Why circadian rhythmicity matters: Associations between sleep irregularity and mental health conditions during the Covid-19 health crisis.

OBJECTIVE: To assess the association between sleep irregularity, anxiety, and depression while controlling for other sleep dimensions and using a longitudinal design. METHODS: Longitudinal cohort study which started in April 2020 during the first French lockdown in the general population. Follow-up questionnaires were completed in June 2020, a period without lockdown measures. Participants were asked about their sleep (regularity, duration, timing, complaints) and their anxiety (General Anxiety Disorder-7) and depressive (Patient Health Questionnaire-9) symptoms. RESULTS: A total of 3745 participants were included (mean age: 28.9 years) with 2945 women (78.6%). At baseline, 38.1% (1428) of participants reported irregular sleep timing, 23.8% (891) anxiety and 28.9% (1081) depressive symptoms. In cross-sectional analyses, irregular sleep timing was associated with a 2.5-fold higher likelihood of anxiety and a 4-fold higher likelihood of depressive symptoms compared to regular sleepers. Associations were not explained by the other sleep dimensions and persisted in a longitudinal analysis, with irregular sleep timing at baseline being associated with anxiety (OR = 3.27[1.58-6.76]) and depressive symptoms (OR = 3.45[1.66-7.19]) during follow-up. CONCLUSION: The results show a strong association between sleep irregularity and mental health. Furthers studies are needed to explore how sleep regularity could promote good mental health in non-clinical populations.

An Escape Game on University Students' Mental Health During the COVID-19 Pandemic: Cocreation Study.

BACKGROUND: The COVID-19 pandemic has had a severe impact on students' mental health. Interventions are needed to promote their psychological well-being and prevent mental illnesses in the aftermath of this unprecedented situation. Digital escape games can be an effective tool to support students' mental health. A cocreation approach can improve the acceptability of these interventions by involving different stakeholders (eg, end users, game designers, and health professionals) to obtain audience-specific games. OBJECTIVE: This study aims to describe the process of testing and optimizing the game "EscapeCovid" on students' mental health, to serve as a model for the cocreation of future similar interventions. METHODS: The PRODUCES (Problem, Objective, Design, End Users, Cocreators, Evaluation, Scalability) framework was used. Cocreation steps (test and optimization) were detailed for replicability. A total of 45 students tested a pilot version of the game, with 10 undergoing a semistructured interview. Meetings with a group of stakeholders and brainwriting were organized to optimize the game. RESULTS: We produced a new version of the game incorporating the suggestions provided by student testers and following the stakeholders' guidelines. Improvements were made to both the content and the form of the new version of the pilot game. The storyline, including the protagonist and the scenes, was adapted to the student population. CONCLUSIONS: Our results suggested that cocreation can contribute to the design of more widely accepted interventions aimed at promoting mental health and preventing psychological disorders. Results also suggest that an end user-centered approach can facilitate intervention tailoring. When conceiving a health-related escape game for students, we recommend using the cocreation approach to enhance players' experience, thus positively influencing their learning process and overall well-being.

Factors related to increased alcohol misuse by students compared to non-students during the first Covid-19 lockdown in France: the Confins study.

