Ideally, decisions in healthcare regarding patient care are based on evidence from trials and formal meta-analyses. The merits of these methods and their impact on clinical practice cannot be overestimated. However, their focus on single outcomes limits their use in multi-attribute decisions. The discrete choice experiment (DCE) technique has been introduced in healthcare to arrive at optimal decisions, dealing with multiple outcomes and preference heterogeneity among decision-makers. The technique, originating from mathematical psychology, has uses in marketing, transport and environmental economics as well, where it is used to predict individual and collective choices. In a DCE, respondents are confronted with a selected series of choices between two or more options, where options are characterized by attributes each with a given attribute level. The stated preferences, after complex Nobel prize-winning econometric modeling, result in the ranking of all possible options. Currently the lack of insight into external validity hampers DCE taking a key position in healthcare: are stated preferences consistent with actual healthcare utilization (so-called revealed (true) preferences)? To support claims based on DCEs, external validity is widely recognized as the single most important research question. My project aims to provide improvements to the DCE technique for healthcare and beyond by 1) measuring external validity; and 2) unraveling its determinants. Specifically: 1) External validity will be estimated directly at the patient level; 2) Two sources for inconsistency between DCE-outcomes and actual utilization are studied in-depth: A) Imperfections of DCE design and analysis (the role of the researcher); B) Effects of personal characteristics (the role of the respondent). I will use a mixed methods design and three areas (influenza vaccination, colorectal cancer screening, and prostate cancer treatment). The project findings will lead to dual knowledge utilization: for those who investigate multi-attribute decisions, and for those who make multi-attribute decisions in healthcare.

Sexuality and intimacy are vital aspects of human life and wellbeing, regardless of one’s health. Incurable cancer and its treatment can cause sexual health issues, impacting both patients and their partners. Given the double taboo of sexuality and death, the impact of incurable cancer on sexual wellbeing is often neglected. Recognizing and addressing sexual health is crucial for enhancing quality of life of these patients. This project therefore aims to understand sexual wellbeing and perceptions of the double taboo of people with incurable cancer and their partners, to support them in their needs and wishes.

The global fight against HIV took a dramatic turn in 2011 with what Science called the ?scientific breakthrough of the year?: the proof of concept that antiretroviral therapy (ART) substantially reduces HIV transmission. A series of recent modelling studies has shown that expanded access to ART can eliminate HIV, yet these studies used simplistic models of the HIV epidemic and also failed to take realistic economic effects and health system constraints into account. In addition, they failed to address two potential barriers for elimination: the development of drug resistance and behavioural disinhibition. There is an urgent need for studies that turn the promise of HIV elimination into efficient and feasible interventions. I aim to fundamentally improve the use of mathematical modelling to investigate HIV elimination strategies in sub-Saharan Africa. I address the above-mentioned limitations by integrating insights from different disciplines such as health systems research, virology, and behavioural sciences into a comprehensive microsimulation model of the HIV epidemic. This has never been done before and is highly innovative. I will use the HIV epidemic in KwaZulu-Natal, South Africa ? one of the most severe epidemics in the world ? as a case study, and will ultimately develop a user-friendly policy tool that can define the efficiency and feasibility of HIV elimination strategies for all countries of sub-Saharan Africa. This work builds on existing collaborations between Erasmus MC, Africa Centre for Health and Population Studies, Harvard School of Public Health, Brown University, and Imperial College. During just 3 years of PhD-research, I have become a key scientist in this field, as demonstrated by a series of high-impact publications and invitations for high-level meetings on the development of ART guidelines. My network guarantees a broad societal impact of the project, and will aid to reap maximum benefit from last year?s scientific breakthrough.

Rural-urban regions feel an increasing need for landscape services such as clean drinking water, recreational space and space for living and working. While these demands are greatest in cities, the potential to provide these services is greatest in rural areas. It is possible to manage this - under the right preconditions - but it does require spatial interventions, strong policies and the financial-organizational matching of supply and demand. Landscape services can thus form the necessary extra link in the transformation towards sustainability, contributing to a more beautiful landscape and fertile soils for current and future generations.

CONNEXION identifies and addresses critical connections between water management and human health in the Inkomati-Usuthu water management area (South Africa). We combine disease and water-energy-food (WEF) interaction models to better understand these connections. We visualise results in a dashboard for decision making, supporting WEF and health managers in their policy and daily practice. Our consortium includes a broad team of researchers and practitioners in WEF, nutrition, and infectious diseases, who will work together with various local stakeholders to co-create potential scenarios and recommendations. CONNEXION will contribute to improved resilience, community livelihoods, health, and wellbeing in the research area and beyond.