Kai J. Jonas

Kai J. Jonas
Maastricht University | UM · Department of Work and Social Psychology

About

150
Publications
78,365
Reads
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6,853
Citations
Citations since 2017
78 Research Items
5602 Citations
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20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Additional affiliations
January 2008 - present
University of Amsterdam
Position
  • Professor (Assistant)
August 2002 - December 2007
Friedrich Schiller University Jena
Position
  • PostDoc Position
July 2002 - December 2007
Friedrich Schiller University Jena
Position
  • PostDoc Position

Publications

Publications (150)
Preprint
Full-text available
Background: In the transitioning era towards the COVID-19 endemic, there is still a sizable population that has never been vaccinated against COVID-19 in the Netherlands. To identify regions and populations that have a lower chance of vaccination uptake, this study provides a spatio-temporal estimation of the relative chance of COVID-19 vaccination...
Article
Full-text available
HIV treatment adherence in Indonesia is a major challenge. Although previous studies have demonstrated several barriers and facilitators to adherence, studies providing a comprehensive analysis from both PLHIV and HIV service providers’ perspectives are limited, especially in Indonesia. In this qualitative study with 30 people living with HIV on tr...
Article
Full-text available
Background Partner notification (PN) after a sexually transmitted infection (STI) diagnosis is being promoted as a means to interrupt transmission chains. We investigated whether Internalised Homonegativity (IH) is associated with PN among men having sex with men (MSM). Methods PN, defined as notifying at least one partner after diagnosis of syphi...
Article
Background: The prevalence of chemsex has been reported by multiple systematic reviews among men who have sex with men (MSM) focussing predominantly on the Global North. An Asian perspective with meta-analytical evidence is missing. This meta-analysis summarised the prevalence of substance use associated with chemsex, and chemsex activity among MS...
Article
Full-text available
Despite men-who-have-sex-with-men (MSM) from Latin America (LA) are still a vulnerable population for known health-related conditions and social problems, availability of comparable data across LA countries for assessment and monitoring purposes is limited. The objective of this article is to present the study design and the questionnaire of LAMIS-...
Preprint
Full-text available
Long-acting injectable PrEP (LAI-PrEP) is efficacious in preventing HIV among MSM and will be soon available in Europe. This study investigates the intention to use LAI-PrEP among MSM in the Netherlands by employing a diffusion of innovation approach, comparing PrEP naive, discontinued MSM, oral PrEP early adopters and majority users. 309 MSM were...
Article
Full-text available
Background Sexual minority men are at greater risk of depression and suicidality than heterosexuals. Stigma, the most frequently hypothesized risk factor for this disparity, operates across socioecological levels-structural (e.g., laws), interpersonal (e.g., discrimination), and individual (e.g., self-stigma). However, there is limited data on whet...
Article
Full-text available
The current monkeypox epidemic is most prevalent among men who have sex with men (MSM). PrEP users and MSM with HIV (MSMHIV) are considered at highest risk of monkeypox infection in The Netherlands, and are being targeted for monkeypox vaccination. Together with the epidemiological evidence, perceived concern and risk are also relevant for decision...
Preprint
Full-text available
The current monkeypox epidemic is most prevalent among men-who-have-sex-with-men (MSM). PrEP users and MSM with HIV (MSMHIV) are considered having the highest risk for monkeypox infection in the Netherlands and being targeted for monkeypox vaccination. Next to the epidemiological evidence, perceived concern/risk are also important in decision makin...
Article
Full-text available
Monkeypox is a zoonotic disease and leads to a smallpox-like disease in humans. The current epidemic in European countries requires informed responses. We investigated the ability to self-diagnose a potential infection, and determinants of vaccination and self-isolation intention after diagnosis among 394 MSM in the Netherlands. We found that about...
Preprint
Full-text available
The current monkeypox epidemic is most prevalent among men-who-have-sex-with-men (MSM). Vaccination programs are being rolled-out to curb the epidemic. Behavioural measures have been called for as well, e.g., by the WHO to reduce the number of sexual partners and sexual activity. We investigated intentions and determinants among Dutch MSM to follow...
Preprint
Monkeypox is a zoonotic disease and leads to a smallpox-like disease in humans. The current epidemic in European countries requires informed responses. We investigated the ability to self-diagnose a potential monkeypox infection, and determinants of vaccination intention and self-isolation intention after exposure among MSM in the Netherlands. We f...
Article
Full-text available
PrEP uptake in the Netherlands is growing but remains at suboptimal levels. Hence, the analysis of hurdles is paramount. Given the initial focus of PrEP provision among men-who-have-sex-with-men (MSM) via a demonstration project that was launched in June 2015, AmPrEP in Amsterdam, and pharmacies in the main urban areas (so called “Randstad”, entail...
