Table 2.
Improvements in treatment-related variables for the first to second half of the participants enrolled (N=16).
| Postquit date and treatment-related variables | All participants | First half enrolled | Last half enrolled | P valuea,b | |
| Weeks 1-4, median (range) | |||||
|
|
Days carbon monoxide-confirmed abstinentc (out of 21) | 5.0 (0.0-20.0) | 3.0 (0.0-11.0) | 8.5 (1.0-20.0) | .07 |
|
|
Completed smoking status assessmentsc (out of 21) | 16.0 (1.0-21.0) | 10.0 (1.0-20.0) | 19.5 (14.0-21.0) | .02 |
|
|
Telephone counseling sessions completed (out of 5) | 5.0 (1.0-5.0) | 4.5 (1.0-5.0) | 5.0 (4.0-5.0) | .20 |
|
|
Abstinence-contingent incentives earned (US $; up to US $150) | 28.0 (0.0-135.0) | 20.0 (0.0-72.0) | 60.0 (16.0-167.0) | .05 |
| Week 8, median (range) | |||||
|
|
Days carbon monoxide-confirmed abstinentd (out of 5) | 0.0 (0.0-4.0) | 0.0 (0.0-1.0) | 1.0 (0.0-4.0) | .13 |
|
|
Completed smoking status assessmentsd (out of 5) | 3.0 (0.0-5.0) | 2.0 (0.0-5.0) | 4.0 (0.0-5.0) | .16 |
|
|
Abstinence-contingent incentives earned (US $; up to US $50) | 0.0 (0.0-24.0) | 0.0 (0.0-8.0) | 4.0 (0.0-24.0) | .28 |
| Week 12 | |||||
|
|
Days carbon monoxide-confirmed abstinentd (out of 5), median (range) | 0.0 (0.0-3.0) | 0.0 (0.0-1.0) | 0.0 (0.0-3.0) | .65 |
|
|
Completed smoking status assessmentsd (out of 5), median (range) | 1.50 (0.0-4.0) | 1.50 (0.0-3.0) | 1.50 (0.0-4.0) | .57 |
|
|
Weeks of NRTe (out of 12), median (range) | 10.0 (2.0-12.0) | 10.0 (2.0-12.0) | 10.0 (2.0-12.0) | .86 |
|
|
Abstinence-contingent incentives earned (US $; up to US $50), median (range) | 0.0 (0.0-16.0) | 0.0 (0.0-16.0) | 0.0 (0.0-16.0) | .51 |
|
|
Attended in-person follow-up visit, n (%) | 13.0 (81.0) | 6.0 (75.0) | 7.0 (88.0) | .52 |
|
|
Carbon monoxide-confirmed 7-day point prevalence abstinence, n (%) | 3.0 (19.0) | 1.0 (13.0) | 2.0 (25.0) | .52 |
| Week 26 | |||||
|
|
Attended in-person follow-up visit, n (%) | 11.0 (69.0) | 5.0 (63.0) | 6.0 (75.0) | .59 |
|
|
Carbon monoxide-confirmed 7-day point prevalence abstinence, n (%) | 2.0 (13.0) | 0.0 (0.0) | 2.0 (25.0) | .13 |
aMann-Whitney U tests were conducted for continuous variables, and chi-square analyses were conducted for dichotomous variables.
bP values reflect the difference between the first 8 participants and the last 8 participants enrolled in the study.
cSelf-reported and carbon monoxide–confirmed abstinence were assessed on the day after quitting and on 5 days per week for 4 weeks after the scheduled quit attempt (21 total assessments).
dSmoking status was additionally assessed 5 times per week during weeks 8 and 12 postquit date. Assessments where participants self-reported smoking but did not complete the iCO assessment were not considered missing.
eNRT: nicotine replacement therapy.