Table 2.
Smoking cessation and engagement with cessation program at 2-month follow-up. Results are adjusted for 2 stratification factors (heavy smoking and education). Cessation results are adjusted for baseline self-efficacy.
| Outcome variable | Overall (N=398) | Control (n=199) | Intervention (n=199) | ORa/IRRb/estimatec (95% CI) | P value | |
| Engagement with SmartQuit app | ||||||
| At least one log-in, n (%) | 287 (72) | 151 (76) | 136 (68) | 0.69 (0.44 to 1.07) | .10 | |
| Number of log-ins, mean (SD) | 20.54 (34.16) | 21.61 (37.74) | 19.46 (30.20) | 0.90 (0.61 to 1.21) | .38 | |
| Number of days used, mean (SD) | 11.96 (16.90) | 11.73 (16.14) | 12.19 (17.64) | 1.00 (0.72 to 1.37) | .97 | |
| Completion certificate, n (%) | 119 (30) | 58 (30) | 61 (31) | 1.08 (0.70 to 1.65) | .74 | |
| Number of Acceptance and Commitment Therapyd exercises completed, mean (SD) | 11.92 (19.93) | 11.74 (17.03) | 12.12 (22.50) | 0.95 (0.69 to 1.32) | .77 | |
| Smoking cessation | ||||||
| 30-day PPAe, complete case, n (%) | 56 (15) | 25 (13) | 31 (17) | 1.64 (0.90 to 3.00) | .10 | |
| 30-day PPA, missing=smoking, n (%) | 56 (14) | 25 (12) | 31 (16) | 1.54 (0.86 to 2.76) | .15 | |
| Change in cigarettes per day, mean (SD) | −3.81 (7.88) | −3.01 (8.37) | −4.66 (7.27) | −1.90 (−4.00 to 0.18) | .07 | |
| Change in Fagerström Test for Nicotine Dependence, mean (SD) | −1.33 (1.92) | −1.11 (1.73) | −1.55 (2.08) | −0.53 (−1.07 to 0.01) | .05 | |
aOR: odds ratio in logistic regression for binary variables.
bIRR: incident rate ratio in negative binomial regression for count variables (ie, number of times logged in and length of use of website).
cPoint estimate: difference between arms for continuous variables.
dModules inside SmartQuit.
ePPA: point prevalence abstinence.