Background
The consequences of population aging in China are likely to be exacerbated by the rising prevalence of chronic, non-communicable diseases. The bulk of disease burden in China has shifted away from infectious diseases and reproductive complications in the last two decades, [
1] with the prevalence of non-communicable diseases rising rapidly and now accounting for over 80 % of the overall disease burden [
2]. Cardiovascular disease (CVD) plays the leading role among the set of non-communicable diseases, with stroke, ischemic heart disease, and chronic obstructive pulmonary disease as the leading causes of death in China in 2010 [
1]. About 230 million patients, or approximately one in five adults in China, suffer from CVD [
3]. The
Global Burden of Disease reported that stroke was the leading cause of death in China in 2010, with coronary heart disease (CHD) close behind and gaining ground [
4,
5]. In general, the CVD burden in China is expected to rise as the Chinese population becomes more sedentary and diets become more geared towards red meat, sugars, and saturated fats [
3].
Evidence of this epidemiological transition has already been highlighted in China, [
6] most recently with the aid of the
Global Burden of Disease series [
1]. These studies suggest that the proportion of total deaths attributable to CVD is rising at approximately 2 % annually, more quickly in urban areas than in rural areas [
6]. The studies also highlight that although age is a strong predictor of CHD risk, the total increase in mortality rates is greater than the increase in mortality rates attributable solely to aging. The age-standardized CHD mortality rate has been rising at 1 % annually in the last decade, which accounts for about half of the total increase in mortality rates.
Although CVD factors in China are approaching those in Western nations, the use of primary and secondary prevention technologies has lagged behind that of the US and Europe, which have seen declines in CVD deaths partly due to expanded use of evidence-based CVD therapies [
7]. In addition, the benefits of better CVD screening and prevention have not been realized in China. For example, around 30 % of hypertension in the Chinese population remains undiagnosed, [
8] which is almost four times the corresponding rate in the US [
9]. However, this suggests that Chinese health policymakers are presented with a major opportunity to prevent CVD by using one or more available prevention approaches. This was recognized by the Chinese government in a recent policy report suggesting that impending health policy reforms should highlight a shift from a health system that has traditionally been treatment-based towards one which has a greater emphasis on primary and secondary prevention [
10].
A number of health care technologies and public health interventions have been shown to be successful in slowing the rise in the burden of CVD in industrialized countries. Systematic reviews demonstrate that prevention strategies for CHD and heart failure reduce hospital admissions; [
11] enhance quality of life; [
11,
12] improve health outcomes; [
12‐
15] and reduce healthcare costs [
12]. While some reviews have reported uncertainty about survival improvement; [
11] recurrent cardiovascular incidents; [
11] and cost effectiveness; [
11,
12] others have seen statistically significant improvement in mortality; [
16] cardiac events; [
16] and gains in cost per quality-adjusted life years [
15].
In addition to the more widely accepted use of blood pressure medication in China, statins have been shown to have a major impact on reducing CVD burden in many other countries [
17]. The efficacy of statins in lowering the risk of cardiovascular events is well recognized around the world [
18‐
21]. The EVANS study in France found that if statin-treated patients discontinued use, 4992 major cardiovascular events and 1159 deaths would occur in the first year after discontinuation [
20]. The cost effectiveness of statins has varied across studies depending on the drug price and the patient’s level of risk. In general, patients who have higher baseline cardiovascular risk recoup comparably larger health and economic benefits [
22‐
25]. Moreover, as the price of the drug falls, the cost-effectiveness of statins improves across all risk groups [
25,
26]. Despite this, the current use of statins in low-income countries remains low. According to the Prospective Urban Rural Epidemiological study, the level of statin use was just 1.7 % in China, much lower than levels in the US and Europe (50–60 %) [
27].
The Chinese government is currently working towards a more systematic approach to managing hypertension and diabetes. However, healthcare professionals and administrators only recently began to pay more attention to hyperlipidemia. Epidemiological transition theory [
4] and recent evidence of growth in cholesterol levels [
28] suggest that this is about to change. The current stage of evolution of the Chinese healthcare system presents a unique opportunity to intervene, due to its near universal health insurance coverage, the introduction of the New Rural Cooperative Medical System in 2003, and other schemes for employees of private and state-owned enterprises. Moreover, many insurance schemes in China have annual caps on inpatient and outpatient benefits, with coinsurance rates for inpatient care of 60 % [
29]. The limits on inpatient coverage place even greater importance on the coverage of primary and secondary prevention. Measures aimed at improving lipid management and CVD prevention in China should play a significant role in this regard. While some studies have examined the burden of CVD in China with an aging population, there is a dearth of literature comprehensively accounting for the impact of China’s epidemiological transition and estimating the potential value of measures to mitigate the rise in mortality and morbidity from non-communicable disease. This study assessed the burden of CVD and the potential value of lipid and blood pressure control strategies in China.
