Quitting and softening in the Singapore smokers survey cohort, 2019/2020-2023

As smoking prevalence declines, it is important to understand whether those who continue to smoke soften or harden (become more or less amenable to quitting, respectively) to inform the development of tobacco control programmes. This study examined quitting, softening and hardening, and the characteristics of those who quit or softened, from 2019/2020 to 2023 in a cohort of Singaporean smokers.

We analysed baseline (2019/20) and follow-up (2023) data from 1059 Singaporean adults who were currently smoking at baseline. We categorised them as having quit, softened, hardened or remained unchanged based on cigarettes per day, quit attempts and quit intentions. We used multinomial logistic regression to identify sociodemographic and behavioural traits associated with quitting or softening.

From 2019/2020 to 2023, 19.5% of participants quit, 13.7% softened, 9.0% hardened and the proportion of 'middle' (not hardcore or soft) smokers decreased from 75.4% to 57.8%, primarily due to quitting or softening. Current vaping increased from 3.1% to 21.0% and was associated with softening (adjusted OR (AOR) 2.22; 95% CI 1.20 to 4.10), but not quitting. Quitting was independently associated with non-daily smoking (AOR=7.15), frequent physical activity (AOR=3.16), unemployment (AOR=2.36) and female gender (AOR=2.06).

As smoking declined, the cohort showed trends of quitting and softening but not hardening. Softening and quitting were associated with distinct characteristics, pointing to a need for targeted interventions to support quitting among 'softeners'. Vaping was associated with softening but not quitting, suggesting caution in interpreting vaping as a cessation aid.