Liebetrau G
Z Erkr Atmungsorgane. 1981;156(3):225-31.
Within the drainage area of the Central Hospital for Diseases of Heart and Lungs at Bad Berka/ GDR 337 persons (210 male, 127 female) with alveolitis and pulmonary fibrosis were observed during a period of 17 years (1963-1979). The average-age of the patient was 43.5 (11-70) years. The mean duration of the illness was to 9 years. The time elapsing up to the confirmation of the diagnosis amounts to approximately 4.35 years. The yearly incidence of alveolitis and pulmonary fibrosis are estimated at one case among 40,000 people. During the last years more attention has been given to these diseases but there seems to be also a true increase of the frequency of these conditions.