Discussion
Cardiovascular disease and other non-communicable diseases play an increasingly important role in the disease burden faced by a number of emerging market societies, including China. For example, CVD now accounts for more deaths in China than any other illness. While the transformation appears remarkable at first glance, China now finds itself on a well-worn path familiar in other developed economies. Increasingly sedentary lifestyles and dietary changes, combined with progress in the treatment of infectious disease, frequently increase the burden of CVD. Historically this transition begins with a greater prevalence of hypertensive heart disease and hemorrhagic stroke and evolves into a second stage characterized by rising rates of ischemic heart disease, diabetes, hyperlipidemia, and obesity. China is thought to be somewhere between these two stages, with CVD burden dominated by stroke over the past decade and CHD now emerging as a parallel threat.
The incidence of CVD in China is expected to continue to grow, with one study suggesting that annual CVD events will increase more than two-fold between 2010 and 2030 based on population growth alone. When factors such as projected trends in blood pressure and cholesterol are accounted for, annual CVD events are expected to grow by an additional 23 %. These estimates imply an annual increase of 21.3 million CVD events and 7.7 million CVD-related deaths by 2030 [
50]. These trends are mirrored in the results of the burden estimation part of our study.
To validate our model, we compared the outputs from our baseline year against other peer-reviewed studies that look at the burden of CVD in China. Yang et al. (2013) use results from the recent
Global Burden of Disease study and suggest CHD (or ischemic heart disease) deaths of just under one million in 2010, with various types of CVD deaths of over 3 million [
1]. Both are shown to have risen rapidly since 1990 at around 3–6 % annually, which would suggest approximately 1.1 million deaths in 2013. Our model started with an estimate of CVD deaths of 1,185,064 in 2013, well within the range seen in the literature. In terms of morbidity, Moran et al. (2010) suggest that we should expect 3.2 million AMIs in 2010 and rising [
50]. We estimated 3.7 million AMIs for 2013.
To determine the potential value of future policies in controlling the inevitable rise of CVD burden in China and the resulting costs to the healthcare system and the population, it is important to estimate the potential size of this burden over time and to highlight key drivers of this growth. The World Bank estimates that reducing CVD mortality by 1 % per year for 2010–2040 would save China more than $10.7 trillion, or 68 % of China’s real GDP in 2010 [
51]. Our work highlights, more specifically, the potential value of intervening in just two of the CVD risk factors and predicts a net social value of up to $1.5 trillion between 2016 and 2030.
Our study has a number of limitations. We did not explicitly differentiate between primary and secondary prevention in the empirical model. Because our model relies on a regional risk data set that was taken from studies covering a population of almost 2 billion people, it may not be a perfect fit to the Chinese population and should be viewed as a meta-level model. Although major risk confounders have been stratified, there are likely to be sources of heterogenetiy that have not been included. We also focused on the potential value attributable to averted deaths, which may underestimate the social value of CVD prevention, as it excludes the considerable morbidity burden from CVD. Counter to this, although a limitation, we have excluded any adverse effects from statins and blood pressure medication since studies have suggested that the adverse effects of both sets of drugs, while noticeable, are significantly outwieghed by the benefits [
52,
53]. Lastly, due to limitations on available data, many of our efficacy and risk inputs were not specific to the Chinese population. We focused on identifying parameters estimated with high levels of statistical significance, prioritized meta-analyses over individual trial results, and used the East Asia region-specific risk data from
GloboRisk.
Two particular aspects of the social value of reducing the burden of CVD in China have been touched upon elsewhere. A recent World Bank report [
51] suggested that the combination of the low reproductive rate over the past two decades and the fast aging of the population will likely place a major strain on China’s workforce in the next 20 years. Considering that, approximately half of all CVD burden is currently within the population under 65 years of age, failing to prioritize CVD control which could severely impact the quantity and quality of human capital available to China in the coming decades.
Conclusion
Cardiovascular disease is quickly becoming the dominant cause of preventable death in emerging economies, and the speed of its future growth is a rising concern, especially in China where the impact of rapid economic growth over the past two decades is now seen in a swift health burden transition. Using evidence on the impending demographic changes to China’s population as well as empirical evidence suggesting the impact of economic growth on future prevalence of major CVD risk factors, our model predicted that the burden of CVD in China will grow rapidly in the next 15 years if left unchecked. Our study underscored this risk to the Chinese population.
In addition, we modeled the likely impact of taking an early and aggressive stance on managing hyperlipidemia along with blood pressure, the potential surplus that would accrue to the health system, and the value of intervening to society. At a time when the Chinese government is taking steps towards a more systematic approach to health care delivery, primary and secondary prevention of CVD should be high on the agenda.
Availability of data and materials
The data supporting the conclusions of this article are included within the article, the Appendix, and 16 additional tables provided as an additional file.
Competing interests
WS and DP are employees and DNL is a Chief Strategy Officer at Precision Health Economics, which was compensated by Pfizer Inc. to perform the study. Precision Health Economics provides consulting and other research services to pharmaceutical, device, governmental, and non-governmental organizations. JZL and LZL are Pfizer employees.
Authors’ contributions
WS conceptualized and designed the study, drafted and revised the manuscript. DP provided support in research, data collection, and drafted and revised the manuscript. JZL, LZL, GL, and RG critically reviewed and revised the manuscript. DNL conceptualized the study, critically reviewed and revised the manuscript. All authors read and approved the final manuscript.