National trends in sexual intercourse and usage of contraception among Korean adolescents.

BACKGROUND: The exact influence of the COVID-19 pandemic on sexual intercourse and usage of contraception remains largely uncharted territory. To bridge this gap in knowledge, we conducted a comprehensive, cross-sectional examination of long-term trends in the prevalence of sexual intercourse and usage of contraception among South Korean adolescents from 2006 to 2022. METHODS: In our research, we drew upon data encompassing 1,138,799 South Korean adolescents aged 12 to 18 years, derived from the Korean Youth Risk Behavior Web-based Survey (KYRBS) over a period spanning from 2006 to 2022. We focused on the prevalence of sexual intercourse, contraception utilization, and the underlying associated factors among this demographic. The KYRBS data was collected using a complex sampling strategy to determine the national prevalence estimates and shifts in prevalence before (2006-2019) and during (2020-2022) the COVID-19 pandemic era. RESULTS: During the pre-pandemic period, a decrease in adolescent sexual intercourse was observed (6.34% in 2006, 5.53% in 2012, and 5.87% in 2019). However, in the post-pandemic period (2020-2022), there was a surge in sexual intercourse (4.55% in 2020 and 6.20% in 2022). This evident alteration in sexual intercourse trajectory between pre- and post-pandemic periods was statistically significant [ßdiff, 0.950; 95% confidence interval (CI), 0.756-1.144]. Regarding contraceptive use among South Korean adolescents, there was an increase in the pre-COVID-19 pandemic phase across all demographic segments (14.61% in 2006, 22.30% in 2012, and 47.69% in 2022) but a notable decline when compared with the pre- and post-pandemic periods (ßdiff, - 0.319; 95% CI, - 0.454 to - 0.184). Additionally, during the study period, a decrease in sexual intercourse was observed in the pre-pandemic period (ß, - 0.129; 95% CI, - 0.148 to - 0.110), followed by an increase in the post-pandemic period (ß, 0.821; 95% CI, 0.627 to 1.014). This shift is highlighted by an effect size of 0.96 [weighted odds ratio (wOR); 95% CI, 0.92 to 1.00], indicating a substantial change in adolescent sexual behaviors across study periods. CONCLUSIONS: The increase in sexual intercourse and decrease in usage of contraception observed in our study between the pre- and post-COVID-19 periods suggests a potential threat to sexual health among South Korean adolescents. This trend emphasizes the ongoing necessity of raising awareness about adolescent sexual behavior in South Korea.

Global estimates on the reports of vaccine-associated myocarditis and pericarditis from 1969 to 2023: Findings with critical reanalysis from the WHO pharmacovigilance database.

Due to the limitation of previous studies examining adverse reports of myocarditis and pericarditis associated with vaccines other than the COVID-19 vaccine, there are challenges in establishing a comprehensive understanding of vaccine safety on a global scale. Hence, the objective of this study was to examine the worldwide burden of vaccine-associated pericarditis and myocarditis and the vaccines associated with these indications. This study utilized the World Health Organization international pharmacovigilance database, from which records of vaccine-associated pericarditis and myocarditis between 1969 and 2023 were extracted (over 130 million reports). We calculated global reporting counts, reported odds ratios (RORs), and information components (ICs) to discern the association between 19 vaccines and the occurrence of pericarditis and myocarditis across 156 countries and territories. We identified 49 096 reports (male, n = 30 013) of vaccine-associated pericarditis and myocarditis among 73 590 reports of all-cause pericarditis and myocarditis. There has been a significant increase in reports of vaccine-related cardiac adverse events over time, with a noteworthy surge observed after 2020, attributed to cases of pericarditis associated with COVID-19 mRNA vaccines. Smallpox vaccines were associated with most pericarditis and myocarditis reports (ROR: 73.68 [95% CI, 67.79-80.10]; IC [IC0.25]: 6.05 [5.91]), followed by COVID-19 mRNA vaccine (37.77 [37.00-38.56]; 3.07 [3.05]), anthrax vaccine (25.54 [22.37-29.16]; 4.58 [4.35]), typhoid vaccine (6.17 [5.16-7.38]; 2.59 [2.29]), encephalitis vaccine (2.00 [1.48-2.71]; 0.99 [0.47]), influenza vaccine (1.87 [1.71-2.04]; 0.90 [0.75]), and Ad5-vectored COVID-19 vaccine (1.40 [1.34-1.46]; 0.46 [0.39]). Concerning age and sex-specific risks, reports of vaccine-associated pericarditis and myocarditis were more prevalent among males and in older age groups. The age group between 12 and 17 years exhibited significant sex disproportion. Most of these adverse events had a short time to onset (median time: 1 day) and fatality rate was 0.44%. Our analysis of global data revealed an increase in pericarditis and myocarditis reports associated with vaccines, particularly live vaccines like smallpox and anthrax, notably in young males. While these adverse events are generally rare and mild, caution is warranted, especially for healthcare workers, due to potential myocardial injury-related in-hospital mortality. Further study with validated reporting is crucial to enhance accuracy in evaluating the correlation between vaccines and cardiac conditions for preventive measures.

