Nathalie Bajos

• French Institute of Health and Medical Research

Background Testing for COVID-19 has been strongly recommended for individuals experiencing COVID-19-like symptoms or those with a close relative who tested positive. In France, tests were free of charge until mid-October 2021 and became widely available after June 2020. Our main objective was to investigate whether access to COVID-19 testing in Fra...

Background Sex and gender inequalities in ischemic heart diseases persist. Although ischemic heart disease is less common in women, they experience worse clinical outcomes and are less likely to receive guideline-recommended treatments. The primary scientific literature from which clinical guideline recommendations are derived may not have consider...

It is unclear how the risk of post-covid symptoms evolved during the pandemic, especially before the spread of Severe Acute Respiratory Syndrome Coronavirus 2 variants and the availability of vaccines. We used modified Poisson regressions to compare the risk of six-month post-covid symptoms and their associated risk factors according to the period...

Inconsistent results are found regarding social inequalities related to healthcare appointment cancellations during the COVID-19 crisis. Whether rescheduling was associated with social status is unknown. By studying both cancellations and rescheduling, we comprehensively describe which social groups were affected by care disruption. First follow-up...

This study examines hypertension control beyond the cascade of care framework, which assesses awareness, treatment, and control sequentially. The analysis included 52 434 hypertensive adults (blood pressure (BP) ≥140/90 mm Hg and/or treatment in the past 6 months), aged 25–69, from the French population‐based CONSTANCES cohort from 2012 to 2021. Th...

Objective In many countries, before COVID-19 vaccines became available, reluctance to get vaccinated was particularly prevalent among women, the most disadvantaged social groups and ethnoracial minorities, known to be at higher risk for the virus. Using a longitudinal perspective, we analyse the social determinants that are associated with the tran...

Lockdown imposed in the early phase of the SARS-CoV-2 outbreak represented a specific setting where activity was restricted but still possible. The aim was to investigate the cross-sectional associations between physical activity (PA) and SARS-CoV-2 infection in a French population-based cohort. Participants completed a PA questionnaire. PA was cla...

In metropolitan France, estimates suggest that more than one in three adults has hypertension. Low-cost treatments are available, yet fewer than one in four hypertensive adults has a controlled level of hypertension below 140/90 mmHg. This rate is higher in other high-income countries such as Canada (65%) or Germany (52%). Using a ‘cascade of care’...

Sexual expression is fundamental to human existence and an important topic of enquiry in its own right. Understanding sexual behavior is also essential to establish effective sexual health prevention activities (e.g., education), services and policies, and to assess the progress of policies and action plans. Questions on sexual health are rarely in...

Les violences sexuelles durant l’enfance et l’adolescence représentent un phénomène massif en France, notamment pour les femmes, qui touche tous les milieux sociaux. Les hommes subissent moins de violences et en parlent moins. Les femmes subissent majoritairement des abus de la part de membres ou d’amis de la famille. Les agresseurs sont très major...

Retrouvez toutes nos données sur data.drees juin 2023 n° 1271 Près d'un enfant sur six a eu besoin de soins pour un motif psychologique entre mars 2020 et juillet 2021 La détresse psychologique dont souffrent une minorité grandissante d'enfants et d'adolescents a été aggravée par la crise sanitaire. Ce phénomène, observé dans d'autres pays, semble...

https://www.cairn-int.info/journal-population-2023-3-page-479.htm?contenu=resume Implemented on a massive scale during the Covid-19 pandemic, telework is now an established form of work organization, but its effects on workers’ well-being remain a subject of debate. Drawing on data from a longitudinal survey representative of the French population...

Economic uncertainty and family dynamics are strictly connected. The increasing uncertainty generated by the Covid-19 pandemic is thus likely to affect couple relationships and stability, with potential opposite effects. Using data from the nationally representative EPICOV survey, that followed individuals throughout the first year of pandemic in F...

ABO blood type has been reported as a potential factor influencing SARS-CoV-2 infection, but so far mostly in studies that involved small samples, selected population and/or used PCR test results. In contrast our study aimed to assess the association between ABO blood types and SARS-CoV-2 infection using seroprevalence data (independent of whether...

In the spring of 2020, a national lockdown was declared in France to control the Covid-19 epidemic – the longest and strictest to date. This led to spontaneous population movements, widely publicised in the media as the urban exodus of Parisians. But were departures from large cities to low-density areas the only types of mobility during this perio...

Children’s screen time increased as a result of the COVID-19 pandemic. In the summer of 2021, we explored the association between high screen time over a period of one year since May 2020 and behavioural problems among children and adolescents. The data were derived from the French EpiCov cohort study, collected in spring 2020, autumn 2020, and spr...

