P-33 Risk Factors of Unclassifiable Interstitial Lung Disease: A 9-Year Nationwide Population-Based Study = P-33 Risk Factors of Unclassifiable Interstitial Lung Disease: A 9-Year Nationwide Population-Based Study

다국어 초록 (Multilingual Abstract)

Background: Unclassified idiopathic interstitial lung diseases are categorized by inadequate clinical, radiologic, or pathologic data and major discordance between clinical, radiologic, and pathologic findings. In the community setting, lung biopsy was not easily performed the majority of patients with interstitial lung diseases (ILDs). We aimed at define clinical characteristics of patients with ILDs by radiologic findings without a biopsy. Methods: National registry data were collected from the Korean National Health Insurance Research Database. Patients diagnosed with ILD between 2002 and 2004 were excluded. We also selected subjects self-reported a history of cigarette smoking, more than 40 years old at the entry of cohort. Finally, 312,519 subjects were tracked until 2013. Cox proportional hazard regressions were used to calculate the incidence rate for ILD development with potential confounders. Results: ILD developed 1,972 cases among 312,519 subjects during 9 years (71 per 10,000 person-year). Among ILD cases 456 (22.7%) of ILD were reclassified as IPF at the end of follow-up. Following variables had significantly associated with ILD development such as smoking (hazard ratio [HR] 1.27; 95% confidence interval [CI], 1.14- 1.42), Hepatitis C (HR, 1.61; 95% CI, 1.11-2.36), history of tuberculosis (HR, 1.50; 95% CI, 1.14-1.98), history of pneumonia (HR, 1.53; 95% CI, 1.24-1.88), and COPD (HR, 1.80; 95% CI, 1.56-2.08). Conclusions: Smoking, Hepatitis C, history of tuberculosis, history of pneumonia and COPD were significantly associated with ILD development.