Global and regional burden of vaccine-induced thrombotic thrombocytopenia, 1969-2023: Comprehensive findings with critical analysis of the international pharmacovigilance database.

OBJECTIVE: The scarcity of studies on vaccine-induced thrombosis and thrombocytopenia syndrome (TTS) limits the comprehensive understanding of vaccine safety on a global scale. Therefore, the objective of this study is to assess the global burden of vaccine-induced TTS, identify the vaccines most associated with it, and suggest clinical implications regarding vaccination. METHODS: This study employed the World Health Organization international pharmacovigilance database, extracting records of vaccine-induced immune thrombotic thrombocytopenia from 1969 to 2023 (total reports, n > 130 million). Global reporting counts, reported odds ratios (ROR), and information components (IC) were calculated to identify the association between 19 vaccines and the occurrence of vaccine-induced TTS across 156 countries. RESULTS: We identified 24 233 cases (male, n = 11 559 [47.7%]) of vaccine-induced TTS among 404 388 reports of all-cause TTS. There has been a significant increase in reports of vaccine-induced TTS events over time, with a noteworthy surge observed after 2020, attributed to cases of TTS associated with COVID-19 vaccines. Measles, mumps, and rubella (MMR) vaccines were associated with most TTS reports (ROR [95% confidence interval], 2.87 [2.75-3.00]; IC [IC0.25], 1.51 [1.43]), followed by hepatitis B (HBV, 2.23 [2.07-2.39]; 1.15 [1.03]), rotavirus diarrhea (1.95 [1.78-2.13]; 0.81 [0.53]), encephalitis (1.80 [1.50-2.16]; 0.84 [0.53]), hepatitis A (1.67 [1.50-1.86]; 0.73 [0.55]), adenovirus Type 5 vector-based (Ad5-vectored) COVID-19 (1.64 [1.59-1.68]; 0.69 [0.64]), pneumococcal (1.57 [1.49-1.66]; 0.65 [0.56]), and typhoid vaccines (1.41 [1.12-1.78]; 0.49 [0.11]). Concerning age and sex-specific risks, reports of vaccine-induced TTS were more associated with females and younger age groups. The age group between 12 and 17 years exhibited significant sex disproportion. Most of these adverse events had a short time to onset (days; mean [SD], 4.99 [40.30]) and the fatality rate was 2.20%, the highest rate observed in the age group over 65 years (3.79%) and lowest in the age group between 0 and 11 years (0.31%). CONCLUSION: A rise in vaccine-induced TTS reports, notably MMR, HBV, and rotavirus diarrhea vaccines, was particularly related to young females. Ad5-vectored COVID-19 vaccines showed comparable or lower association with TTS compared to other vaccines. Despite the rarity of these adverse events, vigilance is essential as rare complications can be fatal, especially in older groups. Further studies with validated reporting are imperative to improve the accuracy of assessing the vaccine-induced TTS for preventive interventions and early diagnosis.

Risks of chronic urticaria following SARS-CoV-2 infection: binational population-based cohort studies from South Korea and Japan.

CLINICAL IMPLICATION AND IMPORTANCE: SARS-CoV-2 infection is associated with an increased risk of chronic urticaria, with severe COVID-19 showing a more pronounced association compared to milder cases. Notably, prior vaccination has been shown to reduce the risk of chronic urticaria.

Risks of cutaneous immune-related adverse events in long COVID: Multinational cohort studies in South Korea, Japan, and the UK.

