Summary
Background
The prevalence of diabetes has risen sharply in China. Improving modifiable risk factors such as glycaemia and blood pressure could substantially reduce disease burden and treatment costs to achieve a healthier China by 2030.
Methods
We used a nationally representative population-based survey of adults with diabetes in 31 provinces in mainland China to assess the prevalence of risk factor control. We adopted a microsimulation approach to estimate the impact of improved control of blood pressure and glycaemia on mortality, quality-adjusted life-years (QALYs), and healthcare cost. We applied the validated CHIME diabetes outcomes model over a 10-year time horizon. Baseline scenario of status quo was evaluated against alternative strategies based on World Health Organization and Chinese Diabetes Society guidelines.
Findings
Among 24,319 survey participants with diabetes (age 30–70), 69.1% (95% CI: 67.7–70.5) achieved optimal diabetes control (HbA1c <7% [53 mmol/mol]), 27.7% [26.1–29.3] achieved blood pressure control (<130/80 mmHg) and 20.1% (18.6–21.6) achieved both targets. Achieving 70% control rate for people with diabetes could reduce deaths before age 70 by 7.1% (5.7–8.7), reduce medical costs by 14.9% (12.3–18.0), and gain 50.4 QALYs (44.8–56.0) per 1000 people over 10 years compared to the baseline status quo. The largest health gains were for strategies including strict blood pressure control of 130/80 mmHg, particularly in rural areas.
Interpretation
Based on a nationally representative survey, few adults with diabetes in China achieved optimal control of glycaemia and blood pressure. Substantial health gains and economic savings are potentially achievable with better risk factor control especially in rural settings.
Funding
Chinese Central Government, Research Grants Council of the Hong Kong Special Administrative Region, China [27112518].
Introduction
The recorded prevalence of diabetes in China has risen more than ten-fold from less than 1% in 1980 to 12.8% in 2017, and is expected to further increase as 35.2% of Chinese adults met the American Diabetes Association (ADA) criteria for pre-diabetes in 2017.
,
Diabetes was the 6th leading cause of disability adjusted life years (DALYs) lost in China in 2016, having risen from 22nd place in 1990
; diabetes-related mortality rates increased by 63.5% and attributable DALYs increased by 95% over this period.
,
Improving modifiable risk factors such as glycaemia and blood pressure could substantially reduce disease burden and treatment costs, yet despite the increasing prevalence of diabetes in China over the past few decades; rates of awareness, treatment, and control remain low, imposing a heavy burden both on population health and the economy. In 2018, 66.8% of US adults with diagnosed diabetes achieved risk factor control targets for hemoglobin A1c (HbA1c) and 48.2% achieved blood pressure control
; compared to China, where only 32.9% of people with diabetes reported being treated for hyperglycemia, and only 50.1% of those receiving treatment had adequate glycemic control.
The Central Committee of the Communist Party and the State Council released the Healthy China 2030 blueprint to attain the health indicator performance achieved by high-income countries by 2030.
,
,
The Healthy China 2030 action plan set an even more ambitious goal of a 30% decrease in the premature death rate from diabetes compared to 2015 levels, an awareness rate of diabetes of 60%, and a standard management rate of 70%.
,
The Diabetes Prevention and Control Action plan, one of the four non-communicable diseases prioritized in the Healthy China 2030 Initiative, aims for greater standardization of diabetes management and strengthen control of risk factors.
; but these estimates were based on simulated cohorts that utilized risk equations derived from a 1970s UK cohort (UKPDS, UK Prospective Diabetes Study) known to overpredict mortality and cardiovascular risk in Asian populations.
,
Given the limitations of previous studies, we contribute to the literature by utilizing a nationally representative survey in mainland China to analyze the prevalence of inadequate risk factor control and associated sociodemographic factors among people with diabetes. To inform population-based strategies for achieving the Healthy China 2030 goals, we applied a contemporaneous risk simulation model developed and validated in Chinese populations to estimate the potential health and economic impact of various scenarios of improved risk factor control.
