Dr Alexina Mason


Assistant Professor
of Medical Statistics


15-17 Tavistock Place
United Kingdom

020 7958 8296

After completing a first degree in Mathematics and Computing (University of Bath), my early career was spent working as an aviation forecaster at the Civil Aviation Authority and National Air Traffic Services. This included a year studying at the University of Sheffield, where I gained an MSc in Statistics. I returned to full-time education in 2005, and completed a PhD on Bayesian methods for modelling non-random missing data mechanisms in longitudinal studies at Imperial. Since then I have worked on the BIAS project, which developed Bayesian methods for integrated bias modelling and analysis of multiple data sources in observational studies, and as a trial statistician in the Imperial Clinical Trials Unit, focussing mainly on critical care trials.

I joined the School in October 2014, and my current research is at the interface of statistics, health economics and decision making, and is aimed at improving Bayesian approaches to healthcare evaluation arising from clinical trials. I have ongoing collaborations with the Intensive Care National Audit and Research Centre (ICNARC), the Statistics for Health Economic Evaluation Group at UCL and the statistical researchers at Imperial College London working in clinical trials.


Faculty of Public Health and Policy
Department of Health Services Research and Policy


Centre for Statistical Methodology


I am a module organiser for Bayesian Statistics for the MSc in Medical Statistics.


My main research interests revolve around the development and application of Bayesian approaches in clinical trial settings, and in particular to handling missing data. This includes developing methods and tools to facilitate expert elicitation that allows external knowledge to be incorporated into analysis when there is missing or insufficient information from the trial itself.

Research Area
Clinical trials
Bayesian Analysis
Critical care

Selected Publications

Reduced exposure to vasopressors through permissive hypotension to reduce mortality in critically ill people aged 65 and over: the 65 RCT.
Mouncey PR; Richards-Belle A; Thomas K; Harrison DA; Sadique MZ; Grieve RD; Camsooksai J; Darnell R; Gordon AC; Henry D
Health technology assessment (Winchester, England)
The impact of resuscitation system factors on in-hospital cardiac arrest outcomes across UK hospitals: An observational study.
Couper K; Mason AJ; Gould D; Nolan JP; Soar J; Yeung J; Harrison D; Perkins GD
Effect of Reduced Exposure to Vasopressors on 90-Day Mortality in Older Critically Ill Patients With Vasodilatory Hypotension: A Randomized Clinical Trial.
Lamontagne F; Richards-Belle A; Thomas K; Harrison DA; Sadique MZ; Grieve RD; Camsooksai J; Darnell R; Gordon AC; Henry D
A framework for extending trial design to facilitate missing data sensitivity analyses.
Mason AJ; Grieve RD; Richards-Belle A; Mouncey PR; Harrison DA; Carpenter JR
BMC medical research methodology
A flexible hierarchical framework for improving inference in area-referenced environmental health studies
Pirani M; Mason A; Hansell A; Richardson S; Blangiardo M
Biometrical Journal
Levosimendan in septic shock in patients with biochemical evidence of cardiac dysfunction: a subgroup analysis of the LeoPARDS randomised trial.
Antcliffe DB; Santhakumaran S; Orme RML; Ward JK; Al-Beidh F; O'Dea K; Perkins GD; Singer M; McAuley DF; Mason AJ
Intensive care medicine
Evaluating the clinical and cost-effectiveness of permissive hypotension in critically ill patients aged 65 years or over with vasodilatory hypotension: Statistical and Health Economic Analysis Plan for the 65 trial
Thomas K; Patel A; Sadique MZ; Grieve RD; Mason AJ; Moler S; Gordon AC; Rowan KM; Mouncey PR; Lamontagne F
Journal of the Intensive Care Society
See more Publications