Article
Full-text available
Combination HIV prevention covers a range of biomedical, behavioral, and socio-structural interventions. Despite the growing availability of pre-exposure prophylaxis (PrEP), it is not always accessible in European Centre for Disease Prevention and Control reporting countries and may not meet the needs of all at-risk populations. Based on the Flash!...
Article
Full-text available
Sexually transmitted infections (STIs) remain a major public health threat, disproportionately affecting young people, and men who have sex with men. In this narrative review of the current state of behavioural science research on STI prevention, we consider the definition, health impacts, correlates and determinants, and interventions to promote S...
Preprint
In many countries, HIV infections among MSM (MSMHIV) are closely monitored, and updated epidemiological reports are made available annually, yet the true prevalence of MSMHIV can be masked for areas with small population density or lack of data. Therefore, this study aimed to investigate the feasibility of small area estimation with a Bayesian appr...
Preprint
PrEP uptake in the Netherlands is growing but remains at suboptimal levels. Hence, the analysis of hurdles is paramount. Given the initial focus of PrEP provision among men-who-have-sex-with-men (MSM) via a demonstration project that was launched in June 2015, AmPrEP in Amsterdam, and pharmacies in the main urban areas (so called “Randstad”, entail...
Article
Full-text available
As a result of the COVID-19 pandemic, HIV care and prevention efforts have been disrupted. We investigated pre-exposure prophylaxis (PrEP) use and testing behaviors among MSM in the Netherlands, and the factors that influenced testing behaviors during the COVID-19 pandemic. A cohort of 766 MSM, established in 2017, was asked in August 2020 to repor...
Article
Full-text available
Introduction Transgender individuals are at risk for HIV. HIV risks are dynamic and there have been substantial changes in HIV prevention (e.g., pre-exposure prophylaxis [PrEP]). It is thus time to revisit HIV prevalence and burden among transgender individuals. The objective of this systematic review and meta-analysis was thus to examine worldwide...
Article
Full-text available
Any large dataset can be analyzed in a number of ways, and it is possible that the use of different analysis strategies will lead to different results and conclusions. One way to assess whether the results obtained depend on the analysis strategy chosen is to employ multiple analysts and leave each of them free to follow their own approach. Here, w...
Article
Full-text available
Introduction The SARS-CoV-2 virus can currently pose a serious health threat and can lead to severe COVID-19 outcomes, especially for populations suffering from comorbidities. Currently, the data available on the risk for severe COVID-19 outcomes due to an HIV infection with or without comorbidities paint a heterogenous picture. In this meta-analys...
Article
Sexual minority men are at greater risk of depression and suicidality than heterosexuals. Stigma, the most frequently hypothesized risk factor for this disparity, operates across socioecological levels-structural (e.g., laws), interpersonal (e.g., discrimination), and individual (e.g., self-stigma). Although the literature on stigma and mental heal...
Technical Report
Full-text available
Bi+ people may face various challenges throughout their lives, including heteronormative assumptions, binary frames and monosexual norms. They often experience negative associations, prejudices and discrimination from their (direct) environment concerning being bi+ (Doan Van et al., 2019; Feinstein et al., 2020). These experiences and social norms...
Article
Full-text available
The introduction of biomedical HIV prevention methods, such as pre-exposure prophylaxis (PrEP), holds the potential to overcome the serodivide. We investigated the attitudes of PrEP users towards having sex with partners living with HIV. PrEP users in the Netherlands were recruited online and completed three questionnaires over a period of six mont...
Conference Paper
Background Since its formal introduction in 2019, PrEP uptake in the Netherlands is growing, but remains at suboptimal levels. Hence, the analysis of determinants is paramount. Given the initial focus of PrEP provision among men-who-have-sex-with-men (MSM) via a demonstration project, AmPrEP in Amsterdam, and pharmacies in the main urban areas (so...
Conference Paper
Background Pre-exposure prophylaxis (PrEP) uptake has remained low among men who have sex with men (MSM) eligible for PrEP in the Netherlands, which could partly be due to stigma associated with taking PrEP. Perceptions about PrEP users (e.g., PrEP users have an increased rate of (condomless) sexual encounters) may modify mixing behavior and subseq...
Article
Full-text available
Next to its benefits for HIV prevention, PrEP may have psychosocial benefits relating to improved quality of sex life. The aim of the current study was to investigate the onset of changes in the quality of sex life and sexual pleasure of PrEP users in the first months of commencing PrEP use. Moreover, we investigated what factors were related to th...
Article
Full-text available
Sexual healthcare aims to reduce HIV and sexually transmitted infections (STIs) by promoting testing and prevention. To better reach men who have sex with men (MSM), additional strategies are needed. Here, we describe development of an intervention, which is part of a broader HIV/STI home-care program, targeted to reach MSM and motivate them to use...