Previous research has not investigated the persistent cutaneous immune-related adverse events (cirAEs) related to long COVID to investigate the long-term sequelae. This multinational study, using a propensity-matched overlap weighting method, utilizes large national claims-based cohorts, using ICD-10 code diagnosis, focusing on patients aged ≥20 years from three countries: South Korean, Japanese, and the British cohorts. To estimate the risk of cirAEs in long COVID, the persistence or emergence of cirAEs occurring 4 weeks after the initial SARS-CoV-2 infection, we employed a Cox proportional hazard regression model. The Korean cohort (n = 5,937,373; mean age 49.2 years [SD: 13.2]), the Japanese cohort (n = 4,307,587; 42.5 years [13.6]), and the UK cohort (n = 395,435; 71.0 years [8.07]) were presented. An increased risk of cirAEs in long COVID was observed (HR, 1.10; 95% CI, 1.06-1.14) in Korean cohort, while a similar association was observed in Japanese and UK cohorts. The long-term risk of cirAEs in long COVID was higher in more severe COVID-19 cases (1.31; 1.22-1.39). Unlike the increased risk of cirAEs in long COVID, COVID-19 vaccination attenuated the risk, especially with two or more doses (1.03; 0.95-1.11) or heterologous regimens (0.98; 0.76-1.27). The time attenuation effect indicated a sustained risk for up to 6 months postinfection (<3 months: 1.13 [1.07-1.19]; 3-6 months: 1.14 [1.06-1.22]). SARS-CoV-2 infection is associated with an increased risk of cirAEs in the aspect of long COVID. Vaccination might reduce this risk, highlighting the need for preventive strategies in long COVID management.

Effects and safety of transcranial direct current stimulation on multiple health outcomes: an umbrella review of randomized clinical trials.

Transcranial direct current stimulation (tDCS), which delivers a direct current to the brain, emerged as a non-invasive potential therapeutic in treating a range of neurological and neuropsychiatric disorders. However, a comprehensive quantitative evidence synthesis on the effects of tDCS on a broad range of mental illnesses is lacking. Here, we systematically assess the certainty of the effects and safety of tDCS on several health outcomes using an umbrella review of randomized controlled trials (RCTs). The methodological quality of each included original meta-analysis was assessed by the A Measurement Tool for Assessing Systematic Reviews 2 (AMSTAR2), and the certainty of the evidence for each effect was evaluated with Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). We followed an a priori protocol (PROSPERO CRD42023458700). We identified 15 meta-analyses of RCTs (AMSTAR 2; high 3, moderate 3, and low 9) that included 282 original articles, covering 22 unique health endpoints across 22 countries and six continents. From meta-analyses of RCTs supported by very low to high certainty of evidence, it was found that tDCS improved symptoms related to post-stroke, including post-stroke depression scale score (equivalent standardized mean difference [eSMD], 1.61 [95% confidence level, 0.72-2.50]; GRADE=moderate), activities of daily living independence (7.04 [3.41-10.67]; GRADE=high), motor recovery of upper and lower extremity (upper extremity: 0.15 [0.06-0.24], GRADE=high; lower extremity: 0.10 [0.03-0.16], GRADE=high), swallowing performance (GRADE=low), and spasticity (GRADE=moderate). In addition, tDCS had treatment effects on symptoms of several neurological and neuropsychiatric disorders, including obsessive-compulsive disorder (0.81 [0.44-1.18]; GRADE=high), pain in fibromyalgia (GRADE=low), disease of consciousness (GRADE=low), insight score (GRADE=moderate) and working memory (0.34 [0.01-0.67]; GRADE=high) in schizophrenia, migraine-related pain (-1.52 [-2.91 to -0.13]; GRADE=high), attention-deficit/hyperactivity disorder (reduction in overall symptom severity: 0.24 [0.04-0.45], GRADE=low; reduction in inattention: 0.56 [0.02-1.11], GRADE=low; reduction in impulsivity: 0.28 [0.04-0.51], GRADE=low), depression (GRADE=low), cerebellar ataxia (GRADE=low), and pain (GRADE=very low). Importantly, tDCS induced an increased number of reported cases of treatment-emergent mania or hypomania (0.88 [0.62-1.13]; GRADE=moderate). We found varied levels of evidence for the effects of tDCS with multiple neurological and neuropsychiatric conditions, from very low to high certainty of evidence. tDCS was effective for people with stroke, obsessive-compulsive disorder, fibromyalgia, disease of consciousness, schizophrenia, migraine, attention-deficit/hyperactivity disorder, depression, cerebellar ataxia, and pain. Therefore, these findings suggest the benefit of tDCS for several neurological and neuropsychiatric disorders; however, further studies are needed to understand the underlying mechanism and optimize its therapeutic potential.

