The regression discontinuity design is an elegant and effective way to draw causal conclusions, with an abundance of successful applications in economics, education, political science, social and behavioural sciences and many other areas. Yet it has recently come into focus that the regression discontinuity approach is very underutilized in medical research. This may be due in part because there are still gaps in available methodology for common medical data structures. In this project, we aim to fill these gaps by tailoring recently developed mathematical insights and tools from Bayesian statistics to sharp and fuzzy regression discontinuity designs. In the first work package, a novel Bayesian method to study survival data in a regression discontinuity design is developed and placed on a firm theoretical foundation. A multiscale approach will be adopted, and the priors for the hazard will be of piecewise constant form to allow for flexible inclusion of covariates while preserving reliable uncertainty quantification. Second, we aim to combine evidence from multiple hospitals, with the cut-off varying from hospital to hospital. The local estimates from each center will be combined in a nonparametric Bayesian regression approach using the BART prior, which has previously found great success in other statistical problems. Theoretical results will be derived to justify the accompanying uncertainty quantification. The end result will be a flexible method to combine evidence, which can be used for continuous and survival data. Third, we design and rigorously evaluate (through posterior contraction and Bernstein-Von Mises theorems) a prior distribution for the situation where it is unclear what the cut-point is, or whether a cut-point was used at all. The Bayesian approach is highly promising here since it yields automatic uncertainty quantification, and in case multiple data sets are available, it allows for borrowing of strength between the data sets in a natural way. Finally, data from the Dutch Arthroplasty Register is analysed in close collaboration with orthopaedic surgeons, to study which type of fixation is optimal in terms of hip implant survival. This is the application that inspired the three aforementioned work packages. Interwoven with all work packages is the development of an R package and a workshop, so that the novel methods will become easily accessible to researchers working in a variety of research fields. The overall result of all work packages combined will be that medical as well as other researchers can apply the regression discontinuity design in more settings, opening up more observational data sets for causal inference.

The research project Cities of Readers: Religious Literacies in the Long Fifteenth Century aims to supply a new phase in the scholarly exploration of the later Middle Ages by studying the active participation of laypeople in the production and the transmission of religious knowledge through their engagement in reading, textual and performative activities. The project will innovatively approach religious readership in terms of dynamics, exchanges and negotiations and will consider individuals and groups (communities of interpretation, formal and informal textual communities sharing texts and knowledge) as objects of research. Reading activities will moreover be studied in relation to the specific places and spaces in which they were generated. The complexity of the topic and the broad varieties of selected sources (ranging from personal miscellanies to post-mortem inventories) require an interdisciplinary and programmatic approach that will be conducted along three main methodological lines: a) the study of the multiformity of readership and modes of transmission (textuality, orality, aurality and performativity); b) the role of communities of interpretation; c) a spatial approach to cultural dynamics striving towards the reconstruction of a late medieval religious taskscape, i.e. identifying the place where religious knowledge was made, discussed and exchanged. The research lines will be combined in three complementary research projects and in the final co-authored monograph that will contribute to the evaluation of material from the Low Countries in a wider European perspective. The project will result in the writing of new narratives concerning the crucial role of active readership during a pivotal period in European history.

When researchers wish to compare two groups and are unable to do so through an experiment, they need to account for all factors that went into the group assignment. This research develops new statistical methods which indicate the impact on the research conclusions in case a relevant factor was missed.

User involvement is essential to make preventive activities effective. The 21/22 NWO prevention projects consist of: 1. How can local health policy makers address what really matters to citizens?; 2. How can nutritional interventions be personalised to client groups; 3. Transitioning towards a healthier supermarket environment through co-creation with end-users.

Although the health benefits of physical activity (PA) are well-established, the prevalence of insufficient PA among older adults is alarmingly high and points to a considerable scope and need for improvement. Research is urgently needed to identify modifiable aspects of the neighbourhood that may be entry-points for interventions to make environments more conducive to PA for older adults. This project aims to overcome earlier methodological limitations and gain novel insights on environmental determinants of PA in old age. We propose that walkability is a crucial environmental construct for older adults’ PA. In our project, we will combine fine-scale spatial data from different geo-data sources to create walkability measures for various years and personalized exposure areas covering the whole of the Netherlands. We will link these objective measures to PA-data of older adults from the Longitudinal Aging Study Amsterdam. We will then (a) examine associations between changes in walkability, and its components, with changes in PA, and (b) assess whether these associations differ by individual characteristics and contextual conditions. The findings will offer perspectives to policymakers, urban planners and public health professionals on how to optimally design neighbourhoods to increase older adults’ PA, which subsequently will promote active and healthy aging.