Observational Studies

This page is part of the central academic repository of Prof. dr. Maurice Zeegers, Professor of Epidemiology at Maastricht University, the Netherlands.

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Observational studies (also called Real World Evidence, RWE) refers to clinical and epidemiological datasets derived from routinely collected human data outside the context of randomized controlled trials, such as patient registries, electronic health records and large population-based cohorts, to which we have access through multiple high-quality data sources. Our observational studies span multiple (disease) outcomes and determinants. For most researched areas, selected example publications and projects are provided.

(Disease) Outcomes

Oncology

Current Projects/Datasets: UKBiobank, BCPP

Current Researchers: Anke Wesselius, Anna-Roos Leerschool, Iris Boot, Manuel Origgi, Xiaoman Jin, Evan Wu, Yanan Dai, Yiming Chen, Yufeng Rao, Maurice Zeegers

1. Yu, Minghao, Anshita Goel, Benjamin Tura, e.a. ‘Towards Epigenetic-Based Subtyping of Bladder Cancer: DNA Methylation Predicts Molecular Subtypes of Non-Muscle-Invasive Bladder Cancer’. European Urology, 7 maart 2025, S0302-2838(25)00126-5. https://doi.org/10.1016/j.eururo.2025.02.011.
2. Fan, Yu-Ping, Yu-Ting Zhang, Guiyuan Zhang, e.a. ‘Proteomic Profiling of Urinary Large Extracellular Vesicles for the Diagnosis of Prostate Cancer’. Analytical Chemistry, advance online publication, 16 juli 2025. https://doi.org/10.1021/acs.analchem.5c01320.
3. Saeed, Azad K., Panagiotis Triantafyllakis, Naheema S. Gordon, et al. “The Role of HAI-1 in Urothelial Bladder Cancer: Tissue Expression, Ectodomain Shedding and Clinical Outcomes.” Biochemistry and Biophysics Reports 46 (June 2026): 102600. https://doi.org/10.1016/j.bbrep.2026.102600.

Cardiovascular & Metabolic Diseases

Current Projects/Datasets: SportNL DNA databank, Maastricht Study, MEFAB

Current Researchers: Anke Wesselius, Marij Gielen, Farahnaz Haeri Mehrizy, Yiming Chen, Maurice Zeegers

1. Ren, Huiying, Qirong Qin, Quanbin Dong, e.a. ‘Smartphone-Measured Heart Sounds for Atrial Fibrillation Screening in Community Populations’. Circulation 152, nr. 4 (2025): 283-85. https://doi.org/10.1161/CIRCULATIONAHA.125.073828.
2. Rao, Yufeng, Shiqiu Meng, Evan Yi-Wen Yu, e.a. ‘Antidiabetic Medications and Bladder Cancer Risk in Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials’. Endocrine Practice: Official Journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 17 december 2025, S1530-891X(25)01328-X. https://doi.org/10.1016/j.eprac.2025.11.017. OSF
3. Chen, Yiming, Enyu Tong, Yufeng Rao, Evan Yw Yu, Maurice Zeegers, en Anke Wesselius. ‘The Association between Insomnia (Related Symptoms) and Glycaemic Control: A Systematic Review and Meta-Analysis’. Journal of Global Health 15 (februari 2025): 04016. https://doi.org/10.7189/jogh.15.04016.

Neurology & Psychiatry

Current Projects/Datasets: MADYMO, Forensic Mental Health Services, Forensic Hospitalisation following Psychotic Disorder, USA NASS-CDS, USA Hospital Data, Canadian Health Administrative Data (ICES)

Current Researchers: Ellen Strommer, Fatemah Mirjalili, Jack Freeman, Joshua Goldenberg, Manuel Origgi, Rebecca Rodrigues, Maurice Zeegers

1. Mirjalili, Fatemeh, Sara Jambarsang, Ehsan Farashahi Yazd, et al. “Adherence to Empirically Derived Dietary Patterns and Risk of Depression Symptoms and Anxiety Disorder: The Maastricht Cohort Study.” The American Journal of Clinical Nutrition, June 26, 2026, 101415. https://doi.org/10.1016/j.ajcnut.2026.101415.
2. Zhang, Yu-Ting, Hao Zhang, Weichao Su, e.a. ‘Age-(in)Dependent Altered Molecular Mechanisms in Parkinson’s Disease through Extracellular Vesicle Proteome and Lipidome’. Cell Reports. Medicine, 5 november 2025, 102432. https://doi.org/10.1016/j.xcrm.2025.102432.
3. Hanff, Anne-Marie, Christopher McCrum, Armin Rauschenberger, e.a. ‘Sex-Specific Progression of Parkinson’s Disease: A Longitudinal Mixed-Models Analysis’. Journal of Parkinson’s Disease 15, nr. 4 (2025): 805-18. https://doi.org/10.1177/1877718X251339201. OSF

