Table 2.
Fit Indices for the Confirmatory Factor Models of the Minnesota Nicotine Withdrawal Scale at Baseline, Week 1, Week 2, Week 4, and Week 6
| Model | χ2 | df | p | GFI | NNFI | CFI | SRMR | RMSEA |
|---|---|---|---|---|---|---|---|---|
| Baseline | ||||||||
| Model 1 | ||||||||
| AB | 27.59 | 11 | <.05 | .94 | .58 | .78 | .07 | .12 |
| MF | 68.29 | 11 | <.05 | .92 | .87 | .93 | .04 | .15 |
| NXP | 63.36 | 11 | <.05 | .95 | .92 | .96 | .04 | .11 |
| Model 2 | ||||||||
| AB | 22.30 | 6 | <.05 | .94 | .40 | .76 | .08 | .15 |
| MF | 63.78 | 6 | <.05 | .91 | .82 | .93 | .05 | .20 |
| NXP | 55.17 | 6 | <.05 | .95 | .89 | .96 | .04 | .15 |
| Model 3 | ||||||||
| AB | 45.54 | 20 | <.05 | .92 | .67 | .76 | .09 | .10 |
| MF | 89.66 | 20 | <.05 | .91 | .90 | .93 | .05 | .12 |
| NXP | 132.90 | 20 | <.05 | .92 | .90 | .93 | .05 | .12 |
|
| ||||||||
| Week 1 | ||||||||
| Model 1 | ||||||||
| AB | 18.47 | 11 | .07 | .94 | .93 | .96 | .05 | .10 |
| NXP | 51.06 | 11 | <.05 | .95 | .87 | .93 | .05 | .12 |
| Model 2 | ||||||||
| AB | 15.48 | 6 | <.05 | .94 | .87 | .95 | .05 | .15 |
| NXP | 46.80 | 6 | <.05 | .94 | .79 | .92 | .06 | .17 |
| Model 3 | ||||||||
| AB | 27.27 | 20 | .13 | .92 | .96 | .97 | .07 | .07 |
| NXP | 71.84 | 20 | <.05 | .93 | .90 | .93 | .06 | .10 |
|
| ||||||||
| Week 2 | ||||||||
| Model 1 | ||||||||
| MF | 32.36 | 11 | <.05 | .93 | .89 | .94 | .05 | .13 |
| NXP | 67.95 | 11 | <.05 | .93 | .81 | .90 | .06 | .15 |
| Model 2 | ||||||||
| MF | 22.41 | 6 | <.05 | .94 | .88 | .95 | .05 | .15 |
| NXP | 62.59 | 6 | <.05 | .92 | .72 | .89 | .06 | .20 |
| Model 3 | ||||||||
| MF | 44.99 | 20 | <.05 | .92 | .92 | .94 | .05 | .10 |
| NXP | 73.29 | 20 | <.05 | .93 | .89 | .92 | .05 | .11 |
|
| ||||||||
| Week 4 | ||||||||
| Model 1 | ||||||||
| MF | 33.25 | 11 | <.05 | .93 | .84 | .92 | .05 | .13 |
| NXP | 51.39 | 11 | <.05 | .94 | .84 | .92 | .05 | .13 |
| Model 2 | ||||||||
| MF | 29.29 | 6 | <.05 | .93 | .77 | .91 | .06 | .18 |
| NXP | 49.18 | 6 | <.05 | .93 | .75 | .90 | .05 | .18 |
| Model 3 | ||||||||
| MF | 55.12 | 20 | <.05 | .90 | .85 | .89 | .06 | .12 |
| NXP | 70.64 | 20 | <.05 | .93 | .88 | .91 | .05 | .11 |
|
| ||||||||
| Week 6 | ||||||||
| Model 1 | ||||||||
| MF | 20.07 | 11 | <.05 | .94 | .93 | .96 | .05 | .09 |
| NXP | 39.37 | 11 | <.05 | .95 | .90 | .95 | .04 | .11 |
| Model 2 | ||||||||
| MF | 15.57 | 6 | <.05 | .95 | .89 | .96 | .05 | .13 |
| NXP | 34.12 | 6 | <.05 | .95 | .85 | .94 | .04 | .15 |
| Model 3 | ||||||||
| MF | 31.41 | 20 | .05 | .93 | .94 | .96 | .06 | .08 |
| NXP | 66.50 | 20 | <.05 | .93 | .90 | .93 | .05 | .11 |
Note. GFI = goodness-of-fit index; NNFI = nonnormed fit index; CFI = comparative fit index; SRMR = standardized root mean square residual; RMSEA = root mean square error of approximation; AB = abstinence study (baseline n = 115; Week 1 n = 72); MF = message framing study (baseline N = 238; Week 2 n = 124; Week 4 n = 118; Week 6 n = 103); NXP = naltrexone + patch study (baseline N = 370; Week 1 n = 242; Week 2 n = 240; Week 4 n = 214; Week 6 n = 205). For Model 1, Factor 1 = irritability, anxiety, difficulty, concentrating, and restlessness; Factor 2 = appetite and insomnia; Factor 3 = craving. For Model 2, Factor 1 = irritability, anxiety, difficulty concentrating, and restlessness; Factor 2 = appetite; Factor 3 = insomnia. For Model 3, unitary factor = craving, irritability, anxiety, difficulty concentrating, restlessness, increased appetite or weight gain, depression, and insomnia.