Quasi-experimentally examining the impact of introducing tobacco pictorial health warnings: Findings from the International Tobacco Control (ITC) 4C and Netherlands surveys in the Netherlands, Australia, Canada, United Kingdom, and the United States

Background: Our study evaluated the short-term impact of introducing European Union's tobacco pictorial health warnings (PHWs). Methods: Longitudinal data were collected at two time-points from adult smokers, participating in the International Tobacco Control (ITC) surveys, conducted in the Netherlands, Australia, Canada, the United Kingdom and the United States. In the Netherlands, textual health warnings (THWs) were replaced by PHWs between both time-points. Health warning policies did not change in the other countries. Data from continuing smokers were used (N = 3,487) and analyzed using Generalized Estimating Equations. Results: Between both time-points, only Dutch smokers showed increases in noticing health warnings (beta = 0.712, p < 0.001), self-reports of health warnings leading to a cognitive response such as thinking about smoking health-risks (SHRs) (OR = 1.834, p < 0.001), knowledge about SHRs (beta = 0.369, p < 0.001), and avoiding health warnings (OR = 9.869, p < 0.001). However, Dutch smokers showed no changes in attitude towards smoking (beta = 0.035, p = 0.518), intention to quit smoking (OR = 0.791, p = 0.157), self-efficacy to quit smoking (beta=-0.072, p = 0.286), or reporting that health warnings helped them to resist having a cigarette (OR = 1.091, p = 0.714). Conclusions: Results suggest that introducing the European PHWs was effective in provoking changes closely related to health warnings, but there was no direct impact on variables more closely related to smoking cessation.