Disease prevention and diagnosis
The core aim of preventive medicine is to ensure that premature death or major disease events, routinely defined as death before the age of 65, is uncommon and that morbidity in the population is minimized. Services to prevent disease are among the most important and potentially cost-effective provided by the NHS and most preventive strategies are provided in primary care. Their content and delivery needs to be underpinned by a firm evidence base. However, a remarkably low proportion of medical research expenditure in many countries including the UK is committed to prevention research, hence the focus for the SPCR – prevention is a key NHS priority but the evidence base is limited by under-investment.
In terms of a focus for our SPCR disease prevention research, our principal efforts focus upon cardiovascular disease and cancer. The WHO stated in 2010 that the main sequelae of cardiovascular disease, ischaemic heart disease and stroke, were the most important causes of premature death and major disability (and therefore health system costs) on the planet and also that the risk factors for CVD (like smoking, high blood pressure) the most important to modify. Many questions remain as to how we can effect change in these major health issues, with ongoing SPCR research to answer some.
Moreover, prevention is not absolute. Disease will still occur and primary care also has a key role to play in ensuring that it is diagnosed at an early and treatable stage. This is particularly important for cancer, where the chances of survival, and the costs of NHS care, are determined more by diagnostic delay than any other health service factor. Early diagnosis is also important for other diseases with major economic implications for the NHS such as stroke. For example, failure to diagnose and treat a transient ischaemic attack in primary care increases the risk of major stroke causing death or serious disability.
As the diagnostic value of symptoms and signs and investigation depends on the prevalence of the disease and also on the care setting, and since the evolution of disease is often poorly understood, research on diagnosis in primary care must take place in primary care rather than hospital settings. Likewise, research on behavioural change is essential in order to understand how potentially effective interventions can most efficiently produce change at individual and population level.
Closely linked to diagnostic research is the study of prognosis, another relatively neglected field of investigation in primary care. Characterising the risk of poor outcome early in the presentation of illness offers exciting opportunities to target interventions at reducing that risk and improving the outcome, and links the study of diagnosis with other School themes and clinical topics. For example the early identification of depression in patients presenting with physical symptoms offers the potential to improve patient prognosis, a topic which draws on expertise across the School.