Table 1.
Demographics and smoking history assessed at baseline.
| Characteristics | Overall (n = 438)a | VLNC cigarettes (n = 220)a | NNC cigarettes (n = 218)a |
|---|---|---|---|
| Age, mean (SD), y | 44.5 (11.9) | 44.0 (11.8) | 44.9 (12.0) |
| Median (IQR) | 44 (35–54) | 43 (34–54) | 44 (35–56) |
| Female, No. (%) | 225 (51.4%) | 123 (55.9%) | 102 (46.8%) |
| Race, No. (%) | |||
| White | 282 (64.4%) | 143 (65.0%) | 139 (63.8%) |
| Black | 99 (22.6%) | 45 (20.5%) | 54 (24.8%) |
| Otherb | 57 (13.0%) | 32 (14.5%) | 25 (11.5%) |
| Hispanic, No. (%) | 35 (8.0%) | 16 (7.3%) | 19 (8.7%) |
| Education, No. (%) | |||
| <High school | 22 (5.0%) | 10 (4.5%) | 12 (5.5%) |
| High school | 82 (18.7%) | 34 (15.5%) | 48 (22.0%) |
| >High school | 334 (76.3%) | 176 (80.0%) | 158 (72.5%) |
| Employment, No. (%) | |||
| Regular full-time work | 149 (34.0%) | 71 (32.3%) | 78 (35.8%) |
| Part-time work | 91 (20.8%) | 50 (22.7%) | 41 (18.8%) |
| Casual work (irregular or informal work) | 33 (7.5%) | 17 (7.7%) | 16 (7.3%) |
| Unemployed | 165 (37.7%) | 82 (37.3%) | 83 (38.1%) |
| Years of regular smoking, mean (SD) | 26.3 (12.3) | 25.8 (12.3) | 26.8 (12.3) |
| Median (IQR) | 25 (17–36) | 25 (17–35) | 26 (16–37) |
| Menthol cigarettes, No. (%) | 206 (47.0%) | 103 (46.8%) | 103 (47.2%) |
| cNRT use in the past 30 days, No. (%) | 13 (3.0%) | 6 (2.7%) | 7 (3.2%) |
| dUse any other tobacco product in the past 30 days, No. (%) | 154 (35.2%) | 75 (34.1%) | 79 (36.2%) |
| eUse any other combusted tobacco product in the past 30 days, No. (%) | 91 (20.8%) | 42 (19.1%) | 49 (22.5%) |
| fUse any non-combusted tobacco product in the past 30 days, No. (%) | 86 (19.6%) | 44 (20.0%) | 42 (19.3%) |
| Previous quit attempts for one day or longer, median (IQR) | 2 (1–3) | 2 (1–3) | 2 (1–3) |
| Cigarettes per day in Phase 1, mean (SD) | 15.7 (6.9) | 15.7 (6.8) | 15.7 (7.1) |
| Median (IQR) | 15.0 (10.1–19.7) | 15.1 (10.0–20.0) | 14.5 (10.1–19.5) |
| Cigarettes per day in Phase 2, mean (SD) | 15.5 (7.3) | 15.6 (6.9) | 15.5 (7.6) |
| Median (IQR) | 14.6 (10.0–19.8) | 14.9 (10.3–19.9) | 14.2 (9.7–19.8) |
| Carbon monoxide in Phase 1, ppm, mean (SD) | 22.6 (11.2) | 22.2 (11.4) | 23.0 (11.0) |
| Median (IQR) | 20.5 (13.5–29.5) | 20.0 (13.1–29.0) | 21.5 (14.0–29.5) |
| Carbon monoxide in Phase 2, ppm, mean (SD) | 21.4 (11.1) | 21.0 (10.9) | 21.8 (11.4) |
| Median (IQR) | 18.5 (13.5–28.5) | 18.5 (13.0–27.5) | 19.5 (13.5–28.5) |
| Total nicotine equivalents in Phase 1, nmol/mg creatinine, mean (SD) | 75.2 (47.7) | 74.9 (40.6) | 75.5 (54.0) |
| Median (IQR) | 66.9 (45.2–95.0) | 67.5 (44.9–95.6) | 66.4 (45.4–94.6) |
| Total nicotine equivalents in Phase 2, nmol/mg creatinine, mean (SD) | 78.9 (108.3) | 84.9 (146.6) | 72.9 (43.4) |
