Table 2. Adjusted Mean Differences for Secondary Outcomes.
| Outcome | Condition Comparison | AMD (95% CI) | P value | Outcome | Condition Comparison | AMD (95% CI) | P value |
|---|---|---|---|---|---|---|---|
| Wk 16 study CPD | VLNC + PF vs NNC | −15.13 (−18.83 to −11.42) | <.001 | Days abstinent | VLNC + PF vs NNC | 22.61 (14.89 to 30.33) | <.001 |
| VLNC + TF vs NNC | −12.58 (−16.51 to −8.65) | <.001 | VLNC + TF vs NNC | 8.31 (3.02 to 13.59) | .004 | ||
| VLNC vs NNC | −10.34 (−14.44 to −6.25) | <.001 | VLNC vs NNC | 2.18 (−0.09 to 4.46) | .18 | ||
| VLNC + PF vs VLNC | −4.78 (−7.80 to −1.77) | .004 | VLNC + PF vs VLNC | 20.43 (12.43 to 28.43) | .002 | ||
| VLNC + PF vs VLNC + TF | −2.55 (−5.33 to 0.24) | .23 | VLNC + PF vs VLNC + TF | 14.30 (4.99 to 23.62) | .047 | ||
| VLNC + TF vs VLNC | −2.24 (−5.52 to 1.05) | .47 | VLNC + TF vs VLNC | 6.12 (0.44 to 11.81) | .60 | ||
| Wk 16 nonstudy CPD | VLNC + PF vs NNC | 0.20 (−0.23 to 0.63) | .76 | Wk 16 B–WISDM PDM | VLNC + PF vs NNC | −2.64 (−4.35 to −0.93) | .007 |
| VLNC + TF vs NNC | 0.88 (0.29 to 1.46) | .005 | VLNC + TF vs NNC | −1.08 (−2.87 to 0.71) | .59 | ||
| VLNC vs NNC | 0.86 (0.28 to 1.44) | .005 | VLNC vs NNC | −1.20 (−2.95 to 0.55) | .46 | ||
| VLNC + PF vs VLNC | −0.66 (−1.26 to −0.06) | .08 | VLNC + PF vs VLNC | −1.44 (−3.15 to 0.27) | .30 | ||
| VLNC + PF vs VLNC + TF | −0.68 (−1.28 to −0.07) | .08 | VLNC + PF vs VLNC + TF | −1.56 (−3.31 to 0.19) | .26 | ||
| VLNC + TF vs VLNC | 0.02 (−0.70 to 0.73) | .96 | VLNC + TF vs VLNC | 0.12 (−1.68 to 1.92) | .99 | ||
| Wk 16 breath CO | VLNC + PF vs NNC | −8.86 (−14.22 to −3.49) | .001 | Wk 16 QSU-Brief Factor 1 | VLNC + PF vs NNC | −1.77 (−2.51 to −1.02) | <.001 |
| VLNC + TF vs NNC | −4.43 (−10.41 to 1.56) | .36 | VLNC + TF vs NNC | −1.40 (−2.19 to −0.61) | <.001 | ||
| VLNC vs NNC | −1.07 (−7.20 to 5.07) | .98 | VLNC vs NNC | −0.71 (−1.46 to 0.05) | .07 | ||
| VLNC + PF vs VLNC | −7.79 (−13.07 to −2.52) | .006 | VLNC + PF vs VLNC | −1.06 (−1.18 to -.0.31) | .002 | ||
| VLNC + PF vs VLNC + TF | −4.43 (−9.53 to 0.67) | .23 | VLNC + PF vs VLNC + TF | −0.37 (−1.15 to 0.41) | .61 | ||
| VLNC + TF vs VLNC | −3.36 (−9.27 to 2.54) | .59 | VLNC + TF vs VLNC | −0.69 (−1.48 to 0.10) | .11 | ||
| Wk 16 NNAL | VLNC + PF vs NNC | −0.94 (−1.41 to −0.47) | <.001 | QSU-Brief Factor 1 across wks | VLNC + PF vs NNC | −1.32 (−1.96 to −0.68) | <.001 |
| VLNC + TF vs NNC | −0.46 (−1.01 to 0.09) | .30 | VLNC + TF vs NNC | −0.88 (−1.54 to −0.22) | .004 | ||
| VLNC vs NNC | −0.47 (−1.01 to 0.06) | .21 | VLNC vs NNC | −0.56 (−1.20 to 0.08) | .11 | ||
