Characteristics of studies included in the meta-analysis of aspirin use and risk of lung cancer.

∗: Represents ‘Post-trial of Randomized Controlled Trial’.£: McCormack VA et.al investigated 8 studies from ILCCO that had data on aspirin or NSAID use prior to diagnosis, including 7 case-control studies and 1 cohort study.Ф: In this cohort, ‘total average use over the 10 years’ was estimated by multiplying usual days per week by the number of years, using the midpoints of the categories, divided by 10.Я: Reference defined as “no self-reported use or prescriptions more than 1 year before index date”.Adjustment: 1. Age, 2. Education, 3. Fruit consumption, 4. Vegetable consumption, 5. Housing type, 6. History of cancer in 1st degree relative, 7. Sex, 8. Race, 9. Body mass index, 10. Smoking status, 11. Pack-years, 12. History of chronic obstructive pulmonary disease, 13. History of ulcer, migraine or chronic headache, osteoarthritis or chronic joint pain, rheumatoid arthritis, coronary artery disease, 14. Use of other NSAIDs, 15. Year of birth, 16. Study, 17. Study region, 18. Interview year, 19. Alcohol use, 20. Physical activity level, 21. Use of hormone replacement therapy, 22. History of mammography or colorectal endoscopy, 23. History of PSA testing, 24. Diabetes, 25. Hypertension, 26. Calendar year.Abbreviation: VITAL: VITamins And Lifestyle cohort, RCT: Randomized controlled study, C: case-control study, H: Hospital-based, P: Population-based, d: day, Wk: week, y: year, vs: versus, F: female, M: male, RR: relative risk, OR: odds ratio, ILCCO: International Lung Cancer Consortium, SCLC: Small cell lung cancer, CPS II NC: Cancer Prevention Study II Nutrition Cohort, IWHS: Iowa Women’s Health Study, HPFS: The Health Professionals Follow-Up Study, NHEFS: NHANES I Epidemiologic Follow-up Studies, NHANES: National Health and Nutrition Examination Survey.Characteristics of studies included in the meta-analysis of aspirin use and risk of lung cancer.