Messages About Tobacco and Alcohol Co-users.

Objective: People who use both alcohol and combustible tobacco have an increased risk of developing cancer. Few interventions have been developed to inform people about the risks of co-use. This study developed and tested messages about the risks of alcohol and combustible tobacco co-use among adults.

Method: In June-July 2021, we surveyed 1,300 U.S. adults who used both alcohol and combustible tobacco products within the past 30 days. After reporting their awareness of diseases caused by tobacco and alcohol co-use, participants were randomly assigned to four between-subjects experiments that manipulated specific cancer health effects vs. the word "cancer"; cancer health effects vs. noncancer health effects; different descriptions of co-use (e.g., Using alcohol and tobacco…, Drinking alcohol and smoking tobacco…); and co-use vs. single-use messages. Participants saw one message for each experiment and rated each message using a validated perceived message effectiveness (PME) scale.

Results: Awareness of health effects caused by alcohol and tobacco co-use ranged from moderately high for throat cancer (65.4%) to moderately low for colorectal cancer (23.1%). Messages about cancer health effects increased PME more than messages about non-cancer health effects (B=0.18, p=0.01). Messages about some specific cancers-including oral cancer (B=-0.20, p=0.04) and colorectal cancer (B=-0.22, p=0.02) decreased PME more than messages with only the word "cancer." No significant differences were identified for descriptions of co-use or co-use vs. single-use messages.

Conclusions: Messages about some cancer health effects of co-using alcohol and tobacco may be effective when communicating the harms of both drinking alcohol and using tobacco.