2018年5月15日，由澳大利亚四大历史名校之一的塔斯马尼亚大学（University of Tasmania)Wicking 认知症研究和教育中心所推出的《预防认知症》大型开放式网络免费公开课将再次开启。
《预防认知症》课程适合任何人 - 无论是对大脑健康和降低认知症风险感兴趣的个人，还是医疗专业人员，临床医师，老年护理服务照护者或卫生保健政策专业人员， 都可以参加此课程 - 本课程旨在提供方便吸引不同背景的人参与学习。
模块4 - 预防性干预
J.O & J.R Wicking 信托（股权信托）公司为Wicking 认知症研究和教育中心提供核心资金。Wiking 中心是塔斯马尼亚大学一流的学术机构。该机构开设以认知症看护、成因及预防为主题的高精研究，采用领先的线上学习技术，致力于解决认知症带来的全球影响。
Dr. Maree Farrow
Maree Farrow 博士
My name is Maree Farrow and I am the Senior Academic Lead for Dementia MOOCs at the Wicking Dementia Research and Education Centre at the University of Tasmania.
On behalf of the Wicking team, it is my great pleasure to welcome you to the Preventing Dementia Massive Open Online Course or MOOC. The Preventing Dementia MOOC was developed by the Wicking Centre in partnership with internationally leading researchers in the area of dementia prevention.
We developed this course in response to the growing global challenge of increasing numbers of people affected by dementia, and the need for improved awareness of the potential for dementia prevention. In fact, we regard dementia to be the public health issue of the twenty-first century.
The purpose of the Preventing Dementia MOOC is to learn about the potentially modifiable risk factors for dementia and what the current evidence suggests you can do to reduce your risk. We also want to help you to separate fact from fiction, and to understand what those headlines about the latest way to prevent dementia really mean.
Here is an overview of the dementia prevention issues you will learn about and the activities you can undertake during the Preventing Dementia MOOC.
In the Preventing Dementia MOOC you will learn about the important risk factors for dementia – the ones that we can’t change, and also the ones that we can do something about. We know that much of the risk for dementia is associated with ageing and genetics. Older age is in fact the biggest risk factor for dementia and the incidence of dementia increases rapidly after the age of 65.
While inherited forms of dementia are very rare, genetics do play a role in everyone’s risk and that’s something that at the moment we can’t change. Our friends in the Wicking laboratory will explain how our genes and environment interact to influence our risk of dementia.
While genes are important, it’s also estimated that around one-third of dementia cases are potentially preventable by addressing modifiable risk factors. These include things like physical inactivity, low education, and diabetes, and each of the factors will be covered in some detail during the MOOC.
The media reports a seemingly endless stream of risk factors for various conditions and dementia is no exception. However, some of these reported factors are supported by reliable evidence, while others are not, and we will explain the difference.
In the Preventing Dementia MOOC, we’re going to focus on the most significant risk factors for dementia that are supported by the most up-to-date evidence. We’re also going to dispel some of the myths about supposed causes of dementia.
The MOOC is made up of four modules, or sections, and at the end of each module there is a short quiz for you to test what you’ve learned.
As part of the Preventing Dementia MOOC, you will have the opportunity be involved in online discussion forums, to share your ideas about dementia prevention, and to hear those of your fellow MOOC participants from all around the world.
You will also have the opportunity to be involved in research related to dementia prevention. To be successful, this research relies on the participation of people like you, with an interest in improving how we develop initiatives to reduce dementia risk in our community. This research is entirely voluntary of course, and it’s entirely up to you whether you participate or not.
If you are keen to get a measure of your own dementia risk, there will also be an opportunity to undertake an individual dementia risk assessment during the MOOC.
At the end of the Preventing Dementia MOOC, you will be eligible to receive your free personalised certificate of completion, and we also have some enhanced certificate options available.
On behalf of the Preventing Dementia MOOC team at the Wicking Centre, I sincerely hope that you find the MOOC useful and informative, and we’re looking forward to your engagement throughout the course.
Hello, my name is Shannon, and I’m a part of the academic team behind the Preventing Dementia MOOC.
