Serial Cross-sectional Surveys Research Articles

Trends in Intention to Take the Second Booster COVID-19 Vaccination and Associated Factors in China: Serial Cross-Sectional Surveys.

The escalating complexity of the COVID-19 epidemic underscores the need for heightened attention to booster vaccinations. This study aims to examine the changing trend in the public's intention to receive the second COVID-19 booster vaccination over time and the associated factors following the COVID-19 policy optimization in China. Eight cross-sectional surveys utilizing SMS questionnaire links were conducted in Guangzhou, China, from December 2022 to April 2023. The Mann-Kendall test was employed to analyze the trend in intentions to receive the second booster vaccination across the survey time. Adjusted and multivariate logistic analyses were used to analyze the factors associated with vaccination intention. Parallel analyses were performed for two subgroups with different COVID-19 infection statuses. A total of 9860 respondents were surveyed in the eight rounds, of which 8048 completed the first booster vaccination and were included in the analysis. The overall COVID-19 infection rate was 60.0% (4832/8048), while the overall vaccination intention was 72.2% (5810/8048) among respondents. The vaccination intention exhibited a significant declining trend over time, decreasing from 81.5% in December 2022 to 52.2% in April 2023. An adjusted logistic regression analysis revealed that anxiety and depression were negatively associated with an intention to receive the second booster vaccination, while COVID-19-related preventive behaviors and a high engagement in COVID-19-related information were positively associated with an intention to receive the second booster vaccination. A subgroup analysis revealed that the association between psychological and behavioral characteristics and vaccination intention remained relatively stable among individuals with different histories of COVID-19 infections. There was a significant decline in the intention to receive the second booster vaccination following the optimization of the COVID policy in China. Our findings emphasize the urgency of the second booster vaccination and provide a foundation for the development of tailored interventions to enhance and sustain vaccination intention among the public.

Evaluation of the population-level impacts of the LiveLighter® obesity prevention campaign from 2012 to 2019 based on serial cross-sectional surveys

BackgroundHalting and reversing the upward trend in obesity requires sustained implementation of comprehensive, evidence-based strategies at the population-level. The LiveLighter® program targets adults using a range of public education strategies, including mass media campaigns, to support healthy lifestyle changes to attain or maintain a healthy weight and reduce the risk of chronic disease. LiveLighter® has been implemented in Western Australia (WA) since 2012 and, to our knowledge, includes the longest running adult-targeted mass media campaign for healthy weight and lifestyle promotion and education globally. This evaluation assessed the impact of LiveLighter® on WA adults’ knowledge, intentions and behaviours as they relate to healthy eating and body weight from 2012 to 2019.MethodsLiveLighter® mass media campaigns, which are TV-led and aired statewide, depict genuine, graphic imagery of visceral fat around internal organs to raise awareness about the link between excess body weight and chronic diseases; demonstrate how unhealthy food and drink consumption can contribute to unhealthy weight gain; and recommend healthy alternatives. Cross-sectional telephone surveys were conducted at baseline and following each campaign phase with an independent, randomly selected sample of WA adults aged 25 to 49 years (n = 501 to n = 1504 per survey) to assess their knowledge of the link between excess body weight and chronic diseases, and their intentions and behaviours related to healthy eating and weight. Multivariable logistic regression models were undertaken to assess differences in responses between baseline and each post-campaign survey.ResultsCompared to baseline, there were significant increases in the proportion of respondents reporting knowledge of excess body weight as a risk factor for certain cancers and type 2 diabetes, intentions to eat more fruit and vegetables and drink less sugar sweetened beverages (SSBs) in the next seven days, and the proportion of respondents who reported meeting guidelines for daily vegetable intake. Reported consumption of SSBs significantly decreased.ConclusionsLiveLighter® is associated with improvements in knowledge of the health risks associated with excess body mass, increased vegetable intake and reduced SSB consumption in WA adults. These findings support the use of sustained, well-designed healthy lifestyle promotion and education programs as part of a comprehensive obesity prevention strategy.

Influence of School Type and Class Level on Mean Caries Experience in 12-Year-Olds in Serial Cross-Sectional National Oral Health Survey in Germany-Proposal to Adjust for Selection Bias.

