Identification of early cognitive change in diverse African populations. A harmonisation consortium to inform future dementia prevention studies.

这项研究将使生活在非洲的老年人受益，他们有患痴呆症的风险，特别是阿尔茨海默病，这是世界上最常见的痴呆症。全世界超过三分之二的痴呆症患者生活在被列为“低收入和中等收入”的国家。这些“低收入和中等收入”国家应对痴呆症挑战的人均资源较低。这包括大多数非洲国家，那里的痴呆症患者人数正在迅速增长，因为人们的寿命因更好的医疗保健而延长。我们知道，高达40%的痴呆症是可以预防的。尽管如此，几乎所有关于如何预防痴呆症的研究都是在像英国这样的“高收入”国家进行的。阿尔茨海默病最早的变化发生在诊断前几年。当出现明显的记忆困难时，潜在的大脑损伤已经广泛存在，而且可能是不可逆转的。研究人员已经开始创造方法，通过测试大脑功能来测量这些最早的变化，这些功能可能比记忆更早受到影响。这些测试包括语言测试，以及一个人找路（导航）的能力。目前，我们没有测试来确定非洲老年人阿尔茨海默病的这些早期变化。众所周知，文化和教育影响认知测试的表现，高收入国家设计的衡量标准不太可能奏效。我们需要在非洲对我们所知道的在早期阿尔茨海默病中受到影响的大脑功能进行测试，这些测试与高收入国家的测试相当，以便进行联合研究。这项研究将在社区团体、痴呆症患者、卫生部代表和具有在其他国家设计早期阿尔茨海默病测试经验的学术研究人员之间建立正式的伙伴关系，以解决这些问题。在坦桑尼亚，我们将与当地社区和痴呆症团体合作，评估对阿尔茨海默病最早受影响的大脑功能进行的现有测试，对这些测试进行调整，使其为他们所接受，并就如何最好地向老年人解释测试，使他们感到自在地尝试这些测试达成一致。我们将在医院诊所和农村社区开展一系列验证性研究，将我们采用的早期测试与非洲使用的现有痴呆症测试以及专科医生对阿尔茨海默病的临床诊断进行比较。我们将与志愿者、社区和坦桑尼亚卫生部合作，调查坦桑尼亚老年人的正常测试分数应该是多少。我们将邀请700多名60岁及以上的人志愿参加政府的健康促进活动，并按年龄、教育程度、性别和地理位置编制有关考试成绩的数据。我们将与乞力马扎罗山的另一项人口研究合作，利用人口普查数据帮助我们建立一项社区基线研究和试点后续行动，以确定我们的测试在研究随时间的变化方面是否可能可行和有用。一旦我们对坦桑尼亚的测试进行了适当评估，非洲痴呆症联盟网络将通过培训早期职业研究人员，在他们各自的国家重复我们关于正常测试分数的工作。计划在贝宁、埃塞俄比亚、肯尼亚、乌干达、尼日利亚、加纳和莫桑比克开展这项额外工作。这项工作将有助于我们的研究人员合作开发未来的非洲痴呆症预防研究。这项工作以后可能也会使研究英国少数民族的研究人员受益。我们的目标是发布一套有效的测试，其他研究人员可以很容易地使用。我们希望非洲老年人无论住在哪里，都能参与全球痴呆症预防研究，这样他们就能获得有关如何降低风险的可靠信息。有确凿的证据表明非洲早期阿尔茨海默病测试存在并且有用，这是实现这一目标的第一步。

This study will benefit older people living in Africa who are at risk of getting dementia, specifically Alzheimer's disease, the most common type of dementia worldwide. Over two thirds of people with dementia worldwide live in countries classified as 'low and middle income'. These 'low and middle income' countries have lower resources per person to cope with the challenges of dementia. This includes most African countries, where numbers of people with dementia are growing rapidly, because people are living longer due to better healthcare. We know that up to four in ten dementias could be prevented. Despite this, almost all research on how to prevent dementia has been done in and for, 'high income' countries like the UK. The earliest changes of Alzheimer's disease happen years prior to diagnosis. By the time there is obvious memory difficulty, the underlying brain damage is widespread and may be irreversible. Researchers have started to create ways of measuring these earliest changes through tests of brain functions which may be affected earlier than memory. These include tests of language, and one's ability to find one's way (navigation). Currently, we do not have tests to identify these early Alzheimer's disease changes in older people in Africa. It is well-known that culture and education affect performance on cognitive tests, and that measures designed in high income countries are unlikely to work well. We need African tests of the brain functions we know to be affected in early Alzheimer's disease, that are comparable to high-income country tests so that joint studies can be conducted. This study will create a formal partnership of community groups, people with dementia, Ministry of Health representatives, and academic researchers with experience of designing tests for early Alzheimer's disease in other countries to address these issues. In Tanzania, we will collaborate with local communities and dementia groups to evaluate existing tests of the brain functions affected earliest in Alzheimer's disease, adapt these tests to be acceptable to them and agree on how best to explain tests to older people so that they feel comfortable trying them. We will conduct a series of validation studies in hospital clinics and in a rural community, comparing performance on our adapted early tests to existing dementia tests used in Africa and with clinical diagnosis of Alzheimer's disease by a specialist doctor. Working with volunteers, communities, and the Tanzanian Ministry of Health, we will investigate what the normal test scores should be for an older person in Tanzania. We will ask over 700 people aged 60 and over to volunteer at Government health promotion events, and produce data on test performance by age, educational level, sex, and geographical location. We will work with another population study in Kilimanjaro, to use census data to help us establish a community baseline study and pilot follow-up to find out if our tests are likely to be feasible and useful in studies of change over time. Once we have properly evaluated the tests in Tanzania, the African Dementia Consortium network will repeat our work on normal test scores in their individual countries by training early career researchers. This additional work is planned for Benin, Ethiopia, Kenya, Uganda, Nigeria, Ghana, and Mozambique. This work will help our partnership of researchers to develop a future African dementia prevention study. This work may later also benefit researchers who work with minority populations in the UK. Our goal is to publish a set of effective tests, which other researchers can easily use. We want African older people to be able to take part in global dementia prevention studies wherever they live so that they have sound information on how to reduce their risk. Having firm evidence that African early Alzheimer's disease tests exist and are useful is the first step in making this happen.