Table 3.
Treatment engagement and satisfaction. All items were assessed at 12-month follow-up, with the exception of the last two, satisfaction and recommendation, which were assessed at 3-month follow-up.
| Variable | Overall (n=2637) | Smokefree (n=1318) | WebQuit (n=1319) | OR, IRR, or point estimate (95% CI)1 | p-value |
|---|---|---|---|---|---|
| Number of times logged in, mean (SD) | 7.2 (22.8), median=3 | 5.1 (11.9), median=3 | 9.2 (29.9), median=3 | 1.79 (1.64, 1.96) | <0.0001 |
| High engagers (>=5 logins CBT, >=7 ACT), n (%) | 757 (29%) | 401 (30%) | 356 (27%) | 0.84 (0.91, 1.00) | 0.180 |
| Length of use of website in days, mean (SD) | 57 (84), median=21 | 57 (84), median=22 | 57 (84), median=19 | 1.00 (0.89, 1.12) | 0.988 |
| Time spent on each session (minutes), mean (SD) | 5.6 (6.1), n=2624 | 3.6 (4.1), n=1309 | 7.6 (7.1), n=1315 | 4.0 (3.6, 4.5) | <0.0001 |
| Number of web pages visited per login, mean (SD) | 4.5 (3.5), n=2624 | 3.1 (3.1), n=1309 | 5.8 (3.4), n=1315 | 2.8 (2.5, 3.0) | <0.0001 |
| Time spent on each web page (minutes), mean (SD) | 1.1 (0.9), n=2345 | 1.4 (1.2), n=1245 | 0.9 (0.6), n=1245 | -0.44 (-0.51, -0.36) | <0.0001 |
| Website was useful for quitting, n (%) | 1448 (69%), n=2099 | 719 (67%), n=1067 | 729 (71%), n=1032 | 1.16 (0.96, 1.40) | 0.227 |
| Satisfied with assigned website, n (%) | 1681 (81%), n=2068 | 846 (80%), n=1063 | 835 (83%), n=1005 | 1.26 (1.01, 1.57) | 0.180 |
| Would recommend assigned website, n (%) | 1703 (93%), n=1839 | 846 (90%), n=936 | 857 (95%), n=903 | 2.00 (1.38, 2.89) | 0.001 |
1
OR indicates odds ratio in logistic regression for binary variables, IRR indicates incident rate ratio in negative binomial regression for count variables (i.e., number of times logged in and length of use of website), and point estimate indicates difference between treatment arms for continuous variables. Results are adjusted for the three factors used in stratified randomization: daily smoking frequency, education, and gender.