Caries data from the 2016 NOHSC were adjusted for each federal state on the basis of two additional large-scale datasets for school type and class level. Twelve-year-olds in all grades in Saxony-Anhalt (n = 96,842) exhibited significantly higher DMFT values than 12-year-olds in 6th grade (n = 76,456; +0.10 DMFT; ~14.2%, p < 0.001). Adjustments for school type had effects on DMFT on the level of federal states but almost balanced out on the national level (-0.01 DMFT; ~2%). Due to putatively similar structures of the federal states, the national mean DMFT for 12-year-olds in the latest NOHSC (2016; n = 55,002) was adjusted from 0.44 to 0.50 DMFT, correcting for selection bias. Selection bias in this NOHSC leads to an underestimation of caries levels by about 15%. Due to very low caries experience in children in Germany, these precise adjustments (+0.06 DMFT) have only a minor effect on interpretations of the national epidemiologic situation. Consequently, other national caries studies worldwide using the robust marker of DMFT should also adjust for systematic selection bias related to socio-economic background rather than increasing efforts in examination strategy.

Trends in Income Inequities in Cardiovascular Health Among US Adults, 1988-2018.

Mean cardiovascular health has improved over the past several decades in the United States, but it is unclear whether the benefit is shared equitably. This study examined 30-year trends in cardiovascular health using a suite of income equity metrics to provide a comprehensive picture of cardiovascular income equity. The study evaluated data from the 1988-2018 National Health and Nutrition Examination Survey. Survey groupings were stratified by poverty-to-income ratio (PIR) category, and the mean predicted 10-year risk of a major cardiovascular event or death based on the pooled cohort equations (PCE) was calculated (10-year PCE risk). Equity metrics including the relative and absolute concentration indices and the achievement index-metrics that assess both the prevalence and the distribution of a health measure across different socioeconomic categories-were calculated. A total of 26 633 participants aged 40 to 75 years were included (mean age, 53.0-55.5 years; women, 51.9%-53.0%). From 1988-1994 to 2015-2018, the mean 10-year PCE risk improved from 7.8% to 6.4% (P<0.05). The improvement was limited to the 2 highest income categories (10-year PCE risk for PIR 5: 7.7%-5.1%, P<0.05; PIR 3-4.99: 7.6%-6.1%, P<0.05). The 10-year PCE risk for the lowest income category (PIR <1) did not significantly change (8.1%-8.7%). In 1988-1994, the 10-year PCE risk for PIR <1 was 6% higher than PIR 5; by 2015-2018, this relative inequity increased to 70% (P<0.05). When using metrics that account for all income categories, the achievement index improved (8.0%-7.1%, P<0.05); however, the achievement index was consistently higher than the mean 10-year PCE risk, indicating the poor persistently had a greater share of adverse health. In this serial cross-sectional survey of US adults spanning 30 years, the population's mean 10-year PCE risk improved, but the improvement was not felt equally across the income spectrum.

Change in intention and hesitancy regarding COVID-19 vaccines in a cohort of adults in Quebec during the pandemic

ABSTRACT Although COVID-19 vaccine uptake was high in Quebec for the primary series, vaccine acceptance decreased for the subsequent booster doses. This article presents the evolution of vaccine intention, self-reported vaccination behaviors, and vaccine hesitancy over 2 years. A series of cross-sectional surveys were conducted in Quebec between March 2020 and March 2023, with a representative sample of 3,330 adults recruited biweekly via a Web panel. Panelists could have answered multiple times over the course of the project. A cohort of respondents was created to assess how attitudes and behaviors about COVID-19 vaccines evolved. Descriptive statistics and multivariate logistic regressions were performed. Among the 1,914 individuals with no or low intention of getting vaccinated in Fall 2021 (Period 1), 1,476 (77%) reported having received at least two doses in the Winter 2023 (Period 2). Not believing in conspiracy theory (OR = 2.08, 95% CI: 1.65–2.64), being worried about catching COVID-19 (OR = 2.12, 95% CI: 1.65–2.73) and not living in a rural area (ORs of other areas are 2.27, 95% CI: 1.58–3.28; 1.66, 95% CI: 1.23–2.26; 1.82 95% CI: 1.23–2.73) were the three main factors associated with being vaccinated at Period 2. Among the 11,117 individuals not hesitant at Period 1, 1,335 (12%) became hesitant at Period 2. The three main factors significantly associated with becoming vaccine hesitant were the adherence to conspiracy theories (OR = 2.28, 95% CI: 1.95–2.66), being a female (OR = 1.67, 95% CI: 1.48–1.90) and being younger than 65 years old (the ORs for 18–34, 35–49, and 50–64 compared with 65 and over are 2.82, 95% CI: 2.32–3.44; 2.39, 95% CI: 2.00–2.86 and 1.82, 95% CI: 1.55–2.15 respectively). As the pandemic is over, monitoring the evolution of vaccine attitudes and uptake will be important.