Methods
Study design
These individual-level outcomes over a ten-year period are weighted and aggregated to derive the population estimates.
This baseline scenario was compared to simulated scenarios of increased blood pressure and glucose control to estimate the changes in mortality, quality-adjusted life years and treatment costs. CCDNS, China Chronic Disease and Nutrition Surveillance; CHIME, Chinese Hong Kong Integrated Modeling and Evaluation model.
Participants
,
In brief, the CCDNS study was designed to assess the national profile of chronic diseases and related risk factors using a multistage stratified cluster-randomised sampling design. It has been conducted every 3–5 years since 2004 on community-based Chinese residents who have been living in their current residence for at least 6 months in the 12 months before the survey. Data collected included demographics, education, occupation, household income, urban/rural residence, clinical biomarkers, diabetes-related complications, and prescribed medications. Urban residency was defined as living in urban subdistricts and rural residency as living in rural townships.
Simulated scenarios
,
,
,
,
,
We simulated scenarios where 70%, 80% and 100% of participants achieve control of targets and also a 20 percentage point increase in the control rate from baseline levels.
Outcomes
Annual direct medical costs associated with diabetes-related complications in China were derived from a rapid review of recent published sources detailed below.
Literature review of cost estimates
However, the study participants only covered the urban population, namely the urban employee basic medical insurance (UEBMI) or urban resident basic medical insurance (URBMI) schemes.
Estimates of medical costs in rural settings were scarce with no cost estimates identified for half of the diabetes-related complications. For complications that were not reported by Duan et al., we used estimates derived from urban populations reported by He et al. for neuropathy and retinopathy,
and Wang et al. for amputation.
Model input for total annual direct medical costs of type 2 diabetes and related complications are shown in Appendix Table S3.
Statistical analysis and modelling
The prevalence of optimal risk factor control among people with diabetes was calculated accounting for the complex sampling weight, stratification, and clustering. Estimates for HbA1c, blood pressure and combined control were computed for the overall sample and by subgroups of age, sex, and urban/rural residency. Multivariable logistic regression was used to analyze the demographic and socioeconomic factors (age, sex, urban or rural residence, household income, occupation, and education level) associated with achieving optimal risk factor control individually and combined.
The CHIME model is an individual-level discrete-time outcomes model for diabetes and related complications derived and validated in Chinese (East Asian) populations. Details of the CHIME model have been previously described.
Individual-level inputs are entered in the simulation to estimate the probability of each outcome in the 1-year cycle; if the individual is predicted to survive the 1-year cycle, then the individual’s age, duration, history of events, and risk factor values are used to predict the occurrence of outcomes in the next annual cycle. The discrete-time cycles are repeated sequentially for 10 years. The CHIME model was developed using Hong Kong SAR Hospital Authority data (97,628 participants) from 2006 to 2017, and externally validated against the China Health and Retirement Longitudinal Study (CHARLS; 4567 participants) from 2011 to 2018 and nine published trials: Acarbose Cardiovascular Evaluation (ACE), Action to Control Cardiovascular Risk in Diabetes (ACCORD), Action in Diabetes and Vascular disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE), Diabetes Prevention Program (DPP), Japan Diabetes Complications Study (JDCS), Japan Elderly Diabetes Intervention Trial (J-EDIT), Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes trial (JPAD), and UK Prospective Diabetes Study 33 and 80 (UKPDS 33 and 80).
The outcomes modeled include cumulative incidence and time to onset of complications, life expectancy, quality-adjusted life expectancy, and direct costs arising from treatment of diabetes-related complications. The 12 health outcomes in the CHIME model were all-cause mortality, diabetes-related macrovascular events (myocardial infarction, ischemic heart disease, heart failure, cerebrovascular disease), and microvascular events (peripheral vascular disease, neuropathy, amputation, ulcer of the skin, chronic kidney disease, cataracts, retinopathy).
Ethical approval
The CCDNS study was approved by the ethical review committee of the National Center for Chronic and Non-communicable Disease Control and Prevention, China CDC (approval number 201819). Written informed consent was obtained from all CCDNS participants.
