Table 2.
Multilevel model estimates.
| Predictors | Model 2 (effects of time) |
Model 3 (covariates) |
Model 4 (final) |
|||
|---|---|---|---|---|---|---|
| b (SE) | t (df) | b (SE) | t (df) | b (SE) | t (df) | |
| Intercept | 0.05 (0.01) | 15.27 (224)* | 0.05 (0.01) | 15.01 (220)* | 0.05 (0.01) | 15.33 (217)* |
| Internet versus email group | <0.01 (0.01) | 0.75 (220) | <0.01 (0.01) | 0.63 (217) | ||
| Internet versus discussion group | <–0.01 (0.01) | –0.66 (220) | <–0.01 (0.01) | –0.47 (217) | ||
| BMI | –0.01 (0.01) | –1.56 (220) | <–0.01 (0.01) | –1.37 (217) | ||
| Age | <0.01 (0.01) | 1.02 (220) | <0.01 (0.01) | 1.00 (217) | ||
| Health reason | <0.01 (0.01) | 0.53 (217) | ||||
| Appearance to others | <–0.01 (0.01) | –0.06 (217) | ||||
| Appearance to self | –0.01 (0.01) | –1.48 (217) | ||||
| –PRPE %: χ 2 (∆ df) | 67.94% | 567.02 (5) | 0.45% | 14.29 (4)* | 0.46% | 33.75 (3)* |
| Change over time (linear) | –0.03 (0.01) | –2.31 (224)* | –0.03 (0.01) | –2.60 (220)* | –0.03 (0.01) | –2.91 (217)* |
| Internet versus email group | 0.04 (0.02) | 2.13 (220)* | 0.03 (0.02) | 1.90 (217) | ||
| Internet versus discussion group | –0.03 (0.02) | –1.83 (220) | –0.03 (0.02) | –1.57 (217) | ||
| BMI | <0.01 (0.01) | 0.06 (220) | 0.01 (0.01) | 0.67 (217) | ||
| Age | –0.03 (0.01) | 2.29 (220)* | 0.04 (0.01) | 3.00 (217)* | ||
| Health reason | –0.02 (0.01) | –1.60 (217) | ||||
| Appearance to others | 0.02 (0.02) | 1.07 (217) | ||||
| Appearance to self | –0.04 (0.02) | –2.31 (217)* | ||||
| –PRPE %: χ 2 (∆ df) | 3.20% | 17.55 (4)* | 3.49% | 18.63 (3)* | ||
| Change over time (curvilinear) | <0.01 (0.01) | 0.20 (224) | <0.01 (0.01) | 0.48 (220) | 0.01 (0.01) | 0.66 (217) |
| Internet versus email group | –0.03 (0.02) | –1.84 (220) | –0.03 (0.01) | –1.67 (217) | ||
| Internet versus discussion group | 0.03 (0.02) | –1.84 (220) | 0.02 (0.01) | 1.60 (217) | ||
| BMI | <0.01 (0.01) | 0.48 (220) | <–0.01 (0.01) | –0.06 (217) | ||
| Age | –0.02 (0.01) | –2.22 (220)* | –0.03 (0.01) | –2.80 (217) | ||
| Health reason | 0.03 (0.01) | 1.29 (217) | ||||
| Appearance to others | –0.01 (0.01) | –0.83 (217) | ||||
| Appearance to self | 0.04 (0.01) | 2.04 (217)* | ||||
| –PRPE %: χ 2 (∆ df) | 2.94% | 9.89 (4) | 3.02% | 13.28 (3)* | ||
SE: standard error; BMI: body mass index; PRPE: proportional reduction in preduction error.
Model 2 is compared to the unconditional model that included no predictors of the dependent variable.