Effect of Cigarette Constituent Messages With Engagement Text on Intention to Quit Smoking Among Adults Who Smoke Cigarettes: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) is required to communicate the risks of tobacco constituents to the public. Few studies have addressed how FDA media campaigns can effectively communicate about cigarette smoke constituents. Objective: To examine whether messages about cigarette smoke constituents are effective in reducing smoking intentions and behaviors among adults who smoke. Design, Setting, and Participants: This randomized clinical trial enrolled participants who were aged between 18 and 65 years, were English speakers, were living in the United States, and who smoked at least 100 cigarettes during their lifetime and now smoked every day or some days. Participants received daily messages via email for 15 days. Participants were randomized to 1 of 2 message conditions or a control group and reported their previous-day smoking behaviors daily. Follow-up surveys were conducted on days 16 and 32. Data were collected from June 2017 to April 2018 and analyzed from April to September 2018. Interventions: The 3 groups were (1) constituent plus engagement messages (eg, "Cigarette smoke contains arsenic. This causes heart damage.") that included the FDA as the source and engagement text (eg, "Within 3 months of quitting, your heart and lungs work better. Ready to be tobacco free? You can quit. For free nicotine replacement, call 1-800-QUIT-NOW"); (2) constituent-only messages that did not list the FDA as the source or include engagement text; and (3) a control condition with messages about littering cigarette butts. Main Outcomes and Measures: The primary outcome was the change in quit intentions (range, 1-4, with higher scores indicating stronger intentions) from pretest to day 16. Secondary outcome measures included daily smoking behaviors and quit attempts. Results: A total of 789 participants (mean [SD] age, 43.4 [12.9] years; 483 [61.2%] women; 578 [73.3%] White; 717 [90.9%] non-Hispanic) were included in the study. The mean (SD) quit intention score was 2.5 (0.9) at pretest. Mean (SE) change in quit intention score from pretest to day 16 was 0.19 (0.07) points higher in the constituent plus engagement condition than in the control condition (P = .005) and 0.23 (0.07) points higher in the constituent-only condition compared with the control condition (P = .001). Participant reports of cigarettes smoked, forgone, and butted out were similar across study conditions at baseline and did not differ significantly at days 16 and 32 across study conditions. Viewing more messages was associated with an estimated decrease of 0.15 (SE, 0.01) cigarettes smoked per day per message viewed overall across conditions. Conclusions and Relevance: To our knowledge, this is the first longitudinal test of cigarette constituent campaign messages in a national sample of adults who currently smoke. Messages about cigarette smoke constituents, with or without engagement text and source information, increased participants' intentions to quit, lending support to FDA efforts to educate consumers about such constituents. Trial Registration: ClinicalTrials.gov Identifier: NCT03339206.