Among whom is cigarette smoking declining in the United States? The impact of cannabis use status, 2002-2015

Objectives: To 1) estimate changes in the prevalence of daily and non-daily cigarette smoking among current (past 30-day) daily, non-daily, and non-cannabis users in the United States (U.S.) population; 2) examine time trends in current (past 30-day) cigarette smoking in daily, non-daily, and non-cannabis users ages 12+ from 2002 to 2015. Methods: Data collected annually from the 2002 to 2015 National Survey on Drug Use and Health (NSDUH) were employed. Linear time trends of daily and non-daily cigarette smoking were assessed using logistic regression with year as the predictor. Results: In 2015, the prevalence of current (past 30-day) cigarette smoking was highest among daily (54.57%), followed by non-daily (40.17%) and non-cannabis users (15.06%). The prevalence of non-daily cigarette smoking increased among daily cannabis users from 2002 to 2015, whereas non-daily cigarette smoking declined among non-daily cannabis users and non-cannabis users from 2002 to 2015. Daily cigarette smoking declined among both cannabis users and non-users; the most rapid decline was observed among daily cannabis users, followed by non-daily and then by non-cannabis users. However, the relative magnitude of the change in prevalence of daily cigarette smoking was similar across the three cannabis groups. Conclusions: Despite ongoing declines in cigarette smoking in the U.S., non-daily cigarette smoking is increasing among current cannabis users, a growing proportion of the U.S. population. Daily and non-daily cigarette smoking continue to decline among those who do not use cannabis. Efforts to further tobacco control should consider novel co-use-oriented intervention strategies and outreach for the increasing population of cannabis users.