Interactions between ENDS and cigarette use: evidence from a 2022 national telephone survey in South Africa.

Introduction: Electronic nicotine delivery systems (ENDS) may serve as a cessation tool for people who smoke cigarettes. However, for people who do not smoke, ENDS may be a gateway to nicotine addiction and cigarette use. This paper aims to quantify these behaviours in South Africa.

Methods: We analysed a nationally representative telephone survey of 21 263 South Africans living in urban areas. For those respondents who had used both products (N=771), we developed a typology that describes the sequence in which cigarette and ENDS initiation occurred. 'On-rampers' describe people who used ENDS first and later initiated cigarette smoking. 'Off-rampers' describe people who used cigarettes first, took up ENDS and later quit cigarettes while still using ENDS. 'Failed off-rampers' describe people who started using ENDS while smoking cigarettes but later quit using ENDS. 'Continuing dual consumers' describe people still using both products at the time of the interview.

Results: Of the overall sample (N=21 263), 1.7% used or had used ENDS but had no history of using cigarettes. Of dual consumers (N=771), 8.8% were classified as 'on-rampers', 13.9% as 'off-rampers', 20.9% as 'failed off-rampers' and 56.4% as 'continuing dual consumers'. Roughly half of those classified as off-rampers, failed off-rampers or continuing dual consumers stated that they started using ENDS to help them quit cigarettes.

Conclusions: The typology reveals a multifaceted relationship between ENDS and cigarette use in South Africa. Policy interventions should aim to minimise on-ramping and maximise off-ramping. Given the high prevalence of continued dual use and failed off-ramping, targeted cessation support should be provided for people who use ENDS and are trying to quit cigarettes.