Smoking cessation: Q&A with respiratory specialist Dr Ong Kian Chung

24 Feb 2019
Smoking cessation: Q&A with respiratory specialist Dr Ong Kian Chung

Dr Ong Kian Chung, a respiratory specialist at the KC Ong Chest & Medical Clinic, Mount Elizabeth Medical Centre, Singapore shares his insights with Pearl Toh on the evils of tobacco use and how clinicians can help in smoking cessation.  


Smoking poses serious health risks. Can you attach any numbers on the prevalence and disease burden of smoking?

Yes, smoking kills! About 16.1 percent of working adults smoke in Singapore.  

Approximately 5 million deaths worldwide per year can be attributed to smoking-related illnesses. This is roughly equivalent to 1 person dying every 10 seconds from the effects of smoking. And this is not inclusive of the effects of second-hand or passive smoking or the effects of maternal smoking during pregnancy on unborn children. As smoking contributes significantly to mortality and morbidity worldwide, it is the largest single preventable cause of death.

Tobacco use is a significant public health problem in Singapore. As a risk factor, it is the second-highest contributor to the burden of disease in Singapore. More than 2,000 Singaporeans die prematurely from smoking-related diseases each year. This works out to about six Singaporeans dying prematurely from smoking-related diseases each day. The social cost of smoking in Singapore has been conservatively estimated to be at least $600 million a year in direct healthcare costs and lost productivity. []

What is the current trend of smoking in Singapore? Do you see it increasing or decreasing and which age groups are most affected?

According to the 2010 National Health Survey, smoking prevalence in Singapore has risen from 12.3 percent in 2004 to 14.3 percent in 2010 — this is a reversal of a long-term decline previously. This trend is mainly driven by increased smoking among young adults, aged 18–39. []

It is quite clear that most smokers couldn’t last a day without lighting up a cigarette, and I should say it is a form of addiction that is second to none. Could you graphically illustrate the untold evils of tobacco use that is not usually seen by those hooked to it? 

From the more obvious ill-effects of cigarette smoke on the respiratory system (viz., mouth, throat, wind-pipe, bronchi, lungs) and cardiovascular system, these effects extend to almost every bodily system or function. For instance, most people are aware that smoking is a major risk factor for lung cancer but fewer individuals are aware that smoking is also heavily linked to other cancers such as bladder cancer and lymphoma/leukaemia.

Most people only associate smoking with serious medical conditions but not “lifestyle” or “aesthetic” effects such as erectile dysfunction/ subfertility, premature skin wrinkling, poor dentition etc. Thus, it is helpful for physicians and counsellors to point out these inimical effects of smoking when dealing with young and healthy individuals who are smoking. 

Passive smoking (exposure to environmental tobacco smoke [ETS]) is also harmful – young children are most affected by ETS and least able to avoid it. Most of their exposure to SHS comes from adults (parents or others) smoking at home. Studies show that children whose parents smoke:

  • Get sick more often
  • Have more lung infections (like bronchitis and pneumonia)
  • Are more likely to cough, wheeze, and have shortness of breath
  • Get more ear infections

ETS can also trigger asthma attacks, make asthma symptoms worse, and even cause new cases of asthma in kids who didn’t have symptoms before.

Some of these problems might seem small, but they can add up quickly. Think of the expenses, doctor visits, medicines, lost school time, and often lost work time for the parent who must stay home with a sick child. And this doesn’t include the discomforts that the child goes through.

In very young children, SHS also increases the risk for more serious problems, including sudden infant death syndrome (SIDS).

Alternatives to cigarettes have been the talk of the town in the respiratory community.  Do you consider such products as a new ray of hope for those wanting to quit or do you see those as just a hype that is even more dangerous than smoking?

Most young people are unaware of the harm of cigarette alternatives such as shisha, chewable tobacco and electronic nicotine delivery devices (ENDS).  For instance, a shisha session typically lasts for about 2 hours, whereas, a cigarette hardly lasts more than 5 minutes. So, it is obvious that shisha smokers actually inhale more tobacco smoke than cigarette smokers, in one session.

The water in a shisha does not do what it is purported to do which is filter out the toxic ingredients in the tobacco smoke. Instead, the water cools down the smoke and makes it less irritating, allowing the smoker to go on for hours – much longer than they would with cigarettes. In an average water-pipe session, a person inhales about 2-3 times the amount of nicotine compared with a cigarette. []

In addition, the mouth piece of the shisha pipe is shared among many which can lead to infectious diseases being spread such as pneumonia, tuberculosis, and even herpes (cold sores on the mouth).

The debate on the harms and benefits of ENDS seem never-ending (pun intended). Most experts, in my opinion, will accept that E-cigarettes are generally less harmful than conventional ones.