BACKGROUND: The closure of bars and lockdowns related to the Covid-19 pandemic changed alcohol use levels in France during the spring of 2020. We wondered whether this sudden cessation of social interactions impacted students more than non-students and what factors specific to students would explain the increase in alcohol misuse. The aims of this study were to compare self-reported changes in alcohol misuse (alcohol intake and binge-drinking frequency) during the first Covid-19 lockdown from March 17 to May 10, 2020, between French students and non-students and describe factors associated with this alcohol misuse in each subgroup. METHODS: Data collected in the Confins study from April 8 to May 10, 2020, were used in cross-sectional analyses stratified by student status. Multiple logistic regression was performed to estimate the association between self-reported increase in alcohol intake or binge-drinking frequency (at least six drinks of alcohol on one occasion) and demographic, socioeconomic, and clinical factors, as well as conditions associated with the Covid-19 pandemic. The population-attributable fraction was then used to estimate the contribution of identified risk factors to increased alcohol misuse in students and non-students. RESULTS: Among both students and non-students, a self-reported decrease or no change in alcohol intake or binge-drinking was more common than an increase. However, the risk factors explaining an increase in alcohol intake differed among students (≥ 25 years old, not working or studying in the health field, and having suicidal ideation during the last 7 days) and non-students (having a medical diagnosis of mental disorders). The risk factors explaining an increase in binge-drinking frequency were similar in the two subgroups (being a tobacco smoker before lockdown and not practicing any physical activity during the last 7 days), except suicidal thoughts, which was a risk factor for alcohol misuse specific to students. CONCLUSIONS: These results highlight the vulnerability of certain French students to alcohol misuse and the necessity of combining both mental health and substance use-related screening in the student population.

Effectiveness of digital games promoting young people's mental health: A review of reviews.

Objectives: Digital games are a popular form of entertainment for youth. They are often used as a therapy for psychological problems, a mental health promotion intervention, and a preventative measure. Systematic reviews and meta-analyses have been conducted to assess the effectiveness of mental health-related digital games. However, a synthesis considering all evaluation results to inform their development is missing. Methods: We performed a review of reviews to synthetize results of previous research to describe the impact of digital games on the mental health of young people aged <30 years old. We considered systematic reviews and meta-analyses published between 2012 and 2022. Searches were conducted in Scopus, Google Scholar, Pubmed, and Cochrane library systematic reviews (CENTRAL) during October 2023. Results: Our final selection included 10 systematic reviews and meta-analyses on interventions targeting youth of both sexes aged 2-29 years old across the world. In total, 218 interventions were identified. Selected articles reported different types of games, e.g., active and non-active video games, virtual reality games, serious games. Not all digital games were conscientiously evaluated, but, in general, their impact on mental health was positive. Regarding the quality, 5 studies were of high quality, 3 of moderate quality and 2 of low quality. Conclusions: Overall, elements of gamification were well-accepted, but they lacked assessment through rigorous experimental conditions. Digital games for mental health are promising, but in order to be consistently effective in promoting young people's mental health and prevent psychological diseases, they should present specific features.

Adverse Childhood Experiences and Illegal Drug Use Among College Students: Findings from a French Sample.

BACKGROUND: While studies have demonstrated the negative impact of adverse childhood experiences (ACEs) on lifelong health, less is known about the relationship between ACEs and illegal drug use. Thus, the objective of the study was to examine the relationship between ACEs and illegal drug use among college students. METHODS: French college students between 18 and 30 years enrolled in a university cohort study were eligible for inclusion. Multivariate logistic regression models were conducted for each drug. RESULTS: Among the sample (n = 1,157), 30.6% had no ACE exposure, 29.6%, 19.2%, and 20.7% had 1, 2 and ≥ 3 ACEs, respectively. Students with ACEs had a higher likelihood of using illegal drugs (p = 0.0067). After controlling for potential confounders, having ≥ 3 ACEs increased the risk of lifetime use of multiple drugs (aOR:10.9; 95% CI: 4.6-26.0), stimulants (aOR: 3.6; 95% CI:1.7-7.7), hallucinogens (aOR: 2.0; 95% CI: 1.1-3.5), cannabis (aOR: 4.7; 95% CI: 2.7-8.0), and risky illegal drugs (e.g., higher lifetime frequency drug use) (aOR: 2.9; 95% CI: 1.5-5.8). Estimates for illegal drug use were highest with parental substance use (aOR: 2.6; 95% CI; 1.5-4.4), sexual abuse (aOR: 2.3; 95% CI; 1.4-3.8), and divorce (aOR: 1.9; 95% CI: 1.3-2.7). CONCLUSIONS: ACEs increase the risk for lifetime illegal drug use and risky drug use in a dose-respondent fashion. These findings suggest that university students with higher levels of ACEs may benefit from additional support and services from clinical practitioners and university administrators.

