Table 2 Comparison of outcomes for participants with and without mental illness displaying both pooled and intervention level results for the three interventions (21 mg nicotine patch, 16 mg e-cigarette, 0 mg e-cigarette)
Outcome | Intervention | Mental Illness (n = 86, 13%) patch n = 35, 16 mg e-cigarette n = 39, 0 mg e-cigarette n = 12 | No Mental Illness (n = 571, 87%) patch n = 260 , 16 mg e-cigarette n = 250, 0 mg e-cigarette n = 61 | Difference (p value) |
|---|---|---|---|---|
Biochemically verified continuous abstinence at six months % (n) | All interventions pooled | 8% (7) | 6% (34) | 0.435 |
21 mg nicotine patch | 14% (5) | 5% (12) | 0.038a | |
16 mg e-cigarette | 5% (2) | 7% (19) | 0.750a | |
0 mg e-cigarette | 0% (0) | 5% (3) | - | |
Relapse rate at six months % (n) | All interventions pooled | 79% (68) | 67% (380) | 0.020 |
21 mg nicotine patch | 71% (25) | 67% (175) | 0.931 | |
16 mg e-cigarette | 85% (33) | 66% (164) | <0.0001 | |
0 mg e-cigarette | 83% (10) | 67% (41) | 0.239 | |
Mean reduction in CPD from baseline to six months in those that did not quit Mean (SD) | All interventions pooled | 7.7 (6.7) | 8.4 (7) | 0.508 |
21 mg nicotine patch | 5.7 (6.3) | 7.4 (7) | 0.299 | |
16 mg e-cigarette | 9.9 (7) | 9.4 (7.1) | 0.743 | |
0 mg e-cigarette | 4.7 (3.5) | 8.3 (5.9) | 0.129b | |
Percentage reduction in CPD from baseline to six months in those that did not quit Mean (SD) | All interventions pooled | 40% (30%) | 46% (33%) | 0.154 |
21 mg nicotine patch | 29% (30%) | 41% (35%) | 0.147 | |
16 mg e-cigarette | 49% (28%) | 51% (31%) | 0.660 | |
0 mg e-cigarette | 31% (26%) | 47% (28%) | 0.245b | |
Treatment compliance at three months % (n) | All interventions pooled | 39% (30) | 37% (167) | 0.757 |
21 mg nicotine patch | 20% (6) | 18% (34) | 0.752 | |
16 mg e-cigarette | 53% (19) | 51% (107) | 0.861 | |
0 mg e-cigarette | 46% (5) | 54% (26) | 0.741 | |
Adverse events rate (events/person month) | All interventions pooled | 0.078 | 0.084 | 0.666 (IRR 0.93, 95% CI 0.68-1.28) |
16 mg e-cigarette and 0 mg e-cigarette combined | 0.05 | 0.05 | 0.592 (IRR 0.89, 95% CI 0.59-1.35) | |
Acceptability of intervention at six months | ||||
‘Would recommend to a friend’ % (n) | All interventions pooled | 65% (49) | 72% (313) | 0.207 |
21 mg nicotine patch | 37% (11) | 63% (19) | 0.122 | |
16 mg e-cigarette | 83% (30) | 85% (175) | 0.752 | |
0 mg e-cigarette | 80% (8) | 89% (42) | 0.594a | |
‘Stopped as didn’t like it ’ % (n) | All interventions pooled | 34% (21/62) | 32% (108/343) | 0.711 |
21 mg nicotine patch | 41% (12/29) | 41% (169/169) | 0.956 | |
16 mg e-cigarette | 29% (7/24) | 23% (33/146) | 0.482 | |
0 mg e-cigarette | 22% (2/9) | 21% (6/28) | 1.000a | |