Sian Floyd BSc MSc

Associate Professor in Epidemiology and Medical Statistics


Sian Floyd joined the school in 1998. She obtained an MSc in Biometry from Reading University in 1993, and then worked as a biometrician in the agricultural and natural resources sector for four years, first in the Caribbean and then in the UK.




Sian is a co-organiser, with James Lewis, for the distance-learning Advanced Statistical Methods in Epidemiology module (since 2004). Prior to this she was co-organiser for the in-house Statistical Methods in Epidemiology study unit, from 2000-2003. She currently teaches on the study units Statistical Methods in Epidemiology, and Epidemiology and Control of Communicable Diseases.


Sian works as a statistician/epidemiologist on the Karonga Prevention Study (KPS), which is based in northern Malawi. Her research on this project focuses on quantifying and understanding the extent to which the provision of free anti-retroviral therapy (ART) reverses the impact of the HIV epidemic. Important outcomes that are being measured include: child and adult mortality; social and economic consequences such as orphanhood, educational achievement of children, and household poverty; HIV incidence and sexual behaviour at the population level; and the percentage of the adult population who know their HIV status. She also contributes to the work of the Alpha-Network (Analysis of Longitudinal data on HIV/AIDS on Africa), which is led by Professor Basia Zaba. This network brings together researchers from demographic surveillance sites (DSS) in sub-Saharan Africa (including in Malawi, South Africa, Tanzania, Uganda, and Zimbabwe), and combines research with capacity-building through themed workshops.

Sian has also worked on case-control and cohort studies of tuberculosis, including immuno-epidemiological studies,  and is currently a member of an expert group convened by WHO whose mandate is to support 21 global focus countries to design, implement, and analyse TB prevalence surveys between 2008 and 2015.

Research areas

  • Clinical trials
  • Complex interventions
  • Randomised controlled trials
  • Vaccines


  • Epidemiology
  • Immunoepidemiology
  • Statistics

Disease and Health Conditions

  • Tuberculosis


  • Sub-Saharan Africa (all income levels)


  • Benin
  • Cambodia
  • Gambia, The
  • Guinea
  • Malawi
  • Senegal
  • South Africa
  • Uganda
  • Zambia

Other interests

  • Cluster Randomised Trials
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