Choi WI, et al. - Given the risk factors related to the development of interstitial lung disease might be important to understand the pathogenetic mechanism of interstitial lung disease as well as prevention, researchers investigated independent risk factors of interstitial lung disease development in this retrospective cohort study with nationwide population-based 9-year longitudinal data. The included subjects were > 40 years of age at cohort entry and provided a history of cigarette smoking. The factors that showed a significant link with interstitial lung disease development included smoking, hepatitis C, history of tuberculosis, history of pneumonia, chronic obstructive pulmonary disease, male sex, and older age.