Construction of China cardiovascular health index

With 17.9 million deaths, the 2015 Global Burden of Disease (GBD) study reported that cardiovascular disease (CVD) was the primary cause of deaths worldwide. Among them, 15.2 million people died of ischemic heart disease (IHD) and stroke, accounting for 85.1% of the total CVD deaths [1]. CVD is not only the primary cause of death in developed western countries, but also its disease burden is increasing in China. With lifestyle changes linked to economic development, population ageing and accelerating urbanization, CVD risks have risen significantly in China over the past 30 years. For example, the mortality of CVD was 271.8/100000 in 2015. The prevalence of cerebral vascular disease increased from 9.8% in 1993 to 12.3% in 2013. The prevalence of hypertension in Chinese residents ages 18 years and above was 25.2% which was on the rise compared with that of 2002 [2, 3]. The proportion of China’s IHD disability adjusted of life years (DALYs) increased from 3.59% in 1995 to 6.24% in 2015, and the proportion of stroke increased from 8.15 to 10.11%. In 2013, 3.72 million Chinese people died of CVD, about 46% more than the 2.56 million CVD deaths in 1990. During the same period, the IHD death toll rose 91% from 0.745 million to 1.394 million [4]. China’s most recent CVD report estimated that 290 million people suffered from CVD [5], with fatality and mortality rates higher in rural areas than those in urban areas since 2009. The report also showed that inpatient CVD expenses had increased faster than the growth in GDP since 2004 [5]. Today, CVD is the single greatest risk factor facing Chinese people’s health.

The prevention and control of CVD is a gradual process, requiring either individual interventions, especially through education, that change lifestyles or expensive medical interventions. Long-term and sustained prevention measures need action at both the global and national levels, with the initial step the effective evaluation of the prevalence of CVD, CVD risks and the effectiveness of CVD prevention and control. To implement this initial step, monitoring systems and relevant indices must be established to measure the extent and change in CVD. In the Global Action Plan for the Prevention and Control of NCDs 2013–2020, the World Health Organization (WHO) indicated that with effective monitoring early deaths caused by CVD, tumors, diabetes and chronic obstructive pulmonary disease (COPD) could be reduced by 25% [6]. The American Health Association’s (AHA) 2020 goals to improve Americans’ CVD health status, called for preventative measures to reduce CVD stroke deaths by 20%. Many Chinese health policies, such as Healthy China 2030 and China’s Medium and Long Term Plan of Preventing and Controlling Chronic Diseases, also called for the reduction of critical chronic diseases deaths [7, 8]. For example, China’s Medium and Long Term Plan of Preventing and Controlling Chronic Diseases set the goal to reduce CVD mortality rates by 10% by 2020 and 15% by 2025 and Healthy China 2030 promoted a 10% reduction in probability of premature deaths by 2020 and 30% by 2030, compared with 2015 rates.

To realize China’s national goals of CVD prevention and control, effective evaluation and monitoring measures of China’s cardiovascular health status are required. While the proportion of percutaneous coronary intervention (PCI) among patients with ST segment Elevation Myocardial Infarction (STEMI) can reflect CVD treatment, the index does not measure population cardiovascular health status. Although the probability of premature deaths is a commonly used index proxing the prevalence of CVD, it is both poorly understood by the public and ineffective in predicting individual-level intervention and education. What is needed is a simple and direct evaluation index system that reflects the Chinese people’s cardiovascular health status; monitors, compares and evaluates the prevalence, severity and control level of CVD; and measures the effectiveness of prevention and treatment of people with CVD. An effective index system should provide a significant reference point for issuing and implementing health policies, so as to gradually monitor the improvement in the Chinese people’s health expectancy and to effectively control the CVD burden.

Importantly, an innovative Chinese CVD index should facilitate policy makers understanding of China’s current CVD situation; improve the general public awareness of CVD; and help health professionals find breakthrough points in improving CVD rates. We propose a cardiovascular health index (CHI) for China that collects all relevant data about cardiovascular health to objectively, scientifically and impartially reflect the cardiovascular health status of Chinese population. Specifically, this paper describes the establishment of the CHI, specifying the methods for constructing various sub-indices, and also proposes a future research plan using the CHI.

In order to evaluate the Chinese population’s cardiovascular health status, a comprehensive CHI should reflect the current prevalence of CVD and its risks; provide measures for preventing and treating CVD; and emphasize public health policies and basic population and community interventions. To construct the CHI, we undertook a literature review, sought expert consultations and utilized the Delphi Method and the analytical hierarchy process (AHP) method. Figure 1 diagrammatically displays the steps in the CHI construction from literature review, expert discussion, index screening and weight defining to the final CHI.

This study is carried out by multi center cooperation. The team researchers come from the National Center for Noncommunicable Disease Control and Prevention, heart disease specialist hospitals, stroke specialist hospitals, and health administration departments. All the data required to calculate the CHI are from high-quality research such as Research on Provincial Burden of Disease and Improving Care for Cardiovascular Disease in China (CCC Research), and official released Chinese data (such as the health statistics yearbook of the National Health Commission, the national surveillance on chronic disease and risk factors for adult in China, the Traffic Management Bureau). These data are the most representative data so far which are supposed to ensure the consistency and stability of the research. CHI adopted the comprehensive index method, applying the exponentiation of indices and comprehensive comparison among indices with different characteristics, categories and measurement units. We employed the commonly used Delphi methods for constructing comprehensive indices [14‐17], and undertook a literature review and Delphi method that are most commonly used in evaluating and monitoring the prevention and control system of chronic disease [10]. Based on literature review, we combined qualitative and quantitative analysis, summarized experts’ back-to-back individual evaluation results and face-to-face group evaluation opinions by using Delphi method and AHP, and finally established the CHI system and gained the weight of each index.