I’d like to present an overview of how to navigate the MOOC. This presentation is intended for people who are unfamiliar with how the course works, or just need a refresher. You’re welcome to use this guide before you begin the course, or you can delve straight in and return to this video later if required.
我想介绍一下如何使用慕课。 此演示主要面向不熟悉课程操作流程或仅需要复习的参与者。 欢迎您在开始课程之前使用本指南，或者您可以先进入课程，需要时再返回到此视频。
Changing your Profile Picture
Firstly, I'll show you how to change your profile photo. At the top right of the screen you'll see your name. Click on this and then Profile from the menu - you'll get some options. You can change your Nickname, add a little Tagline, or click this button to change your Picture. Click Upload and then Browse to where your photo is stored, and then click Choose. Once you've selected it click Add, and then Save and Close. Note that your image must be less than 1000 pixels wide and 1000 pixels high. It must be either a JPG or a GIF file and can't be any larger than 1 MB. In other words, just make sure your image isn't too large. And please, only upload an image of yourself.
首先，我会向您展示如何更换头像。 你会在屏幕右上方看到你的名字。 点击你的名字，然后从菜单中选择“我的账户”-你会看到一些选项。 你可以更改昵称，添加个性签名，或者点击按钮更改头像。 点击“上传”，浏览你所存储的照片，然后选择所要上传的照片。 选好之后点击“添加”，然后“保存”并“关闭”。 注意照片应小于1000像素×1000像素。 照片格式必须是JPG或者GIF，且不得大于1MB。 也就是说，要确保你的照片不能过大。 并且，请上传你本人的照片。
Now I'll give you a demonstration of this top navigation bar. This will be on all the pages within the MOOC. Clicking the left-hand button - the Home button - will always bring you back to this front page.
现在我给大家演示一下这个顶部导航栏。 它会出现在慕课所有的页面中。 点击左边的主页按钮会返回到首页。
Next is the Content button. This is probably the most important one, because it is through this that you're going to access all the content that's inside the MOOC. I'll explain more about this a little later.
接着是内容按钮。 这个可能最为重要，因为通过它你将可以访问慕课里面的所有内容。 稍后我会对此做进一步讲解。
The Discussions tool is where a list of discussion topics is located. This is where you may go to participate in text conversations with your fellow participants and Wicking experts or engage in different activities that we provide within the MOOC.
Next, the Grades tool is where you can see which quizzes you have successfully submitted, and the highest score you have achieved on each quiz.
And finally, the Glossary tool is where we’ll list dictionary definitions of the various terms you’ll come across in the MOOC.
I’d now like to present an overview of the Content in the MOOC, because it’s within the content that you’ll probably spend most of your time as you learn about dementia.
We’ve tried to present the content in an accessible, engaging, and flexible way. We’ve simplified the navigation so that you can step through each page like a book. Whenever we present an activity to you, we’ll link to it directly so that you never have to navigate to it yourself.
我们尽量以容易理解的、有趣的以及灵活的方式来表述这一部分。 我们已经对使用导引进行了简化，这样你就可以像看书一样，浏览每一页。 当我们向你展示一个任务时，我们会直接给出任务的链接，这样你就不用再通过使用导引自己寻找了。
Once you’ve logged in and entered the course, you’ll find the Content link in the navigation bar at the top here. Click the link and you’ll land on the course overview page.
You’ll notice on the left-hand side there is a Table of Contents. We’ve split the course into weeks, so that you can roughly gauge how far you’ve progressed. Content is released weekly, and can then be accessed once you have completed certain activities.
你会注意到左手边有一个目录列表。 我们把课程分成了几周，这样你就可以大致估计自己的学习进度。 内容会按周发布，只有完成特定任务才能看到新发布的内容。
If you click the Table of Contents you'll see a list of topic pages. Within a module, you can visit any page in any order, but we highly recommend that you start from the beginning and work your way through page by page.
Any pages with the word Quiz in the title will contain a link to a Quiz for you to complete.
Click a link to see that page. Each page contains information that will advance your understanding of dementia. In the Introduction, we will ask you to spend some time familiarising yourself with the MOOC.
