Table 3.
Effect of transtheoretical model intervention relative to control group on smoking status for whole sample and subgroups (baseline smokers and baseline non-smokers)
| Characteristics of sample | Unadjusted analysis
|
Odds ratio (95% CI)
|
|||||
|---|---|---|---|---|---|---|---|
| % smokers in control group | % smokers in intervention group | % difference (95% CI) | Unadjusted | Adjusted for baseline smoking status | Fully adjusted | ||
| All participants | |||||||
| All participants in comparison, those lost to follow up counted as smokers | 26.80 | 27.69 | 0.89 (−2.89 to 5.02) | 1.05 (0.86 to 1.28) | 1.08 (0.87 to 1.32) | 1.02 (0.83 to 1.25) | |
| All participants in comparison, those lost to follow up counted as non-smokers | 15.49 | 16.64 | 1.16 (−1.60 to 4.34) | 1.09 (0.88 to 1.35) | 1.14 (0.92 to 1.41) | 1.10 (0.89 to 1.37) | |
| All participants in comparison, those lost to follow up assumed to have same smoking habit as at baseline. (Unknown baseline counted as smokers) | 18.32 | 19.56 | 1.24 (−1.74 to 4.62) | 1.08 (0.89 to 1.33) | 1.16 (0.96 to 1.42) | 1.14 (0.94 to 1.39) | |
| All participants in comparison, those lost to follow up assumed to have same smoking habit as at baseline. (Unknown baseline counted as non-smokers) | 18.24 | 19.45 | 1.21 (−1.76 to 4.57) | 1.08 (0.88 to 1.32) | 1.16 (0.95 to 1.42) | 1.14 (0.93 to 1.39) | |
| Only those participants followed up and whose smoking status was known included | 17.48 | 18.76 | 1.28 (−1.87 to 4.89) | 1.09 (0.87 to 1.36) | 1.16 (0.93 to 1.43) | 1.12 (0.89 to 1.39) | |
| Only those participants followed up and whose smoking status was known and whose answers were completely consistent included | 17.48 | 19.06 | 1.58 (−1.58 to 5.2) | 1.11 (0.89 to 1.38) | 1.19 (0.96 to 1.46) | 1.14 (0.92 to 1.42) | |
| Only regular smokers at baseline | |||||||
| All participants in comparison, those lost to follow up counted as smokers | 80.30 | 79.71 | −0.59 (−5.80 to 3.78) | 0.96 (0.72 to 1.30) | Only smokers included | 0.96 (0.69 to 1.32) | |
| All participants in comparison, those lost to follow up counted as non-smokers | 59.00 | 57.74 | −1.26 (−8.35 to 5.52) | 0.95 (0.71 to 1.26) | Only smokers included | 0.91 (0.71 to 1.18) | |
| Only those participants followed up and whose smoking status was known included | 74.93 | 73.94 | −0.99 (−7.34 to 4.49) | 0.95 (0.70 to 1.29) | Only smokers included | 0.92 (0.66 to 1.29) | |
| Only those participants followed up and whose smoking status was known and whose answers were completely consistent included | 77.66 | 75.99 | −1.67 (−8.14 to 3.79) | 0.91 (0.66 to 1.26) | Only smokers included | 0.89 (0.62 to 1.27) | |
| Only participants not known to be regular smokers at baseline | |||||||
| All participants in comparison, those lost to follow up counted as smokers | 18.95 | 20.29 | 1.34 (−1.95 to 5.09) | 1.09 (0.88 to 1.35) | 1.09 (0.87 to 1.37) | 1.02 (0.82 to 1.27) | |
| All participants in comparison, those lost to follow up counted as non-smokers | 9.30 | 11.01 | 1.70 (−0.38 to 4.2) | 1.21 (0.95 to 1.52) | 1.22 (0.95 to 1.56) | 1.17 (0.91 to 1.51) | |
| All participants in comparison, those lost to follow up assumed to have same smoking habit as at baseline. (Unknown baseline counted as smokers) | 9.38 | 11.14 | 1.75 (−0.35 to 4.28) | 1.21 (0.96 to 1.53) | 1.22 (0.95 to 1.56) | 1.18 (0.93 to 1.52) | |
| All participants in comparison, those lost to follow up assumed to have same smoking habit as at baseline. (Unknown baseline counted as non-smokers) | 9.30 | 11.01 | 1.70 (−0.38 to 4.2) | 1.21 (0.95 to 1.52) | 1.22 (0.95 to 1.56) | 1.17 (0.91 to 1.51) | |
| Only those participants followed up and whose smoking status was known included | 10.32 | 12.16 | 1.84 (−0.51 to 4.66) | 1.20 (0.95 to 1.53) | 1.21 (0.94 to 1.56) | 1.16 (0.89 to 1.50) | |
| Only those participants followed up and whose smoking status was known and whose answers were completely consistent included | 10.21 | 12.30 | 2.09 (−0.25 to 4.89) | 1.23 (0.97 to 1.56) | 1.26 (0.98 to 1.61) | 1.20 (0.93 to 1.55) | |