UK-China Health And Social Challenges Ageing Project: present and future burden of dementia, and policy responses

中国有1040万痴呆症患者，这个数字还会上升。中国的快速老龄化过程发生在比英国等国家更早的经济发展阶段，对健康和护理服务提出了很大的要求。应对这一情况的政策制定将受益于权威的预测，即到2050年中国老年人口的疾病负担、相关的医疗和社会护理成本以及未来预防心血管疾病、痴呆症和残疾的前景的流行病学和经济学。英国和中国的65岁以上人口分别为1270万和173万。对不同国家的卫生和社会保健政策进行深思熟虑的比较，将对政策制定者具有科学启发性和价值。我们建议在最近为英国(BMJ 2017，《柳叶刀公共卫生2017》)开发的模型的基础上，建立一个针对中国人口的模拟模型，用于直接比较2050年的总体统计数据和指标。该模型综合了主要观察到的流行病学和人口学趋势，以预测未来30年痴呆症、残疾和心血管疾病的疾病负担以及预期寿命(总预期寿命(LE)、残疾LE和无残疾LE)。痴呆症未来负担的一个关键决定因素是其发病率趋势。我们对中国纵向健康长寿研究(CLHLS)的纵向分析显示，在考虑了非随机辍学和竞争风险后，经年龄调整的痴呆症发病率在1998-2014年间每年下降2.8%。疾病发生的如此迅速的变化，加上中国的人口老龄化，意味着目前的预测可能不准确。内置情景建模功能，允许用户模拟吸烟和肥胖等风险因素中的健康干预和社会趋势对痴呆症和其他与年龄相关的结果的影响(Diabetologia 2019)。我们的方法是使用CLHLS和中国健康与退休纵向研究健康(CHARLS)中的认知和身体功能重复测量来识别符合DSM4标准的痴呆病例。我们计划一项验证性研究，以临床神经心理学家访谈为参照点。对于该模型的社会经济功能，健康和社会护理成本，包括与护理相关的间接成本，将利用世卫组织-SAGE-中国以及CLHLS和CHARLS的数据。该项目将使用建模的预测来检查预测的抚养负担与政策反应之间的契合度，特别是长期护理(LTC)。这一目标涉及混合方法，由两国经验丰富的政策分析师执行。第一步是定性分析中国目前LTC试点的政策制定过程。第二，将由政策分析员和模型小组在评估相对经济成本的同时，对所述政策意图和试点项目可能在多大程度上满足预期需求进行量化评估。我们计划采用“转换”方法(Sen 1993)，同时考虑内部观点(CN系统的CN研究者)和外部视角(CN系统的英国研究者)，从而明确观察的文化(或位置)依赖。协调不同的“位置”观察会带来有用的理解，而不是以其他方式实现的。我们的跨学科团队将由来自伦敦大学学院和中山大学(SYSU)的流行病学家以及经济学家(UCL/中山大学财政研究所、广州医科大学(GZMU))、统计学家和数学家(SYSU)、神经心理学家(GZMU)、临床医生(GZMU、UCL)、政策分析师(纳菲尔德信托、SYSU)和其他人领导。除了为期三年的项目外，这项研究还将在中国、英国和国际上做出重大的科学和政策相关贡献。

There are 10.4M cases of dementia in China, and this number will rise. China's rapid ageing process is occurring at an earlier stage of economic development than UK and other countries, posing great demands on health and care services. Policy development in response to this situation would benefit from authoritative forecasts, to 2050, of the epidemiology and economics of China's older population in respect of disease burden, related costs of health and social care, and prospects for future prevention of cardiovascular disease, dementia and disability. The 65+ population of UK and China is 12.7 M and 173 M respectively. Thoughtful comparison of health and social care policy across the contrasting countries will be scientifically illuminating and valuable to policy makers. We propose to build a simulation model for the Chinese population, based on that recently developed for UK (BMJ 2017, Lancet Public Health 2017), for direct comparison of headline statistics and indicators to 2050. The model synthesises the major observed epidemiological and demographic trends, in order to forecast disease burden for dementia, disability and cardiovascular disease, and life expectancy (total life expectancy (LE), disabled LE, and disability-free LE) for the next three decades. A key determinant of the future burden of dementia is its incidence trend. Our longitudinal analysis of the Chinese Longitudinal Healthy Longevity Study (CLHLS) shows age-adjusted dementia incidence declined 2.8% per year in the period 1998-2014, after accounting for non-random dropout and competing risks. Such rapid changes in disease occurrence, together with China's ageing demographic, mean that current forecasts are likely to be inaccurate. Scenario-modelling functions are built in to allow the user to simulate the impacts of health interventions and social trends in risk factors, such as smoking and obesity, on dementia and other age-related outcomes (Diabetologia 2019). The robustness of modelled estimates is tested with sensitivity analysis.Our approach is to use repeat measures of cognitive and physical function in CLHLS and the China Health and Retirement Longitudinal Study Health (CHARLS) to identify DSM4-compliant dementia cases. We plan a validation study using a clinical neuropsychologist interview as point of reference. For the socioeconomic function of the model, health and social care costs, including indirect costs associated with caregiving, will draw on WHO-SAGE-China as well as CLHLS and CHARLS data. The project will use the modelled forecasts to examine the fit between projected dependency burden and policy responses, particularly Long-Term Care (LTC). This objective involves mixed methods, carried out by experienced policy analysts in both countries. The first step will be qualitative analysis of the policy development process for the current LTC pilot projects in China. Second, quantitative evaluation of the extent to which the stated policy intentions, and pilot projects, are likely to meet projected needs, will be conducted jointly by policy analysts and modelling teams along with assessment of relative economic costs. We plan a 'trans-positional' approach (Sen 1993), to consider both the internal view (CN researcher of CN system) and external view (UK researcher of CN system) thereby making explicit the cultural (or positional) dependence of observation. Reconciling divergent 'positional' observations leads to useful understanding, not otherwise achieved. Our interdisciplinary team will be led by epidemiologists from UCL and Sun Yat-Sen University (SYSU) together with economists (UCL/Institute for Fiscal Studies, SYSU, Guangzhou Medical University (GZMU)), statisticians and mathematician (SYSU), neuropsychologists (GZMU), clinicians (GZMU, UCL), policy analysts (Nuffield Trust, SYSU) and others. The study will make significant scientific and policy-relevant contributions in China, UK and internationally, beyond the three-year project.