Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
Skip to main content


Missing data is a common issue in cost-effectiveness analysis (CEA) of randomised trials. Methods such as multiple imputation are now commonly used to account for the missing values, assuming the data to be ‘missing at random’ (MAR). In many settings, it seems however plausible that the data may be ‘missing not at random’ (MNAR, or ‘informative’). For example, patients whose health status is relatively poor may be less likely to return quality-of-life questionnaires. In these circumstances, guidelines recommend assessing whether conclusions are robust to different missing data assumptions. But this is rarely done in practice, perhaps due to a lack of clear guidance on how to conduct such sensitivity analysis.

In this presentation, I will start by a review of the current practice for addressing missing data in trial-based CEA. I will then outline several possible approaches for conducting sensitivity analysis, and focus on one particularly accessible approach based on multiple imputation. Its’ implementation will be illustrated with a trial of a brief intervention for weight loss in primary care. I will finish by discussing an alternative method for longitudinal data, where the missing data are imputed assuming a distribution borrowed from a reference group.


Baptiste Leurent is an assistant professor in medical statistics and epidemiology at the London School of Hygiene and Tropical Medicine (LSHTM). He is currently conducting a NIHR-funded PhD on missing data in cost-effectiveness analysis, in the Medical Statistics Department. Previously he worked as a statistician in different research institutions in the UK and Thailand (PHPT, UCL, MRC), on clinical trials and epidemiological studies in HIV, mental health and primary care. Before starting his PhD, he worked at LSHTM with the ACT Consortium, looking at improving the use of artemisinin-based combination therapy for malaria. He is particularly interested in applied methods to improve the design and analysis of randomised trials.

Forthcoming events

Oxford-Peking University Joint Symposium on Precision Medicine

Thursday, 19 September 2019, 10am to 6pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

CKB Workshop - Infections, immunity and cancer: aetiology and beyond

Friday, 20 September 2019, 1pm to 5pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

NDPH Seminar - Changing the way medical research is funded: Some lessons from Australia

Thursday, 26 September 2019, 4pm to 5pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

Ethox/WEH Seminar - Reclaiming a Sense of Common Humanity: A Confucian Ethical Vision

Wednesday, 02 October 2019, 11am to 12.30pm @ Level 1 Ax Meeting Room, BDI, Old Road Campus, OX3 7LF

UVBO Seminar - Can wearable sensors and machine learning enhance our understanding of lifestyle health behaviours?

Thursday, 17 October 2019, 1pm to 2pm @ L1 Meeting room, Richard Doll Building, Old Road Campus, OX3 7LF

UVBO Seminar - Nutrient timing and human health

Thursday, 24 October 2019, 1pm to 2pm @ School of Anthropology, 61 Banbury Road, OX2 6PE