Int. J. Environ. Res. Public Health 2011, 8 1684 3.4. Price Minimizing Behaviors as Predictors of Cessation among Those Reporting Quit Attempts There were no significant associations between use of price minimizing behaviors and successful quit attempts based on univariate analyses (Table 3). After adjusting for covariates, respondents who used discount or generic brand cigarettes were about 25% less likely to report a successful quit attempt (OR = 0.75, 95% CI: 0.59–0.97). Based on the main effect analysis, it appears that purchasing from low and untaxed sources may result in reduced success, but this failed to reach statistical significance. However, a statistically significant interaction was present between using low/untaxed sources and SES for this cessation outcome (p = 0.043). After stratifying by SES, in both the moderate and low SES strata, respondents using low and untaxed sources were about 55% less likely to successfully quit after making an attempt, whereas in the high SES strata, respondents using low and untaxed sources appear to be more likely to successfully quit. However, this relationship was only statistically significant among respondents with moderate SES (Table 3, legend). There were no differences in successful quit attempts among those who did and did not purchase tobacco in cartons or with any use of price or tax avoidance behaviors. However, simultaneous use of two or more price/tax avoidance behaviors was associated with a 32% reduction in successful quit attempts (OR = 0.68, 95% CI: 0.47–0.98). No other statistically significant interactions were present. 3.5. Long Term Cessation Associated with Low/Untaxed Source Use among the 3-Wave Cohort Reported use of low or untaxed sources at waves 5 and at wave 6 was associated with a 57% reduction in making a quit attempt between wave 6 and wave 7 (OR = 0.43, 95% CI: 0.29–0.62; Table 4), compared to those who reported purchasing from a full tax source in both survey waves. Table 4. Changing location of last purchase between waves 5 and 6 as predictors of Long Term Cessation Outcomes at Wave 7 follow-up. Long Term Cessation Outcome at Wave 7 Purchase Location at Quit Attempt Cessation (n = 3,117) (n = 3,117) Wave 5 Wave 6 N OR (95% CI) N OR (95% CI) Full Tax Source Full Tax Source 2,620 1.00 2,620 1.00 Full Tax Source Low/Untaxed Source 157 0.68 (0.46–1.00) 157 0.60 (0.31–1.17) Low/Untaxed Source Full Tax Source 113 1.12 (0.76–1.64) 113 1.63 (0.99–2.69) Low/Untaxed Source Low/Untaxed Source 227 0.43 (0.29–0.62) 227 0.53 (0.29–0.97) Bolded entries represent significant associations at p < 0.05 level; All models adjusted for: SES, Country, Age, Sex, Ethnicity, and Heaviness of Smoking Index. Quit attempt and Cessation between wave 6 and 7 were assessed among participants with complete data who were current smokers at both waves 5 and 6. P for interaction between tax status change and SES on making a quit attempt at wave 6: p = 0.935. P for interaction between tax status change and SES on making a quit attempt at wave 6: p = 0.763. Additionally, participants who reported switching from a full taxed venue at wave 5 to a low or untaxed venue at wave 6 were 32% less likely to report making a quit attempt between waves 6 and 7 (OR = 0.68, 95% CI: 0.46–1.00).