Health, Health Inequality, and Cost Impacts of Annual Increases in Tobacco Tax: Multistate Life Table Modeling in New Zealand

Background: Countries are increasingly considering how to reduce or even end tobacco consumption, and raising tobacco taxes is a potential strategy to achieve these goals. We estimated the impacts on health, health inequalities, and health system costs of ongoing tobacco tax increases (10% annually from 2011 to 2031, compared to no tax increases from 2011 [“business as usual,” BAU]), in a country (New Zealand) with large ethnic inequalities in smoking-related and noncommunicable disease (NCD) burden. Methods and Findings: We modeled 16 tobacco-related diseases in parallel, using rich national data by sex, age, and ethnicity, to estimate undiscounted quality-adjusted life-years (QALYs) gained and net health system costs over the remaining life of the 2011 population (n = 4.4 million). A total of 260,000 (95% uncertainty interval [UI]: 155,000–419,000) QALYs were gained among the 2011 cohort exposed to annual tobacco tax increases, compared to BAU, and cost savings were US$2,550 million (95% UI: US$1,480 to US$4,000). QALY gains and cost savings took 50 y to peak, owing to such factors as the price sensitivity of youth and young adult smokers. The QALY gains per capita were 3.7 times greater for Māori (indigenous population) compared to non-Māori because of higher background smoking prevalence and price sensitivity in Māori. Health inequalities measured by differences in 45+ y-old standardized mortality rates between Māori and non-Māori were projected to be 2.31% (95% UI: 1.49% to 3.41%) less in 2041 with ongoing tax rises, compared to BAU. Percentage reductions in inequalities in 2041 were maximal for 45–64-y-old women (3.01%). As with all such modeling, there were limitations pertaining to the model structure and input parameters. Conclusions: Ongoing tobacco tax increases deliver sizeable health gains and health sector cost savings and are likely to reduce health inequalities. However, if policy makers are to achieve more rapid reductions in the NCD burden and health inequalities, they will also need to complement tobacco tax increases with additional tobacco control interventions focused on cessation. Using a multistate life table modeling approach, Frederieke van der Deen and colleagues estimate the potential impact of annual increases in tobacco tax on health and health inequalities in New Zealand.Background: Worldwide, approximately 21% of the population aged 15 and above smoke cigarettes and other tobacco products. However, tobacco is a killer. Half of all tobacco users die because of cancer, lung disease, heart disease, or another tobacco-related disease. Tobacco caused 100 million deaths in the 20th century; if current trends continue, it could cause a many more deaths in the 21st century. In response to this global tobacco epidemic, individual countries are considering how to reduce or even end tobacco consumption (the “tobacco endgame”), and international bodies have drawn up various tobacco control directives. The World Health Organization, for example, has developed an international instrument for tobacco control called the Framework Convention on Tobacco Control (FCTC). Countries that are party to the FCTC agree to implement a wide range of measures designed to reduce tobacco use. For example, they agree to implement bans on tobacco advertising, promotion, and sponsorship and to protect people from tobacco smoke exposure in public spaces and indoor workplaces. Why Was This Study Done?: An important tobacco control measure is the implementation of taxation policies aimed at reducing tobacco consumption, promoting cessation, and preventing young people from taking up smoking. But less is known about the impact on population health, health inequality (higher rates of illness and death in specific parts of the population), and health system costs of annual tobacco tax increases, a strategy that is being used or considered by many countries. Here, the researchers estimate the impact of annual tobacco tax increases compared with no tax increases in New Zealand using a mathematical approach called multistate life table modeling. In New Zealand, a country that collects data on disease incidence and mortality by sociodemographic status and has implemented annual tobacco taxation increases since 2010, there are marked health inequalities between indigenous Māori (15% of the population) and non-Māori residents. Smoking is a major cause of these existing health inequalities (as in many other countries)—33% of Māori smoke compared to 14% of New Zealand Europeans. A life table shows, for each age, the probability that a person of that age will die before his or her next birthday. What Did the Researchers Do and Find?: The researchers estimated quality-adjusted life-years (QALYs; a measure of disease burden that includes both the quantity and quality of life lived) gained and net health system costs over the remaining life of New Zealand’s 2011 population exposed to annual 10% tobacco tax increases or to no tax increases by modeling 16 tobacco-related diseases in parallel using national data on all-cause mortality and morbidity (illness). Compared to the 2011 population exposed to no tax increases, 260,000 QALYs were gained among the population exposed to annual tax increases from 2011 to 2031 and followed up for the remainder of their lives. The net health system cost savings associated with this intervention were estimated at US$2,550 million over the remainder of the 2011 population’s life. Both the health gains and cost savings began to accrue immediately but took five decades to peak. The QALY gains per capita associated with annual tobacco tax increases were 3.7-fold higher for Māori than for non-Māori because of higher smoking levels and price sensitivity among Māori (the tobacco purchasing behavior of Māori is affected more by the price of tobacco than non-Māori because they have less disposable income). Finally, projected health inequalities measured by the difference in mortality rates among Māori and non-Māori aged 45+ y were 2.3% lower in 2041 with ongoing tax rises than with no tax rises. What Do These Findings Mean?: These findings suggest that in New Zealand (and probably in other similar populations), ongoing tobacco tax increases should deliver sizeable health gains and health system cost savings and should modestly reduce health inequalities. Notably, the health gains and cost savings will not peak for several decades because smoking is more common among younger age groups and the tobacco tax effect is greater among young people (who have limited disposable income) but young people do not benefit maximally from reduced rates of tobacco-related diseases for many decades. As with all modeling studies, the accuracy of these findings depends on the assumptions built into the model and the data fed into it. Overall, however, these findings support the use of annual increases of tobacco tax as a way to improve population health, save health system costs, and reduce health inequalities but suggest that policy makers will need to introduce other tobacco control interventions focused on smoking cessation among middle-age to older smokers if they want to achieve more rapid reductions in tobacco-related diseases and health inequalities. Additional Information: This list of resources contains links that can be accessed when viewing the PDF on a device or via the online version of the article at http://dx.doi.org/10.1371/journal.pmed.1001856.