Table 3.
Results of Linear Mixed Models for Laboratory and Field data
| n1 | n2 | Group | Group x Time | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| df | PE | SE | F | p | df | PE | SE | F | P | |||
| Lab Data | ||||||||||||
| VP Bias (ms) | 183 | 55 | 1,126 | −19.24 | 6.34 | 9.20 | .003 | 1,125 | 10.02 | 12.14 | 0.68 | .41 |
| Stroop (ms) | 93 | 55 | 1,37 | 51.39 | 32.94 | 2.43 | .13 | 1,36 | −28.73 | 49.35 | 0.34 | .56 |
| SABQ (0–4) | 101 | 56 | 1,44 | −0.07 | 0.15 | 0.25 | .62 | 1,43 | −0.02 | 0.21 | 0.01 | .93 |
| QSU (0–5) | 101 | 56 | 1,44 | 0.13 | 0.24 | 0.28 | .60 | 1,43 | 0.04 | 0.25 | 0.03 | .86 |
| CO (ppm) | 105 | 57 | 1,47 | −0.54 | 1.25 | 0.19 | .67 | 1,46 | 0.02 | 1.50 | 0.00 | .99 |
| Cotinine (ng/mL) | 101 | 57 | 1,43 | −11.39 | 46.87 | 0.06 | .81 | 1,42 | 51.25 | 50.58 | 0.32 | .57 |
| Field Data | ||||||||||||
| VP Bias (ms) | 481 | 53 | 1, 374 | −24.06 | 9.68 | 6.18 | .01 | 1, 374 | 0.34 | 2.63 | 0.02 | .90 |
| Self-Reported Attention (1–7) | 2249 | 56 | 1, 2081 | −0.23 | 0.23 | 0.95 | .33 | 1, 2081 | 0.02 | 0.02 | 1.12 | .29 |
| Advertisements (1–5) | 2241 | 56 | 1, 2075 | 0.05 | 0.12 | 0.20 | .65 | 1, 2075 | 0.00 | 0.12 | 0.00 | .96 |
| Cued Craving (1–7) | 2276 | 56 | 1, 2108 | −0.45 | 0.28 | 2.50 | .11 | 1, 2108 | 0.02 | 0.03 | 0.44 | .51 |
| Craving (1–7) | 2276 | 56 | 1, 2108 | −0.39 | 0.28 | 2.00 | .16 | 1, 2108 | 0.03 | 0.03 | 1.20 | .27 |
| Smoking (PDA) (1–5) | 2225 | 56 | 1, 2057 | 0.02 | 0.24 | 0.01 | .93 | 1, 2057 | −0.04 | 0.02 | 3.91 | .04 |
| No. Cigs (Diary) | 738 | 54 | 1, 683 | 1.25 | 1.07 | 1.38 | .24 | 1, 682 | −0.01 | 0.05 | 0.05 | .82 |
Note. n1 = number of level 1 units, i.e., assessments, visits, or days; n2 = number of subjects (level two units) who completed at least one assessment at visit 2 or visit 3 (lab data) and at least one PDA assessment (field data). Columns labeled Group show the results for the main effect of Group. The comparison category is CON (Negative parameter estimates indicate lower values for AR vs. CON). Columns labeled Group x Time shows the results for the Group x Visit (lab data) or Group x Day (field data) interaction term. Visit is a categorical variable with two levels (visit 2 vs. visit 3). All models include main effects for Group and Visit. The LMM for VP Bias also includes Picture Type (old vs. new) as an additional within-subject factor (lab data). In addition, the baseline (pre-intervention) measure for each dependent variable was included as a covariate. Data for analysis of VP Bias use all assessments with no more than one reported interruption (see text). Key: CO = expired carbon monoxide, QSU = Brief Questionnaire for Smoking Urges, SABQ = Subjective Attentional Bias Questionnaire, VP Bias = Visual Probe attentional bias score, PE = (unstandardized) parameter estimate; SE = standard error; F = F value from mixed model