单击链接以查看该页。 每一页都包含可以促进你对认知症的理解的信息。 在引言中，我们将要求你花一些时间熟悉慕课。
Here, for example, is a map of the course modules and content. It is possible to step through the pages of the course using the buttons at either the top or the bottom of the page. This is like turning the pages of a book.
例如，这是课程模块和内容的映射。 可以使用页面顶部或底部的按钮来浏览课程页面。 就像翻书一样。
We often feature short videos of discussions within the content. You can play these videos directly on the page. If you cannot watch the video, or would prefer to read text, we have also provided transcripts for each video.
内容中会经常出现简短的讨论视频。 你可以直接在页面上播放这些视频。 如果你不能观看视频，或者更喜欢阅读文本，我们也提供了每个视频的文本资料。
If you find that the summary within the videos is too quick to read, you can pause the videos at any time. Simply click on the screen while it's playing, and click it again to continue playing. Alternatively, you can click Play or Pause at the bottom-left of the video. If you want to re-watch part of the video, you can simply drag the playerhead at the bottom of the clip to the desired location.
如果觉得视频中的摘要播放得太快，可随时暂停视频。 播放状态点击屏幕就可暂停播放，再次点击即可继续播放。 也可点击视频左下方的“播放”或“暂停”按钮来进行操作。 如果想重看视频的某部分，只需将视频下方的进度条拖到想要观看的视频位置即可。
I’m on a different page now. You will notice the activity box. Once you are ready, you can participate in discussion forums about the topic. Occasionally, we may ask you to complete a quiz.
我不在当前页面。 你会注意到任务框。 一旦准备好了，您就可以去讨论区参加这个话题的讨论。 有时，我们可能要求您完成一个小测验。
You'll notice at the top of each page a series of links that we call breadcrumbs. You can use these to locate where you are within the content.
After the introduction, the course is divided into four modules, which will open on successive Thursdays.
When you have visited a topic page within a section of the course, a tick will appear next to that topic in the Table of Contents. After all topics are viewed, you will see above the topic list a message that the section is “100% complete.” Please note that this feature is intended to allow you to keep track of where you are up to in the course. A tick on a page only shows that you have visited it, but not necessarily that you have completed all activities on that page, such as watching a video or submitting a quiz. To confirm whether you have successfully submitted a quiz, please check under “Grades.”
当你在课程的某一节查看了一个主题页后，该主题对应的目录旁边就会出现一个标记。 当你查看了所有主题之后，主题列表上方会出现一条消息，显示此节“100%完成”。请注意这个功能是为了方便你跟踪自己在课程中的完成情况。 页面上的标记只能说明你查看过该页，并不代表你已经完成了该页的所有任务，比如观看一段视频或者提交了小测验。 可通过在“成绩”下查询分数，来确认自己是否已经成功提交了测验。
So that’s a quick overview of Content within the Preventing Dementia MOOC.
Next I’d like to present an overview of the Discussions tool in the MOOC, because it is a vital part of the way that we communicate during the course.
Discussion topics allow you to interact with your peers and get guidance from academic staff in a way that is similar to what would happen in a university class tutorial. You can get feedback on your ideas, be exposed to new ideas and perspectives, and discuss important aspects of the material you are learning and its implications.
So how do you get to the Discussions? Well, once you’ve logged in to the course you’ll find in the top, navigation bar a link called Discussions. Just click on this link and you’ll be taken to the list of discussion topics.
那么如何进行讨论呢? 当登录进课程，在顶部导航栏有个名为“讨论”的链接。 点击这个链接，就会进入讨论主题列表。
You’ll notice a number of topics. The first ones are general topics.
Use the ‘Your Course Feedback’ discussion to highlight any feedback that you consider important regarding any aspect of the course. All participants will be able to see your comments.
The Social Space discussion is a place to chat, or to have off-topic conversations with your peers.
There is also a Technical Issues topic where you might want to report computer problems related to the MOOC. It’s certainly worth having a look in here to see whether somebody else has answered your problem. If you have figured out how to solve a problem yourself then you are more than welcome to report your solution here.
还有一个是有关技术问题的，您可能需要报告与慕课有关的计算机问题。 可以在这里查看是否已经有人回答了你的问题。 如果你的问题得到了解决，那么非常欢迎你在这里报告自己的解决方案。
So what does a discussion topic look like?