Role of the funding source
The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.
Results
Table 2Weighted percentage of adults with controlled diabetes and hypertension among adults with diabetes in 2018–19.
(95% confidence interval); HbA1c, glycated hemoglobin; SBP/DBP, systolic/diastolic blood pressure. Strict: HbA1c <6.5% (48 mmol/mol) and BP < 130/80 mmHg, UK NICE: HbA1c < 6.5% (48 mmol/mol) and BP < 140/90 mmHg, World Health Organization/Chinese Diabetes Society/American Diabetes Association: HbA1c < 7% (53 mmol/mol) and BP < 130/80 mmHg, Loose: HbA1c < 7% (53 mmol/mol) and BP < 140/90 mmHg.
,
; QALY, quality-adjusted life years; WHO, World Health Organization. WHO targets for blood pressure (systolic blood pressure < 130 mm Hg or diastolic < 80 mm Hg) and glycaemic control (HbA1c ≤ 7% [53 mmol/mol] or fasting plasma glucose < 7 mmol/L [126 mg/dL]).
Table 3Mortality, quality-adjusted life years and medical cost at 10 years.
Higher control rates were associated with greater health improvements. Achieving 100% control of the WHO/Chinese Diabetes Society targets of HbA1c < 7% and blood pressure < 130/80 mmHg was projected to reduce mortality before age 70 by 11.4% (9.2–14.0), with associated utility gains of 80.6 QALYs (71.7–89.6) per 1000 people and cost savings of 23.8% (19.7–28.8); whereas 70% control was estimated to lead to a 7.1% (5.7–8.7) reduction in mortality before age 70, utility gains of 50.4 QALYs (44.8–56.0) per 1000 people, and direct cost savings of 14.9% (12.3–18.0) over 10 years. A 20-percentage point increase in control rates from baselines levels yielded comparable health benefits despite initial population control rates at baseline varying from 17.4% for the strictest targets (HbA1c < 6.5% and BP 130/80 mmHg) to 69.1% for HbA1c < 7% (53 mmol/mol).
; BP, blood pressure; CDS, Chinese Diabetes Society
; HbA1c, glycated hemoglobin; UK NICE, National Institute for Health and Care Excellence
,
; QALY, quality-adjusted life years; WHO, World Health Organization.
Discussion
Using a nationally representative cross-sectional survey (CCDNS) of the mainland Chinese population, we estimated that only 1 in 5 people with diabetes achieved the recommended target for glycaemia and blood pressure in 2018–19. We found fewer people with diabetes met their blood pressure control targets than for glycaemia. Achievement of glycemic control was consistent across age groups, sex, and urban/rural residence at around 70%; however, less than one-third of people with diabetes had optimal control of blood pressure.
Our modelling found that achieving control of blood glucose and blood pressure in people with type 2 diabetes was associated with substantial health gains, reductions in early deaths and medical cost savings. If 70% of people with diabetes achieved control, there was still a two-fold difference between the least stringent targets of HbA1c < 7% and blood pressure < 140/80 mmHg compared to adopting the most stringent international targets of HbA1c < 6.5% and blood pressure < 130/80 mmHg. A particular focus on improving blood pressure management is warranted as the current control rates are low among people with diabetes. Our findings suggest substantial health gains from strategies that include strict blood pressure control targets, particularly when aimed at rural residents. Achieving 70% control at the current WHO/Chinese Diabetes Society targets of HbA1c < 7% and blood pressure < 130/80 mmHg was estimated to cut deaths before age 70 by 7.1% and direct medical costs by 14.9% over the next 10 years; higher control rates were associated with even greater gains.
,
The potential health gains and economic savings from improved risk factor control, such as poor glycemic control, have been shown elsewhere.
,
,
,
Studies on UKPDS participants indicated that HbA1c was not the driving factor in reducing the incidence of complications, with reductions in blood pressure shown to provide significant benefits.