However, less harmful certainly does not mean they are harmless. Toxic substances found in E-cigarettes have been linked with lung disorders as well as a higher chance of cardiovascular morbidity. And countries where E-cigarettes are unrestricted face the possibility of rampant use of E-cigarettes among the young. There is also the possibility of rising E-cigarettes use serving as a gateway to tobacco use in such individuals later on.  Opponents of E-cigarettes also raise concern that compounds in E-cigarettes such as flavourings can still be harmful and may promote teen vaping.

Some experts consider E-cigarettes to be beneficial as a quit-aid in smoking cessation, although others caution that this opinion is not supported by scientific evidence. A recent study found that E-cigarettes are more effective than NRT for smoking cessation when both are combined with behavioural therapy. [N Engl J Med 2019;380:629-637] This is the first study of its kind directly comparing E-cigarettes vs NRT use in smoking cessation and concluded that E-cigarettes use achieved quit rates double those of NRT. However, 80 percent of the successful quitters in the E-cigarettes group were still using E-cigarettes at end of 1 year compared with 9 percent in the NRT group still using NRT at the end of a year. So it remains debatable how effective E-cigarettes are in achieving total abstinence.

What are the risk factors that can help identify people more likely to take on smoking?

The young and impressionable are most susceptible to peer-pressure in smoking initiation. Thus, it is unsurprising that most smokers in Singapore (as in other countries) start smoking before they are 21 years old. Adults who are stressed or anxious or depressed are more likely to smoke. In addition, smokers with mental disorders encounter more difficulty in quitting.

The abrupt and complete cessation of smoking may be difficult for smokers. What are the treatments currently available to help them quit the addiction?

A variety effective quit smoking aids available include medication such as varenicline, nicotine replacement therapy (NRT), and acupuncture.

Varenicline reduces nicotine cravings while decreasing the pleasurable effects of smoking by blocking receptors associated with nicotine addiction in the brain. It is different from other treatments such as gums or patches that deliver nicotine without the use of tobacco products. Studies have shown that varenicline was effective in chronic obstructive pulmonary disease (COPD) and smoking cessation was associated with improved lung function in these patients. [Eur Respir Rev 2013; 22: 127, 37-43; Thorax 2017;72:905-911]

How about non-pharmacological strategies for smoking cessation?

A combination of behavioural support and medication quadruples the chances of a successful quit

attempt. Hence, current smoking guidelines recommend a combination of counselling by a trained professional in addition to at least one medication to treat nicotine dependence. The goal of counselling is to help the smoker identify the triggers for smoking and develop coping strategies during the period of smoking cessation/reduction.

How can GPs help in the nationwide campaign to reduce smoking prevalence?

Although most smokers want to stop smoking, only about 15 percent, are ready to stop smoking at any given time (preparation phase). Of the remaining 85 percent of smokers, 15 percent are actually in the process of stopping smoking (action phase), and 70 percent of smokers are not actively thinking about stopping smoking (precontemplation and contemplation phases).

A professional can easily ascertain if a current smoker is ready to stop smoking by asking if he/she has thought of quitting. If the answer is affirmative and the smoker intends to do so within one month, he/she is in the action/preparation phase and should be actively helped. If the smoker is thinking of quitting, but not anytime “soon”, he/she is in the contemplation phase and should be encouraged and offered support when he/she is ready to quit.

For the 70 percent of smokers not thinking about stopping smoking, the healthcare provider need not spend much time, but the time spent is critically important. The patient should clearly and unambiguously hear from the healthcare provider that stopping smoking is the single most important thing the patient can do to improve health.

Here, the doctor should take the opportunity of including the advice of smoking cessation in the treatment plan of the patient who has any illness caused by or associated with smoking. Familiarizing oneself with the harmful effects of smoking as well as the benefits of quitting is elemental in providing advice for smoking cessation. Even a brief period of advice given by a medical professional can significantly enhance a smoker’s long-term quit rate.

Do you see it as a social responsibility for doctors to help smoking cessation?

The responsibility of health professionals like us is to help patients stop smoking and this is an important aspect of the treatment of many diseases, especially those related to smoking. Any intervention to assist smokers to quit smoking is likely to have major impact on reducing the burden of disease, not only for the individual patient but also for the society. In fact, smoking cessation is considered the most cost-effective medical intervention for any healthcare service. No other preventive intervention is more cost-effective than smoking cessation.

Dr Ong Kian Chung, KC Ong Chest & Medical Clinic, Mount Elizabeth Medical Centre,

Dr Ong Kian Chung, KC Ong Chest & Medical Clinic, Mount Elizabeth Medical Centre,

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