Increase of unmotivated and hardened smokers in Hong Kong: a repeated cross-sectional trend analysis.

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.