Adverse Childhood Experiences and ADHD Symptoms Among French College Students.

To examine the relationship between adverse childhood experiences (ACEs) and Attention-deficit Hyperactivity Disorder (ADHD) among college students. We investigated the association between ACEs and ADHD symptoms among French college students enrolled in the i-Share cohort using multivariate logistic regression models. The sample comprised of 1062 participants with a mean age of 20.3 (SD = 2.3) of which 30.6% had no ACEs exposure, 29.6% had 1 ACE, 19.2% had 2 ACEs, and 20.6% had ≥ 3 ACEs. After controlling for potential confounders, every increase in ACE exposure heightened the risk of ADHD symptoms with the respective adjusted Odds Ratios and 95% confidence intervals: 1 ACE: 2.1 (0.7-6.3) / 2 ACEs: 4.5 (2.6-12.8)/ ≥ 3 ACEs: 5.2 (1.8-14.8). Estimates for ADHD symptoms were higher with sexual abuse, emotional and physical neglect, and bullying. Findings suggest that ACEs heighten the risk for developing ADHD symptoms among college students and bear important implications for prevention and clinical practice.

Evaluating a Public Health Information Service According to Users' Socioeconomic Position and Health Status: Protocol for a Cross-Sectional Study.

BACKGROUND: The increasing use of information technology in the field of health is supposed to promote users' empowerment but can also reinforce social inequalities. Some health authorities in various countries have developed mechanisms to offer accurate and relevant information to health care system users, often through health websites. However, the evaluation of these sociotechnical tools is inadequate, particularly with respect to differences and inequalities in use by social groups. OBJECTIVE: Our study aims to evaluate the access, understanding, appraisal, and use of the French website Santé.fr by users according to their socioeconomic position and perceived health status. METHODS: This cross-sectional study involves the entire French population to which Santé.fr is offered. Data will be collected through mixed methods, including a web-based questionnaire for quantitative data and interviews and focus groups for qualitative data. Collected data will cover users' access, understanding, appraisal, and use of Santé.fr, as well as sociodemographic and socioeconomic characteristics, health status, and digital health literacy. A validation of the dimensions of access, understanding, appraisal, and use of Santé.fr will be conducted, followed by principal component analysis and ascendant hierarchical classification based on the 2 main components of principal component analysis to characterize homogeneous users' profiles. Regression models will be used to investigate the relationships between each dimension and socioeconomic position and health status variables. NVivo 11 software (Lumivero) will be used to categorize interviewees' comments into preidentified themes or themes emerging from the discourse and compare them with the comments of various types of interviewees to understand the factors influencing people's access, understanding, appraisal, and use of Santé.fr. RESULTS: Recruitment is scheduled to begin in January 2024 and will conclude when the required number of participants is reached. Data collection is expected to be finalized approximately 7 months after recruitment, with the final data analysis programmed to be completed around December 2024. CONCLUSIONS: This study would be the first in France and in Europe to evaluate a public health information service, in this case the Santé.fr website (the official website of the French Ministry of Health), according to users' socioeconomic position and health status. The study could discover issues related to inequalities in access to, and the use of, digital technologies for obtaining health information on the internet. Given that access to health information on the internet is crucial for health decision-making and empowerment, inequalities in access may have subsequent consequences on health inequalities among social categories. Therefore, it is important to ensure that all social categories have access to Santé.fr. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/51123.

Improving Children's Mental Health Literacy Through the Cocreation of an Intervention and Scale Validation: Protocol for the CHILD-Mental Health Literacy Research Study.