Global and regional prevalence of polypharmacy and related factors, 1997-2022: An umbrella review.

OBJECTIVE: Limited comprehensive evidence exists on the global prevalence of polypharmacy. This knowledge gap contributes to increased healthcare system costs and related public health concerns. Thus, we aimed to synthesize the current evidence on polypharmacy prevalence and associated factors in the general and older populations using an umbrella review. METHODS: Our primary outcomes were global prevalence and related indicators of polypharmacy. We systematically searched Google Scholar, PubMed/MEDLINE, Embase, and CINAHL for studies published between the inception of each database until April 30, 2023. RESULTS: Eleven meta-analyses incorporating 295 studies and 59,552,762 participants from 41 countries across six continents were identified. The global prevalence of polypharmacy in the general population is 37 %, with higher rates in older individuals (45 %), outpatients (48 %), and inpatients (52 %). North America showed a higher prevalence (52 %) than Asia (36 %) and Europe (36 %). Among frail elderly individuals, the prevalence of polypharmacy is 59 %, with the highest rates in Europe (68 %) and hospital settings (71 %). CONCLUSION: The global prevalence of polypharmacy and its associated factors in older adults present a complex, multifaceted, and conflicting picture. Understanding the prevalence of polypharmacy and its associated factors may help reduce the number of multidrug prescriptions.

Global and regional burden of vaccine-associated facial paralysis, 1967-2023: Findings from the WHO international pharmacovigilance database.

The scarce and conflicting data on vaccine-associated facial paralysis limit our understanding of vaccine safety on a global scale. Therefore, this study aims to evaluate the global burden of vaccine-associated facial paralysis and to identify the extent of its association with individual vaccines, thereby contributing to the development of a more effective vaccination program. We used data on vaccine-associated facial paralysis from 1967 to 2023 (total reports, n = 131 255 418 418) from the World Health Organization International Pharmacovigilance Database. Global reporting counts, reported odds ratios (ROR), and information components (ICs) were computed to elucidate the association between the 16 vaccines and the occurrence of vaccine-associated facial paralysis across 156 countries. We identified 26 197 reports (men, n = 10 507 [40.11%]) of vaccine-associated facial paralysis from 49 537 reports of all-cause facial paralysis. Vaccine-associated facial paralysis has been consistently reported; however, a pronounced increase in reported incidence has emerged after the onset of the coronavirus disease 2019 (COVID-19) pandemic, which is attributable to the COVID-19 mRNA vaccine. Most vaccines were associated with facial paralysis, with differing levels of association, except for tuberculosis vaccines. COVID-19 mRNA vaccines had the highest association with facial paralysis reports (ROR, 28.31 [95% confidence interval, 27.60-29.03]; IC, 3.37 [IC0.25, 3.35]), followed by encephalitis, influenza, hepatitis A, papillomavirus, hepatitis B, typhoid, varicella-zoster, meningococcal, Ad-5 vectored COVID-19, measles, mumps and rubella, diphtheria, tetanus toxoids, pertussis, polio, and Hemophilus influenza type b, pneumococcal, rotavirus diarrhea, and inactivated whole-virus COVID-19 vaccines. Concerning age- and sex-specific risks, vaccine-associated facial paralysis was more strongly associated with older age groups and males. The serious adverse outcome and death rate of vaccine-associated facial paralysis were extremely low (0.07% and 0.00%, respectively). An increase in vaccine-induced facial paralysis, primarily owing to COVID-19 mRNA vaccines, was observed with most vaccines, except tuberculosis vaccines. Given the higher association observed in the older and male groups with vaccine-associated facial paralysis, close monitoring of these demographics when administering vaccines that are significantly associated with adverse reactions is crucial.

Acute and post-acute respiratory complications of SARS-CoV-2 infection: population-based cohort study in South Korea and Japan.

