Table 2. Biochemically Confirmed 7-Day Point Prevalence Abstinence Rates at Weeks 23 and 52 and Prolonged Abstinence Rates by Treatment Main Effects of Medication Type and Duration.
| Abstinent, No. (%)a | Main effects | Site-adjusted OR (95% Cl)c | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Medication type | Medication duration | Medication type | Medication duration | ||||||||
| Varenicline monotherapy (n = 626) |
Varenicline plus nicotine patch (n = 625) |
12 wk (n = 629) | 24 wk (n = 622) | Abstinence RD for monotherapy vs combination therapy, % (95% CI)b |
P value | Abstinence RD for 12 wk vs 24 wk, % (95% CI)b |
P value | Medication type of monotherapy vs combination therapy | Medication duration of 12 wk vs 24 wk | Medication type × medication duration interaction | |
| 7-d point prevalence abstinence d | |||||||||||
| At 23 wk | 136 (21.7) | 156 (25.0) | 140 (22.3) | 152 (24.4) | −3.2 (−7.9 to 1.5) | .18 | −2.2 (−6.9 to 2.5) | .37 | 1.1 (0.96 to 1.2) | 1.1 (0.9 to 1.2) | 1.0 (0.9 to 1.2) |
| At 52 wke | 155 (24.8) | 152 (24.3) | 153 (24.3) | 154 (24.8) | 0.4 (−4.3 to 5.2) | .85 | −0.4 (−5.2 to 4.3) | .86 | 1.0 (0.9 to 1.1) | 1.0 (0.9 to 1.2) | 1.0 (0.9 to 1.2) |
| Prolonged abstinence | |||||||||||
| At 23 wkf | 137 (21.9) | 139 (22.2) | 138 (21.9) | 138 (22.2) | −0.4 (−5.0 to 4.2) | .90 | −0.3 (−4.8 to 4.4) | .93 | 1.0 (0.9 to 1.2) | 1.0 (0.9 to 1.2) | 1.1 (0.9 to 1.2) |
| At 52 wkg | 101 (16.1) | 104 (16.6) | 102 (16.2) | 103 (16.6) | −0.5 (−4.6 to 3.6) | .83 | −0.3 (−4.5 to 3.8) | .89 | 1.0 (0.9 to 1.2) | 1.0 (0.9 to 1.2) | 1.1 (0.96 to 1.3) |
Abbreviations: OR, odds ratio; RD, risk difference.
a
Missing values were imputed.
b
Tested via SAS Proc Freq.
c
Based on a logistic regression analysis controlling for site.
d
Biochemically confirmed via exhaled carbon monoxide testing (level of ≤5 ppm).
e
This is the primary outcome.
f
No smoking from day 7 to week 23 after the target quit day.
g
No smoking from day 7 to week 52 after the target quit day.