I’ll enter the ‘Social Space’ topic as an example. So I just click on the link and you’ll notice that we have a thread in here already.
To start a thread, click the Start a New Thread button. Now, just like writing an email, you need to enter a subject and then the message. Then, when you’ve finished, press the Post button.
点击“创建新帖”按钮，开始创建帖子。 现在，就像写电子邮件一样，你需要输入一个主题，然后输入信息。 完成后，按下“发布”按钮。
Only create threads when you’re certain that no other thread covers that same topic; that is, only create a new thread when you’re starting a new conversation. Often you’ll be responding to threads that are already there.
If you want to make a reply to somebody else's thread, click on the message subject line. You are taken to a new page, where you can click Reply to Thread. You can fill in the message just as you would when you're posting the first message of a new thread.
如果您想要回复其他人的帖子，则点击信息主题栏。 然后打开新页面，点击“回帖”按钮。 就如发表一个新帖子的首条信息时，输入所需的信息。
To return to the list of messages within a discussion topic, you can click on the View Topic breadcrumb up here, or you can jump back even further and list all of the discussions using the Discussions List breadcrumb.
Now, eventually there will be perhaps hundreds of threads with thousands of messages, and you’ll need ways of managing those. The fastest way to look for a particular thread or message is to search for it. In the top-right corner of the topic list and thread list is the search box. You can enter the name of a person or a snippet from the message, and the messages or threads which match will be returned.
最终可能有数百个帖子附带数千条信息，你可能需要一些方法来管理这些帖子和信息。 查找某个特定帖子或信息，最快的方法就是搜索。 搜索框位于主题列表和帖子列表的右上角。 输入人名或信息的字段，匹配的信息或帖子将会出现。
A handy tip is to search for your own name. That will bring up all your messages within a particular discussion board. This may include replies to someone else’s thread. If you then click on “clear search” you will be able to see other replies within each thread.
一个小窍门就是搜索你自己的名字。 将会出现你在某特定讨论板中的所有信息。 其中可能包含了对其他人的帖子的回复。 点击“清除搜索”，将会出现每个帖子中的其他回复。
You can subscribe to any post or thread. For any post or thread that you have created, the platform will automatically subscribe you to this thread. That means, you will be notified if anyone writes back to you. Click on the Subscribe to this thread and make sure the box is ticked if you want to follow any of the conversations. You will see a notification alert under the Bell symbol if someone replies to you.
您可以订阅任何帖子或线程。 对于您创建的任何帖子或线程，平台将自动订阅您的线程。 也就是说，如果有人写信给你，你会得到通知。 单击此线程的“订阅”，并确保如果您想执行任何会话，则该框被勾选。 如果有人回复你，你会在铃铛符号下看到通知提醒。
There are ways that you can sort your messages or threads. You can flag the ones that are important to you by selecting the drop-down arrow beside the name and selecting Flag Thread or Flag Post. This is useful later when you want to filter messages to just those that you’ve flagged, by clicking Flagged like so. Likewise, you can filter to just those messages that haven’t been read.
你可以通过下列方法对信息或线程进行排序。 选择名称旁边的下拉箭头，选择重要的线程或帖子，对其做出重要标记。 通过单击这样的标记，可以很容易筛选出标记过的重要信息。 同样，您也可以筛选出那些未被读取的信息。
So, there are a few tips in how to manage your discussions, but you also need to know about netiquette, which is a term that means how to behave online. Even when you’re anonymous, you need to be respectful of others. We’re sure you will be, but nonetheless we will be monitoring activity to ensure that everybody remains polite and respectful during the discussions.
以上是关于如何管理自己在讨论中的行为的一些建议，同时你还需要了解网络礼仪，即，在网上如何表现。 即使你是匿名的，你也需要尊重他人。 我们相信你会这样做，但我们还是会对其进行监控，以确保大家在讨论中都能保持礼貌和尊重。
You need to remember that the messages you post are open to anyone in the world, so only say what you would ever be willing to share publicly. You need to consider whether the information you are discussing is confidential or private.