Considering the significant burden of post-acute COVID-19 conditions among patients infected with SARS-CoV-2, we aimed to identify the risk of acute respiratory complications or post-acute respiratory sequelae. A binational population-based cohort study was conducted to analyze the risk of acute respiratory complications or post-acute respiratory sequelae after SARS-CoV-2 infection. We used a Korean nationwide claim-based cohort (K-COV-N; n = 2,312,748; main cohort) and a Japanese claim-based cohort (JMDC; n = 3,115,606; replication cohort) after multi-to-one propensity score matching. Among 2,312,748 Korean participants (mean age, 47.2 years [SD, 15.6]; 1,109,708 [48.0%] female), 17.1% (394,598/2,312,748) were infected with SARS-CoV-2. The risk of acute respiratory complications or post-acute respiratory sequelae is significantly increased in people with SARS-CoV-2 infection compared to the general population (acute respiratory complications: HR, 8.06 [95% CI, 6.92-9.38]; post-acute respiratory sequelae: 1.68 [1.62-1.75]), and the risk increased with increasing COVID-19 severity. We identified COVID-19 vaccination as an attenuating factor, showing a protective association against acute or post-acute respiratory conditions. Furthermore, while the excess post-acute risk diminished with time following SARS-CoV-2 infection, it persisted beyond 6 months post-infection. The replication cohort showed a similar pattern in the association. Our study comprehensively evaluates respiratory complications in post-COVID-19 conditions, considering attenuating factors such as vaccination status, post-infection duration, COVID-19 severity, and specific respiratory conditions.

Machine Learning-Based Prediction of Suicidal Thinking in Adolescents by Derivation and Validation in 3 Independent Worldwide Cohorts: Algorithm Development and Validation Study.

BACKGROUND: Suicide is the second-leading cause of death among adolescents and is associated with clusters of suicides. Despite numerous studies on this preventable cause of death, the focus has primarily been on single nations and traditional statistical methods. OBJECTIVE: This study aims to develop a predictive model for adolescent suicidal thinking using multinational data sets and machine learning (ML). METHODS: We used data from the Korea Youth Risk Behavior Web-based Survey with 566,875 adolescents aged between 13 and 18 years and conducted external validation using the Youth Risk Behavior Survey with 103,874 adolescents and Norway's University National General Survey with 19,574 adolescents. Several tree-based ML models were developed, and feature importance and Shapley additive explanations values were analyzed to identify risk factors for adolescent suicidal thinking. RESULTS: When trained on the Korea Youth Risk Behavior Web-based Survey data from South Korea with a 95% CI, the XGBoost model reported an area under the receiver operating characteristic (AUROC) curve of 90.06% (95% CI 89.97-90.16), displaying superior performance compared to other models. For external validation using the Youth Risk Behavior Survey data from the United States and the University National General Survey from Norway, the XGBoost model achieved AUROCs of 83.09% and 81.27%, respectively. Across all data sets, XGBoost consistently outperformed the other models with the highest AUROC score, and was selected as the optimal model. In terms of predictors of suicidal thinking, feelings of sadness and despair were the most influential, accounting for 57.4% of the impact, followed by stress status at 19.8%. This was followed by age (5.7%), household income (4%), academic achievement (3.4%), sex (2.1%), and others, which contributed less than 2% each. CONCLUSIONS: This study used ML by integrating diverse data sets from 3 countries to address adolescent suicide. The findings highlight the important role of emotional health indicators in predicting suicidal thinking among adolescents. Specifically, sadness and despair were identified as the most significant predictors, followed by stressful conditions and age. These findings emphasize the critical need for early diagnosis and prevention of mental health issues during adolescence.

Editorial: Mental Health Distress in Long COVID Condition Among the Pediatric Population: A Contemporary Medical Challenge.

As the COVID-19 pandemic continues, a body of emerging evidence suggests that individuals who had been infected with SARS-CoV-2 suffered from lingering adverse health consequences. Such long-term conditions, also known as "long COVID" or "post-acute COVID syndrome," are reported to bring both pulmonary and extrapulmonary manifestations.1 The most common features of long COVID include fatigue and headache, which frequently occur with neuropsychiatric impairments. Given that the onset of mental disorders occurs primarily in late childhood and adolescence, it is essential to focus on the pediatric population to determine the risk of mental disorder diagnosis following SARS-CoV-2 infection.