Preprint
Full-text available
We present consensus-based guidance for conducting and documenting multi-analyst studies. We discuss why broader adoption of the multi-analyst approach will strengthen the robustness of results and conclusions in empirical sciences.
Article
Full-text available
The aim of this qualitative study was to explore the experiences of informal PrEP users regarding access to PrEP and PrEP-related healthcare, community responses, sexual behavior and well-being. We interviewed 30 men who have sex with men (MSM) in semi-structured online interviews between March and August 2018. Interviews were analyzed using interp...
Article
Full-text available
The term “Pre-exposure prophylaxis (PrEP) tourists” refers to individuals who obtain PrEP in other countries and use it in their home countries. A prospective observational cohort study was conducted among a group of men who have sex with men (MSM) who obtained PrEP in private clinics in Thailand and used it in Hong Kong. Participants completed two...
Article
Full-text available
Despite the improved availability and affordability of PrEP in the Netherlands, PrEP uptake is low among men who have sex with men (MSM). To optimize uptake, it is important to identify facilitators and barriers of PrEP use. During our study period, the price of PrEP dropped significantly after generic PrEP was introduced. We investigated whether t...
Article
Full-text available
The World Health Organization recommends pre-exposure prophylaxis (PrEP) for all populations at substantial risk of HIV infection, including women. However, data regarding PrEP interest among women is lacking, particularly in Europe. Factors associated with interest in using PrEP were assessed among women respondents to the Flash! PrEP in Europe (F...
Preprint
The introduction of biomedical HIV prevention methods, such as pre-exposure prophylaxis (PrEP), holds the potential to overcome the serodivide. We investigated the attitudes of PrEP users towards having sex with partners living with HIV. PrEP users in the Netherlands were recruited online and completed three questionnaires over a period of six mont...
Preprint
Next to its benefits for HIV prevention, PrEP may have psychosocial benefits relating to improved quality of sex life. The aim of the current study was to investigate the onset of changes in quality of sex life and sexual pleasure of PrEP users in the first months of commencing PrEP use. Moreover, we investigated what factors were related to the qu...
Preprint
Despite the improved availability and affordability of PrEP in the Netherlands, PrEP uptake is low among men who have sex with men (MSM). To optimize uptake, it is important to identify facilitators and barriers of PrEP use. During our study period, the price of PrEP dropped significantly after generic PrEP was introduced. We investigated whether t...
Article
An online assessment among social media-using young men who have sex with men found that 87% were willing to use HIV self-testing with online supervision. Correlates included never tested, having higher numbers of sexual partners, and seeking partners online. HIV self-testing with online supervision may be appropriate for young men who have sex wit...
Article
Full-text available
Despite increased availability of pre-exposure prophylaxis (PrEP), PrEP uptake has remained low. To promote uptake, factors related to PrEP interest among relevant target populations warrant investigation. The aim of this study was to provide an analysis of PrEP interest among men who have sex with men (MSM) in the Netherlands, while taking study r...
Article
Full-text available
Western studies suggest that perceived pressure from family members, peers, and the media to achieve muscularity ideals are associated with higher muscle dissatisfaction and that such associations are mediated through different psychological processes. However, how such findings apply to young Chinese men has not been explored. Using an online surv...
Article
LGBT-related hate crime is a conscious act of aggression against an LGBT citizen. The present research investigates associations between hate crime, psychological well-being, trust in the police and intentions to report future experiences of hate crime. A survey study was conducted among 391 LGBT respondents in the Netherlands. Sixteen percent expe...
Article
HIV-related factors and suicide-risk status were assessed among YMSM aged 18–24 years recruited through various MSM-related online social apps in Bangkok (N = 1394). The online survey assessed demographic characteristics, sexual behaviours and suicide-risk status. Measure of suicide risk was taken from the Suicidal Behaviors Questionnaire-Revised (...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
We present a consensus-based checklist to improve and document the transparency of research reports in social and behavioural research. An accompanying online application allows users to complete the form and generate a report that they can submit with their manuscript or post to a public repository.
Preprint
Full-text available
The current research focuses on a bias in intensity perception and tests the hypothesis that individuals perceive facial expressions of emotions in ethnic outgroup members as less intense than those of ingroup members’ expressions. In addition to nine previously conducted and reported studies (focussing only on embarrassment, Kommattam, Jonas, & Fi...
Article
Full-text available
The quality of interactions between individuals from different ethnic groups partly depends on how emotions of individual ethnic group members are interpreted. Previous research has found that facial expressions of emotions of a different ethnic group are recognized less accurately than facial expressions of members of the same ethnic group. The cu...
Conference Paper
Background In Europe and the Americas, men-who-have-sex-with-men (MSM) are heavily affected by HIV. Having traditionally relied mainly on condoms and sero-adaptive behaviours to prevent HIV transmission, more recently biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) among HIV-negative and viral suppression among HIV-diagnose...
