a large national survey has found.
“Over the past decade, there has been an increase in the use of cannabis among cigarette smokers and prevalence of cigarettes and cannabis co-use, suggesting that the negative consequences of cigarette–cannabis co-use may also become more prevalent over time,” wrote Andrea H. Weinberger, PhD, of Yeshiva University, New York, and colleagues. They noted that the prevalence of cigarette smoking is nearly three times higher among persons who use cannabis and have cannabis use disorders relative to those who do not.
The 2019 National Survey of Drug Use and Health estimated that 15.9% of Americans aged 12 years or older used cannabis in the past year. This number has been rising throughout the 2000s.
In that same report, cannabis use disorder (or marijuana use disorder) was defined as when an individual experiences clinically significant impairment caused by the recurrent use of marijuana, including health problems, persistent or increasing use, and failure to meet major responsibilities at work, school, or home. The report stated that approximately 1.6% of Americans aged 12 or older in 2018 had marijuana use disorder.
In the study published in Tobacco Control, the researchers used the National Survey on Drug Use and Health data to analyze cigarette smoking quit ratios among U.S. adults with and without cannabis use and cannabis use disorders. “Quit ratio was calculated as the proportion of former smokers among lifetime smokers and is considered a measure of total cessation in a population,” the researchers said.
In 2016, the quit ratios for adults with a history of cannabis use or cannabis use disorders were 23% and 15%, respectively, compared with 51% and 48%, respectively, in those with no cannabis use or cannabis use disorders.
Overall, quit ratios did not change significantly from 2002 to 2016 for individuals with cannabis use disorders after controlling for multiple demographic factors and other substance use disorders. However, during the same time period, quit ratios showed a nonlinear increase in cannabis users, nonusers, and individuals without cannabis use disorders.
The study findings were limited by several factors including the inability to generalize results to youth or individuals living outside the United States, the use of DSM-IV criteria to identify cannabis use disorder, the use of self-reports, and the inability to examine the timing of cannabis use as related to attempts to quit smoking, the researchers noted. However, the results highlight the need to consider offering smoking cessation treatment to individuals being treated for cannabis use disorders, and to include cannabis users in smoking cessation programs, the researchers noted.
“Based on our results, both public health and clinical efforts to improve cigarette quit outcomes may benefit from including those with any cannabis use,” they said. More research is needed to determine whether trends in the quit ratio change over time for cannabis users or those with cannabis use disorder, they added.
The study was funded by the National Institute on Drug Abuse. The researchers had no financial conflicts to disclose.
SOURCE: Weinberger AH et al. Tob Control. 2020;29(1):74-80. doi: 10.1136/tobaccocontrol-2018-054590.