National trends in counseling for stress and depression and COVID-19 pandemic-related factors among adults, 2009-2022: A nationwide study in South Korea: Stress, depression, and pandemic.

To investigate the long-term trends in counseling for stress and depression using data from a nationwide survey in South Korea. We conducted a nationwide serial, large-scale, cross-sectional, survey-based study using data from 2,903,887 Korean adults from the Korea Community Health Survey, 2009-2022. Our study investigated the trends and risk factors for counseling for stress and depression during the pre-pandemic (2009-2019) and pandemic era (2020-2022). The prevalence of counseling for stress and depression increased across pre-pandemic (counseling for stress: ß, 0.217 [95 % CI, 0.194 to 0.241]; counseling for depression: ß, 0.136 [0.118 to 0.154]) and pandemic periods (ß, 0.324 [0.287 to 0.360]; ß, 0.210 [0.182 to 0.239], respectively). The prevalence of counseling for stress and depression showed steeper slopes for increasing trends after the outbreak. In addition, subgroups with female sex, urban residence, lower household income, lower self-rated health, shorter sleep time, and higher worries about contracting COVID-19 were the risk factors associated with the increased prevalence of counseling for stress and depression. Our study analyzed the trends in counseling for stress and depression among over two million South Korean adults in 2009-2022, revealing a significant escalation during the pandemic. These findings emphasize the need for mental health policies to support vulnerable groups during the pandemic.

National trends of allergic diseases and pandemic-related factors among individuals with obesity in South Korea: A nationwide representative serial study, 2005-2021.

Background: Although obesity is known to be related to allergic diseases, few studies have investigated the prevalence of allergic diseases in individuals with obesity, especially during the COVID-19 pandemic. Thus, this study aimed to analyze national trends of allergic diseases among individuals with obesity and sociodemographic factors. Methods: This study used data from the Korea National Health and Nutrition Examination Survey to examine the prevalence of allergic diseases among individuals with obesity in South Korea from 2005 to 2021. A nationally representative sample of 118,275 participants aged over 2 years or above was divided into six groups for analysis. This study used weighted multivariate regression analysis to examine the estimates of related factors. It assessed the weighted odds ratios or ß-coefficients for these factors across different categories, including age, sex, region of residence, education level, household income, and body mass index for the entire population. Results: All allergic diseases showed a general upward trend from 2005 to 2021, but each disease showed different prevalence trends when compared by age. Before the pandemic, those aged ≤39 years had an increasing trend for asthma and AD, but those aged ≥40 years had a decreasing trend. For asthma, ß-coefficients were 0.629 (95 % CI, 0.299 to 0.958) for 19-39 years, -0.245 (-0.450 to -0.040) for 40-59 years, and -0.668 (-1.024 to -0.313) for ≥60 years. For AD, ß-coefficients were 2.514 (1.258-3.769) in those aged 2-18 years, 0.630 (0.173-1.086) in those aged 19-39 years, -0.458 (-0.648 to -0.268) in those aged 40-59 years, and -0.253 (-0.454 to -0.052) in those aged ≥60 years. However, for both asthma and AD, there were no significant changes in prevalence during the pandemic. In the case of AR, trends were different from those of asthma and AD. Before the pandemic, AR showed an increasing trend in those aged ≤39 years and those aged ≥40 years: ß-coefficients were 3.067 (2.344-3.790) in 19-39 years, 2.051 (1.609-2.493) in 40-59 years, and 1.173 (0.820-1.526) in ≥60 years. During the pandemic, there was an increasing trend only among those aged 40-59, with no significant changes in other age groups: ß-coefficients were 1.438 (0.065-2.811) in 40-59 years. Conclusions: From 2005 to 2021, all allergic diseases (asthma, AD, and AR) increased overall, but with different age-related trends. No significant link was found between COVID-19 and allergic diseases, possibly due to preventive measures like mask-wearing and social distancing. Anxiety about accessing healthcare during the pandemic likely contributed to a decline in allergy diagnoses, highlighting the need for comprehensive strategies to manage and prevent allergic diseases.

Risks of alopecia areata in long COVID: Binational population-based cohort studies from South Korea and Japan.