Conference Paper
Full-text available
Background Despite public-health efforts, men who have sex with men (MSM) are still not sufficiently reached with current HIV/STI care. We developed a regional MSM home-care program, used by public-health STI care, hospital HIV care, and general practitioners. The program combines home-based self-sampling testing for HIV, syphilis, chlamydia and go...
Poster
Full-text available
Background: PrEP is recommended for all populations at risk for HIV infection, including MSM. However, access to PrEP is limited across Europe. This analysis identified factors associated with interest in using PrEP among MSM respondents to the Flash! PrEP in Europe (FPIE) survey. Methods: FPIE is a community-based survey conducted in June-July 201...
Presentation
Full-text available
HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Madrid, SPAIN, OCT 21-25, 2018
Article
Factors such as race, masculinity, and sexually transmitted infections have been documented to influence partner selection in men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) has received mixed evaluations as a responsible step in HIV prevention and as an enabler of risker sexual practices. PrEP may consequently serve as an addition...
Article
This qualitative study focuses on youth perceptions of cyberbullying (definition, causes, consequences, and management). We also articulate how perceptions of cyberbullying among Thai youth are influenced by Thai culture, including Thai youth culture. Data were collected from 15 to 24 year-olds in Central Thailand through 22 focus group discussions...
Article
Full-text available
Pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate in combination with emtricitabine (FTC) is a highly effective form of HIV prevention. Endeavors of health-care providers and activists in many countries over the world are directed at making access to PrEP possible, or increasing PrEP use among men-who-have-sex-with-men (MSM). We ar...
Preprint
Bio-medical HIV pre-exposure prophylaxis (PrEP) is the use of an antiretroviral drug shown to drastically decrease the transmission of HIV between sexual partners. However, there are reports that peer evaluations are an important factor among men who have sex with men (MSM) who are considering or taking PrEP. We used a trait transference paradigm t...
Conference Paper
HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Madrid, SPAIN, OCT 21-25, 2018
Preprint
Full-text available
Carney, Cuddy, and Yap (2010) found that --compared to participants who adopted constrictive body postures-- participants who adopted expansive body postures reported feeling more powerful, showed an increase in testosterone and a decrease in cortisol, and displayed anincreased tolerance for risk. However, these power pose effects have recently com...
Presentation
Full-text available
HIV prevention has evolved greatly in the last decade, with an increasing number of risk-reduction methods and strategies. Pre-exposure prophylaxis (PrEP), use of anti-retroviral drugs by HIV-negative individuals, is a highly effective HIV prevention method recommended by WHO for specific populations. However, little information is known regarding...
Presentation
Full-text available
Pre-exposure prophylaxis (PrEP), the use of HIV anti-retroviral drugs by HIV-negative individuals, has been recommended by WHO (2015) for all population groups at substantial risk of HIV infection. Some women at risk may benefit from this prevention tool, but PrEP uptake in this group is largely dependent on knowledge, self-assessed HIV risk and in...
Preprint
We outline an array of journal policies that JPSP:ASC could adopt to further promote transparent and responsible research practices; in turn, these practices will increase the reliability of research findings published in JPSP:ASC.
Article
Full-text available
The question how intergroup bias can be alleviated is of much theoretical and practical interest. Whereas diversity training and the multiculturalism ideology are two approaches prominent in practice, most theoretical models on reducing intergroup bias are based on social-identity theory and self-categorization theory. This social-identity perspect...
Data
SPSS data file providing the raw data of experiment 1. (SAV)
Data
SPSS data file providing the raw data of experiment 2. (SAV)
Data
SPSS data file providing the raw data of experiment 3. (SAV)
Preprint
Full-text available
Carney, Cuddy, and Yap (2010) found that --compared to participants who adopted constrictive body postures-- participants who adopted expansive body postures reported feeling more powerful, showed an increase in testosterone and a decrease in cortisol, and displayed an increased tolerance for risk. However, these power pose effects have recently co...
Article
Little is known about mobile application (app)-based behavior of men who have sex with men (MSM) in Thailand. A cross-sectional online assessment of app users in Bangkok found that more than a quarter have never tested for human immunodeficiency virus (HIV) and 1 in 3 never tested for sexually transmitted infections (STI). STI testing patterns and...
Article
Full-text available
Earlier work found that – compared to participants who adopted constrictive body postures – participants who adopted expansive body postures reported feeling more powerful, showed an increase in testosterone and a decrease in cortisol, and displayed an increased tolerance for risk. However, these power pose effects have recently come under consider...
Article
Full-text available
Embarrassment displays show others that one is aware of one's own misbehavior and willing to make up for it. The facial actions of embarrassment, however, are partly similar to those of disinterest, which has an opposite function, signaling that one is not concerned about one's self in relation to others. In the context of negative intergroup relat...