Types of interstitial lung diseases and comparison on survival of idiopathic and secondary types in a tertiary care setting of Sri Lanka

Objectives The interstitial lung diseases (ILDs),heterogeneous. Our objectives were to identify the sub categories of ILD s, find secondary causes and to compare survival. Methods All the patients who were diagnosed to have ILD in the respiratory unit Kandy from May 2009 to April 2011were recruited. All were investigated for secondary causes. They were classified into sub classes of idiopathic or secondary. Diagnosis and treatment was according to the ERS\ATS consensus guide lines 2002. Survival of these patients during the two year period was recorded. The two groups were compared using Fisher9s Exact test. Results There were 41 patients with interstitial lung disease. Twenty one (51.3%) were idiopathic and 20 (49.7%) had secondary causes. There were 6 (27%) males with an average age of 71 years ,and 15 (73%) females with an average age of 61 in idiopathic group. In the secondary group there were 6 (30%) males with average age of 53 years and 14 (70%) females with average age of 54 years .Secondary causes identified were , rheumatoid arthritis (n=8, 19.5%), 7.3%),systemic sclerosis (n=2, 4.8%),%), polymyositis (n=1, 2.4%) , Hypersensitivity pneumonitis(n=2, 4.8%), amiadarone lung (n=1, 2.4%), and sarcoidosis (n=1, 2.4%) silicosis (n=3, berylliosis (n=1, 2.4%), Idiopathic group consisted of 10 (45%) with UIP and 8 (36%) with NSIP. Three had other varieties. During the 2 years. 5 (23.8%) of idiopathic group died. One (5%) of secondary group died [FET, p = 0.0002]. Conclusions 50% of the patients with ILD had secondary causes. Patients with idiopathic diseases had a poor survival compared to the patients with secondary diseases.