Feasibility and acceptability of using biometric fingerprinting to track migrations and support retention in HIV prevention research in fishing population in East Africa

IntroductionFishing populations constitute a suitable key population amongst which to conduct HIV prevention trials due to very high HIV prevalence and incidence, however, these are highly mobile populations. We determined the feasibility and acceptability of using fingerprinting and geographical positioning systems to describe mobility patterns and retention among fisherfolks on the shoreline of Lake Victoria in South-western Uganda.MethodsBetween August 2015 and January 2017, two serial cross-sectional surveys were conducted during which fingerprinting of all residents aged 18–30 years on the shoreline of Lake Victoria was done. A mapper moving ahead of the survey team, produced village maps and took coordinates of every household. These were accessed by the survey team that assigned household and individual unique identifiers (ID) and collected demographic data. Using the assigned IDs, individuals were enrolled and their fingerprints scanned. The fingerprinting was repeated 6 months later in order to determine the participant’s current household. If it was different from that at baseline, a new household ID was assigned which was used to map migrations both within and between villages.ResultsAt both rounds, over 99% accepted to be fingerprinted. No fingerprinting faults were recorded at baseline and the level was under 1% at round two. Over 80% of the participants were seen at round two and of these, 16.3%, had moved to a new location whilst the majority, 85%, stayed within the same village. Movements between villages were mainly observed for those resident in large villages. Those who did not consider a fishing village to be their permanent home were less likely to be migrants than permanent residents (adjusted odds ratio = 0.37, 95%CI:0.15–0.94).ConclusionUse of fingerprinting in fishing populations is feasible and acceptable. It is possible to track this mobile population for clinical trials or health services using this technology since most movements could be traced within and between villages.

Trends and correlates of naloxone possession and use among people who inject drugs in Seattle, Washington

BackgroundNaloxone distribution has been implemented as an essential opioid overdose prevention measure for people who inject drugs (PWID), and many jurisdictions in the United States have implemented policy change to increase naloxone access. This project describes temporal trends in and correlates of naloxone possession and use among PWID in the Seattle area of Washington State. MethodsUsing a repeat cross-sectional design, we utilized two sets of serial cross-sectional surveys of PWID, which included biennial surveys of Seattle area syringe service program (SSP) clients and community-based National HIV Behavioral Surveillance surveys of PWID (NHBS-PWID) conducted from 2012-2019. Survey participant characteristics were descriptively compared between participants reporting naloxone possession to those not reporting naloxone possession. Multivariable Poisson regression was used to calculate prevalence ratios for naloxone possession comparing later to earlier survey years, adjusting for age, gender, race/ethnicity, primary drug, and experiencing and witnessing an overdose in the past 12 months. ResultsNaloxone possession and use increased in both survey populations. The prevalence of possessing naloxone was 2.8 times greater [2019 vs. 2013= 95% CI: 2.40-3.33] among SSP participants and 2.8 times greater [2018 vs. 2012=95% CI: 2.41-3.16] among NHBS-PWID participants for the most recent time period. The prevalence of naloxone use was 1.3 times greater [2019 vs. 2017= 95% CI: 1.13-1.58] and 2.1 times greater [2015 vs. 2012=95% CI:1.62-2.73] among SSP and NHBS-PWID participants, respectively, for the most recent time period. ConclusionNaloxone possession and use increased in PWID in the Seattle area from 2012-2019, and is, at least in part, likely the result of numerous policy and programmatic efforts to facilitate easier naloxone accessibility in the wake of dramatic increases in overdose mortality. Further research on disparities in naloxone possession are needed to ensure equitable access.

National trends in the prevalence of hepatitis B and C in South Korea, before and during the COVID-19 pandemic (2007-2021) - a nationwide representative study.

