Inclusion and exclusion criteria
Studies with the following criteria were included:1) Only randomized controlled trials (RCTs) evaluating the effect of different drugs on smoking cessation were included. 2) Population: alcohol-drinking smokers, each trial had reports on consumption of alcohol and smoking. 3) Intervention: the experimental group accepted pharmacotherapies and the control group received a placebo; 3) Outcomes: only the indicators related to smoking were included, smoking cessation rate signified the number of people who quit smoking (such as continuous abstinence and point prevalence abstinence), recorded at the end of each treatment.
Studies that were duplicate reports or with insufficient data, such as protocols, conference proceedings, or abstracts, were excluded. Studies written in languages other than English were not included.