Below this video you’ll find a link to a page which contains further information on netiquette and the expectations we have of how the discussion boards should be used. Please take the time to read through it, as it will help ensure that everyone has an enjoyable time using the discussion boards.
So, there you have it. That’s an overview of the Discussions system.
I’d now like to present an overview of the quizzes in the MOOC, because it’s these quizzes which we'll use to assess your knowledge of dementia.
The important quizzes come at the end of modules 1, 2, 3 and 4. In those you have unlimited attempts, but you must score 70% or more in your highest attempt to progress on to the next module. We don’t enforce a time limit on these quizzes.
重要的测验在模块1, 2, 3和4的末尾出现。 这些测验没有测试次数限制，但是你必须取得70%或更高的分数，才能进入下一个模块。 这些测验也没有时间限制。
So, when will you need to do a quiz? Once you’ve logged in to the course and you've navigated through the content you’ll come across a task box similar to this one, and that indicates it is time to take a quiz.
Whenever you come across this, click the button, and your page will reload with the quiz.
You’ll land on the description page, which details how the quiz works before you actually attempt it. You’ll see under Time Allowed that you have unlimited attempts; along with this it will give an estimated time for completion - again, that is not enforced.
Under attempts you’ll see how many times you’ve already attempted this quiz.
So, read through these instructions carefully, and when you’re ready, you'll click the Start Quiz button, and then OK, to begin.
To look more closely at the quiz function, let’s consider the simple, one question quiz in the Introduction. This quiz actually serves two purposes, it is a Practice quiz to ensure you know how to use the quiz function. It also gives you the opportunity to decide whether or not you give consent for us to use the information, or data, that you provide during your participation in the MOOC in our research. Research participation is entirely voluntary and your decision will not affect your participation in the MOOC in any way.
为了更深入了解测试的功能，我们来看一下引言中里的一个试题测验。 该测试实际上有两个目的，这是一个实践测试，确保你了解如何使用测试功能。 另一个目的是让你有这一个机会，决定你是否同意我们使用你在参加我们慕课调研时提供的信息或数据。 调研是完全自愿的，你的决定不会对你参与慕课有任何影响。
To start with, click on ‘Go to quiz’ and this will take you to the quiz page.
For this particular quiz, there is only one question, with a possible answer either ‘yes’ or ‘no.’ Please select the one that indicates your preference. Regardless of whether you want to give us your consent or not, you will need to complete this quiz. There are no incorrect answers as we are simply asking you for a ‘Yes’ or ‘No’ on whether you want to give your consent.
这个特定的测验只有一个问题，回答“是”或“否”。请任选其一表明你的意愿。 不论你是否同意，你都得完成这个测验。 答案没有对错，因为我们就是想知道你是否同意。
In later quizzes, there will be around ten questions. As well as yes/no questions, there may be multiple choice, true or false, or a single word answer (it will be necessary to spell this correctly, but you will be able to check spelling if required).
As you progress through the quiz, we would recommend that you save your answers as you go. There is a 'save' button associated with every question, and you can either click that after putting in your answer, or you can scroll right down to the bottom and save all of your answers in one go.
You’ll notice that there's a floppy disk icon beside each question, and in the left-hand column, which shows you which ones you've saved.
You can change your mind about any questions, whether you’ve saved them or not. When you’ve finished the quiz, you’ll need to submit your answers to us. You may have saved as you went along, but you still won’t have submitted them.
你可以对答案进行修改，不管是否已经保存。 当你完成测验时，你需要把答案提交给我们。 你可能已经保存了，但并不代表你已经提交了。
Click 'Go to Submit Quiz.'
If you have neglected to answer some questions, and then you hit 'submit', you’ll be met with a prompt and a list of those questions you haven’t answered. You can click ‘Submit Quiz,’ in which case you’ll get 0 for those unanswered questions, or you can click on the link for each question to return to it and fill it in.
So, once they’re all answered, click on ‘Go To Submit Quiz,’ but beware, once you have submitted your answers, you can’t change any of them. You can, of course, attempt the whole quiz again. If you’re unsure, though, click on any of the question numbers in the left-hand column to return to any questions you’d like to retry.