BACKGROUND: Children's mental health is a public health priority, with 1 in 5 European children younger than 12 years having a behavioral, developmental, or psychological disorder. Mental health literacy (MHL) is a modifiable determinant of mental health, promoting psychological well-being and reducing mental health problems. Despite its significance, no interventions or scales currently exist for increasing and measuring MHL in this population. OBJECTIVE: This study has dual objectives: (1) cocreating and evaluating an intervention on children's MHL, and (2) developing and validating a scale that measures children's MHL. METHODS: Our study focuses on children aged 9-11 years attending primary school classes in various settings, including urban and rural areas, and priority education zones within a French department. Using a participatory research approach, we will conduct workshops involving children, parents, teachers, and 1 artist to cocreate an intervention comprising multiple tools (eg, a pedagogical kit and videos). This intervention will undergo initial evaluation in 4 classes through observations, interviews, and satisfaction questionnaires to assess its viability. Concurrently, the artist will collaborate with children to create the initial version of the CHILD-MHL scale, which will then be administered to 300 children. Psychometric analyses will validate the scale. Subsequently, we will conduct a cluster randomized controlled trial involving a minimum of 20 classes, using the CHILD-MHL scale scores as the primary end point to evaluate the intervention's efficacy. Additional interviews will complement this mixed methods evaluation. Both the intervention and the scale are grounded in the Child-Focused MHL model. RESULTS: The first tool of the intervention is the pedagogical kit Le Jardin du Dedans, supported by the public organization Psycom Santé Mentale Info and endorsed by UNICEF (United Nations Children's Fund) France. The second tool is a handbook by the Pan American Health Organization and the World Health Organization, which is addressed to teachers to sensitize them to children's mental health problems. The third is a 5-page supplementary leaflet produced by the nongovernmental organization The Ink Link, which teaches children the notion of MHL. Finally, we produced 56 items of the MHL Scale and listed existing education policies for children's mental health. CONCLUSIONS: After its robust evaluation, the intervention could be extended to several schools in France. The scale will be the first in the world to measure children's MHL. It will be used not only to evaluate interventions but also to provide data for decision makers to include MHL in all educational policies. Both the intervention and the scale could be translated into other languages. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/51096.

Attention deficit hyperactivity disorder symptoms and lifetime use of psychoactive substances among French university students: A cross-sectional study.

In a cross sectional study of 13,837 university students, we aimed to explore the association between attention deficit hyperactivity disorder (ADHD) symptoms and lifetime psychoactive substance use (LPSU) on a wide range of illicit substances. Logistic and Hurdel multivariable regressions were used. ADHD symptoms were significantly associated with the lifetime use of ketamine, magic mushrooms, poppers, and nine other psychoactive substances. There was an association between ADHD symptoms and both LPSU and truncated count of lifetime psychoactive substance use. High levels of ADHD symptoms are associated with the use of a large variety and multiple LPSU.

A mixed-methods project on the impact of the mental health first aid training on French university students' knowledge, attitudes and practices.

AIM: University students are increasingly affected by mental health problems and need prompt support. The aim of this project was to assess the impact of the mental health first aid (MHFA) training on students' knowledge, attitudes and practices (KAP) concerning mental health in the short, mid and long-term. METHODS: Three studies were conducted in Bordeaux, France, from May 2021 to March 2022. The first study collected data from 55 students 1 to 6 months after they had followed the training to examine its efficacy in the mid-long term. The second study collected data immediately before and after the training to evaluate the KAP of 52 students in the short-term (1 to 10 days). The third study consisted of 14 semi-structured interviews with students trained since 2020 to identify the training's long-term impact (3 to 18 months). Descriptive statistics were used for studies one and two, and framework analyses for study three. RESULTS: Most participants reported that their KAP about mental health had improved after the training. In the first study, 94.2% of students reported being ready to intervene during a psychotic crisis in their peers. In the second study, 75.0% of students reported improved mental health-related knowledge and decreased stigma. All students in the third study reported that they had assisted at least one person after the training. CONCLUSIONS: These were the first data on the impact of the French MHFA on KAP. While not exhaustive, findings suggest that deploying the training would be beneficial to French students.

Association between ADHD symptoms and illicit stimulants use following 1 year among French university students of the i-Share cohort.