The sudden and unanticipated shocks to employment and the almost total retreat into the domestic sphere caused by the COVID-19 lockdowns provide a unique opportunity to explore the resilience of the three classical theoretical paradigms of the gendered division of labor within couples, that is, the time availability theory, the relative resource th...

In France, the first pandemic peak fell disproportionately on the most disadvantaged, as they were overrepresented in contaminations and in developing severe forms of the virus. At that time, and especially during lockdown, the French healthcare system was severely disrupted and limited. The issue of social differences in the use of healthcare by p...

Background Despite declines in cardiovascular disease mortality, evidence suggests women have a higher mortality and worse prognosis after ischemic events compared with men. This work investigates to what extent clinical recommendations made by cardiovascular guidelines might include sex and gender biases. Methods We reviewed the primary literatur...

Objectives To assess the impact on the estimated glomerular filtration rate (eGFR) of different tenofovir disoproxil/emtricitabine dosing regimens for HIV pre-exposure prophylaxis (PrEP). Patients and methods We included in the study individuals with baseline eGFR > 50 mL/min/1.73 m2 who initiated PrEP in the ongoing ANRS-PREVENIR PrEP cohort. We...

This study aims to estimate and compare Roman Catholic Church-related child sexual abuse (CSA) prevalence and characteristics to CSA in other social spheres in France since 1950. Using a cross-sectional representative web-based survey of 28,026 adults in 2021, the weighted prevalence of CSA was estimated according to six social spheres of perpetrat...

Objective To assess whether lack of trust in the government and scientists reinforces social and racial inequalities in vaccination practices. Design A follow-up of the EpiCov random population-based cohort survey. Setting In July 2021, in France. Participants Eighty-thousand nine hundred and seventy-one participants aged 18 years and more. Mai...

We aimed to analyze inequalities in social isolation among older adults in a time of COVID-19 social restrictions, using a gender perspective. A random population-based survey, including 21,543 older adults (65+) was conducted during and post COVID-19 lockdown in France. Our main outcome was a three-dimension indicator of social isolation based on...

Background We aimed to study whether social patterns of exposure to SARS-CoV-2 infection changed in France throughout the year 2020, in light to the easing of social contact restrictions. Methods A population-based cohort of individuals aged 15 years or over was randomly selected from the national tax register to collect socio-economic data, migra...

Background: Immigrants and ethnic/racialized minorities have been identified as being at higher risk of COVID-19 infection, but few studies report on their exposures and prevention behaviours. This study aims to examine the social distribution of COVID-19 exposure (overcrowding, working outside the home, use of public transport to go to work) and...

Background: Preterm children are at higher risk of developing mental health problems than full-term children. Deterioration of children's mental health was observed during COVID-19 pandemic restrictive measures. Our study compared emotional and attention-deficit/hyperactivity disorder (ADHD) symptoms during school closure between preterm and full-...

Objective To assess whether mistrust in the government and scientists reinforces social and racial inequalities in vaccination practises Design A follow-up of a random population-based cohort survey. Setting In July 2021, in France. Participants 80,971 participants aged 18 years and more. Main outcome measures Adjusted odds ratios of Covid-19 v...

Background Military sexual trauma (MST) is a major public health concern, given its prevalence and mental health sequelae. This phenomenon is particularly prevalent among women in the US military, although more cases involve men given their overrepresentation. Little is known about MST and its consequences in other military settings, including in E...

Background The interplay between age and symptoms intensity on antibody response to SARS-CoV-2 infection has not been studied in a general population setting. Methods We explored the serologic profile of anti-SARS-CoV-2 antibodies after the first wave of the pandemic, by assessing IgG against the spike protein (ELISA-S), IgG against the nucleocaps...

Introduction et but de l’étude L’alimentation apporte les nutriments essentiels au bon fonctionnement du système immunitaire et de nombreuses hypothèses suggèrent ainsi un rôle de la nutrition dans la prévention de la COVID-19. Toutefois, il n’existe pas à notre connaissance de données prospectives à ce sujet. Notre objectif était donc d’étudier le...

Equal Access to the COVID-19 vaccine for all remains a major public health issue. The current study compared the prevalence of vaccination reluctance in general and COVID-19 vaccine hesitancy and social and health factors associated with intentions to receive the vaccine. A random socio-epidemiological population-based survey was conducted in Franc...

