Assessing the relationship between ad volume and awareness of a tobacco education media campaign

BACKGROUND: The relation between aided ad recall and level of television ad placement in a public health setting is not well established. We examine this association by looking back at 8 years of the California's Tobacco Control Program's (CTCP) media campaign. METHODS: Starting in July 2001, California's campaign was continuously monitored using five telephone series of surveys and six web-based series of surveys immediately following a media flight. We used population-based statewide surveys to measure aided recall for advertisements that were placed in each of these media flights. Targeted rating points (TRPs) were used to measure ad placement intensity throughout the state. RESULTS: Cumulative TRPs exhibited a stronger relation with aided ad recall than flight TRPs or TRP density. This association increased after log-transforming cumulative TRP values. We found that a one-unit increase in log-cumulative TRPs led to a 13.6% increase in aided ad recall using web-based survey data, compared to a 5.3% increase in aided ad recall using telephone survey data. CONCLUSIONS: In California, the relation between aided ad recall and cumulative TRPs showed a diminishing return after a large volume of ad placements These findings may be useful in planning future ad placement for CTCP's media campaign.