Table 3.
Outcomes at 4 weeks after quit date.
| Outcome and group | Treatment | Control | Chi-square test (df) | t test (df) | P value | RRa (95% CI) | Group difference (95% CI) | ||
| Primary outcome |
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7-day abstinence, n (%) |
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ITTb (n=530) | 118 (44.5) | 75 (29.3) | 13.7 (1) | N/Ac | <.001 | 1.55 (1.23 to 1.96) | N/A |
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PPd,e (n=456) | 118 (52.4) | 75 (32.5) | 17.8 (1) | N/A | <.001 | 1.62 (1.29 to 2.02) | N/A | |
| Secondary outcomes |
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14-day abstinence, n (%) |
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ITT (n=530) | 91 (34.3) | 62 (23.3) | 7.2 (1) | N/A | .007 | 1.47 (1.12 to 1.93) | N/A |
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PPe (n=456) | 91 (40.4) | 61 (26.4) | 9.5 (1) | N/A | .002 | 1.53 (1.17 to 2.0) | N/A | |
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Any additional quit attempt beyond initial quit date, n (%) |
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ITT (n=530) | 68 (25.6) | 86 (32.5) | 2.6 (1) | N/A | .10 | 0.79 (0.6 to 1.03) | N/A |
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PPf (n=443) | 68 (30.9) | 86 (38.6) | 2.5 (1) | N/A | .11 | 0.8 (0.62 to 1.04) | N/A | |
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Knowledge improved, n (%)g |
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ITT (n=530) | 104 (39.2) | 77 (29.1) | 5.7 (1) | N/A | .02 | 1.35 (1.06 to 1.72) | N/A |
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PPf (n=443) | 104 (47.3) | 76 (34.1) | 7.5 (1) | N/A | .006 | 1.39 (1.1 to 1.75) | N/A | |
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Confidence improved, n (%)g |
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ITT (n=530) | 84 (31.6) | 65 (24.5) | 3.0 (1) | N/A | .08 | 1.29 (0.98 to 1.7) | N/A |
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PPf (n=443) | 84 (38.2) | 64 (28.7) | 4.1 (1) | N/A | .04 | 1.33 (1.02 to 1.74) | N/A | |
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Attitude improved, n (%)g |
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ITT (n=530) | 100 (37.7) | 103 (38.8) | 0.0 (1) | N/A | .86 | 0.97 (0.78 to 1.21) | N/A |
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PPf (n=443) | 100 (45.5) | 101 (45.3) | 0.0 (1) | N/A | >.99 | 1 (0.82 to 1.23) | N/A | |
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Change in SASEQh (24-point scale), mean (SD) |
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ITT (n=530) | 4.2 (7.0) | 3.1 (6.7) | N/A | 1.7 (527) | .09 | N/A | 1.0 (–0.161 to 2.17) |
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PPi (n=440) | 5.1 (7.4) | 3.6 (7.0) | N/A | 2.0 (436) | .04 | N/A | 1.4 (0.052 to 2.75) | |
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Change in WEMWBSj (56-point scale), mean (SD) |
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ITT (n=530) | 0.7 (7.0) | 0.6 (6.5) | N/A | 0.2 (525) | .83 | N/A | 0.13 (–1.02 to 1.28) |
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PPi (n=440) | 0.9 (7.7) | 0.8 (7.0) | N/A | 0.2 (433) | .88 | N/A | 0.11 (–1.26 to 1.48) | |
| Unregistered outcomes |
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Cigarettes per day in those that failed to quit, mean (SD) |
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PP (n=222) | 7.9 (6.4) | 7.5 (5.9) | N/A | 0.5 (180) | .65 | N/A | 0.39 (–1.29 to 2.06) |
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% reduction in cigarettes per day in those that failed to quit, mean (SD) |
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PP (n=222) | 48.1 (28.2) | 48.9 (29.3) | N/A | –0.2 (194) | .83 | N/A | –0.83 (–8.57 to 6.91 |
aRR: risk ratio.
bITT: intention to treat.
cN/A: not applicable.
dPP: per protocol.
eTreatment: n=225; control: n=231.
fTreatment: n=220; control: n=223.
gAs measured by percentage of participants reporting “strongly agree.”
hSASEQ: Smoking Abstinence Self-efficacy Questionnaire.
iTreatment: n=219; control: n=221.
jWEMWBS: Warwick-Edinburgh Mental Well-being Scale.