Comparative analysis of connective tissue disease-associated interstitial lung disease and idiopathic pulmonary fibrosis from a tertiary care centre in Pakistan

Objective: To compare the characteristics of connective tissue disease-associated interstitial lung disease with idiopathic pulmonary fibrosis at a tertiary care hospital. Methods: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised demographical, clinical and radiological data of patients with interstitial lung disease between October 2016 and October 2017 accessed through the outpatient data registry. Data was compared in terms of characteristics and key features of patients with connective tissue disease-associated interstitial lung disease with those of idiopathic pulmonary fibrosis. Statistical analysis was done using STATA 12. Results: Of the 184 patients, 52(29.3%) had connective tissue disease-associated interstitial lung disease and 62(35%) had idiopathic pulmonary fibrosis. The most prevalent conditions among connective tissue disease-associated interstitial lung disease patients were rheumatoid arthritis 22(42.3%) and scleroderma 13(25%). Compared to patients with idiopathic pulmonary fibrosis, those with connective tissue disease-associated interstitial lung disease were predominantly younger (p<0.001) and female (p<0.001). History of gastroesophageal reflux disease was also significantly lower in connective tissue disease-associated interstitial lung disease (p=0.05). Conclusion: Connective tissue disease-associated interstitial lung disease patients were found to be younger and predominantly female compared to patients of idiopathic pulmonary fibrosis.