PURPOSE: Although attention deficit hyperactivity disorder (ADHD) has been associated with illicit stimulants use, less is known about their prospective association in university students. We aimed to examine the association between ADHD symptoms at inclusion and illicit stimulants use following 1 year among university students. METHODS: The i-Share cohort recruited French students from February 2013 to July 2020. The study included 4270 participants. The Adult ADHD Self-Report Scale (ASRS) was used to evaluate ADHD symptoms at inclusion. Illicit stimulants use was assessed at inclusion and 1 year after inclusion. Multivariable logistic regressions were conducted to assess the association between ADHD symptoms at inclusion and illicit stimulants use following 1 year. RESULTS: High levels of ADHD symptoms at inclusion were associated with a greater probability of illicit stimulants use following 1 year (adjusted OR: 2.42 (1.51-3.8)). The adjusted odds ratio was 2.7 (1.08-7.84) among participants who had used illicit stimulant at least once (continuation) and 2.25 (1.04-4.37) among participants who had never used illicit stimulants at inclusion (initiation). CONCLUSION: High levels of ADHD symptoms are a feature that may promote both initiation and continuation of illicit stimulants use among university students. Our findings suggest that university students with high levels of ADHD symptoms may benefit from screening to help identify those at risk of illicit stimulants use.

Study of the association between cannabis use and sleep disturbances in a large sample of University students.

Sleep complaints and cannabis use are common among University students and are related to detrimental effects on health. The aim of this study was to explore their association. This cross-sectional study based on the i-Share e-cohort included French students between 18 and 30 years old (n = 14,787). Frequency of cannabis use was categorized into daily, weekly, monthly, and never/rarely use. Sleep complaints were defined using four items (i.e., insomnia, sleepiness, poor sleep quality, and sleep deprivation). In the whole sample (mean age: 20.4 years, 75.5% of females), 22.7% had insomnia, 18.3% had sleepiness, 22.4% had poor sleep quality, 52.5% had sleep deprivation, and 5.8% used cannabis weekly or daily. After adjustment, the likelihood of insomnia was significantly higher by 45% in cannabis users compared to non-users. The estimates steadily increased with frequency of use, reaching a 2.0-fold higher likelihood of insomnia in daily users compared to never/rarely users. Results were similar for the other sleep complaints. These findings provide support for an association between cannabis use and sleep complaints, particularly insomnia, among University students. Though direction and causality cannot be established in this setting, these results suggest warning students and health professionals about the association between cannabis use and sleep complaints.

Australian Youth Resilience and Help-Seeking during COVID-19: A Cross-Sectional Study.

The COVID-19 pandemic has seriously impacted youth mental health. Their resilience, defined as the ability to respond to adversity, has also been impaired. Help-seeking refers to the activity of addressing oneself to others when facing trouble. The objective of this study was to understand the levels of youth resilience and help-seeking during COVID-19 in 2021. Data were collected online from 181 Australian adolescents aged 12-17 years. The General Help-Seeking Questionnaire, the Actual Help-Seeking Questionnaire, and the Resilience Scale were used. Mean and frequency analysis and independent samples t-tests were performed. The Pearson correlation coefficient was calculated. Resilience was in the low range (mean = 66.56, SD 15.74) and associated with no help-seeking. For a personal problem and suicidal ideation, participants were most likely to contact a mental health professional, with means of 4.97 (SD 1.75) and 4.88 (SD 1.97), respectively. The majority did not seek help (n = 47) for challenges with anxiety or depression. This study corroborates previous findings on limited help-seeking in youth because of self-reliance and low confidence in others. Resilience decreased during COVID-19 in parallel with help-seeking. Strategies aiming to increase resilience and help-seeking, such as school-based programs, are needed given their decrease in Australian youths due to the COVID-19 pandemic.

An interactive video increasing French students' mental health literacy: a mixed-methods randomized controlled pilot study.

