Transitions to smokeless tobacco use among adult cigarette smokers in the Population Assessment of Tobacco and Health (PATH) Study, Waves 3–5 (2015–2019)

ObjectiveExamine patterns of dual use of cigarettes and smokeless tobacco and complete switching over time among adult current cigarette smokers using data from the Population Assessment of Tobacco and Health Study Wave 3 (2015–2016), Wave 4 (2016–2018) and Wave 5 (2018–2019).MethodsWe examined four tobacco use states among 6834 exclusive smokers and 372 dual users at Wave 3 with two waves of follow-up data: exclusive cigarette use, exclusive smokeless tobacco use, dual use and use of neither product.ResultsAmong exclusive smokers at Wave 3, only 1.6% (95% CI: 1.3% to 2.1%) transitioned to dual use at Wave 4, and 0.1% (95% CI: 0.07% to 0.2%) switched to exclusive smokeless tobacco use. Among exclusive smokers who switched to dual use, 53.1% (95% CI: 40.9% to 64.9%) returned to exclusive cigarette smoking, 34.3% (95% CI: 23.8% to 46.6%) maintained dual use and 12.6% (95% CI: 7.0% to 21.7%) did not smoke cigarettes after an additional wave of follow-up. Dual users at Wave 3 were likely to maintain their dual use status at Wave 4, 51.2% (95% CI: 46.1% to 56.3%) and Wave 5, 47.9% (95% CI: 40.1% to 55.8%).ConclusionsVery few cigarette smokers transition to smokeless tobacco use, and among those who do, dual use is more common than exclusive smokeless tobacco use. Further, the majority of exclusive cigarette smokers who transition to dual use at Wave 4 continue smoking cigarettes at Wave 5, either as dual users or as exclusive smokers.

Smokeless tobacco use and reproductive outcomes among women: a systematic review

Background: Both smoked and smokeless tobacco use have deleterious effects on most major organ systems including the reproductive system. We conducted a systematic review on smokeless tobacco (SLT) use and reproductive outcomes among women. Methods: We searched Pubmed, ProQuest, Cochrane, Wiley and Emerald databases for studies involving smokeless tobacco use in women with any or a combination of three conditions: infertility, menstrual disorders and pelvic inflammatory disease (PID). Eligibility criteria included English language publications from 1st January 1990 - 31st October 2020. CADIMA software used for filtering the studies and modified SIGN checklist for the quality assessment. The findings are reported as per the PRISMA guidelines. The AXIS and ROBIN E tool were used for assessment of risk of bias. Results: In total, three studies addressed our research question. Two studies addressed infertility (prospective cohort: n=501, cross sectional: n=192) of which, the cross-sectional study compared the mean cotinine levels between those with infertility, menstrual disorders and PID. This study also explored the association between SLT and PID. PID was the most common gynecological complaint. Women with PID had significantly higher urinary cotinine levels = 24.95±12.259) ng/ ml (p=0.0144). Mean urinary cotinine in women with menstrual complaints was 19.32±10.29 ng/ml. The other study used population-based sampling of 501 couples who attempted pregnancy (enrolled in the LIFE Study). Results showed that only 2% (n=28) of men and none of the women used smokeless tobacco. Compared with never users of tobacco, smoking by females was individually associated with longer time-to-pregnancy; smoking among males remained significant when modeling partners together. Conclusions: Available studies exploring associations between SLT and reproductive outcomes are inconclusive due to limitations in the study methodologies. More studies with robust study designs are required from low- and middle-income countries with high prevalence of SLT use.