Key sample characteristics (n=83) at each observed week 6 cotinine level
| Natural log of week 6 cotinine | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
| Sample size | 2 | 0 | 1 | 2 | 16 | 21 | 24 | 6 | 5 | 6 |
| Percentage in 2013 study | 100 | 100 | 0 | 56.3 | 47.6 | 75.0 | 83.3 | 100 | 66.7 | |
| Percentage smoking 0.09 mg yield | 0 | 100 | 0 | 25.0 | 33.3 | 70.8 | 66.7 | 60.0 | 66.7 | |
| Study CPD (week 6) | 0 | 2.6 | 7.9 | 8.7 | 16.9 | 17.8 | 17.2 | 11.4 | 18.0 | |
| Non-study CPD (week 6) | 0 | 0 | 0 | 0 | 0 | 0.2 | 0.7 | 4.2 | 6.7 | |
| Percentage non-compliant | 0 | 100 | 0 | 12.5 | 14.3 | 33.3 | 50.0 | 80.0 | 66.7 | |
| Percentage abstinent (week 12) | 100 | 100 | 100 | 81.3 | 57.1 | 47.1 | 16.7 | 20 | 16.7 | |
Participants who completed the week 6 visit (n=83) were divided into 10 groups based on their natural log of week 6 cotinine levels (binned by rounding to the nearest whole number). Each column in the table provides descriptive statistics (means or proportions) of study outcomes for individuals who had the specified cotinine level (refer to sample size for n). The data provide qualitative support for factors that may explain the linear relation between cotinine level and quit rates. Of note, only two participants stopped smoking the very low nicotine content (VLNC) cigarettes before week 6 because they had quit smoking all cigarettes. Furthermore, the number of VLNC cigarettes appeared to differentiate individuals at cotinine level 4 from those at cotinine level 5, whereas non-compliance and a higher nicotine yield of the study cigarette (0.05 mg vs 0.09 mg) appeared to differentiate individuals at cotinine level 5 from those at cotinine level 6.
CPD, cigarettes per day.