Report on the incidence of interstitial lung diseases in Spain.

BACKGROUND AND AIM OF THE WORK: Almost no epidemiological data are available on a worldwide basis on the prevalence, incidence or relative frequency of interstitial lung diseases (ILD). We report the results of a registration of ILD by 23 centers of pulmonary medicine in Spain over one year (from October 2000 to September 2001).

METHODS: A standardized questionnaire was sent to the centers, together with guidelines for classification and diagnostic evaluation. This questionnaire included questions about the explorations performed to establish the diagnosis.

RESULTS: A total of 511 cases were registered. The mean age of the patients was 61 +/- 0.7 (x +/- SEM) yrs. The male to female ratio was 1.2:1. The estimated incidence of ILD was 7.6 per 100,000/year. The most frequent disease was idiopathic pulmonary fibrosis (38.6%), followed in decreasing order by sarcoidosis (14.9%), cryptogenic organizing pneumonia (10.4%), ILD associated with collagen vascular diseases (9.9%) and hypersensitivity pneumonitis (6.6%). In 5.1% of cases ILD was unclassified. HRCT scan was performed in 91.9% of cases, bronchoalveolar lavage in 67.9%, transbronchial lung biopsy in 59.9%, and surgical lung biopsy in 22.7%.

CONCLUSIONS: This registration provides interesting information on the occurrence of ILD in Spain and on the procedures used to establish the diagnosis.