Prof Paddy Farrington
I joined the Statistics Department in 1998, after 11 years as a statistician at the Communicable Diseases Surveillance Centre in London. In the early 80s, I worked for a few years in Vietnam, and got to know some doctors specialising in infectious diseases at the Bach Mai Hospital in Hanoi. But I had no idea then that I would later work on statistical methods for infectious diseases.
- Statistical methods in epidemiology, especially infectious diseases. Specific areas I’m interested in include estimation of vaccine efficacy, and estimation of transmission and threshold parameters such as the reproduction number. I’m most interested in methods that can be applied using commonly available data, such as surveillance reports and serological surveys.
- Statistical methods for evaluating drug safety, and in particular the self-controlled case series method (now beginning to be used quite widely). In particular, I have worked on issues such as the safety of MMR vaccine and autism.
- Generalised linear models, in particular assessing goodness of fit when data are sparse. Once topic I’m currently interested in is goodness of fit for sparse product multinomial models.
- Statistical models for interval-censored data, including model fitting, regression diagnostics, and informative censoring.
- Profile likelihood methods for calculating approximate confidence regions.
Self-controlled case series method
This is a method I first published back in 1995, to investigate adverse reactions to vaccines. Its key feature is that it uses data only on cases, which makes it easy to use. It also avoids many sources of confounding, as in effect cases are matched with themselves. The method has been used in many vaccine studies (including MMR and autism), and to investigate drug safety more generally. Heather Whitaker has programmed the method in several stats packages and put together an excellent website at http://statistics.open.ac.uk/sccs. Currently I'm working with Heather and a postdoc, Mounia Hocine, to develop the method further.
Parameter estimation for infectious diseases
This involves estimating contact parameters and other quantities such as reproduction numbers. I've been working on this since 2000, collaborating with Heather Whitaker at the OU and Mona Kanaan (ex OU, then American University of Beirut). Heather Whitaker and I are currently taking part in a European collaboration (POLYMOD) to collect data on contacts and serological profiles. I jointly supervise (with Kevin McConway) two part-time PhD students who are working on the epidemiology of infectious diseases: Ardiana Gjini, and George Kafatos.