1. Department of Pharmacoepidemiology; Faculty of Medicine; University of Tokyo; Tokyo; Japan
2. Department of Respiratory Medicine; Japan Labor Health and Welfare Organization; Okayama Rosai Hospital; Okayama; Japan
3. Department of Respiratory Medicine; National Hospital Organization Yamaguchi - Ube Medical Center; Yamaguchi; Japan
4. Department of Radiology; Okayama University Hospital; Okayama; Japan
5. Division of Biostatistics; Graduate School of Medicine; Tohoku University; Miyagi; Japan
6. NPO (Nonprofit Organization) Drug Safety Research Unit Japan; Tokyo; Japan