Infectious Diseases

Current Projects/Datasets: Luxembourg Health Data

Current Researchers: Anke Wesselius, Dritan Bejko, Piotre Wilk, Maurice Zeegers

1. Bejko, Dritan, Corinna Ernst, Anne Vergison, Saverio Stranges, Maurice P. Zeegers, en Joël Mossong. ‘High Vaccine Effectiveness against Severe COVID-19 Outcomes and Population Preventable Fraction during the Omicron Era in Luxembourg: A Nationwide Retrospective Risk Factor Analysis’. Vaccine, 1 juni 2024, S0264-410X(24)00636-4. https://doi.org/10.1016/j.vaccine.2024.05.059.
2. Wilk, Piotr, Valerie Moran, Maria N. Pi Alperin, e.a. ‘The Role of Multimorbidity and Socio-Economic Characteristics as Potential Risk Factors for Long Covid: Evidence from the Multilevel Analysis of the Survey of Health, Ageing and Retirement in Europe’s Corona Surveys (2020-2021)’. Age and Ageing 52, nr. 12 (2023): afad225. https://doi.org/10.1093/ageing/afad225.
3. Meilia, Putri Dianita Ika, Maurice P. Zeegers, Herkutanto, en Michael D. Freeman. ‘Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach’. International Journal of Environmental Research and Public Health 18, nr. 14 (2021): 7530. https://doi.org/10.3390/ijerph18147530.

Patient-Centered Outcomes

1. Hanff, Anne-Marie, Claire Pauly, Laure Pauly, e.a. ‘Determinants of Patient-Reported Functional Mobility in People with Parkinson’s Disease: A Systematic Review’. Gait & Posture 108 (februari 2024): 97-109. https://doi.org/10.1016/j.gaitpost.2023.11.013.
2. Schmitz, Susanne, Tatjana T. Makovski, Roisin Adams, Marjan van den Akker, Saverio Stranges, en Maurice P. Zeegers. ‘Bayesian Hierarchical Models for Meta-Analysis of Quality-of-Life Outcomes: An Application in Multimorbidity’. PharmacoEconomics 38, nr. 1 (2020): 85-95. https://doi.org/10.1007/s40273-019-00843-z.
3. Osch, Frits H. M. van, Duncan Nekeman, Neil K. Aaronson, e.a. ‘Patients Choose Certainty over Burden in Bladder Cancer Surveillance’. World Journal of Urology, advance online publication, 23 maart 2019. https://doi.org/10.1007/s00345-019-02728-4.

Determinants

Genetics

Current Projects/Datasets: UKBiobank, BCPP, SportNL DNA databank, Maastricht Study

Current Researchers: Anke Wesselius, Anna-Roos Leerschool, Fatemah Mirjalili, Xiaoman Jin, Yanan Dai, Yiming Chen, Yufeng Rao, Maurice Zeegers

1. Hof, Jasper P., Tessel E. Galesloot, Katja K. H. Aben, et al. “Comprehensive Genome-Wide Association Study into Multiple Recurrence and Progression Risk in Non-Muscle Invasive Bladder Cancer.” Cancer Genetics 306–307 (June 2026): 106–15. https://doi.org/10.1016/j.cancergen.2026.06.004.
2. Leerschool, Anna Roos, Anke Wesselius, Daša Kokole, en Maurice P. Zeegers. ‘Changes in Acceptability, Consideration, Intention, and Uptake of Direct-to-Consumer Genetic Tests in the Netherlands from 2017 to 2022’. Journal of Genetic Counseling 34, nr. 1 (2025): e1919. https://doi.org/10.1002/jgc4.1919. OSF
3. Rao, Yufeng, Evan Yi-Wen Yu, Tzu-Yao Lin, e.a. ‘Interaction between Coffee Consumption and Polygenic Risk Score in Relation to Diabetes: Insights from the Maastricht Study’. European Journal of Nutrition 64, nr. 6 (2025): 263. https://doi.org/10.1007/s00394-025-03782-y. OSF

Genomics

Current Projects/Datasets: UKBiobank, BCPP, Maastricht Study

Current Researchers: Anke Wesselius, Manuel Origgi, Xiaoman Jin, Maurice Zeegers

1. Neil, Jessica L., Naheema S. Gordon, Anshita Goel, e.a. ‘Development of an Extended Version of GALEAS Bladder: Detection of FGFR3 Fusions in Urine and Associations between Genomic Alterations and Gene Expression’. Bladder Cancer (Amsterdam, Netherlands) 12, nr. 2 (2026): 23523735261447112. https://doi.org/10.1177/23523735261447112.
2. Saeed, Azad K., Panagiotis Triantafyllakis, Naheema S. Gordon, et al. “The Role of HAI-1 in Urothelial Bladder Cancer: Tissue Expression, Ectodomain Shedding and Clinical Outcomes.” Biochemistry and Biophysics Reports 46 (June 2026): 102600. https://doi.org/10.1016/j.bbrep.2026.102600.
3. Goel, Anshita, Benjamin J. Tura, Joanne D. Stockton, e.a. ‘Detection of Genome-Wide Methylation Changes in Bladder Cancer by Long-Read Sequencing of Urinary DNA’. Clinical Epigenetics 17, nr. 1 (2025): 141. https://doi.org/10.1186/s13148-025-01946-5.

