Brief Advice on Smoking Reduction vs. Abrupt Quitting for Smoking Cessation in Chinese Smokers: 18-Month Results of a Cluster Randomized Controlled Trial

Abstract

Background and Objectives: Effects of brief advice on cut-down-to-quit (CDTQ) and quit immediately (QI) on smoking abstinence are uncertain. Most related studies were based on intensive counseling or cessation medication in Western populations. We investigated the long-term effect of a brief advice on CDTQ vs. QI in Chinese adult smokers proactively recruited in the community in Hong Kong. Methods: Of 1307 smokers who enrolled in 2014 Hong Kong Council on Smoking and Health “Quit to Win” Contest, 1077 consented and were randomized to CDTQ (n=559) and QI (n=518) based on 67 recruitment sessions. Participants in CDTQ received brief advice and a card on smoking reduction strategies. Participants in QI received brief advice and a cessation leaflet on QI. All received a 12-page cessation booklet at baseline and corresponding CDTQ or QI brief booster advice through telephone at 1-week, 1-month and 2-month follow-up. Primary outcome was self-reported past 7-day point prevalence abstinence (PPA). Secondary outcomes were smoking reduction by ≥50% from baseline (including quitters), cessation/reduction attempt (including quitters) and self-efficacy on quitting. Analysis was by intention to treat. Adjusted odds ratio (AOR) and β-coefficient (β) of the outcomes were calculated, adjusting for baseline sex, age, employment and nicotine dependence. The retention rates at 18-month were 71.2% in CDTQ and 74.3% in QI. Results: Participants (mean age 42.0, SD 15.5; 81.4% male) shared similar socio-demographic characteristics and smoking, quitting behaviors except that those in CDTQ were more likely to have paid employment and higher level of nicotine dependence (p <0.05). Participants in CDTQ and QI groups had similar rates on 7-day PPA (12.5% vs. 13.7%; AOR 0.94, 95%CI 0.65-1.36) and cessation/reduction attempt (57.8% vs. 60.8%; 0.87, 0.68-1.12) at 18-month. Less participants in CDTQ had smoking reduction (33.3% vs. 39.6%; 0.77, 0.59-0.99; P=0.04). Both groups had similar perceived difficulty (β 0.20, 95%CI -0.04 to 0.45) and confidence (0.19, -0.13 to 0.51) of quitting, but those in CDTQ perceived quitting as more important (0.55, 0.27 to 0.82; P<0.001). Conclusions: Consistent with our previously reported 6-month findings, brief advice on CDTQ and QI for community smokers had similar effect on smoking abstinence at 18-month follow-up.