Brief advice on smoking reduction versus abrupt quitting for smoking cessation in Chinese smokers: a cluster randomized controlled trial

Abstract

Aims: To compare the efficacy of brief advice about cut-down-to-quit (CDTQ) with that of brief advice about quit immediately (QI), as delivered by trained volunteers, without the use of pharmacological therapy, to outreach-recruited Chinese smokers in Hong Kong who intend to quit smoking. Methods: Smokers (N = 1077) who enrolled in the Quit and Win Contest 2014 and intended to quit or reduce smoking were randomized in participation sessions to CDTQ (n = 559) and QI (n = 518) groups. Subjects in the CDTQ group received brief advice and a card about smoking reduction. Subjects in the QI group received brief advice and a leaflet about quitting smoking. All received a smoking cessation booklet and corresponding CDTQ or QI brief telephone advice at intervals of 1 week, 1 month, or 2 months. The primary outcomes were self-reported 7-day point prevalence abstinence (PPA) at the 3-month and 6-month follow-ups. The secondary outcomes included abstinence rate as validated by biochemical tests, smoking reduction (.50% reduction from baseline), and quit attempt (QA). The outcome assessors were blinded as to group assignment. Results: By intention to treat, the QI and CDTQ groups showed similar results as regards (i) selfreported PPA (10.6% [95% CI 8.1%.13.6%] vs. 9.1% [95% CI 6.9%.11.8%]), (ii) validated abstinence rate (5.6% [3.8%.7.9%] vs. 5.4% [3.6%.7.6%]), and (iii) QA rate (59.2% [53.5%.64.8%] vs. 54.1% [48.7%.59.3%]) at 6-month. However, the CDTQ group showed a significantly higher reduction rate than the QI group (20.9% [CI 17.6%.24.5%] vs. 14.5% [11.6%.17.8%]). The overall intervention adherence was suboptimal (45.4%), particularly in the CDTQ group (42.3%). Self-efficacy as regards quitting of smoking was similar between the groups at 6 months. Conclusions: Brief advice on CDTQ and QI had similar short-term PPAs. Longer-term follow-up is needed to understand the latent effect of smoking reduction on abstinence. Implications: This is the first randomized controlled trial in ethnic Chinese smokers to evaluate the relative efficacy of brief advice on (a) CDTQ and (b) QI as regards quitting. The two interventions showed similar effects as regards PPA. The findings suggested that brief advice on CDTQ may be as effective as brief advice on QI in smokers recruited in community settings.