| VLNC + PF vs VLNC | −0.46 (−0.83 to −0.10) | .03 | VLNC + PF vs VLNC | −0.76 (−1.40 to −0.12) | .01 | ||
| VLNC + PF vs VLNC + TF | −0.47 (−0.87 to −0.08) | .04 | VLNC + PF vs VLNC + TF | −0.44 (−1.10 to 0.22) | .31 | ||
| VLNC + TF vs VLNC | 0.01 (−0.46 to 0.48) | .99 | VLNC + TF vs VLNC | −0.33 (−0.99 to 0.34) | .58 | ||
| NNAL across wks | VLNC + PF vs NNC | −1.13 (−1.57 to −0.70) | <.001 | Wk 16 QSU-Brief Factor 2 | VLNC + PF vs NNC | −1.24 (−1.87 to −0.61) | <.001 |
| VLNC + TF vs NNC | −0.72 (−1.20 to −0.23) | .007 | VLNC + TF vs NNC | −0.75 (−1.42 to −0.08) | .02 | ||
| VLNC vs NNC | −0.66 (−1.15 to −0.18) | .01 | VLNC vs NNC | −0.45 (−1.09 to 0.19) | .26 | ||
| VLNC + PF vs VLNC | −0.47 (−0.76 to −0.17) | .002 | VLNC + PF vs VLNC | −0.79 (−1.42 to −0.15) | .008 | ||
| VLNC + PF vs VLNC + TF | −0.41 (−0.71 to −0.12) | .01 | VLNC + PF vs VLNC + TF | −0.49 (−1.15 to 0.18) | .23 | ||
| VLNC + TF vs VLNC | −0.05 (−0.42 to 0.31) | .99 | VLNC + TF vs VLNC | −0.30 (−0.97 to 0.37) | .65 | ||
| Wk 16 anatabine | VLNC + PF vs NNC | −6.23 (−10.26 to −2.21) | .003 | QSU-Brief Factor 2 across wks | VLNC + PF vs NNC | −0.88 (−1.44 to −0.32) | <.001 |
| VLNC + TF vs NNC | −2.70 (−7.54 to 2.15) | .65 | VLNC + TF vs NNC | −0.39 (−0.98 to 0.19) | .30 | ||
| VLNC vs NNC | −3.30 (−7.89 to 1.29) | .42 | VLNC vs NNC | −0.31 (−0.87 to 0.26) | .50 | ||
| VLNC + PF vs VLNC | −2.93 (−6.40 to 0.53) | .27 | VLNC + PF vs VLNC | −0.57 (−1.13 to −0.01) | .045 | ||
| VLNC + PF vs VLNC + TF | −3.54 (−7.34 to 0.26) | .18 | VLNC + PF vs VLNC + TF | −0.48 (−1.06 to 0.09) | .14 | ||
| VLNC + TF vs VLNC | 0.60 (−3.79 to 5.00) | .99 | VLNC + TF vs VLNC | −0.09 (−0.67 to 0.50) | .98 | ||
| Anatabine across wks | VLNC + PF vs NNC | −6.25 (−9.56 to −2.95) | <.001 | NA | NA | NA | NA |
| VLNC + TF vs NNC | −4.07 (−7.76 to −0.38) | .09 | NA | NA | NA | ||
| VLNC vs NNC | −5.46 (−8.86 to −2.06) | .001 | NA | NA | NA | ||
| VLNC + PF vs VLNC | −0.80 (−2.96 to 1.37) | .87 | NA | NA | NA | ||
| VLNC + PF vs VLNC + TF | −2.19 (−4.78 to 0.40) | .27 | NA | NA | NA | ||
| VLNC + TF vs VLNC | 1.39 (−1.32 to 4.10) | .69 | NA | NA | NA |
Abbreviations: AMD, adjusted mean difference; B–WISDM PDM, Brief–Wisconsin Inventory of Smoking Dependence Motives Primary Dependence Motives; CPD, cigarettes smoked per day; NA, not applicable; NNAL, urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NNC, normal nicotine content (15.8 mg/g tobacco); PF, e-cigarettes in preferred flavor (participants selected 3 from 8 flavors); QSU-Brief, Questionnaire on Smoking Urges–Brief; TF, e-cigarettes in tobacco flavor; VLNC, very low nicotine content (0.4 mg/g tobacco).