Table 3.
Regression of T2 Adherence on Condition and Control Variables
| Variable | Intention-to-Treat Analysis | Per-Protocol Analysis | ||||
|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | Model 4 | Model 5 | Model 6 | |
| Intercept | 4.48 (0.05)*** | 1.77 (0.65) ** | 4.48 (0.05)*** | 2.27 (0.20)*** | 1.29 (0.38)*** | 0.95 (0.49) |
| Condition | 0.06 (0.07) | −1.08 (0.85) | ||||
| Commitment | 0.53 (0.07) *** | 0.52 (0.04)*** | 0.26 (0.06)*** | 0.27 (0.06)*** | ||
| Condition × Commitment | 0.03 (0.10) | |||||
| Self-control | 0.01 (0.07) | |||||
| Condition × Self-Control | 0.16 (0.10) | |||||
| Boredom | 0.02 (0.07) | |||||
| Condition × Boredom | 0.12 (0.09) | |||||
| If-then Planning | 0.09 (0.09) | |||||
| Condition × If-Then Planning | 0.04 (0.11) | |||||
| Condition (intenders) | 0.18 (0.07)* | 0.12 (0.06)* | 0.10 (0.05)* | 0.11 (0.05)* | ||
| Condition (non-intenders) | −0.31 (0.15)* | −0.09 (0.12) | −0.05 (0.10) | −0.05 (0.10) | ||
| T2 Difficulty | −0.05 (0.04) | −0.05 (0.04) | ||||
| T1 Adherence | 0.46 (0.08)*** | 0.46 (0.09)*** | ||||
| T1 Difficulty | 0.02 (0.04) | −0.01 (0.05) | ||||
| Demographics | included | |||||
| Num. obs. | 451 | 451 | 451 | 451 | 451 | 451 |
| R2 | 0.00 | 0.38 | 0.04 | 0.37 | 0.46 | 0.51 |
| Adj. R2 | −0.00 | 0.37 | 0.03 | 0.37 | 0.45 | 0.48 |
| L.R. | 0.65 | 216.63 | 17.08 | 211.00 | 278.21 | 326.25 |
Note. We report unstandardized coefficients with robust standard errors in parentheses. “Condition” refers to a dummy variable coded as 0 for the control condition and as 1 for the planning condition (or intenders and non-intenders). The demographic variables comprised age, gender, education, employment status, and income. *p < .05. **p < .01. ***p < .001