Change in cigarette risk beliefs
SE
During baseline, participants predominately held factually correct risk perceptions of their own cigarettes (Mean = 6.02, SE = 0.17) and very few incorrect responses (Mean = 0.31, SE = 0.05). Visual examination of the eight risk belief items over time revealed that anything other than correct perceptions were largely driven by uncertainty and not incorrect beliefs. Further, the proportion holding incorrect beliefs did not increase over time (eFigure 
Change in cigarette incorrect or uncertain risk beliefs across cigarette pack color use periods by warning label groupExposure to the text-only warning increased the baseline rate of 1.48 (SE = 0.21) uncertain or incorrect beliefs to 2.52 (SE = 0.34; IRR = 1.70 [95%CI = 1.43, 2.03]) when the experimental pack color matched the smokers preference (i.e., congruent), to 2.98 (SE = 0.40; IRR = 2.01 [95%CI = 1.70, 2.38]) when pack color did not match the preference (i.e., incongruent), and to 3.19 (SE = 0.43; IRR = 2.16 [95%CI = 1.82, 2.55]) when the pack was plain (Table Within the text-only warning condition, the odds of reporting an incorrect or uncertain risk belief increased from baseline for all eight risk belief items regardless of the experimental pack color condition (ORs range:2.39–25.55; Table 
Post-hoc pairwise multiple comparisons of change in incorrect or uncertain risk beliefs using adjusted between and within subject contrasts** 