Table 1.

Multivariate linear models predicting smoking intention and smoking refusal self-efficacy from exposure to pro-smoking media, and their persistence over time as estimated by piecewise linear regression

Variables	Smoking intention				Smoking refusal self-efficacy
	Instant exposure impact (R2 = 0.2206)		Exposure Persistence (R2 = 0.2294)		Instant exposure impact (R2 = 0.1565)		Exposure Persistence (R2 = 0.1623)
	b (95% CI)	p	b (95% CI)	p	b (95% CI)	p	b (95% CI)	p
Continuous Persistence timea
Slope between 0 and 7 days			−0.12 (−0.19, −0.05)	0.002			0.09 (0.02, 0.16)	0.02
Slope for more than 7 days			0.01 (−0.08, 0.10)	0.83			−0.01 (−0.10, 0.08)	0.81
Pro-smoking media Exposureb	0.56 (0.26, 0.87)	< 0.001			−0.42 (−0.75, −0.10)	0.01
Never smokerc	−2.23 (−2.86, −1.59)	< 0.001	−2.20 (−2.82, −1.58)	< 0.001	1.76 (1.13, 2.39)	< 0.001	1.74 (1.12, 2.36)	< 0.001
Gender: Male	0.12 (−0.65, 0.89)	0.76	0.12 (−0.65, 0.88)	0.76	0.14 (−0.58, 0.86)	0.70	0.14 (−0.57, 0.86)	0.70
Racial/ethnic minority statusd	−0.01 (−0.77, 0.74)	0.98	−0.05 (−0.78, 0.68)	0.90	−0.18 (−0.93, 0.57)	0.63	−0.16 (−0.90, 0.59)	0.68
Weekende	0.02 (−0.06, 0.09)	0.66	−0.01 (−0.09, 0.07)	0.83	0.00 (−0.07, 0.07)	0.99	0.02 (−0.06, 0.10)	0.63

Note. Number of observations = 6793

^aContinuous persistence time from the last exposure in days

^bVersus random prompt

^cEver smoker is the reference category

^dCompared with non-Hispanic White