Mental health literacy (MHL) is a determinant of psychological well-being in young people. A randomized controlled design was used to evaluate the appreciation and effectiveness of an interactive video on French University students' MHL (knowledge about depression and suicidal behavior, mental health help-seeking behaviors, stigma and misconceptions about mental health). At the baseline, all participants (n = 101) completed a questionnaire including several scales on MHL. One month after, participants were randomly assigned to two homogeneous groups (intervention, n = 50 or control, n = 51) and again completed the questionnaire on MHL. Through a mixed-methods approach, semi-structured interviews were also conducted with the intervention group to collect information on the appreciation of the interactive video. Quantitative data indicated that MHL scores increased or remained stable in the intervention group. Comparison with the control group and multivariate logistic regression models did not show statistically significant differences, due to the small sample of the study. According to qualitative data, users appreciated the content and the format of the intervention. It was suggested that the video could be disseminated in other University campuses in France and internationally to promote MHL among students.

Profiling Hesitancy to COVID-19 Vaccinations in Six European Countries: Behavioral, Attitudinal and Demographic Determinants.

Vaccination hesitancy is an important barrier for the effective control of the COVID-19 pandemic. Identifying determinants of COVID-19 vaccination hesitancy is essential in order to reduce mortality rates. Further, given the variability of the factors and the different recommendations used in each country, it is important to conduct cross-country research to profile individuals who are hesitant toward COVID-19 vaccinations. This cross-sectional study aimed to examine cross-country differences and the behavioral, attitudinal and demographic characteristics of vaccine hesitant individuals. Adults living in six European countries (Cyprus, France, Germany, Italy, Poland, and Spain) were eligible to participate. A total of 832 individuals completed the online survey, with 17.9% reporting being hesitant to COVID-19 vaccination. Vaccine accepters were significantly older (M = 38.9, SD = 14.3), more educated (master/postgraduate studies) and lived in a place with a higher number of residents (>500,000 people) compared to those hesitant to COVID-19 vaccination. Discriminant analysis confirmed that the hesitant profile includes a person of younger age, living alone in smaller communities, and without children. Additionally, hesitant participants reported COVID-19-specific characteristics such as lower institutional trust, less adherence to COVID-19 protective behaviors and higher pandemic fatigue. When tackling COVID-19 vaccination hesitancy both socio-demographic and behavioral/attitudinal aspects should be taken into account. Stakeholders are advised to implement targeted vaccination programs while at the same time building trust with population illness cognitions addressed in order to reduce hesitancy rates. Further, stakeholders and public health authorities in each country are suggested to target interventions according to different population characteristics as behavioral and attitudinal determinants of COVID-19 vaccination hesitancy differed between countries.

Measuring Digital Vaccine Literacy: Development and Psychometric Assessment of the Digital Vaccine Literacy Scale.

BACKGROUND: The use of the internet to look for information about vaccines has skyrocketed in the last years, especially with the COVID-19 pandemic. Digital vaccine literacy (DVL) refers to understanding, trust, appraisal, and application of vaccine-related information online. OBJECTIVE: This study aims to develop a tool measuring DVL and assess its psychometric properties. METHODS: A 7-item online questionnaire was administered to 848 French adults. Different psychometric analyses were performed, including descriptive statistics, exploratory factor analysis, confirmatory factor analysis, and convergent and discriminant validity. RESULTS: We developed the 7-item DVL scale composed of 3 factors (understanding and trust official information; understanding and trust information in social media; and appraisal of vaccine information online in terms of evaluation of the information and its application for decision making). The mean DVL score of the baseline sample of 848 participants was 19.5 (SD 2.8) with a range of 7-28. The median score was 20. Scores were significantly different by gender (P=.24), age (P=.03), studying or working in the field of health (P=.01), and receiving regular seasonal flu shots (P=.01). CONCLUSIONS: The DVL tool showed good psychometric proprieties, resulting in a promising measure of DVL.

Validation of the Mental Health Literacy Scale in French University Students.