Therapeutics

Current Projects/Datasets: UKBiobank, BCPP, Maastricht Study

Current Researchers: Anke Wesselius, Xiaoman Jin, Yufeng Rao, Maurice Zeegers

1. Ye, Tian, Benjamin Tura, Ben Abbotts, e.a. ‘Clinical Outcomes of BCG-Treated Patients with High-Risk Non-Muscle-Invasive Bladder Cancer According to Pre- and Post-2021 European Association of Urology Risk Classifications’. BJU International, advance online publication, 23 maart 2026. https://doi.org/10.1111/bju.70247.
2. Rao, Yufeng, Shiqiu Meng, Evan Yi-Wen Yu, e.a. ‘Antidiabetic Medications and Bladder Cancer Risk in Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials’. Endocrine Practice: Official Journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 17 december 2025, S1530-891X(25)01328-X. https://doi.org/10.1016/j.eprac.2025.11.017.
3. Zhang, Hao, Gui-Yuan Zhang, Wei-Chao Su, e.a. ‘High Throughput Isolation and Data Independent Acquisition Mass Spectrometry (DIA-MS) of Urinary Extracellular Vesicles to Improve Prostate Cancer Diagnosis’. Molecules (Basel, Switzerland) 27, nr. 23 (2022): 8155. https://doi.org/10.3390/molecules27238155.

Nutrition

Current Projects/Datasets: UKBiobank, BCPP, Maastricht Study, MEFAB

Current Researchers: Anke Wesselius, Marij Gielen, Farahnaz Haeri Mehrizy, Fatemah Mirjalili, Iris Boot, Raman Mahajan, Yanan Dai, Yiming Chen, Yufeng Rao, Maurice Zeegers

1. Dai, Ya-Nan, Benjamin Tura, Evan Yi-Wen Yu, e.a. “Pro-Inflammatory Diet Predicts Poorer Survival in Bladder Cancer: Results from the Bladder Cancer Prognosis Programme”. Clinical Nutrition (Edinburgh, Scotland) 62 (juli 2026): 106679. https://doi.org/10.1016/j.clnu.2026.106679.
2. Rao, Yufeng, Evan Yi-Wen Yu, Tzu-Yao Lin, e.a. ‘Interaction between Coffee Consumption and Polygenic Risk Score in Relation to Diabetes: Insights from the Maastricht Study’. European Journal of Nutrition 64, nr. 6 (2025): 263. https://doi.org/10.1007/s00394-025-03782-y.
3. Rostampoor, Zahra, Sima Afrashteh, Mohammad Mohammadianpanah, Haleh Ghaem, Maurice P. Zeegers, en Mohammad Fararouei. ‘Lifestyle, Dietary Pattern and Colorectal Cancer: A Case-Control Study’. BMC Nutrition 10, nr. 1 (2024): 138. https://doi.org/10.1186/s40795-024-00950-x.

Environment

Current Projects/Datasets: USA Hospital Data, EFPTS

Current Researchers: Marij Gielen, Ellen Strömmer, Maurice Zeegers

1. Strömmer, E. M. F., Wendy Leith, Maurice P. Zeegers, en Michael D. Freeman. ‘Injuries Due to Law Enforcement Use of Force in the United States, 2006-2015: Trends in Severity and by Race’. Journal of Racial and Ethnic Health Disparities, advance online publication, 8 augustus 2023. https://doi.org/10.1007/s40615-023-01733-z.
2. Figaroa, M. N. S., M. Gielen, L. Casas, e.a. ‘Early-Life Residential Green Spaces and Traffic Exposure in Association with Young Adult Body Composition: A Longitudinal Birth Cohort Study of Twins’. Environmental Health: A Global Access Science Source 22, nr. 1 (2023): 18. https://doi.org/10.1186/s12940-023-00964-1.
3. Verhaegh, Bas P. M., Esmee M. Bijnens, Tim R. A. van den Heuvel, e.a. ‘Ambient Air Quality as Risk Factor for Microscopic Colitis - A Geographic Information System (GIS) Study’. Environmental Research 178 (november 2019): 108710. https://doi.org/10.1016/j.envres.2019.108710.