Table 3.

Means and Standard Errors of Least-Squares Mean Differences Week 20 Between Age Groups (Age 18–24 and Age ≥25) as a Function of Treatment Group

Outcome	Interaction test p-value	Immediate reduction		Gradual reduction		Control
		Mean difference	p	Mean difference	p	Mean difference	p
CES SSa	.71	−0.91 (0.31)	<.01	−0.71 (0.31)	.02	−0.49 (0.39)	.21
CES PR a	.60	−0.52 (0.23)	.03	−0.56 (0.23)	.02	−0.20 (0.29)	.49
CES ERTSa	.62	−0.82 (0.32)	.01	−0.67 (0.32)	.03	0.33 (0.40)	.41
CES CRa	.61	−1.07 (0.41)	.01	−0.54 (0.41)	.18	−1.03 (0.51)	.04
CES AVa	.48	−0.01 (0.17)	.93	−0.05 (0.17)	.76	−0.32 (0.21)	.12
Total CPDa	.69	−3.92 (0.06)	.06	−2.82 (1.21)	.17	−4.88 (2.30)	.03
Log TNEsa	.98	−0.12 (0.36)	.74	−0.04 (0.37)	.92	−0.00 (0.45)	1.00

Interaction test p-values represent the outcome of tests for overall significant interactions between age category and nicotine reduction group and mean differences between age groups at visit 20. Mean difference p-values represent the outcome of post hoc contrast test probing the interaction for significant differences by nicotine group. Positive mean differences values indicate higher values in the younger adults compared with older adults. Regression model adjusted for age group (18–24, ≥25), nicotine content group, value of the given outcome at baseline, FTND at baseline, race (White, African American, other), nicotine metabolite ratio at baseline, and gender. Bold values indicate significant p-value at α = 0.05. CES = Cigarette Evaluation Scale; SS = Smoking Satisfaction, PR = Psychological Reward; ERTS = Enjoyment of Respiratory Tract Sensations; CR = Craving Reduction; AV = Aversion; CPD = cigarettes per day; TNEs = total nicotine equivalents.