,
A previous study estimated optimal management of type 2 diabetes in China can improve life expectancy by an average of 3.2 years in the total population; however, these estimates used simulated cohorts of individuals with notably worse baseline risk factor values than the nationally representative 2018–19 CCDNS participants in this study.
Furthermore, the underlying risk prediction used in the IQVIA model were based on the UKPDS Outcomes Model version 1 that has higher predicted event rates for complication than the newer UKPDS Outcomes Model version 2–itself shown to overpredict complications in Chinese populations.
More recent studies using the IQVIA model in Sweden have reported far more modest gains in life expectancy.
Our estimates of the quality-adjusted life-years gained from achieving the WHO targets are comparable to another study using disability-adjusted life-years estimates in low-income and middle-income countries in East Asia.
,
,
This large-scale national study on the prevalence of risk factor control in people with diabetes in China highlights the health and economic burden that is potentially avoidable by improved risk factor control. Importantly, expanding and improving the provision of healthcare above the 32.9% of people with diabetes currently being treated in 2018 will incur additional costs, offsetting some of these estimated cost savings from delayed progression and averted complications.
Further healthcare spending could be justifiable as previous studies in East Asia, such as rural Zhejiang and the economically developed Hong Kong Special Administrative Region of China showed increased health spending on diabetes care and hypertension had a positive net value, indicating cost increases have been more than offset by quality improvements from reduced mortality.
,
The underlying reasons for inadequate risk factor control such as adherence and self-management warrant attention. Further research on implementation strategies and their cost effectiveness in China will be crucial to help health policy makers and public health practitioners reduce the health and economic burden from inadequate risk factor control and achieve the goal of a healthier China.
Second, we also lacked contemporary estimates for direct medical costs in rural areas and applied the same pricing as urban areas to assess relative changes, which may overestimate actual costs in rural areas. Third, an inherent limitation for all health economic modelling analyses is the uncertainty around predicting future outcomes. Given the chronic pathophysiology and long-term management of diabetes, modelling is unavoidable to analyze long-term health and economic outcomes; indeed, some benefits of risk factor control for type 2 diabetes are only observed over the long term. For example, significant benefits in cardiovascular outcomes with intensively controlled HbA1c were not observed until after 10 years for UKPDS.
,
We applied a recent health economic outcomes model of type 2 diabetes for Chinese populations that was externally validated against a nationally representative sample of Chinese residents (CHARLS: China Health and Retirement Longitudinal Study) and nine diabetes trials.
The use of a contemporaneous validated model using constant parameter inputs (other than HbA1c and blood pressure) during the simulations reduces modelling uncertainty and focuses on the differences between risk factor strategies. A further limitation is that these analyses did not account for potential treatment-related adverse effects, such as hypoglycemia or hypotension, when aiming for lower target levels, and these effects should be considered when assessing individualized therapies.
Conclusions
Diabetes is one of four non-communicable diseases prioritized for prevention and control in the Healthy China Initiative 2019–2030. Analyzing a nationally representative survey conducted in 2018–19, this study found few adults with diabetes in China achieved optimal control for glycaemia and particularly blood pressure with disparities between urban and rural residents. The health and economic burden of poor risk factor control among people with diabetes in China is substantial and potentially avoidable by achieving the control targets in the Healthy China 2030 action plan.
Contributors
JQ, ZZ, and MZ had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. JQ and MZ conceived and designed the study. ZZ, HHYK, and SZ contributed to data collection. JQ, ZZ, and CSN performed the statistical analysis and data visualizations. JQ, CSN, KE, GML, and MZ interpreted the data. JQ obtained funding. JY, RM, XJO, HHYK, and SZ provided administrative, technical, or material support. KE and MZ supervised the study. JQ and MZ drafted the manuscript. All authors critically reviewed the manuscript and approved the final version before submission.
The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.
Data sharing statement
The data that support the findings of this study are available from National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC) but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of China CDC. Data access requests for CCDNS 2018–19 should be addressed to the National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Xicheng District, 100,050, Beijing, China.
Source link