Due to the various changes caused by the COVID-19 pandemic, some infectious diseases showed different epidemiology and prevalence during the pandemic. However, there is a lack of comprehensive studies on trends in the prevalence of hepatitis B and C related to the pandemic. Thus, we compared the prevalence of hepatitis B and C before and during the COVID-19 pandemic in South Korea. We conducted a comprehensive trend analysis with a nationwide serial cross-sectional survey from 2007 to 2021 (n=86,931) using the Korea National Health and Nutrition Examination Survey (KNHANES). The changes in the prevalence of hepatitis B and C were evaluated using a weighted regression model to assess the impact of the COVID-19 pandemic. From 2007 to 2021, 86,931 Korean adults aged 19 or older were included in the KNHANES data. The prevalence of hepatitis B showed a declining trend until the onset of the pandemic (1.80% in 2007-2009; 1.08% in 2016-2019; and 1.01% in 2020), at which point this trend reversed (1.39% in 2021). The prevalence of hepatitis C remained stable (0.14% in 2007-2009 and 0.18% in 2016-2019), with no particular surge related to the COVID-19 pandemic (βdiff, -0.002; 95% CI, -0.761 to 0.756). For hepatitis B, old age was identified as a pandemic-related vulnerable factor (ratio of odds ratio, 1.68; 95% CI, 1.05-2.70). In this study, unlike other infectious diseases, hepatitis B and C did not show a decreasing trend during the pandemic. In particular, hepatitis B showed a rebound trend during the pandemic, which was noticeable in those aged 60 or older. Further studies are needed to support these findings.

Changing trends in Chlamydia and gonorrhea infections among female sex workers in Southern China: a surveillance data analysis spanning 2019 to 2022.

Female sex workers (FSW) are particularly vulnerable to chlamydia and gonorrhea infections. However, there were few studies that detail the evolving patterns of chlamydia and gonorrhea among Chinese FSW. Therefore, our study endeavors to assess the prevalence of chlamydia and gonorrhea epidemics within FSW, investigate their changing trends and scrutinize associated factors. In 2019, China instituted a sentinel surveillance network focused on FSW in Guangdong Province. This network conducted an annual serial cross-sectional survey spanning from April to August. All analyses are predicated on surveillance data accumulated between 2019 and 2022. The prevalence of chlamydia increased from 10.1 to 12.3%, exhibiting an annual percentage shift of 6.8%. Conversely, the prevalence of gonorrhea dwindled from 2.0 to 1.3%, marking an annual percentage decline of 13.4% (P<0.001). After adjusting for covariates, chlamydia exhibited associations with having household registration in other provinces (adjusted odds ratio (aOR=0.55)), displaying symptoms of sexually transmitted infections (STIs) (aOR=1.65) and infected with gonorrhea (aOR=5.68). In parallel, gonorrhea demonstrated associations with providing oral sex to clients (aOR=3.74), manifesting STIs symptoms (aOR=4.27) and those infected with chlamydia (aOR=5.43). Our observations underscore the imperative to implement a comprehensive intervention strategy concentrating on chlamydia, while simultaneously fortifying endeavors to expand the scope of gonorrhea prevention services.

National trends in depression and suicide attempts and COVID-19 pandemic-related factors, 1998–2021: A nationwide study in South Korea

BackgroundDespite the significant psychiatric effects of the COVID-19 pandemic, there's limited data on the prevalence and risk factors of depression and suicide attempts among South Korean adults. MethodsA nationwide cross-sectional study using the Korea National Health and Nutrition Examination Survey (KNHANES) data from 1998 to 2021 was conducted. Changes in prevalence and risk factors for depression and suicide attempts were assessed using weighted odds ratios or weighted beta coefficients. ResultsDuring the observation period (1998–2021), the prevalence of depression increased in the overall population; however, no significant surge was found regarding the COVID-19 pandemic, from 2.78% (95% CI, 2.41–3.15) in 1998–2005–4.96% (4.32–5.61) in 2020 and 5.06% (4.43–5.69) in 2021. However, immediately after the onset of the pandemic, younger ages, male sex, urban residence, higher education, and high economic status became significant vulnerable factors compared to pre-pandemic periods. The prevalence of suicide attempts remained stable, and there was no notable surge specifically related to the COVID-19 pandemic, from 0.23% (95% CI, 0.18–0.28) in 1998–2005–0.45% (0.25–0.66) in 2020 and 0.42% (0.24–0.60) in 2021. Furthermore, no distinct vulnerable factors associated with suicide attempts have been identified. ConclusionThrough this nationwide serial cross-sectional survey study, we emphasized the need for understanding the differential impacts of global crises, such as COVID-19, across varied population subgroups, thereby highlighting the importance of specific and targeted mental health support strategies.

