Background
China has experienced tremendous socioeconomic changes in the past 30 years, during which time rapid economic development substantially influenced the diets and lifestyles of the Chinese population. Meanwhile, a remarkable epidemiological and demographic transition has markedly changed the country’s leading causes of death [
1]. Non-communicable diseases (NCDs) such as cardiovascular disease (CVD), cancer, and chronic respiratory diseases have become top killers in the Chinese population, accounting for 86.6% of total deaths in 2013 [
2]. In contrast, deaths from communicable diseases and injuries have decreased by 73.0% and 23.6% since 1990, respectively [
2]. Unhealthful lifestyle factors, such as tobacco use, drinking, insufficient exercise, and imbalanced diet, are still prevalent in the population despite the behavior modification efforts made by public health practitioners to reduce these risk exposures in the past decades [
3,
4]. Moreover, the prevalence of metabolic risk factors, including excess weight/obesity, hypertension, and hyperglycemia, has been increasing rapidly in the last decade [
5‐
7]. If these risk factors are not well controlled, the disease burden of NCDs will continue to rise.
In 2011, the United Nations (UN) High-level Meeting on NCDs announced a worldwide initiative to prevent and control NCDs [
8]. The World Health Organization (WHO) and its member states subsequently agreed on a target of a 25% reduction by 2025 in the probability of premature death among people aged 30–70 years for four main NCDs: CVD, diabetes, cancer, and chronic respiratory disease [
9]. In September 2015, the UN General Assembly formally released the 2030 Agenda for Sustainable Development, which included a set of 17 bold new Global Goals and 169 specific targets. The agenda also includes the aim of reducing by one third premature mortality from NCDs compared to the current level [
10]. To reach that goal, the WHO Global Monitoring Framework proposed ten specific targeted risk factors to be reduced [
11]. The National Health and Family Planning Commission of the People’s Republic of China has stated strong support for these targets and is planning a corresponding national health policy, known as Health China 2030. Health China 2030 aims to adopt the most pertinent health policies or strategies for improving the overall health of the Chinese population over the next 15 years, and a core component is NCD prevention and control. In order to inform setting priorities when allocating limited resources in Health China 2030, this study has projected premature mortality from NCDs under different scenarios of risk factor reduction and assessed whether and how the goal of a one-third reduction in premature mortality from NCDs can be achieved.
Discussion
Ours is the first study to attempt to provide answers to questions raised during the design of the Health China 2030 program on future trends in premature mortality from NCDs. The findings suggest that a large reduction in these deaths is possible by 2030 if certain targets for risk factor intervention are reached. The UN goal of an overall one-third reduction in premature mortality due to NCDs could be successfully achieved by meeting the organization’s targets for related risk factors, but meeting the goal for cancer and diabetes would require extra efforts. These results provide rich information for setting priorities when allocating limited resources in the Health China 2030 program.
The present study suggests that, despite the fact that mortality from most NCDs is already declining and a great increase in life expectancy has been achieved in China over the past two decades [
2], one million premature deaths due to NCDs could still be avoided in 2030 if the exposure levels of a small number of risk factors were reduced. Loss of productivity due to aging and premature deaths from NCDs is considered a major barrier to poverty alleviation and sustainable development [
14]. Simulations in this study showed it is possible to reach the UN goals for reducing premature mortality from NCDs by the year 2030. The prerequisite for this success is to reduce the population’s exposure to high-impact risk factors, particularly high SBP, smoking, and high BMI.
Although adequate reduction in high SBP would have a notable impact on premature mortality, there remain a number of important obstacles to population-based blood pressure management and control. Recent national surveys show a consistent and rapid increase in hypertension prevalence, from 18.0% in 2002 to 27.8% in 2013 [
15,
16]. Despite joint efforts by public health practitioners and medical professionals in the last decade, awareness, treatment, and control of hypertension remain poor. In 2013, 40.9% of hypertensive individuals were aware of their condition, 32.5% were receiving antihypertensive medication, and only 9.7% had their blood pressure controlled (defined as SBP ≤140 mm Hg and diastolic blood pressure ≤90 mm Hg) [
16]. To reach the WHO’s target of reducing hypertension prevalence by 25%, efforts should be concentrated on two important aspects: prevention and management. Lifestyle modification is the most important strategy in preventing hypertension. However, hypertension-related risk factors remained at a prevalent level in the last decade, including smoking, a diet high in calories from fat, physical inactivity, and excess weight or obesity [
16]. To keep the blood pressure of a hypertensive population within the normal range requires early detection of the condition, good compliance with appropriate antihypertensive treatment, regular visits to doctors, necessary lifestyle modifications, and a robust primary health system [
17‐
19]. However, the situation in China is not promising, particularly in the vast rural areas and underdeveloped urban cities. Therefore, achieving an overall 25% reduction in the prevalence of high blood pressure in the next 15 years presents a significant challenge for the public health system.
