Commentary on Higashi & Barendregt (2012): Smoking cessation therapies in Vietnam


In 2012, an estimated 6 million people will die as a result of tobacco use. The World Health Organization projects that over the course of the 21st century, 1 billion people could die of tobacco-related causes [1]. Smoking remains the most prevalent behavioral threat to life and health across the globe.

Rapidly developing economies of southeast Asia face especially high tobacco-related health burdens. An estimated 47% of Vietnamese men (and 1% of women) smoke. Eighty-two per cent of these smokers smoke daily [2]. Rising per-capital income may increase smoking prevalence by lowering the economic barriers to tobacco use. Economic growth may also support the use of more costly and more effective prevention strategies and smoking cessation therapies that are used widely within more wealthy societies, although not used in Vietnam to this point. Within a US context, a variety of intervention strategies, including the use of bupropion and nicotine replacement therapies (NRT), are highly cost-effective [3]. Given the reality of scarce resources, Vietnamese medical and public health authorities face an especially strong need to evaluate proposed treatment interventions rigorously.

The contribution by Higashi & Barendregt is therefore welcome [4]. These authors perform extensive cohort simulation analyses to examine the cost-effectiveness of personal smoking cessation services within a Vietnamese context and the estimated change in smoking prevalence associated with each several interventions, and express the resulting health outcomes into disability-adjusted life-years (DALYs).

In comparing alternatives, the authors follow recommendations of the World Health Organization's Commission on Macroeconomics and Health [5]. These deem an intervention ‘very cost-effective’ if it costs less than the average per-capita income to save one DALY. In 2010 this amounts to approximately $1200 per DALY, given published economic information regarding the Vietnamese economy [6]. The authors deem an intervention ‘cost-effective’ if it costs less than three times the average per-capita income (approximately $3600) to save one DALY. At this low level of income (compared with the wealthy industrial democracies), Vietnam faces stringent cost-effectiveness constraints in the financing of effective treatment interventions.

The mathematical details in Higashi & Barendregt's analysis are sometimes complex. Moreover, the specific lack of Vietnamese randomized trial data forces the authors to perform reasonable extrapolation at many points in the analysis and to perform correspondingly rich sensitivity analyses. The results remain reasonably clear and robust: brief physician advice is by far the most cost-effective intervention. Standard pharmaceutical therapies are simply too costly at current prices and at current levels of Vietnamese income.

The paper's main findings may also change over time. If gross domestic product (GDP) per capita were to increase by 50%—not an unreasonable possibility, given current growth rates—it becomes cost-effective to complement brief physician counseling with medications such as bupropion and varenicline. Indeed, the Vietnamese government might use the present cost-effectiveness results in bargaining with pharmaceutical firms to indicate maximum prices at which smoking cessation products and medications might be purchased.

If brief physician counseling remains the backbone of smoking cessation efforts, strategies to improve the effectiveness of such counseling warrant special investigation. For example, Vietnamese nurses or other non-physician staff could complement this brief advice in a variety of ways. Inclusion of methods such as motivational interviewing (tailored to local context) may also be effective. Given the low cost of such counseling, measures that produce even small improvements in quit rates are likely to be extremely cost-effective.

Proliferating cellphone use may offer other possibilities for brief counseling or for reinforcement of smoking cessation messages. An estimated 58% of urban Vietnamese and 37% of Vietnamese in rural areas own mobile telephones [7].

The latter two paragraphs highlight an even more important point. Vietnamese authorities and global partners such as the US Centers for Disease Control and Prevention should pursue aggressively rigorous trials of medical and public health interventions supported in the research literature. At current smoking rates, Vietnam will experience extremely high mortality and morbidity associated with tobacco use. Reducing this health toll through evidence-based, locally tailored and evaluated interventions will be a central task for many years to come.

Policy simulations such as Higashi & Barendregt's will usefully inform these efforts. There remains no substitute for well-designed clinical trials on such central matters of life and health.

Declaration of interests