BACKGROUND: Mental health literacy is a determinant of mental health, which can facilitate early detection of psychological problems and endorse timely access to care. Instruments to measure mental health literacy exist, but not in French. Assessment of mental health literacy in young adults is essential to tailor appropriate educational interventions promoting psychological wellbeing and preventing mental health problems in this vulnerable population. The aim of this study was to validate the French version of the Mental Health Literacy Scale (MHLS-FR) in university students. METHODS: A total of 482 students from the University of Bordeaux, France, completed the translated version of the scale. Collected data were used to validate the MHLS-FR through psychometric analyses: descriptive statistics, item distribution, test-retest reliability, exploratory structural equation model, confirmatory factor analysis, Cronbach's alpha and McDonald's omega coefficients, and hypothesis testing. RESULTS: The final scale included 26 items covering 6 dimensions. Cronbach's alpha and McDonald's omega coefficients were 0.744 and 0.961, respectively. With test-retest, about 50% of items had intraclass correlation coefficients superior to 0.5. CONCLUSIONS: The MHLS-FR can be considered as a valid and reliable instrument for measuring mental health literacy in French students.

Persistence of Vaccine Hesitancy and Acceptance of the EU Covid Certificate Among French Students.

Covid-19 vaccine hesitancy among young adults is a current public health issue that needs to be addressed considering the seasonally driven waves of disease and the administration of vaccine boosters. As a prevention measure, the EU Covid certificate had been implemented to increase vaccine uptake, but its application was controversial. Our study investigated students' opinions and attitudes towards Covid-19 vaccination and the EU Covid certificate through a mixed-methods design. An 18-item questionnaire was administered to 200 students during a vaccination campaign in September 2021 at the University of Bordeaux, France. Simultaneously, 30 students attended a semi-structured interview. Collected data were analyzed separately then discussed together through a parallel and convergent approach. Results showed that vaccine hesitancy was high among students, mostly from fear of short-term side effects. However, respondents decided to get vaccinated to obtain the EU Covid certificate, even if they considered it as a violation of their freedom. Straightforward communication about Covid-19 vaccination did not reach students, although this was a strong expectation from governmental and health institutions. Findings suggest that key health personnel should provide evidence-based information about vaccines in efforts of building trust with young people.

Who is hesitant about Covid-19 vaccines? The profiling of participants in a French online cohort.

OBJECTIVES: To report the characteristics of vaccine-hesitant individuals in a French-speaking adult population in the context of the SARS-CoV-2 pandemic; and to identify predictors of hesitancy about Covid-19-related vaccines. METHODS: Between April and May 2020, 1640 French-speaking adults participating in an online cohort were classified according to their attitudes towards vaccination as: "hesitant", "anti-vaccination", and "pro-vaccination". Descriptive statistics, univariate multinomial regression models and multivariate analyses were compiled and carried out. RESULTS: At the time of inclusion, compared to pro-vaccination participants, hesitant participants were more frequently females (p=0.044), not annually vaccinated against flu (p=0.026), less optimistic about the discovery of a treatment against Covid-19 in a few months (p<0.001), less ready to undergo this treatment (p<0.001), presenting less trust in the ability of public health authorities to control the pandemic (p=0.036) and reporting lower scores on knowledge-related scales (p values from <0.001 to 0.002). Univariate analyses confirmed these results with odds ratios ranging from 1.51 [1.05-2.17] to 2.19 [1.56-3.07]. In the multivariate models, the remaining variables associated with hesitant compared to pro-vaccination attitudes were discovery of a treatment against Covid-19 in a few months (OR=2.57 [1.73-3.81]), being ready to undergo this treatment (OR=7.07 [4.89-10.22]), digital vaccine literacy (OR=1.70 [1.14-2.54]) and general health literacy (OR=1.49 [1.03-2.15]). DISCUSSION: In a continuum of relative acceptance of Covid-19-related vaccines, hesitant individuals were situated in between the behaviours and characteristics of pro-vaccination and anti-vaccination groups. While their characteristics were in line with the literature, this study was the first to report data on health literacy, digital vaccine literacy and capacity to detect fake news associated with vaccine hesitancy. CONCLUSIONS: While failing to identify straightforward predictors, findings suggest that continued education and communication campaigns focused on improving vaccine literacy, particularly among women younger than 35 years, could heighten the proportion of persons accepting vaccination.