Background We aimed to estimate the seroprevalence of SARS-CoV-2 infection in France and to identify the populations most exposed during the first epidemic wave. Methods Random selection of individuals aged 15 years or over, from the national tax register (96% coverage). Socio-economic data, migration history, and living conditions were collected...

Plain language summary Sexual and reproductive health receives a lot of attention, globally. Much of this attention focuses on research and clinical services to address health outcomes. Behavioural issues known to be closely linked to health outcomes—that is people’s sexual activity and sexuality—tend to be overlooked. In many countries, there is v...

Background The spread of the coronavirus disease (COVID-19) led many countries to implement lockdown measures, which resulted in changes in dietary behaviours that could persist over the long term and have associated health consequences. Psychological traits may impact these changes given their known association with dietary behaviours. We aimed to...

COVID-19 limitation strategies have led to widespread school closures around the world. The present study reports children’s mental health and associated factors during the COVID-19 school closure in France in the spring of 2020. We conducted a cross-sectional analysis using data from the SAPRIS project set up during the COVID-19 pandemic in France...

Background Sexual harassment (SH) is prevalent in military settings and dependent on the workplace environment. Few studies have investigated this issue in non-US military settings nor have examined how contextual and individual factors related to Military Sexual Trauma (MST) vary by gender. Methods This study draws on a national sexual survey in...

Objective Although social inequalities in COVID-19 mortality by race, gender and socioeconomic status are well documented, less is known about social disparities in infection rates and their shift over time. We aim to study the evolution of social disparities in infection at the early stage of the epidemic in France with regard to the policies impl...

Background Nutritional factors are essential for the functioning of the immune system and could therefore play a role in COVID-19 but evidence is needed. Our objective was to study the associations between diet and the risk of SARS-CoV-2 infection in a large population-based sample. Methods Our analyses were conducted in the French prospective Nut...

Background: We aimed to study whether social patterns of exposure to SARS-CoV-2 infection changed in France throughout the year 2020, in light to the easing of social contact restrictions. Methods: A population-based cohort of individuals aged 15 years or over was randomly selected from the national tax register to collect socio-economic data, migr...

Rapport scientifique commandité par la “Commission indépendante sur les abus sexuels dans l'Église” (CIASE), mise en place le 13 novembre 2018 par Jean-Marc Sauvé, vice-président honoraire du Conseil d’État, à la demande de la Conférence des Évêques de France (CEF) et de la Conférence des religieux et religieuses de France (CORREF).

Background Our main objective was to study the early social dynamics of the COVID-19 epidemic in France, taking into account gender, class, and ethnicity inequalities in living conditions. Methods A random population-based survey was conducted in France in May 2020, during and post COVID-19 lockdown, in which 77,588 participants aged 18-64 were inc...

Obtaining detailed data on gender identity and sex in population-based sexual health studies is important. We convened a group to develop consensus survey items. We identified two items to capture data on gender identity and sex that can be used in diverse settings.

Background: We aimed to estimate the seropositivity to anti-SARS-CoV-2 antibodies in May-June 2020 after the first lockdown period in adults living in three regions in France and to identify the associated risk factors. Methods: Between 4 May 2020 and 23 June 2020, 16 000 participants in a survey on COVID-19 from an existing consortium of three...

In recent decades, France has appeared as a country particularly hostile to vaccination in general. When asked in November 2020 about the intention to take the Covid-19 vaccine, the French public showed, once again, reluctance. Therefore, France appeared as an ideal case study to analyze whether the hostility toward the Covid-19 vaccine has its own...

Background: Population level data on sexual practices, behaviours and health-related outcomes can ensure that responsive, relevant health services are available for all people of all ages. However, while billions of dollars have been invested in attempting to improve sexual and reproductive health (including HIV) outcomes, far less is understood ab...

Background Significant differences in COVID-19 incidence by gender, class and race/ethnicity are recorded in many countries in the world. Lockdown measures, shown to be effective in reducing the number of new cases, may not have been effective in the same way for all, failing to protect the most vulnerable populations. This survey aims to assess so...

Notre pays — et la planète — traverse une crise épidémique majeure. Comme toute crise, elle peut être révélatrice des forces et faiblesses de la société, et de ses composantes : celles de son système de santé, de son système de recherche, du fonctionnement de la démocratie sanitaire… Cet article aborde la question des inégalités sociales au temps d...

Background: the EpiCov study, initiated at the end of the first national lockdown in France, aimed to provide national and regional estimates of the seroprevalence of SARS-CoV-2 infection, and to analyze relations between living conditions and the dynamics of the epidemic. We present and discuss here the survey methodology, and describe the first-r...