In the considering the advantages of the CHI, 3 core concepts were taking into account. First, the power of comprehensive evaluation. The CHI dimensions and indices reflect the need to adapt comprehensive methods to evaluate population cardiovascular health in an ideal state. The CHI includes indices for evaluating clinical doctors’ job quality, indices at population level to reflect the effect of healthy lifestyle on improving cardiovascular health, health behavior indices (e.g. smoking rate, overweight and obesity rate, insufficient physical activity rate, insufficient intake rate of vegetable and fruit and intake level of salt), influencing factors of cardiovascular health (e.g. blood lipid, blood pressure and blood sugar), indices about clinical treatment, and intervention indices based on public health, community and population. The CHI is a concept with multi-dimension and multi-indexes. For China, the CHI is comprised of 30% weights reflecting the prevalence of CVD and 70% weights of three dimensions reflecting measures against CVD.

Second, the concepts of prevention and the importance of risk factors prevention. As for the stair indices, the weight of prevention and control of risk factors was the highest accounting for 36%. Within this dimension, the weight of hypertension controlling rate was 0.0684, taking up the highest proportion; followed by successful smoking cessation rate (weight 0.0596) and treatment rate of hypertension (weight 0.0506). Weights of control rate of hypertension, successful smoking cessation rate and treatment rate of hypertension listed respectively 2–4 among the 52 CHI indices, where the first weight was probability of premature deaths of total vascular diseases with a weight of 0.075. Risks intervention and high risk population intervention were the most important area of population CVD prevention and treatment [18]. Successful experience in risks intervention affirms that risks intervention was effective in reducing morbidity and mortality rates of CVD, and this effect applies to the whole population and individual’s full life circle. For example, half years after Helena Mont Smoke-free Regulation was issued, hospital ACI mortality decreased by 50% year-on-year [19]. There are further examples, such as the studies about salt reduction on reducing blood pressure levels [20‐22], studies about improving physical activities by building supporting environment, projects about building environment in Finland and China Shougang Group CVD prevention and control project [23‐25]. As a developing country, China is relatively deficient in health resources, while prevention and control of risk factors has been proved to be the most cost-effective intervention and the most urgent action in the field of disease control [25]. The results show that the weight of prevention and control of risk factors was the highest, indicating that prevention and control of risk factors is crucial to preventing and controlling CVD among Chinese population. Moreover, in the dimension of public health policy and service ability, the weight of policy was the highest (35%). Considering that health issues are closely related with social and economic factors, Health in All Policies (HiAP) [26] is regarded as an important strategy to solve issues related to health. Our results show that the weights of policy indices were comparatively higher, which agree with that strategy.

Last, the importance of monitoring. WHO study showed that when dealing with prevalence of chronic disease, low and middle income countries performed worse in monitoring and researching disease and risk intervention [10]. This also applied to China. There is a pandemic of CVD in China, led the China government to issue political statement on the need to counter the pandemic [7, 8]. A set of targets, including reducing deaths under 70 years from major NCD. It is important to monitor the progress that provinces and districts are making with reducing the burden of CVD. The CHI will be used for tracking these actions.

The CHI is useful for policy-makers to evaluate the current cardiovascular health situation and changes to population cardiovascular health through a direct and scientific index system. Using the CHI, policy-makers can form on a decision-making basis ways to reduce early deaths caused by CVD, and to effectively monitor, track and improve the early death situation cause by CVD. Further, the indices can show the effect of government policies and investment in cardiovascular health. Since each province grapples with the local prevalence situation of CVD, the monitoring system differs among provinces, making inter-province comparison difficult, especially whether a province is doing well (or not) in controlling CVD morbidity, the prevention and control of CVD risks or CVD treatment. With the CHI, national and provincial governments can make comparisons with other provinces and which dimension has a relatively lower mark within each province, allowing targeted decision making and improvement. The establishment of the CHI also will become an effective public health instrument, and it is anticipated that the use and generalization of CHI will have influence policy-makers, academic institutions, social organizations, private sectors and international organizations; improve public awareness of CVD prevention and control; help evaluate the implementation of WHO’s policies on chronic diseases and CVD; measure progress towards Healthy China 2030; and promote prevention and control of CVD in China.

The CHI will also address the current issues of uncertain or incorrect data sources CVD at province level, which leads to distortion of results and reduction of credibility. To avoid these situations, we suggest strengthening and improving the monitoring of Provincial-level CVD and data usage, and to adjust the selected indices and weights for Province-level circumstances. In the future, we will calculate and periodically publish the national CHI score and the provincial CHI scores. The next step is to carry out research on the regional and municipal level CHI evaluation system. According to the results of the calculation, the CVD prevention and control measures are formulated in the pilot cities.

China CHI is a comprehensive evaluation system raised to effectively control the prevalence of CVD. A comprehensive score of CHI help us to raise the awareness of CVD in a more intuitive and simple way. There are 52 indicators of 5 dimensions in CHI evaluation system that would be used to evaluate the situation of CVD from prevalence of CVD, exposure of risk factors, prevention and control of risk factors, treatment of CVD and public health policy and service ability. These dimensions and indicators allowed different CVD researchers to focus on specific elements. It is highly recommended to collect data and calculate the scores of CHI over several years to identify the CVD changes and to confirm the effect of related strategies and interventions on it.