Eustachian tubes open and close to prevent fluid or air pressure from building inside the ear
Nicotine is one of the reasons that people smoke, along with other factors, such as taste and ritual
The study combined and standardized data from 1,518,028 individuals across 112 cohort studies in 34 countries and 8 geographic regions (North America, Latin America, Western Europe, Eastern Europe and Russia, North Africa, the Middle East, sub-Saharan Africa, Asia, and Australia)
Lung specimens were obtained from the International Institute for the Advancement of Medicine (Edison, NJ) and the Donor Alliance of Colorado
Sensitivity Results Supplemental Table 2 in the online supplement shows the distribution of cigarette pack years and cigarette smoking duration, highlighting the larger range for cigarette pack years as compared to smoking duration that was entered into each respective model