The concerned steward effect: Exploring the relationship between climate anxiety, psychological distress, and self-reported climate related behavioural engagement

Previous research has demonstrated that heightened levels of climate change anxiety are correlated with psychological distress. Some have argued that engagement in pro-environmental behaviour might be associated with lower levels of climate anxiety and psychological distress. As such, this study aimed to explore the association between pro-environmental behavioural engagement, climate change anxiety, and generalized psychological distress. Participants living in British Columbia, Canada aged 16+ completed a serial cross-sectional online survey. We examined inter-relationships between self-reported Climate-related Behavioural Engagement (BE) scores, Climate Change Anxiety Scale (CCAS) scores, and Kessler Psychological Distress (K6) scores using scatterplots, Spearman Rank Correlation and multivariable linear regression. Among 1553 participants, higher CCAS scores and higher BE scores were both associated with greater psychological distress. An interaction term between these variables indicated that as CCAS scores increased, the effect of self-reported behavioural engagement on psychological distress was attenuated. Findings suggest that self-reported behavioural engagement and climate anxiety are correlated, a phenomenon we refer to as the concerned steward effect. However, the association becomes attenuated among those with high levels of distress, perhaps driven by a diminishing return of behavioural engagement or difficulties of behavioural engagement among those with high distress.

Community-based seroprevalence of SARS CoV-2 in an urban district of Karachi, Pakistan

Background Antibody-based serological tests which target households and communities can estimate the true extent of infection in a population. It minimizes the biases of facility-based selective testing and generates scientific data on disease transmission through household asymptomatic cases. The objective of this study was to determine the seroprevalence and trend of SARS-CoV-2 in a densely populated urban community of Karachi. Methods Three serial cross-sectional surveys were conducted in November 2020, February 2021, and December 2021 in Karachi’s District East. Households were selected to provide serum samples for Elecsys® immunoassay for the detection of SARS-CoV-2 antibodies. All household members were eligible to participate regardless of age and infection status. Bayesian regression was used to adjust for assay performance and estimate seroprevalence. Results We enrolled 1506 participants from 501 households. In November 2020, adjusted seroprevalence was estimated as 24.0% (95% confidence interval, CI=18.0-31.0), compared to 53.9% (95% CI=45.5-63.2) in February. In December 2021, it increased to 84.9% (95% CI=78.5-92.3). The conditional risk of infection was 41% (95% CI=29.9-51.6), 56.7% (95% CI=50.4–62.6) and 77.8% (95% CI=73.0-81.7) in surveys 4, 5, and 6 respectively. Only 18.7% of participants who had reactive antibodies for COVID-19 were symptomatic. Conclusions An increase in seroprevalence estimates in Karachi’s District East was observed over time. Community-based seroprevalence studies help to estimate the true proportion of the population that has been infected and predicts the spread of the disease in similar settings.

Trends in Micronutrient Interventions, Anemia, and Iron Deficiency among Women and Children in Guatemala, 2009–2019

BackgroundFood fortification and micronutrient supplementation are public health strategies to improve micronutrient status in Guatemala; their population effectiveness has not been evaluated in recent years. ObjectiveWe evaluated trends in food fortification, micronutrient supplementation, anemia, and iron deficiency among nonpregnant women aged 15–49 y [women of reproductive age (WRA)] and children 6–59 aged mo [preschool age children (PSC)]. MethodNationally representative serial cross-sectional surveys were used to assess changes in hemoglobin, anemia, ferritin, iron deficiency, iron deficiency anemia, and self-reported consumption of fortifiable foods and micronutrient supplements during 2008/2009, 2013, 2015, 2016, 2017/2018, and 2018/2019. Predictors of hemoglobin and ferritin were assessed using generalized linear mixed models adjusted for survey year as random effects, and the consumption of fortifiable foods, supplements, and other potential confounders were fixed effects. ResultsMultiple micronutrient powder consumption among PSC during the previous 3 mo was 53.3% (95% CI: 49.4, 57.2) in 2013 and 33.6% (28.8, 38.4) in 2018/2019. Anemia among PSC was 11.3% (8.0, 14.5) in 2008/2009 and 6.1% (3.6, 8.6) in 2018/2019. Anemia among WRA was 10.7% (7.2, 14.2) in 2008/2009 and 3.9% (2.7, 5.2) in 2018/2019. Iron deficiency among PSC was 15.5% (12.1, 19.0) in 2008/2009 and 10.9% (7.4, 14.5) in 2016 (lowest), but 17.1 (13.3, 21.0) in 2017/2018 (highest). Iron deficiency among WRA was 14.9% (11.6, 18.2) in 2008/2009, 13.8% (11.8, 15.8) in 2013 (lowest), and 18.9% (16.3, 21.6) in 2017/2018 (highest). Wheat flour/bread consumption was positively associated with hemoglobin among PSC, and sugar consumption was positively associated with hemoglobin among WRA. The reported consumption of fortifiable foods was not associated with ferritin among PSC or WRA. ConclusionsGuatemala has implemented multiple food fortification strategies, and anemia has declined. Increases in iron deficiency in 2017–2019 warrant further attention. Secular trends toward poverty alleviation, education, and development might be responsible for changes not explained by the micronutrient interventions evaluated.