Background Our main objectives were to estimate the incidence of illnesses presumably caused by SARS-CoV-2 infection during the lockdown period and to identify the associated risk factors. Methods Participants from 3 adult cohorts in the general population in France were invited to participate in a survey on COVID-19. The main outcome was COVID-19...

Population health surveys are rarely comprehensive in addressing sexual health, and population-representative surveys often lack standardized measures for collecting comparable data across countries. We present a sexual health survey instrument and implementation considerations for population-level sexual health research. The brief, comprehensive s...

Notre pays-et la planète-traverse une crise épidémique majeure. Comme toute crise, elle peut être révélatrice des forces et faiblesses de la société, et de ses composantes : celles de son système de santé, de son système de recherche, du fonctionnement de la démocratie sanitaire… Cet article aborde la question des inégalités sociales au temps du CO...

Objectives To assess social inequalities in the trends in COVID-19 infections following lockdown Design A cross-sectional survey conducted among the general population in France in April 2020, during COVID-19 lockdown. Participants 10 401 participants aged 18-64, from a national cohort who lived in the three metropolitan French regions most affec...

Background Our main objectives were to estimate the incidence of illnesses presumably caused by SARS-CoV-2 infection during the lockdown period and to identify the associated risk factors. Methods Participants from 3 adult cohorts in the general population in France were invited to participate in a survey on COVID-19. The main outcome was possible...

Population health surveys are rarely comprehensive in addressing sexual health, and population-representative surveys often lack standardized measures for collecting comparable data across countries. We present a sexual health survey instrument and implementation considerations for population-level sexual health research. The brief, comprehensive s...

Aim To estimate the seroprevalence of SARS-CoV-2 infection in May-June 2020 after the lockdown in adults living in three regions in France and to identify the associated risk factors. Methods Participants in a survey on COVID-19 from an existing consortium of three general adult population cohorts living in the Ile-de-France (IDF) or Grand Est (GE)...

Background: ANRS IPERGAY found that on-demand pre-exposure prophylaxis (PrEP) with oral tenofovir disoproxil fumarate plus emtricitabine was associated with an 86% relative reduction of HIV-1 incidence compared with placebo among men who have sex with men at high risk of HIV. We aimed to investigate whether on-demand PrEP was similarly effective a...

Background Abortions are known to be underreported in surveys. Previous research has found a number of ways in which survey methodology may affect respondents’ willingness to disclose abortions. The social and political climate surrounding abortion may also create stigma affecting abortion reporting, and this may vary between countries and over tim...

Sub-Saharan African migrants living in France are particularly affected by HIV. Due to the fear of sexual transmission of the virus, those in a relationship could experience a union break-up after an HIV diagnosis. Based on data from the time-event ANRS-Parcours survey that was conducted among a representative sample of sub-Saharan migrants living...

Migrants from sub-Saharan Africa (SSA) are often diagnosed at an advanced stage of HIV, and many of them have harsh living conditions. We aimed to evaluate the entry into care after HIV diagnosis and examine the related social determinants. The ANRS PARCOURS study is a life-event survey conducted in 2012-2013 in the Paris region among. Time between...

Sub-Saharan African migrants living in France are particularly affected by HIV. Due to the fear of sexual transmission of the virus, those in a relationship could experience a union break-up after an HIV diagnosis. Based on data from the time-event ANRS-Parcours survey that was conducted among a representative sample of sub-Saharan migrants living...

Background: Sexual health in the military comprises a range of concerns including sexually transmitted infections (STI), unintended pregnancy, sexual violence and sexual dysfunction. This study aims to estimate the prevalence of sexual health concerns by gender in the French military and compare these prevalences to estimates in the general popula...

Introduction La lutte contre les infections sexuellement transmissibles (IST) et le virus de l’immunodéficience humaine (VIH) représentent un enjeu important de la prévention dans les armées, constituées d’une population jeune plus sujette aux comportements à risque. L’objectif de ce travail est de faire un état des lieux de la prévention des IST e...

Unintended pregnancy is a public health concern throughout Europe. There is no common definition and no standard way to measure unintended pregnancy. Identifying unintended births is difficult and prevalence estimates vary depending on how and when the question is asked. Abortion rates are not a proxy and are themselves notoriously inaccurate. An e...

Introduction Sexually Transmitted Infections (STIs) have always represented a public health concern in the military, yet most studies rely on self-reports among non-random samples of military populations. In addition, most of the studies exploring STI rates among the military focus on US service members. This paper assesses the prevalence and corre...

