Dr Clemence Leyrat


Assistant Professor
in Medical Statistics

G36 (Mon,Thurs,Fri) & 359 (Tues, Wed)

Keppel Street
United Kingdom

+44(0)207 927 2169

After studying cognitive sciences at the University of Bordeaux (France), I obtained a MSc in Biostatistics from the Bordeaux School of Public Health in 2010. Then, I moved to Tours (France) to do a PhD on the use of propensity score methods for the analysis of cluster randomised trials, under the direction of Prof Bruno Giraudeau. During this period, I developed a growing interest in causal inference methods to analyse observational data as well as for trial methodology.  I obtained my doctorate in April 2014, from Paris Diderot University, and moved to London to pursue post-doctoral research with Prof Sandra Eldridge at Queen Mary University on the issues of small samples and non-compliance in cluster randomised trials. 

I joined the department of Medical Statistics at LSHTM in September 2015, to do methodological work on missing data methods in propensity score analysis, working closely with Dr Elizabeth Williamson and Prof James Carpenter. I have been regularly involved in the analysis of observational data, in collaboration with researchers from the Electronic Health Records group at LSHTM. Since October 2018, I have also been working part-time with the Cancer Survival Group (Department of Non-Communicable Disease Epidemiology) on the application of causal inference methods, including emulated trials, to understand cancer inequalities in the UK.


Department of Non-communicable Disease Epidemiology
Faculty of Epidemiology and Population Health
Department of Medical Statistics


Centre for Statistical Methodology


I am currently the organizer of the module "Robust Statistical Methods" for the MSc in Medical Statistics and co-organizer of the distance learning module "Cluster randomised trials".

I also deliver lectures in the following short courses:

  • Design & Analysis of Cluster Randomised and Stepped Wedge Trials short course
  • Cancer Survival: Principles, Methods and Applications
  • Causal inference in epidemiology

I am an Associate Fellow of the Higher Education Academy.


Currently, I am the PI of a work package within the Horizon 2020 project QUALITOP. This project, led by Prof Delphine Maucourt-Boulch (Hospices Civils de Lyon, France) aims at monitoring multidimensional aspects of quality of life after cancer immunotherapy. As of April 2020, I hold an MRC Skills development fellowship allowing me to investigate how machine learning methods may enhance the design and analysis of cluster randomised trials.

Research Area
Clinical trials
Health inequalities
Statistical methods
Electronic health records
Randomised controlled trials
Disease and Health Conditions
United Kingdom
Europe & Central Asia (all income levels)

Selected Publications

Open science saves lives: lessons from the COVID-19 pandemic.
Besançon L; Peiffer-Smadja N; Segalas C; Jiang H; Masuzzo P; Smout C; Billy E; Deforet M; Leyrat C
BMC medical research methodology
Common Methods for Handling Missing Data in Marginal Structural Models: What Works and Why.
Leyrat C; Carpenter JR; Bailly S; Williamson EJ
American journal of epidemiology
Intervention effect estimates in cluster randomized versus individually randomized trials: a meta-epidemiological study
Leyrat C; Caille A; Eldridge S; Kerry S; Dechartres A; Giraudeau B
International Journal of Epidemiology
Cluster randomized trials with a small number of clusters: which analyses should be used? (vol 47, pg 321, 2018)
Leyrat C; Morgan KE; Leurent B; Kahan BC
Propensity score analysis with partially observed covariates: How should multiple imputation be used?
Leyrat C; Seaman SR; White IR; Douglas I; Smeeth L; Kim J; Resche-Rigon M; Carpenter JR; Williamson EJ
Statistical methods in medical research
Timeline cluster: a graphical tool to identify risk of bias in cluster randomised trials.
Caille A; Kerry S; Tavernier E; Leyrat C; Eldridge S; Giraudeau B
BMJ (Clinical research ed)
Propensity score to detect baseline imbalance in cluster randomized trials: the role of the c-statistic.
Leyrat C; Caille A; Foucher Y; Giraudeau B
BMC medical research methodology
A comparison of imputation strategies in cluster randomized trials with missing binary outcomes.
Caille A; Leyrat C; Giraudeau B
Statistical methods in medical research
See more Publications