It’s an exciting time for clinical trials and epidemiology in the UK. The UK Clinical Research Collaboration (UKCRC) and UK Clinical Research Networks (UKCRN) have been established to strengthen clinical research and increase the resources available for clinical epidemiologists, and especially trialists. The success of the National Cancer Research Network in more than doubling recruitment into cancer trials, by providing an improved clinical and NHS infrastructure, has raised the possibility that this can be repeated in other clinical areas and the aim of UKCRN is to increase support provided to all areas of clinical need.

At the Medical Research Council Clinical Trials Unit (MRC CTU), much of the work to provide an evidence base for the therapeutic and preventive interventions used in medicine concerns cancer and HIV infection, which are of major importance in the UK and worldwide. In addition the scope of the trials being carried out extends into other disease areas, such as arthritis, blood transfusion and multiple sclerosis. The MRC CTU has additional roles in providing advice and support for clinicians wishing to develop trials and in increasing the understanding of trials by patients and the public, to facilitate consumer involvement at all stages of the research process.

In some circumstances, randomisation in a trial is not practicable and observational studies are also important to assess the impact of interventions, their longer term safety in routine clinical care and other issues such as prognostic factors. Health economics is also highly relevant to the interpretation and implementation of the results of trials and there are important methodological issues that need to be addressed in this field.

To complete a trial or meta-analysis that results in a major impact on health is the most rewarding aspect of this work. Seeing results that can affect morbidity and/or mortality, with acceptable levels of adverse effects, translated into clinical guidelines and adopted into clinical practice is the ultimate goal.

However, trials that have negative results are equally important. If a new intervention is shown to have no advantage over standard therapy or to be effective but more toxic, trials can prevent patients being given treatments which have no benefit or even carry an increased risk or may be more expensive than the standard treatment.

Developing research methodologies also has great rewards. For example, this might shorten the time needed to achieve a robust trial result or allow more treatments to be assessed at the same time and so shorten the time it takes for new effective therapies to be available to patients.