IntroductionCigarette package graphic health warning labels (GHWL) remain an important means of communicating serious smoking risks. There were significant delays in implementing them in different countries around the world, partly due to tobacco company resistance; additionally, the messages used differ considerably. We expected a reduced cognitive processing of the messages based on the duration since launch. In order to address this question we compared a London (4 years) vs Singapore (8 years exposed) cohort.MethodsWe used a 50-item structured interview; after recording demographics and smoking history, 10 country-specific warning labels were shown. In addition to the emotional response and impact on smoking cessation/prevention, cognitive processing was assessed on a scale from ‘1’ (‘not at all/never’) to ‘5’ (‘all the time/a lot’). Smoking-risk knowledge and their importance in terms of prevention and treatment were elicited.Results266 participants were recruited, 163 from London (52 ± 18 years, 54% male, 35% smokers) and 103 from Singapore (58 ± 15 years, p = 0.012; 78% male, p < 0.001; 53% smokers, p = 0.003). Londoners read the labels more carefully and more often; they talked and thought more about them, even with no warning labels were in sight, and they kept packages more often as a reminder about their messages (overall, 2.0 ± 1.3 vs 1.5 ± 1.0, p < 0.001). The processing differences between the cities were consistent when comparing the London and Singapore smokers (overall, 2.0 ± 1.1 vs 1.6 ± 1.1, p < 0.001) and non-smokers (overall, 2.0 ± 1.4 vs 1.4 ± 0.8, p < 0.001) (Table 1). Londoners experienced more disgust when viewing the images (79% vs 53%, p < 0.001) and felt they were more effective deterrents (51% vs 35%, p = 0.011). One-in-five participants in Singapore were unaware of the association between smoking and lung cancer, despite it being the most deterring risk; blindness was the least well-known consequence in London (24%) and Singapore (34%, p = 0.075) despite being ranked ahead of stroke, oral cancer, and in smokers, ahead of heart disease for importance to prevent/treat.Abstract S77 Table 1Processing of GHWL; comparing all participants, non-smokers and smokers in London vs SingaporeAllNon-smokersSmokersProcessing (/5) (SD)SingLondonpSingLondonpSingLondonpCarefully read labels1.8(1.1)2.2(1.2)0.0041.6(0.9)2.1(1.3)0.0241.9(1.2)2.4(1.1)0.028Often read labels1.7(1.1)2.2(1.3) <0.0011.5(0.9)2.2(1.4)0.0011.9(1.2)2.3(1.0)0.095Ever talked about1.5(1.1)2.2(1.4) <0.0011.6(1.1)2.3(1.5)0.0011.5(1.2)2.0(1.1)0.039Often think about1.6(1.0)2.4(1.4) <0.0011.5(0.9)2.5(1.4)0.0011.8(1.1)2.4(1.3)0.006Inc. when not in sight1.3(0.7)1.8(1.1) <0.0011.1(0.6)1.8(1.2)0.0011.4(0.9)1.8(1.0)0.040Kept labels as reminder1.0(0.3)1.3(0.8)0.0011.0(0.2)1.3(0.9)0.0211.0(0.3)1.3(0.8)0.023ConclusionA desensitisation to graphic health warning labels occurs with extended exposure. Non-smokers are prone to the same desensitisation as smokers are. In pre-empting this, the awareness and impact of specific health risks need to be activ...