Fixed effects logistic regression model of smoking status (current vs ex and never combined)
| 1: family and LFS | 2: 1 plus household income | 3: 1 plus personal income | 4: 3 plus deprivation | 5a: 4 restricted to <25 years* | 5b: 4 restricted to 25+ years* | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model Variable | OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI |
| Family status | ||||||||||||
| Not in family nucleus | 1.80 | 1.29 to 2.50 | 1.83 | 1.31 to 2.55 | 1.77 | 1.27 to 2.47 | 1.77 | 1.26 to 2.47 | 1.56 | 0.85 to 2.89 | 1.63 | 1.07 to 2.49 |
| Sole parent | 0.98 | 0.64 to 1.49 | 0.98 | 0.64 to 1.50 | 0.99 | 0.65 to 1.51 | 1.03 | 0.68 to 1.58 | 0.79 | 0.39 to 1.62 | 1.58 | 0.90 to 2.80 |
| Couple with children | 0.63 | 0.46 to 0.87 | 0.63 | 0.46 to 0.87 | 0.68 | 0.49 to 0.94 | 0.73 | 0.53 to 1.02 | 0.54 | 0.29 to 1.00 | 1.03 | 0.68 to 1.56 |
| Couple only (ref.) | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| p Value† | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.063 | ||||||
| Labour force status (LFS) | ||||||||||||
| Inactive | 0.60 | 0.47 to 0.76 | 0.60 | 0.47 to 0.77 | 0.70 | 0.54 to 0.90 | 0.68 | 0.53 to 0.88 | 0.93 | 0.60 to 1.45 | 0.67 | 0.48 to 0.94 |
| Unemployed | 1.58 | 0.95 to 2.64 | 1.59 | 0.95 to 2.65 | 1.75 | 1.04 to 2.93 | 1.57 | 0.92 to 2.66 | 1.71 | 0.76 to 3.84 | 1.42 | 0.68 to 2.96 |
| Employed (ref.) | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| p Value† | <0.001 | <0.001 | <0.001 | 0.001 | 0.353 | 0.026 | ||||||
| Log household income | 1.06 | 0.94 to 1.20 | ||||||||||
| p Value† | 0.314 | |||||||||||
| Log personal income | 1.23 | 1.12 to 1.36 | 1.22 | 1.11 to 1.35 | 1.42 | 1.16 to 1.74 | 0.99 | 0.87 to 1.11 | ||||
| p Value† | <0.001 | <0.001 | <0.001 | 0.726 | ||||||||
| Individual deprivation‡ | ||||||||||||
| Nil | 1 | 1 | 1 | |||||||||
| 1 to 2 | 1.18 | 0.97 to 1.44 | 1.27 | 0.87 to 1.85 | 1.01 | 0.80 to 1.29 | ||||||
| 3 or more | 1.60 | 1.12 to 2.27 | 1.63 | 0.85 to 3.12 | 1.37 | 0.89 to 2.10 | ||||||
| p Value† | 0.028 | 0.276 | 0.298 | |||||||||
| Neighbourhood deprivation§ | ||||||||||||
| Quintile 1 (least) | 1 | 1 | 1 | |||||||||
| Quintile 2 | 0.96 | 0.64 to 1.45 | 0.92 | 0.46 to 1.84 | 1.06 | 0.63 to 1.81 | ||||||
| Quintile 3 | 1.38 | 0.92 to 2.09 | 1.30 | 0.64 to 2.64 | 1.32 | 0.77 to 2.24 | ||||||
| Quintile 4 | 1.47 | 0.99 to 2.18 | 1.19 | 0.61 to 2.30 | 1.35 | 0.80 to 2.28 | ||||||
| Quintile 5 (most) | 1.83 | 1.18 to 2.83 | 1.31 | 0.64 to 2.66 | 1.80 | 1.00 to 3.25 | ||||||
| p Value† | 0.022 | 0.819 | 0.341 | |||||||||
*In addition to these models run separately for <25 and ≥25 year olds, a model was run with all ages combined with interaction terms of age (dichotomous, <25 vs ≥25 years) with all time-varying covariates shown in this table. Only the interaction with the logarithm of personal income was statistically significant (p<0.001). p Values for other interactions were family status 0.12; labour force status 0.38; individual deprivation 0.31; and neighbourhood deprivation 0.94.
†Type III Wald tests, which for multichotomous categorical variables (eg, labour force status) provides a statistical test of the whole construct (not just one non-referent compared with referent comparison).
‡Models were also run with NZiDep as a continuous variable, coded 0,1,2 for the three levels. The OR (95% CI) by model were 4=1.23 (1.05 to 1.44); 5a=1.28 (0.96 to 1.73); and 5b=1.12 (0.92 to 1.36). Coefficients for other covariates in the model change little.
§Models were also run with NZDep as a continuous variable, coded 0,1,2,3,4 for the five levels. The OR (95% CI) by model were 4=1.17 (1.06 to 1.30); 5a=1.08 (0.92 to 1.27); and 5b=1.14 (1.00 to 1.31). Coefficients for other covariates in the model change little.