Previous studies have proposed alopecia areata (AA) as a potential outcome of COVID-19 infection among autoimmune diseases, yet the findings might be inconclusive and difficult to generalize due to limited sample sizes and evidence levels. Thus, we aimed to investigate in detail the long-term risk of AA following SARS-CoV-2 infection based on large, binational, general population-based cohort studies. Our study investigated the long-term AA risk after SARS-CoV-2 infection by analyzing bi-national, claim-based cohorts in South Korea and Japan: a Korean nationwide cohort (K-COV-N cohort; discovery cohort; total n = 10 027 506) and a Japanese claims-based cohort (JMDC cohort; validation cohort; total n = 12 218 680). AA was identified based on the international classification of diseases 10th revision code (L63) requiring at least three claims within 1 year. After exposure-driven propensity score matching, SARS-CoV-2 infection was associated with an increased risk of incident AA (aHR, 1.66; 95% CI, 1.38-1.99). This increased risk was observed and persisted for up to 6 months. A similar pattern was observed in the validation cohort. As modifiable factors, severe COVID-19 increased the risk of AA, whereas receiving two or more doses of the COVID-19 vaccine before infection decreased the risk of AA. Through a bi-national cohort study in South Korea and Japan, SARS-CoV-2 infection was associated with an elevated risk for incident AA in the aspect of long COVID.

Prenatal and postnatal factors associated with sudden infant death syndrome: an umbrella review of meta-analyses.

BACKGROUND: Comprehensive quantitative evidence on the risk and protective factors for sudden infant death syndrome (SIDS) effects is lacking. We investigated the risk and protective factors related to SIDS. METHODS: We conducted an umbrella review of meta-analyses of observational and interventional studies assessing SIDS-related factors. PubMed/MEDLINE, Embase, EBSCO, and Google Scholar were searched from inception until January 18, 2023. Data extraction, quality assessment, and certainty of evidence were assessed by using A Measurement Tool Assessment Systematic Reviews 2 following PRISMA guidelines. According to observational evidence, credibility was graded and classified by class and quality of evidence (CE; convincing, highly suggestive, suggestive, weak, or not significant). Our study protocol was registered with PROSPERO (CRD42023458696). The risk and protective factors related to SIDS are presented as equivalent odds ratios (eORs). RESULTS: We identified eight original meta-analyses, including 152 original articles, covering 12 unique risk and protective factors for SIDS across 21 countries/regions and five continents. Several risk factors, including prenatal drug exposure [eOR = 7.84 (95% CI = 4.81-12.79), CE = highly suggestive], prenatal opioid exposure [9.55 (95% CI = 4.87-18.72), CE = suggestive], prenatal methadone exposure [9.52 (95% CI = 3.34-27.10), CE = weak], prenatal cocaine exposure [4.38 (95% CI = 1.95-9.86), CE = weak], prenatal maternal smoking [2.25 (95% CI = 1.95-2.60), CE = highly suggestive], postnatal maternal smoking [1.97 (95% CI = 1.75-2.22), CE = weak], bed sharing [2.89 (95% CI = 1.81-4.60), CE = weak], and infants found with heads covered by bedclothes after last sleep [11.01 (95% CI = 5.40-22.45), CE = suggestive], were identified. On the other hand, three protective factors, namely, breastfeeding [0.57 (95% CI = 0.39-0.83), CE = non-significant], supine sleeping position [0.48 (95% CI = 0.37-0.63), CE = suggestive], and pacifier use [0.44 (95% CI = 0.30-0.65), CE = weak], were also identified. CONCLUSIONS: Based on the evidence, we propose several risk and protective factors for SIDS. This study suggests the need for further studies on SIDS-related factors supported by weak credibility, no association, or a lack of adequate research.

Prenatal opioid exposure and subsequent risk of neuropsychiatric disorders in children: nationwide birth cohort study in South Korea.

