Background The South African Medicines Control Council classifies e-cigarettes as Schedule 3 substances and requires them to be dispensed only within pharmacies. e-Cigarettes are however ubiquitous and are marketed as cessation aids. We investigated the relationship between e-cigarette use and smoking cessation among South African adult smokers.

Methods Data came from a 2018 web survey of South African adults aged ≥18 years (n=18 208). Cessation-related attitudes and behaviours were assessed. Using multivariable logistic regression, we measured the association between e-cigarette use and cessation behaviours among ever-established combustible tobacco smokers who tried to quit.

Findings Among current combustible smokers, more e-cigarette ever versus never users believed e-cigarettes could assist smokers to completely quit (35.5% vs 20.4%) or cut down (51.7% vs 26.5%) (all p<0.05). Among ever-established smokers, the odds of sustained quitting at the 12-month mark were lower among those who used e-cigarettes once off/rarely (adjusted OR (AOR)=0.20, 95% CI=0.16–0.24), former e-cigarette users (AOR=0.30, 95% CI=0.24–0.38) and current e-cigarette users (AOR=0.23, 95% CI=0.18–0.29), compared with never e-cigarette users. Among ever-established smokers who had ever tried to quit, 53.6% relapsed into smoking after quitting for any length of time. The odds of relapsing among ever-established smokers who had made a quit attempt and had a quit intention were higher among those who used e-cigarettes once off/rarely (AOR=2.66; 95% CI=2.31–3.08), former e-cigarette users (AOR=1.41; 95% CI=1.18–1.69) and current e-cigarette users (AOR=1.85; 95% CI=1.55–2.22) than never e-cigarette users.

Conclusion e-Cigarette use depressed long-term cessation. These findings can inform restrictions on unsubstantiated claims of e-cigarettes as cessation aids within South Africa.