Prior to working at LSHTM I was Professor of Sociology & Social Policy at University College London and Professor of Sociology & Social Intervention at the University of Oxford. I was also previously Research Team Leader in the UK government’s Social Exclusion Unit.

My main areas of research are on adolescent health, sexual health and evaluation methodology.

My research on adolescent health focuses on how schools and school based interventions can benefit or harm young people’s health. My research on sexual health examines the broader social determinants of adolescent sexual health behaviours and outcomes, and interventions to address these.

In terms of evaluation methodology I have written a number of methodological papers on: theorising and evaluating intervention harms; realist trials which combined rigorous evaluations of intervention effects with quantitative and qualitative analyses of what works for whom under what conditions; systematic reviews not only of effectiveness evidence but also process evaluation, qualitative evidence and theories of change; situations in which randomised trials are not appropriate and what alternatives exist; process evaluation; and empirical assessment of intervention transferability. Recent work on ‘dark logic models’ and 'realist trials' have twice been  awarded the President’s Prize by the European Society for Prevention Research.

I am an NIHR Senior Investigator and was a participant on various SAGE subcommittees advising government on Covid-19.