Objectives To examine the trends in the prevalence of hardening indicators and hardened smokers in Hong Kong, where the low smoking prevalence has plateaued in the recent decade.

Methods This is an analysis of repeated cross-sectional data from 9 territory-wide smoking cessation campaigns conducted annually from 2009 to 2018 (except 2011). Participants were 9837 biochemically verified daily cigarette smokers aged ≥18 years (18.5% female, mean age 43.2±14.2 years) recruited from the communities. Hardening indicators included heavy smoking (>15 CPD), high nicotine dependence (Heaviness of Smoking Index ≥5), no intention to quit within next 30 days and no past-year quit attempt. Perceived importance, confidence and difficulty of quitting were measured (each ranged 0–10). Multivariable regressions were used to model the changes in hardening indicators by calendar year, adjusting for sociodemographic characteristics.

Results From 2009 to 2018, the prevalence of heavy smoking decreased from 57.6% to 39.4% (p<0.001), high nicotine dependence also decreased from 10.5% to 8.6% (p=0.06). However, the proportion of smokers with no intention to quit (12.7%–69.0%) and no past-year quit attempt (74.4%–80.4%) significantly increased (both p values <0.001). Hardened smokers (heavy smoking, no intention to quit, no past-year attempt quit attempt) significantly increased from 5.9% to 20.7% (p<0.001). Mean perceived importance (from 7.9±2.3 to 6.6±2.5) and confidence (from 6.2±2.6 to 5.3±2.4) of quitting also decreased significantly (all p values <0.001).

Conclusions Daily cigarette smokers in Hong Kong were motivational hardening, but not dependence hardening. Effective tobacco control policies and interventions are warranted to motivate quitting to further reduce smoking prevalence.