Parent-Child Nativity, Race, Ethnicity, and Common Mental Health Conditions Among United States Children and Adolescents

To examine associations between race, ethnicity, and parent-child nativity, and common mental health conditions among U.S. children and adolescents. Data were from 2016 to 2019 National Survey of Children's Health, a US population-based, serial cross-sectional survey, and restricted to children who had access to health care. We used weighted multivariable logistic regression to examine the associations between race and ethnicity (Asian, Black, Hispanic, White, Other-race); mental health outcomes (depression, anxiety, and behavior/conduct problems) stratified by household generation; and between household generation and outcomes stratified by race and ethnicity, adjusting for demographics (age, sex, family income to poverty ratio, parental education), and an adverse childhood experience (ACE) score. When stratifying by household generation, racial and ethnic minority children generally had similar to lower odds of outcomes compared with White children, with the exception of higher odds of behavior/conduct problems among third+-generation Black children. When stratifying by race and ethnicity, third+generation children had increased odds of depression compared to their first-generation counterparts. Third+generation, racial and ethnic minority children had increased odds of anxiety and behavior/conduct problems compared with their first-generation counterparts. The associations generally remained significant after adjusting for the ACE score. Lower odds of common mental health conditions in racial and ethnic minority children could be due to factors such as differential reporting, and higher estimates, including those in third+generation children, could be due to factors including discrimination; systemic racism; and other factors that vary by generation and need further investigation to advance health equity.

National Trends in Sadness, Suicidality, and COVID-19 Pandemic–Related Risk Factors Among South Korean Adolescents From 2005 to 2021

Despite the COVID-19 pandemic's effect on daily life, limited research exists on the prevalence and risk factors of suicidality and sadness among South Korean adolescents. To examine whether the observed sadness and suicidality in the early to middle periods of the COVID-19 pandemic differed from the expected level and to investigate changes in risk factors for sadness and suicidality. This nationwide serial cross-sectional survey study used data on 1 109 776 Korean adolescents aged 13 to 18 years from the Korea Youth Risk Behavior Web-based Survey from 2005 to 2021. The COVID-19 pandemic. The pattern of changes in the percentage or proportion of sadness or suicidality, as well as the risk factors for sadness or suicidality. The transitional effect of the COVID-19 pandemic was assessed using weighted odds ratios (wORs) or weighted beta coefficients with 95% CIs. Between 2005 and 2021, 1 109 776 adolescents (mean [SD] age, 15.0 [1.7] years; 51.5% male adolescents; and 51.7% in grades 7-9 and 48.3% in grades 10-12) were included in the Korea Youth Risk Behavior Web-based Survey. The slope of the long-term trends in sadness and suicidality decreased in the prepandemic period (sadness: from 37.8% [95% CI, 37.4%-38.2%] in 2005-2007 to 26.1% [95% CI, 25.9%-26.4%] in 2016-2019; suicidality: from 23.0% [95% CI, 22.7%-23.3%] in 2005-2007 to 12.3% [95% CI, 12.1%-12.5%] in 2016-2019), whereas the slope increased during the COVID-19 pandemic (sadness: from 25.0% [95% CI, 24.5%-25.6%] in 2020 to 26.6% [95% CI, 26.1%-27.1%] in 2021; trend difference in β, 0.249 [95% CI, 0.236-0.262]; suicidality: from 10.7% [95% CI, 10.3%-11.1%] in 2020 to 12.5% [95% CI, 12.1%-12.9%] in 2021; trend difference in β, 0.328 [95% CI, 0.312-0.344]). The trends presented a similar tendency in the subgroups according to sex, school grade, residential area, smoking status, and current alcohol use. Compared with the prepandemic period, the risk factors associated with sadness during the pandemic were younger age (wOR, 0.907; 95% CI, 0.881-0.933), female sex (wOR, 1.031; 95% CI, 1.001-1.062), urban residence (wOR, 1.120; 95% CI, 1.087-1.153), current smoking status (wOR, 1.134; 95% CI, 1.059-1.216), and current alcohol use (wOR, 1.051; 95% CI, 1.002-1.102). Female sex (wOR, 1.064; 95% CI, 1.021-1.109), urban residence (wOR, 1.117; 95% CI, 1.074-1.162), and low economic status (wOR, 1.286; 95% CI, 1.180-1.403) were the risk factors significantly associated with suicidality after the COVID-19 pandemic began. In this nationwide serial cross-sectional survey study of South Korean adolescents, the slope of the prevalence of sadness and suicidality increased during the COVID-19 pandemic after a decrease prior to the pandemic. The findings suggest that public health measures are needed to recognize vulnerable groups with risk factors and to prevent an increase in sadness and suicidality among adolescents during the COVID-19 pandemic.

