Epidemiology

The precise global incidence and prevalence of IPF remain unclear, with incidence estimates ranging from 1.2 to 9.6 per 100 000 person-years. In this chapter, we summarise studies of the incidence and prevalence of IPF before discussing risk factors and comorbid illnesses. Many studies have evaluated risk factors for IPF including smoking, environmental factors, gastro-oesophageal reflux, diabetes mellitus, clotting dysfunction and genetics. Through epidemiological studies there has been considerable progress in identifying factors that are likely to be aetiologically important, and further research into the causes and progression of IPF is vital to identify biomarkers and targets for treatments. The most common cause of death in people with IPF is respiratory failure secondary to lung fibrosis. However, the incidence of comorbidities such as cardiovascular disease and lung cancer is increased in people with IPF. The association between these comorbidities may be important in helping understand the pathogenesis of IPF and the need for a holistic approach to the care of patients.