In total, 6,108 current smokers in PLCO met our criteria for inclusion in this study (Table 1). Over half (62%) of smokers reported smoking their first morning cigarette within 30 minutes of waking, with 16% reporting smoking within 5 minutes of waking. Given that the larger PLCO study was comprised mostly of non-Hispanic whites, our study sample of current smokers is also largely homogenous in terms of race; these current smokers were comprised mostly of non-Hispanic whites (89%). The mean age at baseline was 69, and level of education varied widely; approximately one-third of participants achieved no greater than a high school diploma, and one-quarter had at least a college degree. On average, individuals reported a smoking history of 50 years and accumulated 44 pack-years; at baseline most (80%) of smokers reported a usual smoking intensity of at least 6 cigarettes/day. Most of these current smokers (63%) initiated smoking at the age of 17 or later. A small portion of current smokers (n = 77, 1%) reported a history of lung cancer.