| Median (IQR) | 65.3 (43.3–93.9) | 65.6 (43.2–96.7) | 64.3 (44.0–93.0) |
| gNicotine metabolite ratio in Phase 1, mean (SD) | 0.27 (0.19) | 0.29 (0.21) | 0.26 (0.16) |
| Median (IQR) | 0.23 (0.15–0.34) | 0.24 (0.15–0.36) | 0.23 (0.15–0.32) |
| hFTND in Phase 1, mean (SD) | 4.7 (2.0) | 4.6 (2.0) | 4.8 (2.0) |
| Median (IQR) | 5 (3–6) | 5 (3–6) | 5 (3–6) |
| hFTND in Phase 2, mean (SD) | 4.8 (2.1) | 4.9 (2.1) | 4.8 (2.1) |
| Median (IQR) | 5 (3–6) | 5 (3–6) | 5 (3–6) |
| iWISDM primary dependence motives subscale score in Phase 1, mean (SD) | 4.2 (1.3) | 4.2 (1.3) | 4.2 (1.4) |
| Median (IQR) | 4.2 (3.2–5.3) | 4.1 (3.1–5.2) | 4.2 (3.3–5.3) |
| iWISDM primary dependence motives subscale score in Phase 2, mean (SD) | 4.0 (1.4) | 3.9 (1.4) | 4.1 (1.4) |
| Median (IQR) | 4.0 (2.9–5.1) | 4.0 (2.8–5.1) | 4.1 (3.0–5.2) |
| Plan to quit smoking in the next month, No. (%) | 31 (7.1%) | 19 (8.7%) | 12 (5.6%) |
Acronyms: VLNC, very low nicotine content (0.4 mg nicotine/gram tobacco); NNC, normal nicotine content (15.8 mg nicotine/gram tobacco); SD, Standard Deviation; IQR, Interquartile Range.
Note: Gender was determined by self-reported response to the question, “What is your gender?” A higher percent of females was observed for the VLNC vs. NNC condition (n = 123 [55.9%] vs. n = 102 [46.8%]) as well as higher percent who had higher than high school level of education (n = 176 [80.0%] vs. n = 158 [72.5%]).
The sample size of the VLNC and NNC groups was 220 and 218, respectively, for all characteristics except for total nicotine equivalents in Phase 2 (219 and 217), NMR in Phase 1 (210 and 211), plan to quit smoking in the next month (219 and 216).
Other races include: American India/Alaska Native, Asian, Native Hawaiian, or Other Pacific Islander, and more than one race.
Nicotine replacement therapies (i.e., medicinal nicotine products) include patch, gum, and lozenge.
Other products include cigar, cigarillo, little cigar, pipe, bidis, hookah, marijuana blunts, or spliffs, chewing tobacco, moist snuff, snus, e-cig, dissolvable tobacco, and nicotine pouches.
Other combusted products include cigar, cigarillo, little cigar, pipe, bidis, hookah, and marijuana blunts or spliffs.
Noncombusted products include chewing tobacco, moist snuff, snus, e-cig, dissolvable tobacco, and nicotine pouches.
Nicotine metabolite ratio (free 3′-hydroxycotinine:free cotinine; NMR) reflects the rate of nicotine metabolism that was measured in saliva.
Fagerström Test for Nicotine Dependence; scale ranges from 0 to 10 with higher scores indicating greater nicotine dependence.
Wisconsin Index of Smoking Dependence Motives (WISDM) Primary Dependence Motives scale score ranges from 1 to 7, with higher scores indicating greater smoking dependence.