因此，回答完所有问题后再点击“提交测验”，但注意，一旦你提交了答案，你就无法再进行任何更改。 当然，你可以重新参加全部测验。 如果你没把握，点击左栏中的任一问题编号，返回到你想重新回答的问题。
Once you’re absolutely ready, click 'Submit Quiz', and then confirm that you do indeed want to submit your quiz.
Once you’ve submitted a quiz, you’ll be presented with a page that summarises how you went. If you got a question correct, you will see a score of 1/1 next to the question number, if incorrect you will see 0/1. The total score will appear at the bottom of the summary report. I can navigate back to the content, and if the quiz has been successfully submitted and the required score achieved, the next unit would become available to me when released. You can also click on View Feedback to view some feedback on the questions of the quiz, particularly on those questions that you did not answer correctly.
一旦你提交了测验，你会得到一个总结你的进展的页面。 如果你有一个问题回答正确，你会看到问题编号旁边出现分数1/1，如果不正确，你会看到0/1。 总成绩将出现在总结报告的底部。 返回到内容，如果测验已经成功提交并获得所需的分数，将获准进入已经发布的下一单元。 你也可以点击查看反馈来查看问题的反馈，尤其是那些你回答错了的问题。
That completes my overview of quizzes.
Thank you, and I hope that you enjoy participating in the Preventing Dementia MOOC.
Prof. Carol Brayne
Carol Brayne 教授
We all hope to have prevention. Medical practitioners treat people, and we deal with diseases and disorders when they're present, but most people understand that it's better to think about prevention.
Well, what do we mean by prevention? We mean trying to stop something, a disease, happening at all, and in ageing we know that dementia becomes very much more common and there's a sense that it might be inevitable, but there's also evidence that it might not be as inevitable as we had thought. So although the increase in dementia is very related to age in our populations, there is some evidence that we can reduce our risks of developing dementia, so in some terms that could be viewed as prevention.
So we understand that dementia, particularly in the oldest old where it's most common, is a mixture of classical Alzheimer's type, which most people have heard of, but also of vascular changes. And that's related to earlier life, what we call non-communicable diseases, which includes things like heart disease and diabetes. Now we've got very good understanding of how to prevent those disorders in the population and those relate to both individually-based prevention but also predominantly to societally-based activities or interventions, such as the smoking bans and trying to reduce excessive alcohol and so on. So these are all factors which can improve health earlier in life and reduce the risk of the risk factors for dementia, and so we have pretty good evidence on those.
I've been working in the field of dementia research for 30 years and for decades I thought that we could not reduce our risk of dementia because it was so closely associated with age. But, when we did the research that suggested that - well, which showed that dementia prevalence, that is the proportion of people who had dementia at any given age, has gone down, I realised that we do have the potential to reduce our risk. It does not mean that we will eradicate dementia because what it means is that we still have a lot of dementia in the oldest old because age is such a powerful risk factor. Because we're living longer, we have more people in the oldest age groups. So we can't prevent all dementia but we might reduce our risk at particular ages.
Researchers for decades have been looking at the risk factors for dementia in a variety of different ways. A lot of these have been what we call cohort studies, which is following people over time who start out without dementia and then, having examined what their risk factors, or what might be risk factors, are at baseline, we then follow them up over time and identify who gets dementia or who meets diagnostic criteria for dementia over time and who doesn't.
Those studies have looked at risk factors close to the expression of dementia and have looked at midlife risk factors as well, and also life course risk factors. Putting all of that together requires systematic reviewing and there have been several exercises in systematic reviewing of the risk factors for dementia in the last decade. One of those identified seven risk factors and it was a very rigorous look at the world literature and it came up with seven, and they included things from across the life course, such as low educational attainment, midlife obesity and hypertension, and then depression and diabetes, and so-called lifestyle behaviours such as smoking.
That exercise has been done in the US as well, as well as the Lancet Commission, and the exact risk factors have been sort of changed a little bit, so there's the addition recently of midlife hearing loss in particular.
