Study characteristics
As shown in Table 1, the included RCTs involved 908 smokers with alcohol
dependence (450 in treatment groups and 458 in control groups). All
studies were published between 2005 and 2020 in the United States (n =
8) and Canada (n = 1). Most smokers were over 40 years old and smoked
more than ten cigarettes per day. The treatment group in each RCT
examined one of four drugs, including Varenicline (n = 3), Naltrexone (n
= 3), Topiramate (n = 2), Bupropion (n = 1), and all RCTs gave a placebo
to the control group. The duration of the measurement phase ranged from
two weeks to six months, and the outcome indicator of all studies was
the smoking cessation rate