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

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. Data on 1,109,776 Korean adolescents aged 13-18years 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). 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-19epidemic (current alcohol use: βdiff 0.167; 95% CI 0.150-0.184; substance use: βdiff 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. 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).

Ten-year trends in sex differences in cardiovascular risk factors, in-hospital management, and outcomes of ischemic stroke in China: Analyses of a nationwide serial cross-sectional survey from 2005 to 2015.

Women with stroke differ from men in terms of risk factors, treatment, and outcomes. However, previous inconsistent results in China hampered the development of tailored sex-specific strategies for ischemic stroke management. We performed a nationwide serial cross-sectional survey to obtain national-level estimates to assess the 10-year trends in sex differences in cardiovascular risk factors, in-hospital management, and outcomes in China from 2005 to 2015. We used a two-stage random sampling design, economic-geographical region-stratified random sampling for hospitals first and then systematic sampling for patients, to obtain a nationally representative sample of ischemic strokes in China in 2005, 2010, and 2015. We extracted data on clinical characteristics, management measures (diagnostic tests, interventions, and secondary prevention treatments), in-hospital outcomes (all-cause in-hospital mortality, discharge against medical advice [DAMA], and a composite outcome of in-hospital death and DAMA), and comorbidities. We applied weights proportional to the inverse sampling fraction of hospitals within each stratum and the inverse sampling fraction of patients within each hospital. A total of 26,900 ischemic stroke admissions were analyzed. Compared to men, women had a much lower prevalence of current smokers and a slightly higher prevalence of hypertension, diabetes, dyslipidemia, and atrial fibrillation at admission. Prevalence differences between sex in these cardiovascular risk factors were stable except for atrial fibrillation (decreased from 3.7% [95% CI: 1.8% to 5.7%] to 1.3% [95% CI: 0.5% to 2.0%]) and current smoker (increased from -18.0 [95% CI: -20.2% to -15.9%] to -25.6% [95% CI: -26.6% to -24.6%]). From 2005 to 2015, in-hospital management and outcomes were improved both for women and men, and sex differences in cerebrovascular assessment, cervical vessels assessment, and transthoracic echocardiography/transesophageal echocardiography were improved as well. However, women increased more slowly than men in the administration of clopidogrel (from 0.3% [95% CI: -0.9% to 1.4%) to -7.3% [95% CI: -8.7% to -6.0%]) and aspirin plus clopidogrel (0.3% [95% CI: -5.0% to 1.1%] to -5.0% [95% CI: -6.2% to -3.9%]). Compared to men, women patients with ischemic stroke had a steadily higher prevalence of cardiovascular risk factors, a slower increase rate in the administration of key secondary prevention drugs, and comparable in-hospital outcomes. More effort should be paid to the treatment and control of cardiovascular risk factors and also to the prescription of antiplatelets at discharge for women.

Trends in obesity and severe obesity prevalence in the United States from 1999 to 2018.

The national obesity epidemic and trend of obesity prevalence have been characterized by a series of cross-sectional surveys in the United States, however, less is known about obesity prevalence trajectory by birth cohort. This study aimed to investigate whether trends in obesity and severe obesity prevalence varied by birth cohorts among 1940s-1990s in the United States. Using data from the National Health and Nutrition Examination Survey 1999-2018. The trends of obesity and severe obesity prevalence were conducted with synthetic birth cohort. There were 60 981 participants (weighted mean age, 38.1 years; female, 50.1%) assigned in 6 birth cohorts (1990s, 1980s, 1970s, 1960s, 1950s, and 1940s) over 1999-2018. The prevalence of obesity and severe obesity increased significantly with age during all birth cohorts except for the 1940s (Ptrend <0.001). For obesity, a significant positive quadratic trend was observed among 1990s birth cohort (Pnon-linearity =0.037), while a significant positive linear trend (Plinearity <0.001) among 1980s, 1970s, 1960s, and 1950s birth cohorts. Corresponding to same weighted mean age, the prevalence of both obesity and severe obesity in younger birth cohorts were much higher than the older birth generations. The continued upward trend in obesity and severe obesity prevalence by birth cohort highlighted the need for continuing focus on surveillance of body mass index and identification, implementation, and evaluation of evidence-based interventions to address this major health problem in the United States.

