There is a rare condition causing scarring of the lungs termed interstitial lung disease. This comprises a group of conditions which can be divided into separate diseases. The aim of this study is compare a group of patients (the cases) with 2 types of this disease (fibrotic non-specific interstitial pneumonia (NSIP) and idiopathic pulmonary fibrosis (IPF)) with patients without the disease. The study will look at the 2 groups and their exposures to factors such as medications, smoking, previous jobs, previous medical problems and specifically heart disease and any operations or procedures involving the heart. There have been previous studies showing a link between heart disease and scarring of the lungs. This study will look at whether this association is stronger in one or the other type of lung scarring diseases.

Inclusion Criteria:

• idiopathic fibrotic lung disease

Exclusion Criteria:

• non idiopathic fibrotic lung disease

Cases - patients with IPF or UIP. Controls - hospital clinic attenders.