming is unknown, the analysis was repeated over periods of 0.5, 1, 2, 5, 10, and 15 minutes prereaming and postreaming time intervals. Results: Sixteen subjects with tibia shaft fractures were observed during nailing. Average time from injury to surgery was 35.0 hours (SD, 31.8). Starting and ending perioperative IpH was acidic, averaging 6.64 (SD, 0.21) and 6.74 (SD, 0.17), respectively. Average reaming time lasted 15 minutes. Average IpH during reaming was 6.73 (SD, 0.15). There was no difference in IpH between prereaming, intrareaming, and postreaming periods. IpH did not differ regardless of analysis over short or long time domains compared with the duration of reaming. Conclusions: Reaming does not affect IpH. Both granular and broad time domains were tested, revealing no observable local impact.

How Do Standing Neutral, Supine Lateral, Standing Flexion, and Standing Extension Radiographs Compare in Detecting the Presence and Magnitude of Stable and Dynamic Spondylolisthesis?

BACKGROUND: Clinical guidelines recommend standing radiographs as the most appropriate imaging for detecting degenerative spondylolisthesis, although reliable evidence about the standing position is absent. To our knowledge, no studies have compared different radiographic views and pairings to detect the presence and magnitude of stable and dynamic spondylolisthesis. QUESTIONS/PURPOSES: (1) What is the percentage of new patients presenting with back or leg pain with stable (3 mm or greater listhesis on standing radiographs) and dynamic (3 mm or greater listhesis difference on standing-supine radiographs) spondylolisthesis? (2) What is the difference in the magnitude of spondylolisthesis between standing and supine radiographs? (3) What is the difference in the magnitude of dynamic translation among flexion-extension, standing-supine, and flexion-supine radiographic pairs? METHODS: This cross-sectional, diagnostic study was performed at an urban, academic institution between September 2010 and July 2016; 579 patients 40 years or older received a standard radiographic three-view series (standing AP, standing lateral, and supine lateral radiographs) at a new patient visit. Of those individuals, 89% (518 of 579) did not have any of the following: history of spinal surgery, evidence of vertebral fracture, scoliosis greater than 30°, or poor image quality. In the absence of a reliable diagnosis of dynamic spondylolisthesis using this three-view series, patients may have had flexion and extension radiographs, and approximately 6% (31 of 518) had flexion and extension radiographs. A total of 53% (272 of 518) of patients were female, and the patients had a mean age of 60 ± 11 years. Listhesis distance (in mm) was measured by two raters as displacement of the posterior surface of the superior vertebral body in relation to the posterior surface of the inferior vertebral body from L1 to S1; interrater and intrarater reliability, assessed with intraclass correlation coefficients, was 0.91 and 0.86 to 0.95, respectively. The percentage of patients with and the magnitude of stable spondylolisthesis was estimated on and compared between standing neutral and supine lateral radiographs. The ability of common pairs of radiographs (flexion-extension, standing-supine, and flexion-supine) to detect dynamic spondylolisthesis was assessed. No single radiographic view or pair was considered the gold standard because stable or dynamic listhesis on any radiographic view is often considered positive in clinical practice. RESULTS: Among 518 patients, the percentage of patients with spondylolisthesis was 40% (95% CI 36% to 44%) on standing radiographs alone, and the percentage of patients with dynamic spondylolisthesis was 11% (95% CI 8% to 13%) on the standing-supine pair. Standing radiographs detected greater listhesis than supine radiographs did (6.5 ± 3.9 mm versus 4.9 ± 3.8 mm, difference 1.7 mm [95% CI 1.2 to 2.1 mm]; p < 0.001). Among 31 patients, no single radiographic pairing identified all patients with dynamic spondylolisthesis. The listhesis difference detected between flexion-extension was no different from the listhesis difference detected between standing-supine (1.8 ± 1.7 mm versus 2.0 ± 2.2 mm, difference 0.2 mm [95% CI -0.5 to 1.0 mm]; p = 0.53) and flexion-supine (1.8 ± 1.7 mm versus 2.5 ± 2.2 mm, difference 0.7 mm [95% CI 0.0 to 1.5]; p = 0.06). CONCLUSION: This study supports current clinical guidelines that lateral radiographs should be obtained with patients in the standing position, because all cases of stable spondylolisthesis of 3 mm or greater were detected on standing radiographs alone. Each radiographic pair did not detect different magnitudes of listhesis, and no single pair detected all cases of dynamic spondylolisthesis. Clinical concern for dynamic spondylolisthesis may justify standing neutral, supine lateral, standing flexion, and standing extension views. Future studies could identify and evaluate a set of radiographic views that provides the greatest capacity to diagnose stable and dynamic spondylolisthesis. LEVEL OF EVIDENCE: Level III, diagnostic study.