Detailed biological methods used for pathogens diagnostics, COSEMIL survey. (DOCX)

Objectives Socioeconomic status has been shown to be associated with sexual activity, contraceptive-use, pregnancy and abortion among young people. Less is known about whether the strength of the association differs for each outcome, between men and women, or cross-nationally. We investigate this using contemporaneous national probability survey da...

The article examines contraceptive recommendations made by practitioners to their patients, in order to better understand the central role of the contraceptive pill in the French contraceptive system. A random sample of 1,011 general practitioners and gynaecologists completed a questionnaire in 2010. The paper demonstrates how heterogeneous their r...

Study objective: Most women begin sexual activity as teenagers but nearly 20% of women in France younger than 25 years rely on less effective contraceptive methods (condoms or methods such as withdrawal or periodic abstinence). We sought to analyze the association with less effective contraception among women aged 15-24 years in France and communi...

Background: Data for on-demand pre-exposure prophylaxis (PrEP) are scarce. We implemented a cohort study to assess its efficacy, safety, and effect on sexual behaviour. Methods: We invited men and transgender women who have sex with men, previously enrolled in the randomised placebo-controlled ANRS IPERGAY trial at seven sites (six in France and...

Objective Using a generational approach, this study analyses how unprotected anal intercourse has evolved since 1991 in France across different generations of men who have sex with men (MSM) whose sexual lives began at different periods in the history of the HIV epidemic. Design Data were collected from 18–59 year-old respondents to the French Gay...

Numerical values corresponding to Fig 1: Trends in the percentage of respondents reporting at least one episode of UAId. (XLSX)

Numerical values corresponding to Fig 2: Longitudinal changes from 1997 to 2011 in the percentage of respondents who reported at least 1 episode of UAId. (XLSX)

Contexte et objectif Depuis le début de l’épidémie du VIH/sida, les hommes qui ont des rapports sexuels avec des hommes (HSH) sont dramatiquement touchés par cette maladie. Alors que l’entrée dans la sexualité est un événement constitutif des biographies sexuelles et préventives des individus, l’initiation sexuelle des HSH est rarement étudiée. Nou...

HAART has improved the well-being of many people living with HIV (PLWH). This study aimed at (i) comparing heterosexual practices between PLWH and the general population by gender, and (ii) identifying factors associated with sexual practices and at-risk behaviors in the two populations. Self-reported data were collected among PLWH attending hospit...

Purpose: This study explores transitions in contraceptive use in early sexual life in France and has three objectives: describe predictors of contraceptive use at first sex with first and second partners, describe contraceptive trajectories in these partnerships, and test associations between use at first sex and switching in first partnership on...

Six or seven years after arriving in France, half of sub-Saharan African migrants still do not have all three basic elements of a settled life: a residence permit valid for at least one year, a personal dwelling and an activity that provides enough income to live on. After eleven or twelve years, one-quarter still do not. This long period of insecu...

Background: Reliability of nonprobability online volunteer panels for epidemiological purposes has rarely been studied. Objectives: To assess the quality of a questionnaire on sexual and reproductive health (SRH) administered in a nonprobability Web panel and in a random telephone survey (n = 8,992; n = 8,437, age 16–49 years). Especially, we were...

We estimated the proportion of migrants from sub-Saharan Africa who acquired human immunodeficiency virus (HIV) while living in France. Life-event and clinical information was collected in 2012 and 2013 from a random sample of HIV-infected outpatients born in sub-Saharan Africa and living in the Paris region. We assumed HIV infection in France if a...

Objectives: In Europe, sub-Saharan African migrants are a key population for HIV infection. We analyse how social hardships during settlement in France shape sexual partnerships and HIV risk. Design: PARCOURS is a life-event survey conducted from February 2012 to May 2013 in 74 health-care facilities in the Paris region, among three groups of su...

Advances in ART have led to improvements in reproductive health for women living with HIV. This paper aims to investigate the pattern of contraceptive use among women living with HIV in France. Data were drawn from the ANRS-VESPA2 study, which included a representative sample of HIV-positive people. Contraception methods were documented, including...

To better understand the diversity of practices and behaviours to prevent HIV with casual partners, data from a large convenience sample of men who have sex with men (MSM) in France were categorised into different prevention profiles: no anal intercourse, consistent condom use during anal intercourse, risk-reduction practices (serosorting, seroposi...

In high-income countries, the social and epidemiological contexts surrounding homosexuality and AIDS have changed profoundly in recent decades. This work sought to examine key indicators of the long-term sexual trajectories of successive generations of men who have sex with men (MSM) in France. We performed a longitudinal analysis of the French Gay...