Researchers investigated the impact of health warnings placed on cigarette packages in four countries. Approximately 15,000 adult smokers from the United States, Canada, U.K. and Australia annually completed standardized surveys for four years as part of the International Tobacco Control (ITC) Four Country Survey.
- There was a higher likelihood that Canadian smokers reported being aware of health warnings at Wave 1 as compared to smokers from the other countries.
- After implementation of new health warnings in the UK prior to Wave 2, salience and impact increased significantly when measured at Wave 2 for UK smokers.
- Across all four waves of surveys, smokers in the United States had the lowest levels in the majority of measures of health warning effectiveness.
- Newer health warnings were associated with higher reports of smokers noticing and reading the warning.
- Health warnings that were large and used graphics might have been more effective than text warnings.