If you put all of those risk factors together and try to understand how they operate in different populations, looking at the exposure of the population to the particular risk factors, you can calculate what proportion of people might - what proportion of dementia might be attributed to that risk factor or those risk factors. Now the risk factors cluster. Once you take that clustering into account, all of the different exercises come up with roughly a third of dementia that might be prevented if we assume a causal relationship between the risk factors and dementia. So the ultimate message from those analyses is that, if we pay attention to those risk factors across the life course, we might reduce dementia by about a third over time.
Speaking from a public health perspective, the idea of removal of one risk factor doesn't work terribly well in populations. What we need to do is look at the clustering of the risk factors and see which sectors of the population are at risk with different profiles of those risks, and what is our knowledge about how to address those risks in those populations and in the population at large. So, for example, smoking has reduced enormously and perhaps that is a single risk factor example where we have had a huge effect, but that has been done through legislation and whole-society action. But something as complicated as midlife obesity, midlife hypertension and consequently stroke and so on are much more complicated. So unless we create environments in which we can be healthy and optimise our ageing and our brain health, we're unlikely to be able to affect those particular risks in a big way for the populations.
Not only are risks very complicated in the way that they interact with each other and the behaviour - so we have behaviours, we have disorders and diseases which all interact and they're all our individual profile of risk, but also, when we look at people who have dementia, and it's most common in people aged 80 and over, so if we look in the brains of people who have died with dementia as well as the people who haven't died with dementia, we see that everybody, by the age of 85, 90, has got a mixture of pathologies and changes in their brain, which include atrophy and vascular changes and changes which could be associated with Parkinson's disease as well as the Alzheimer's disease changes, and it's rare to find somebody with a brain at the age of 100 who doesn't have at least some of these pathologies, and the relationship of those with the expression of dementia, with whether the person had dementia, becomes more complicated in the oldest age group.
There is very good evidence now from a variety of different studies, from animal studies through to human studies through to population studies, that there are factors that protect us from dementia, even when we have, say, the neuropathologies that are thought to be classically associated with dementia. So there is good evidence that we can protect the population and protect individuals to some extent, or reduce their likelihood of experiencing dementia during their lives, and these factors probably need to be addressed at different times in the life course.
So we have evidence from early life, from midlife and from later life of the kinds of things that appear to protect us from dementia. We can improve aging, we can improve brain aging and we can probably reduce the amount of dementia at any given age and we can reduce that frailty right at the end of life that is almost inevitable for all of us, but maybe reduce the time that we have to experience that through population health activities and a balance of individual and public health, if you like, actions.
Prof. Carol Brayne
Carol Brayne 教授
Public health defines prevention in several ways. There's primary prevention, secondary prevention and tertiary prevention.
Primary prevention is removing a cause of a disease, so the classic example is smoking and lung cancer. You remove the smoking, you remove the lung cancer that is attributed to smoking. There will be other lung cancers but they are not lung cancers caused by smoking.
Secondary prevention is early detection of a disorder at the point where you can change its natural history in a way that means the survival of the person with the early disease, or the quality of life of that person, is enhanced.
Tertiary prevention is when a disorder is fully manifest, is fully there, and it's about the treatment and the interventions, the care that we can provide that will improve the quality of life of that person in the presence of the disorder, and that includes palliative care, so that includes dying as well as we can.
Put those all together and you have the balance of care and activity required for a society to do the best it can with the resources that it has.
Secondary prevention is effectively screening. That can be done in an intensive case identification method or it can be done at a population level. To implement screening and/or early detection, we need really rigorous evidence and that is - in the UK and many countries such as the US, there are whole commissions looking at screening evidence.
At the moment, dementia is not one of the conditions that is recommended for screening, for systematic screening in the population. At present, our research investments across the world are focused on early detection and diagnostics. The implications of this kind of research is that there will be, in the future, some sort of screening program, whether it's applied at population level or within clinic settings. So we need an evidence base that is robust enough to meet the requirements of a screening program. At present, despite massive investment, the evidence is not sufficient for that and the implications in terms of cost are enormous for societies of implementing that kind of approach. It doesn't mean it won't be possible in the future but it needs to be thought about very, very carefully.