OBJECTIVE: To investigate the potential association between prenatal opioid exposure and the risk of neuropsychiatric disorders in children. DESIGN: Nationwide birth cohort study. SETTING: From 1 January 2009 to 31 December 2020, birth cohort data of pregnant women in South Korea linked to their liveborn infants from the National Health Insurance Service of South Korea were collected. PARTICIPANTS: All 3 251 594 infants (paired mothers, n=2 369 322; age 32.1 years (standard deviation 4.2)) in South Korea from the start of 2010 to the end of 2017, with follow-up from the date of birth until the date of death or 31 December 2020, were included. MAIN OUTCOME MEASURES: Diagnosis of neuropsychiatric disorders in liveborn infants with mental and behaviour disorders (International Classification of Diseases 10th edition codes F00-99). Follow-up continued until the first diagnosis of neuropsychiatric disorder, 31 December 2020 (end of the study period), or the date of death, whichever occurred first. Eight cohorts were created: three cohorts (full unmatched, propensity score matched, and child screening cohorts) were formed, all of which were paired with sibling comparison cohorts, in addition to two more propensity score groups. Multiple subgroup analyses were performed. RESULTS: Of the 3 128 571 infants included (from 2 299 664 mothers), we identified 2 912 559 (51.3% male, 48.7% female) infants with no prenatal opioid exposure and 216 012 (51.2% male, 48.8% female) infants with prenatal opioid exposure. The risk of neuropsychiatric disorders in the child with prenatal opioid exposure was 1.07 (95% confidence interval 1.05 to 1.10) for fully adjusted hazard ratio in the matched cohort, but no significant association was noted in the sibling comparison cohort (hazard ratio 1.00 (0.93 to 1.07)). Prenatal opioid exposure during the first trimester (1.11 (1.07 to 1.15)), higher opioid doses (1.15 (1.09 to 1.21)), and long term opioid use of 60 days or more (1.95 (1.24 to 3.06)) were associated with an increased risk of neuropsychiatric disorders in the child. Prenatal opioid exposure modestly increased the risk of severe neuropsychiatric disorders (1.30 (1.15 to 1.46)), mood disorders, attention deficit hyperactivity disorder, and intellectual disability in the child. CONCLUSIONS: Opioid use during pregnancy was not associated with a substantial increase in the risk of neuropsychiatric disorders in the offspring. A slightly increased risk of neuropsychiatric disorders was observed, but this should not be considered clinically meaningful given the observational nature of the study, and limited to high opioid dose, more than one opioid used, longer duration of exposure, opioid exposure during early pregnancy, and only to some neuropsychiatric disorders.

Opioid use and subsequent delirium risk in patients with advanced cancer in palliative care: a multicenter registry study.

The prevalent use of opioids for pain management in patients with advanced cancer underscores the need for research on their neuropsychiatric impacts, particularly delirium. Therefore, we aimed to investigate the potential association between opioid use and the risk of delirium in patients with advanced cancer admitted to the acute palliative care unit. We conducted a retrospective observational study utilizing a multicenter, patient-based registry cohort by collecting the data from January 1, 2019, to December 31, 2020, in South Korea. All data regarding exposures, outcomes, and covariates were obtained through retrospective chart reviews by a team of specialized medical professionals with expertise in oncology. Full unmatched and 1:1 propensity-score matched cohorts were formed, and stratification analysis was conducted. The primary outcome, delirium, was defined and diagnosed by the DSM-IV. Of the 2,066 patients with advanced cancer, we identified 42.8% (mean [SD] age, 64.4 [13.3] years; 60.8% male) non-opioid users and 57.2% (62.8 [12.5] years; 55.9% male) opioid users, respectively. Opioid use was significantly associated with an increased occurrence of delirium in patients with advanced cancer (OR, 2.02 [95% CI 1.22-3.35]). The risk of delirium in patients with advanced cancer showed increasing trends in a dose-dependent manner. High-dose opioid users showed an increased risk of delirium in patients with advanced cancer compared to non-opioid users (low-dose user: OR, 2.21 [95% CI 1.27-3.84]; high-dose user: OR, 5.75 [95% CI 2.81-11.77]; ratio of OR, 2.60 [95% CI 1.05-6.44]). Patients with old age, male sex, absence of chemotherapy during hospitalization, and non-obese status were more susceptible to increased risk of delirium in patients with cancer. In this multicenter patient-based registry cohort study, we found a significant, dose-dependent association between opioid use and increased risk of delirium in patients with advanced cancer. We also identified specific patient groups more susceptible to delirium. These findings highlight the importance of opioid prescription in these patients with advanced cancer, balancing effective doses for pain management and adverse dose-inducing delirium.