My principal area of research is the study of the development and impact of chronic obstructive pulmonary disease (COPD). I am involved in the day-to-day running of the London COPD cohort. This is an observational cohort of approximately 200 moderate to very severe COPD patients started in November 1995. We have shown a relationship between COPD exacerbations and quality of life and disease progression, and that early treatment of exacerbations reduces the severity and prevents hospital admission. This has led to the development of early intervention strategies that is one of the objectives of the COPD National Services Framework. Our research has strong clinical and basic components and we have shown the importance of infection at exacerbation, the interaction of bacteria and viruses and the rationale for the use of antibiotics at COPD exacerbation in collaboration with Microbiology and Virology at the Royal Free Hospital. We were the first to show the relationship between airway inflammatory markers and decline in lung function. We were also the first group to define the presence of COPD patients with a history of frequent exacerbations and these patients are most prone to have recurrent COPD admissions which impose considerable costs on the NHS. The division of patients into frequent and infrequent exacerbation phenotypes has been incorporated into disease management guidelines for the prescription of maintenance therapy. An analysis of a pharma-epidemiological database (2010) showed the relationship between COPD exacerbation and acute myocardial infarction, and this work has been a stimulus for better treatment of cardiovascular disease in COPD.