His primary research interest concerns clinical trials, both as regards methodological developments and applied collaboration in major trials, mainly in cardiology. He also has interests in observational epidemiology especially pharmaco-epidemiology. His particular methodological areas of expertise include: standards for the statistical reporting of trials and epidemiological studies, the statistical ethical and organisational principles for data monitoring including early stopping guidelines, the win ratio approach to a hierarchical composite of outcomes with clinical priorities, adaptive designs, handling non-proportional hazards, the value of repeat-event analyses, use and misuse of propensity scores, the pros and cons of non-inferiority trials, problems of multiplicity in trial reporting, eg, subgroup analyses, multiple outcomes and covariate adjustment, and the development/validation of prognostic risk scores.