Enhanced photocatalytic activity of cubic ZnSn(OH)6 by in-situ partial phase transformation via rapid thermal annealing.

In this study, a mixed phase ZnSn(OH)6/ZnSnO3 photocatalyst was synthesized by calcining ZHS nanostructures via rapid thermal annealing (RTA) process. The composition ratio of ZnSn(OH)6/ZnSnO3 was controlled by changing the duration of the RTA process. The obtained mixed-phase photocatalyst was characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, ultraviolet photoelectron spectroscopy, photoluminescence, and physisorption analysis. Results showed that ZnSn(OH)6/ZnSnO3 photocatalyst obtained by calcining ZHS at 300 °C for 20 sec displayed the best photocatalytic performance under UVC light illumination. Under optimized reaction conditions, ZHS-20 (0.125 g) demonstrated nearly complete removal (>99%) of MO dye in 150 min. Scavenger study revealed the predominant role of OH• in photocatalysis. The enhanced photocatalytic activity of the ZnSn(OH)6/ZnSnO3 composites was mainly ascribed to the photosensitization of ZHS by ZTO and effective electron-hole separation at the ZnSn(OH)6/ZnSnO3 heterojunction interface. It is expected that this study will provide new research input for the development of photocatalyst through thermal annealing-induced partial phase transformation.

Clinical manifestations of human Mpox infection: A systematic review and meta-analysis.

Little is known about the ongoing monkeypox (mpox) outbreak, and the clinical features of mpox in patients worldwide have not been rigorously analysed. Thus, we aimed to investigate the clinical features associated with mpox infection and understand the pathophysiology and characteristics of the disease. For this systematic review and meta-analysis, we searched PubMed/MEDLINE, Embase, CINAHL, Google Scholar, and the Cochrane Database of Systematic Reviews for articles published till 16 September 2022. We used a random effects model to calculate the pooled prevalence and 95% confidence interval (CI). We used the I2 statistic to assess heterogeneity, Egger's test to assess publication bias, 95% prediction interval to determine the level of uncertainty, and the Newcastle-Ottawa Scale and Joanna Briggs Institute quality assessment tool to assess the risk of bias. Twenty-six relevant articles from 19 countries across 5 continents were included, and data on 5472 mpox patients with 18 unique features were analysed. The pooled prevalence of clinical features of mpox were rash (85.7%, 95% CI: 68.3-94.3; k = 21), chills (77.8%, 95% CI: 70.5-83.7; k = 3), and fever (62.3%, 95% CI: 51.3-71.6; k = 25), lymphadenopathy (58.6%, 95% CI: 47.2-69.2; k = 21), lethargy or exhaustion (46.8%, 95% CI: 30.7-63.5; k = 14), pruritus (40.6%, 95% CI: 28.5-54.0; k = 5), myalgia (36.0%, 95% CI: 24.3-49.7; k = 16), headache (34.6%, 95% CI: 23.4-47.8; k = 17), skin ulcer (31.1%, 95% CI: 18.6-47.1; k = 7), abdomen symptom (24.2%, 95% CI: 17.9-31.9; k = 11), pharyngitis (23.0%, 95% CI: 12.7-37.9; k = 14), respiratory symptom (19.5%, 95% CI: 6.8-44.6; k = 6), nausea or vomiting (13.0%, 95% CI: 4.6-31.9; k = 3), scrotal or penile oedema (10.7%, 95% CI: 6.3-17.7; k = 4), conjunctivitis (7.1%, 95% CI: 2.4-18.9; k = 6), and death (0.9%, 95% CI: 0.4-2.0; k = 26). This is the first international and comprehensive study to examine all clinical presentations of human mpox infection. Our systematic review proposes a comprehensive understanding of the current mpox outbreak and may serve as key data for future studies on the pathological mechanisms and epidemiology of mpox infections.

