INTRODUCTION: Little is known about the extent of the illicit tobacco trade in low- and middle-income countries (LMICs) where more than 80% of tobacco users now live. We systematically reviewed literature from LMICs to investigate the share of illicit tobacco and the methods studies applied. METHODS: We searched nine electronic databases, three websites, and grey literature published in English from January, 2012 to July, 2023. Studies assessing the extent of illicit tobacco trade within LMICs were included. Two independent reviewers screened titles, abstracts, and full-text manuscripts' and extracted the data from those eligible. Studies were critically appraised using a bespoke framework. We conducted meta-analysis of the share of illicit tobacco and pooled the results with random effects. Analysis was stratified by type of tobacco and funding source. Based on the estimation methods for illicit tobacco, sub-group analysis was conducted. The review was registered in PROSPERO (CRD42023450354). RESULTS: Among 48 eligible studies from 39 LMICs, 41 disclosed independent (non-industry) funding sources. Only two studies estimated the share of illicit smokeless tobacco. Studies used three estimation methods: i) pack analysis (n=33), ii) gap analysis (n=13), and iii) trade monitoring (n=2). The pooled share of illicit smoking and smokeless tobacco was 14.4% (95%CI: 10.5-18.9) and 86.9% (95%CI: 51.1-100.0) respectively. CONCLUSIONS: Approximately one in every seven cigarette packs is likely to be illicit in LMICs. The share of illicit smokeless tobacco may be a lot higher, but the estimates were uncertain due to very few studies. IMPLICATIONS: Since the inception of WHO FCTC Illicit Tobacco Trade Protocol (ITP) in 2012 this review is the first attempt to systematically investigate the share of illicit tobacco in LMICs. We found that the evidence is lacking in many LMICs, even among ITP signatories. The share of illicit smokeless tobacco is considerably higher than the smoking tobacco. Given that there is no fiscal marking (e.g. tax stamp) on the packs, studies in LMICs mainly relied on packaging compliance to detect illicit tobacco products. The findings highlight the lack of evidence in LMICs and the importance of robust estimation of the share of illicit tobacco where the evidence is lacking.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)