Primary prevention; we have evidence already about the approaches that we can take to reduce the conditions that are themselves risk factors for dementia. We have evidence of reduction in the prevalence, that is the proportion of people with dementia, in many countries and the incidence, that is the new occurrence of disease in populations. So we have that evidence from the US, from the UK, from some European countries. So we have good evidence that we can change the course of people's ageing and brain ageing.
We also have evidence on how to support people when they have dementia - that's the tertiary prevention side - increasing evidence about improvements in provision of care in care homes and the nature of the interventions that we can make to support people with dementia. So at present we have an imbalance of investment into what effectively would lead to a screening program for dementia and less investment into the primary and the tertiary, and it is clear from a public health point of view that we need to rebalance that.
Thinking about primary prevention of dementia, we need to take into account the context in which that prevention needs to occur. We have a constellation of different risk factors which relate to early, mid and later life, and we have very many different populations across the world that are experiencing ageing, so that the kinds of primary prevention activities that we might want to undertake in Australia might be very different in different groups within the population.
So for example, those in the clusters where, say, smoking and drinking excessively or to harmful levels is more prevalent, we might want to have a different approach to one where people are already doing physical activity and already having very good diets. That might relate to increasing the educational levels or one might think about groups in the population who are socially isolated. So these are all the different types of risk factors that one needs to take into account.
When we think about low and middle income countries or even a country like Japan, the profile of risk factors across the life course will have been very different for the people who are entering old age now. So it is absolutely not one size fits all, but a sense of needing to understand the risk factors that are operating for different age groups in different cultures and what is the evidence base for approaching those risk factors in those cultures.
If I was in the happy position of being in charge of the public health program in Australia, I would first want to map very carefully our knowledge of dementia in the population and different sectors of the population in different regions and different groups. I would then want to map our knowledge of the risk factor and protection factor profiles - so education is a key one there and social integration is another key one - to understand that across the population. Then I would want to bring to bear the evidence base that we have about how to change those factors and what works best, what our understanding is about what works best, at the individual level and at the population level and at the community level.
Then I'd want to create a community-based program which integrated that knowledge for a community and work with the community on the concerns of the community. And then, with embedded evaluation, look to see or basically implement combined interventions going from individual to population in those communities and then follow up the impact over time. So that would be integrating community and individual.
What I would also do, though, is look at the life course risk factors that we know we need national action on, and with that it would need to be a very careful discussion with the commercial sector. So sugar, alcohol and tobacco would probably need national activity.
Thinking from a whole population perspective and from the public health evidence, individually based interventions are pretty ineffective if one thinks about the resources required for individual interventions. So, for example, smoking cessation programs, although they're effective, they're nothing like as effective as doing things at community and population level, at national level. So when we think about the barriers, we need to think very carefully about each individual risk factor and what influences people's behaviours and what approaches we need to use. So a good example of the exultation to eat well is that, in socioeconomically-deprived areas of the UK, so my own nation's experience, fast food companies target opening in socioeconomically deprived areas. So the populations within those areas are at a particular disadvantage because what's available to them in their environment is an obesogenic environment. So it's very difficult to behave in a healthy way if you live in a place which has no areas for physical activity and also you don't have much money and low cost fast food outlets.
从大众群体的角度与从公共健康方面得来的统计数据来考虑，如果考量到个体干预所需的资源，进行个体基本干预效果会很不理想。举例，个体的戒烟项目，尽管它有效果，但是却不如社区，群体及整个国家层面来得有效果。由于这些不利因素，我们需要非常周全地考虑到每个不同个体的风险因素，影响个人行为的因素和其相应的对处方法。举一个恰当的例子，是饮食喜好的定位，在英国本土，快餐业把目标人群定位在这些低收入的经济底层地区。那结果就是生活在这些地区的人群被置于了一种不利的环境 — 一种容易引起肥胖的生活环境里。所以如果你生活在这样一个缺乏运动、低收入以及低成本不健康食物的地区，你很难拥有一个健康的生活方式。
So we have to work with communities and with businesses to shift the way that these things are operating within communities, because in the end businesses don't want to kill people and don't want to make their dementia risk higher. But they do need to make a profit, so we do need to think about what are the huge barriers that exist in terms of vested interests in our own ill health, and even in dementia occurrence. So we need to try to work to turn that around.