E-cigarette use by people who smoke or have recently quit, New South Wales, 2016-2020.

Objective: To examine e-cigarette use by adults who smoke or have recently quit, and demographic characteristics associated with their use; to assess reasons for using e-cigarettes.

Design: The Cancer Institute NSW Tobacco Tracking Survey (CITTS) is an ongoing, serial, cross-sectional telephone survey study (40 interviews each week). This report is based on interviews during 4 January 2016 - 31 December 2020.

Setting, Participants: Randomly selected New South Wales adults who are current smokers (smoked cigarettes, pipes, or other tobacco products daily, weekly, or less often) or recent quitters (smoked tobacco products in the past twelve months but who no longer smoked).

Main Outcomes: E-cigarette use by age group; reasons for using e-cigarettes.

Results: CITTS callers rang 1 494 233 randomly selected numbers; in 203 203 answered calls (13.6%), 11 125 people were eligible for the survey (5.5% of answered calls), of whom 10 004 completed the survey interview, including the question about whether they used e-cigarettes (89.9%). Overall e-cigarette use increased from 6.6% of respondents in 2016 to 13.0% in 2020 (adjusted odds ratio, 1.86; 95% confidence interval [CI], 1.47-2.36). The proportion of respondents aged 18-24 years who reported e-cigarette use increased from 18.4% (95% CI, 12.9-23.9%) in 2018 to 27.2% (95% CI, 20.5-33.9%) in 2020, a larger proportion than for any other age group. The leading reasons offered for e-cigarette use were "to help me quit smoking" (33%; 95% CI, 30-37%) and "to cut down on the number of cigarettes I smoke" (25%; 95% CI, 22-28%).

Conclusion: The increase between 2016 and 2020 in the proportions of young adults who smoke or have recently quit who use e-cigarettes undermines claims that these products are designed for older smokers who have struggled to quit using other methods.