The purpose of this study is to test the effectiveness of using a brief, self-determination intervention on smoking cessation (immediate or progressive) for people attending AEDs.

Cigarette smoking, which causes serious damage to health resulting in many chronic problems including cancer, heart disease, stroke and lung disease, is the single most important, preventable cause of death and diseases. It is therefore crucial that healthcare professionals should promote smoking cessation and help patients quit. The Hong Kong government and community have put enormous efforts on raising tobacco tax, smoke-free legislation, law enforcement, health promotion campaigns and smoking cessation services. The prevalence of daily cigarette smokers has been decreasing from 23.3% in 1982 to 10.7 % in 2012, which is one of the lowest around the world. Nevertheless, about half of the smokers remain reluctant to even try giving up smoking.

Medical attention at Accident and Emergency Departments (AEDs) of smokers who are in physical discomfort can be developed as an excellent "teachable model" as it provides an invaluable opportunity to initiate smoking cessation. Smokers consulting doctors as an emergency are more liable to change their habits to improve their health. According to the Hospital Authority, about 2 million people attend AEDs in Hong Kong each year, of whom 68% are triaged as semi-urgent (level 4) and non-urgent (level 5). The average waiting time for a medical consultation varies among AEDs, but is generally longer than 30 min for triage level 4 and 1-2 h for level 5 - presenting healthcare professionals with a golden opportunity to advise smokers to quit and on the available smoking cessation programmes while they are waiting. However, most of the cessation programmes, including stage-matched interventions, generally take several to more than 30 minutes to implement and hence are not practicable or feasible in busy clinical settings. Indeed, the most common reason cited by healthcare professionals for being unable to help patients to quit smoking is the lack of time, because they are very busy and cannot spare even a few extra minutes to do so. Other barriers include a lack of training and experience, a lack of confidence in the effectiveness of the interventions, and the absence of incentives and deficiencies in support or requirements by hospital management that these programmes should be implemented. Moreover, our previous smoking cessation projects in outpatient clinics have revealed that many patients are too impatient to undergo a long intervention and some are reluctant to participate for fear that they might miss or experience delays in their medical consultation or other medical procedures. To address such problems, further studies are warranted to develop brief and effective interventions with simple, direct, strong, evidence-based warnings for patients who smoke.

Smoking is addictive and quitting is very difficult, with a high rate of relapse, particularly among those with high nicotine dependency. Our previous smoking cessation projects in outpatient clinics and the community have revealed that many smokers who are reluctant to quit are interested in reducing the number of cigarettes smoked per day. Therefore, another potential option would be to help smokers to reduce the number of cigarettes smoked gradually, with the ultimate goal of complete cessation. Several randomised controlled trials in the West have supported that smoking reduction interventions can help smokers first reduce and eventually quit smoking.

What investigators have achieved to date:

Investigators conducted a 'proof-of-principle' pilot randomised controlled trial on a very brief (<30 s) smoking cessation intervention with a 'one in two smokers will be killed by smoking' warning in medical outpatient clinics in Guangzhou. The results showed that more of the smokers who received this brief advice quit or reduced their smoking than did not. This pilot study suggested that even a very brief intervention on smoking cessation is better than no advice in the 'real world' practice for outpatient clinics. Moreover, the study demonstrated the feasibility and acceptability of the implementation of a very brief smoking cessation programme by healthcare professionals in busy clinical settings. In addition, the findings support the need for large randomised controlled trials of brief or minimal interventions with the 'one in two' warning.

In light of the above purpose, investigators designed a study with an experimental intervention for smoking cessation and a placebo comparator to act as control. Smokers randomly assigned to the intervention group were given a very brief (<30 s) smoking cessation intervention during telephone follow-ups with a 'one in two smokers will be killed by smoking' warning, and a self-help quitting leaflet published by the Hong Kong Council on Smoking and Health plus a series of brief interventions using the AWARD model. Whereas smokers randomly assigned to the placebo control group were given a 'placebo' intervention with a 'placebo booster' during telephone follow-ups (that had the same duration as the intervention), except that the content was about increasing physical activity and fruit and vegetable intake.

Inclusion Criteria:

• aged 18 years or above
• triaged as semi-urgent (level 4) or non-urgent (level 5)
• current smokers, either occasional or daily
• express a willingness to quit smoking

Exclusion Criteria:

• poor cognitive state or mental illness
• participation in other smoking cessation programmes or services