School of Medicine, Faculty of Education and Health Sciences
University of Limerick
Email: maurice.oconnell@ul.ie
I am an Associate Professor in Medical Biostatistics at the University of Limerick.
My research develops statistical, causal inference, and machine learning methods for healthcare decision-making using observational, routinely collected healthcare data and randomised controlled trials. I am particularly interested in estimating treatment effects, understanding treatment-effect heterogeneity, and developing methods that support personalised and population-level decision-making under uncertainty.
My work lies at the intersection of:
Statistics
Biostatistics
Causal Inference
Causal Machine Learning
Mathematics
Health Data Science
Health Economics
Electronic Health Records
Healthcare Decision Science
Applications include polypharmacy and multipile long-term conditions, cardiovascular disease, diabetes, mental health, and other areas where evidence from randomised trials is incomplete or unavailable.
Fully Funded PhD in Statistics, Causal Inference and Machine Learning
Applications are currently invited for a fully funded four-year PhD focused on developing novel statistical and causal machine-learning methods for dynamic treatment effects using longitudinal electronic health records.
The project will investigate:
Target Trial Emulation
Dynamic Treatment Regimes
Semiparametric Inference
Debiased Machine Learning
Heterogeneous Treatment Effects
Longitudinal Healthcare Data
Applications are encouraged from candidates with backgrounds in Statistics, Biostatistics, Mathematics, Data Science, Computer Science, Econometrics, Epidemiology, and related quantitative disciplines.
➡ See the PhD Opportunities page for details.
Healthcare systems increasingly rely on observational healthcare data to inform decisions that cannot be addressed through randomised trials alone.
My research aims to develop statistically rigorous methods capable of answering clinically relevant causal questions using real-world healthcare data while addressing challenges such as confounding, treatment heterogeneity, competing risks, dynamic treatment pathways, and limited treatment overlap.
The long-term goal is to improve evidence generation and support safer, more personalised, and more equitable healthcare decision-making.
Statistics is really about solving interesting and important problems and I think the development of new methodology and theory is important. But at the end of the day, it should be connected to real world applications.
Before joining the University of Limerick, I was a Research Associate in Statistics and Causal Inference at The University of Manchester (2022–2026), where I developed causal inference methods using large-scale linked electronic health records.
Previously, I worked as a postdoctoral researcher in biostatistics at the HRB Clinical Research Facility at the University of Galway (2019–2022), contributing to methodological research in causal inference and population health and developing open-source software including the R packages graphPAF and causalPAF.
I completed a PhD in Health Economics and Statistics at the University of Limerick in 2020 and hold a First Class Honours degree in Financial and Actuarial Mathematics from Dublin City University.