Epidemiology of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is only one of a large number of diffuse parenchymal lung diseases characterized by parenchymal inflammation and fibrosis without any known cause (1). Although the term idiopathic pulmonary fibrosis has been in use for several decades in the United States, other terms such as cryptogenic fibrosing alveolitis and idiopathic interstitial pneumonia have been used predominately in other countries. These varying terms and evolving criteria for the diagnosis of the disease have contributed to confusion and controversy for both clinicians and investigators. In an attempt to resolve these problems, a multidisciplinary panel of experts from the American Thoracic Society and European Respiratory Society has developed consensus statements on the diagnosis and management (1) and classification of the idiopathic interstitial pneumonias, including criteria for IPF (2).