Incidence of primary hepatitis C virus infection among people who inject drugs in Australia pre- and post-unrestricted availability of direct acting antiviral therapies.

The 2016 Global Health Sector Strategy (GHSS) on viral hepatitis aims to reduce new hepatitis C virus (HCV) infections by 80% by 2030, including a 30% reduction by 2020. This study aimed to estimate primary HCV incident infection among a national sample of people who inject drugs (PWID) before and after the introduction of unrestricted access to HCV direct-acting antiviral (DAA) therapy via Australia's Pharmaceutical Benefits Scheme in 2016. A simple deterministic linkage method identified repeat respondents in serial cross-sectional surveys conducted among PWID. Two separate retrospective cohorts of HCV antibody-negative respondents were created, corresponding to the pre- (2010-15) and post- (2016-21) DAA time-periods. This study took place in Australia. Among 757 PWID retained (376 pre-DAA, 381 post-DAA), more than half were male (60%), the majority were heterosexual (80%), the median age was 40 years (interquartile range = 33-46 years) and the predominant drugs last injected were heroin (24%), pharmaceutical opioids (27%) and methamphetamine (41%). The primary outcome was HCV seroconversion, defined as a negative HCV antibody test result followed by a positive HCV antibody result. Time to primary incident HCV infection was estimated using the person-years (PY) method. A total 97 of 376 (2010-15) and 41 of 381 (2016-21) HCV seroconversions were identified. Primary HCV incidence more than halved, from 13.6 per 100 PY [95% confidence intervals (CI) = 11.2, 16.6] in 2010-15 to 5.4 per 100 PY (95% CI =3.9, 7.3) in 2016-21. The decline was independent of observed differences in demographic and drug use characteristics over the two time-periods (adjusted hazard ratio =0.47, 95% CI =0.31-0.69, P<0.001). Australia has had a 53% reduction in primary hepatitis C virus (HCV) incidence among people who inject drugs following unrestricted availability of HCV direct acting antiviral therapy in March 2016. Given that PWID are the predominant population at risk of HCV infection in Australia, findings add to the evidence that Australia has probably met its 2020 Global Health Sector Strategy subtarget of a 30% decline in new infections.

Trends in medical students' health over 5 years: Does a wellbeing curriculum make a difference?

Trends in New Zealand (NZ) medical students' health and the influence of a wellbeing curricula are unknown. The author's collected self-report data from NZ medical students on 'Graduation Day' from 2014 to 2018, using a serial cross-sectional survey design with validated scales assessing psychological health, stigma, coping, and lifestyle. Comparisons were made with NZ general population same-age peers. Analyses examined trends, differences between 'cohorts' of students receiving different exposures to a wellbeing curriculum, and correlations between students' own lifestyle practices and their frequency of talking with patients about those topics. Of 1,062 students, 886 participated. The authors found statistically significant self-reported increases from 2014 to 2018 for negative psychological indices, including scores for distress and burnout, suicidal thoughts in the preceding year, and the likelihood of being diagnosed with an anxiety disorder. There was a significant increase in numbers of students reporting having their own doctor as well as increased healthy coping strategies and a significant decrease in stigma scores. Academic cohorts of students who had completed a wellbeing curriculum were more likely to report high distress levels, having been diagnosed with a mood disorder, and being non-drinkers than students without wellbeing training. When compared to NZ peers, medical students smoked less, exercised more, and were less likely to have diagnosed mood and anxiety disorders, but reported more distress. The authors found a significant correlation between the amount of exercise students undertook and their likelihood to discuss exercise with patients. NZ medical students have better physical health than general population peers and are more likely to discuss exercise with patients if exercising themselves. However, cohorts of graduating students report increasing distress despite the implementation of a wellbeing curriculum. Research is needed into mechanisms between students' self-awareness, willingness to report distress, stigma, mind-set, coping, and psychological outcomes, to inform curriculum developers.