Table 2.
Odds Ratios from Models Predicting Spontaneous Quitting with Educational Attainment, Prepregnancy Smoking Rate, and Delay Discounting (N = 349).
| Block 1. Univariate Models | ||
|---|---|---|
| OR (95% CI) | Tjur's D | |
| Discounting (log k)** | 0.87 (0.79, 0.96) | 0.02 |
| Smoking rate*** (per 5 cigarettes) | 0.37 (0.30, 0.47) | 0.30 |
| Education*** | 0.09 | |
| 12 vs. <12 | 1.56 (0.79, 3.07) | |
| >12 vs. <12 | 5.34 (2.65, 10.77) |
| Block 2. Model from Backward Elimination on Saturated Model | ||
|---|---|---|
| OR (95% CI) | Tjur's D | |
| Education*** | ||
| 12 vs. <12 | 2.55 (1.15, 5.68) | |
| >12 vs. <12 | 6.94 (2.93, 16.42) | |
| Log k × smoking rate*a | ||
| at 5 cigarettes | 0.78 (0.66, 0.93) | |
| at 10 cigarettes | 0.85 (0.75, 0.97) | |
| at 15 cigarettes | 0.93 (0.82, 1.04) | |
| at 20 cigarettes | 1.01 (0.86, 1.18) | 0.39 |
| Block 3. Model from Backward Elimination on Saturated Model and Baseline Characteristics | ||
|---|---|---|
| OR (95% CI) | Tjur's D | |
| Education** | ||
| 12 vs. <12 | 2.02 (0.85, 4.80) | |
| >12 vs. <12 | 4.62 (1.70, 12.54) | |
| Log k × smoking rate*a | ||
| at 5 cigarettes | 0.74 (0.61, 0.90) | |
| at 10 cigarettes | 0.84 (0.73, 0.96) | |
| at 15 cigarettes | 0.94 (0.83, 1.07) | |
| at 20 cigarettes | 1.06 (0.89, 1.25) | |
| Self-reported stress* | 0.86 (0.76, 0.97) | |
| Smoking will harm baby greatly* | 14.42 (1.77, 117.25) | |
| Age initiated smoking** | 1.15 (1.04, 1.28) | |
| Married* | 2.45 (1.17, 5.09) | |
| Number of quits during pregnancy* | 1.18 (1.01, 1.37) | 0.48 |
*
p < .05
**
p < .01
***
p < .001
a
The main effects of log k and smoking rate are included in the model, but only the odds ratios for log k at the given levels of smoking rate are presented in the table.