Patients with serious mental illness have higher levels of morbidity and physical illness and a shorter life expectancy compared to the rest of the population. For these patients GP practices are an important and significant point of care. Rowena Jacobs, Professor of Health Economics at the University of York, explains how her study is bringing together data from a range of sources to identify ways of improving the quality of primary care for these patients and the impact such improvements are likely to have not just on the individuals but on NHS services.