Smoking is also a serious and complicated public health problem. The global Adult Tobacco Survey in 2010 reported that 53% of Chinese men aged 15 years and older were current smokers, though the rate was much lower for women (2.4%) [
20]. The smoking prevalence among men has decreased only slightly since 1996 [
21]. Intervention to promote smoking cessation seems ineffective, as smokers quit smoking mainly because of poor health [
21,
22]. In addition, although smoking cessation clinics have been rapidly expanded in urban hospitals, few smokers visit them and seek help [
23]. China officially ratified the WHO’s Framework Convention on Tobacco Control (FCTC) in 2006, but progress has been slow due to multiple political, social, and economic obstacles [
24]. The implementation of “the tax linkage,” which increased the cigarette wholesale and valorem tax rate from 5% to 11%, was not implemented until 2015, nearly ten years after the ratification of the FCTC [
25]. However, the increase in tax still seems very modest compared to that in developed countries; e.g., the price of cigarettes in France grew by 44.7% in 2003–2004 [
26]. China is still one of the countries where the price of cigarettes is very cheap [
25], although raising taxation has been proven as an effective measure to reduce tobacco consumption [
27]. The use of large pictorial health warnings on cigarette packages is a highly cost-effective way to inform the public about the health risks of tobacco consumption, but its implementation in China is still far from satisfactory [
23]. Until early 2017, only 18 cities had legislated to ban smoking in public areas, and the public law enforcement is rare to non-existent outside of the most highly developed cities like Beijing, Shanghai, and Shenzhen. More efforts are still needed to overcome various barriers to reaching the FCTC goals.
The prevalence of excess weight or obesity has seen steady growth in China for nearly 20 years [
28,
29], mainly because of a transformation in dietary patterns and a reduction in physical activity driven by the growth of modern transport [
30]. The Chinese government is fighting an epidemic of obesity in the younger generation. A nationwide campaign, “Eat smart at school,” aims to promote and cultivate a long-term healthful lifestyle in the educational setting. There are also a number of nationwide health promotion campaigns that have incorporated new techniques, such as Internet-based wearable devices or smartphone apps which drive physical activity among users. Despite these public health interventions, the target of halting the rise in overweight and obese people between 2013 and 2030 might only be reached with sustained health education and promotion in the population with appropriate techniques in this country where an obesity epidemic prevails.
We validated the current projection with other methods or assumptions. In the scenario where current trends continue, premature deaths from NCDs increased from 3.2 million to 3.5 million. With the expected increased burden of NCDs over the next 15 years, an increase of only 300,000 premature deaths in such a populous country may be an underestimate. We, therefore, additionally projected deaths for all ages with the same methods adopted in the present study. The total number of deaths in 2013 for NCDs was 8.5 million, which would increase by 43% to 12.2 million in 2030 (Additional file
1: Table S3). It is clear that the majority of deaths from NCDs would occur in people older than 70. An aging population, increasing life expectancy, and improving medical techniques might be important reasons for this. To validate the 2030 projection of NCDs deaths in the scenario with no interventions, we further produced estimates assuming NCD mortality trends continued to 2030 with a constant change rate (proportional change model). We saw very similar results (Additional file
1: Table S4). There was a difference of only 190,000 (5% relative difference) in this projection of total NCD deaths and a 0.8% difference in overall premature mortality. The projection in the present study, we believe, is reliable.
Our study suffered from several limitations. First, the projection relied heavily on estimates driven by GBD 2013; therefore, all the limitations in estimates of deaths, mortality, and attributable burden in the GBD study apply to this analysis. We noticed that RRs for the Chinese population might well differ from global RRs adopted by GBD 2013, and thus the attributable burden of risk factors for China might be biased. However, China-specific estimations of associations between study risk factors and related NCD mortality are still comparatively rare and embryonic, and it is difficult to anticipate the direction and magnitude of these associations until more solid evidence appears. As more and more large population-based cohort studies are emerging in China, e.g., China Kadoorie Biobank [
31], the Shanghai Men's and Women's Health Study Cohorts [
32,
33], and the Taizhou Longitudinal Study [
34], more compelling evidence on China-specific RRs would be available in the future and could be potentially adopted in the future GBD study for China’s specific estimation. Second, as diabetes is 100% attributed to high fasting glucose, and hypertensive heart disease is 100% attributed to high SBP in the comparative risk assessment framework of GBD 2013, there were no unattributable deaths for these risk factors in the present study. Theoretically, the present projected deaths and premature mortality in diabetes and CVD must have been underestimated in the scenarios of fasting glucose, systolic blood pressure, and the combined scenario. However, as the absolute number of deaths for diabetes and hypertensive heart disease is quite small relative to total deaths from all NCDs, this should have little impact on the conclusion. Third, some important risk factors for NCDs were not included in the present study, such as sodium intake, other dietary risk factors, and environmental risk factors. We excluded sodium because the causal relationship between salt intake and SBP makes SBP a perfect substitute in the attribution analysis. Even if we included sodium, its impact on CVD would be erased, as SBP completely mediates that impact. WHO did not set goals for reducing cancer-related dietary and environmental risk factors, so we did not simulate scenarios for these risk factors. This may partly explain why premature mortality from cancer failed to reach the 33% reduction goal in the risk factor reduction scenarios. Fourth, duration of exposure is usually required before outcome occurs, and the time lag in between varies for different exposure-outcome pairs. For example, smoking rapidly increases RR for CVD but only does so slowly for lung cancer or chronic obstructive pulmonary disease, and the same pattern is also observed among those who quit. This was extensively discussed in the GBD study on risk factor burden [
13]. As the differences are already captured in the mortality trends for China estimated for the GBD in the present study, we implicitly assume that the same time durations for exposure and disease outcomes will continue into the future.