National trends in alcohol and substance use among adolescents from 2005 to 2021: a Korean serial cross-sectional study of one million adolescents.

BACKGROUND: Although previous studies have provided data on early pandemic periods of alcohol and substance use in adolescents, more adequate studies are needed to predict the trends of alcohol and substance use during recent periods, including the mid-pandemic period. This study investigated the changes in alcohol and substance use, except tobacco use, throughout the pre-, early-, and mid-pandemic periods in adolescents using a nationwide serial cross-sectional survey from South Korea. METHODS: Data on 1,109,776 Korean adolescents aged 13-18 years from 2005 to 2021 were obtained in a survey operated by the Korea Disease Control and Prevention Agency. We evaluated adolescents' alcohol and substance consumption prevalence and compared the slope of alcohol and substance prevalence before and during the COVID-19 pandemic to see the trend changes. We define the pre-COVID-19 period as consisting of four groups of consecutive years (2005-2008, 2009-2012, 2013-2015, and 2016-2019). The COVID-19 pandemic period is composed of 2020 (early-pandemic era) and 2021 (mid-pandemic era). RESULTS: More than a million adolescents successfully met the inclusion criteria. The weighted prevalence of current alcohol use was 26.8% [95% confidence interval (CI) 26.4-27.1] from 2005 to 2008 and 10.5% (95% CI 10.1-11.0) in 2020 and 2021. The weighted prevalence of substance use was 1.1% (95% CI 1.1-1.2) from 2005 to 2008 and 0.7% (95% CI 0.6-0.7) between 2020 and 2021. From 2005 to 2021, the overall trend of use of both alcohol and drugs was found to decrease, but the decline has slowed since COVID-19 epidemic (current alcohol use: ßdiff 0.167; 95% CI 0.150-0.184; substance use: ßdiff 0.152; 95% CI 0.110-0.194). The changes in the slope of current alcohol and substance use showed a consistent slowdown with regard to sex, grade, residence area, and smoking status from 2005 to 2021. CONCLUSION: The overall prevalence of alcohol consumption and substance use among over one million Korean adolescents from the early and mid-stage (2020-2021) of the COVID-19 pandemic showed a slower decline than expected given the increase during the prepandemic period (2005-2019).

Cannabidiol mediates epidermal terminal differentiation and redox homeostasis through aryl hydrocarbon receptor (AhR)-dependent signaling.

BACKGROUND: Cannabidiol, a non-psychoactive phytocannabinoid, has antioxidant and anti-inflammatory activity in keratinocytes. However, the signaling pathway through which cannabidiol exerts its effect on keratinocytes or whether it can modulate keratinocyte differentiation has not been fully elucidated yet. OBJECTIVE: We investigated whether cannabidiol modulates epidermal differentiation and scavenges reactive oxygen species through the aryl hydrocarbon receptor (AhR) in keratinocytes and epidermal equivalents. METHODS: We investigated the cannabidiol-induced activation of AhR using AhR luciferase reporter assay, qRT-PCR, western blot, and immunofluorescence assays. We also analyzed whether keratinocyte differentiation and antioxidant activity are regulated by cannabidiol-induced AhR activation. RESULTS: In both keratinocytes and epidermal equivalents, cannabidiol increased both the mRNA and protein expression of filaggrin, involucrin, NRF2, and NQO1 and the mRNA expression of the AhR target genes, including CYP1A1 and aryl hydrocarbon receptor repressor. Additionally, cannabidiol showed antioxidant activity that was attenuated by AhR knockdown or co-administration with an AhR antagonist. Moreover, cannabidiol increased the ratio of OVOL1/OVOL2 mRNA expression, which is a downstream regulator of AhR that mediates epidermal differentiation. In addition to increased expression of barrier-related proteins, cannabidiol-treated epidermal equivalent showed a more prominent granular layer than the control epidermis. The increased granular layer by cannabidiol was suppressed by the AhR antagonist. CONCLUSION: Cannabidiol can be a modulator of the AhR-OVOL1-filaggrin axis and AhR-NRF2-NQO1 signaling, thus indicating a potential use of cannabidiol in skin barrier enhancement and reducing oxidative stress.

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. Supplementary file2 (MP4 64897 KB).

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 (ßdiff , -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; ßdiff , -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.