Dementia prevalence, life expectancy, population pyramids, and playing around with graphs and scattered numbers; also, some sundry thoughts

I recently chanced on a newspaper article lauding Bollywood for spreading awareness on “rare” diseases, lumping in this so-called “rare” category genuinely rare diseases like progeria with widely prevalent problems like Alzheimer’s Disease. And I thought, maybe this reporter did not know about Alzheimer’s before watching “Black”, but surely we cannot call a disease rare just because we may not have heard of it!

See, poor awareness about a disease/ syndrome is not the same as low prevalence. A disease may be occurring often and remaining undiagnosed, or perhaps people do not talk about the diagnosis because there is a stigma attached to it; that does not make the disease “rare”, though awareness definitely needs to be spread.

There’s a tragedy happening when a commonly prevalent disease remains undiagnosed because of poor awareness. We add to that tragedy if we call the disease rare, because to call it “rare” diminishes alertness about a disease. Most of us may read an article on a rare disease with curiosity, but assume it is exotic and only something very few get (always “others”, never we or our close ones). Labeling something rare seems (to me) counterproductive to awareness drives.

The newspaper report I mention above started me in a rather disjointed gathering of diverse data and numbers that I have not yet managed to organize mentally, but hey, this is a blog, not a paper, so here goes…

Let’s first knock off the bundling of progeria and Alzheimer’s into one group. Wikipedia’s page on progeria informs me that there are 80 cases worldwide for progeria (1 per 8 million live births). On the other hand, the WHO and ADI report of 2012 (Dementia: A Public Health Priority) estimates dementia cases worldwide as 35.6 million (35,600,000) which is 0.5% of the world population, and most of these cases are either pure Alzheimer’s or mixed dementias (that include Alzheimer’s).

Also, on what is “rare” as a disease, here are some definitions (from this site )

  • A disease or disorder is defined as rare in Europe when it affects fewer than 1 in 2000.
  • A disease or disorder is defined as rare in the USA when it affects fewer than 200,000 Americans at any given time.

I hope that finishes off my explanation of the error in using the “rare” label for dementia or Alzheimer’s.

Onwards, then, to other thoughts on numbers and stuff.

Tiny digression: The problem with numbers is that they often don’t hit as hard as actually knowing someone with a disease. A long string of zeroes at the end to a prevalence number doesn’t often make the number’s vastness hit emotionally quite as much , don’t have quite a same impact on us emotionally as an anecdote of an uncle of a cousin’s brother-in-law’s friend’s sister. An admission: Take the well-known story about how the man bankrupted a King of everything by asking for rice (wheat, if you prefer) grains on the chessboard to be doubled for every square. (Wikipedia explanation here) I admit that howsoever many times I try, I fail to mentally grasp the sheer exponentiation of the numbers in terms of the growing mound of wheat/ rice grains for each subsequent square. Higher than Mount Everest! Oh heck, I cannot truly imagine Mount Everest either.

I may not be alone in my emotional limitation in imagining large numbers. I’ve read that this related to how our brains are wired; maybe we didn’t have to cope with neighborhoods having 35 million tigers ready to pounce on us. Or if we did, we didn’t stop to count them before we sprinted to save our lives 😦

So I think that expecting people to grasp the impact of something by quoting large numbers is not the same as finding ways to make the danger hit viscerally…The former is for policy makers, the latter for how I view people around me and also my choices related to the risk factors of a disease.

Ending the digression, and returning to dementia….

First, the impression of many persons in India that dementia and Alzheimer’s do not happen much in India. The Dementia India Report 2010 estimated 37 lakhs (3.7 million) cases in India (the population of India is around 1.2 billion); this puts dementia cases at a rather low-sounding 0.31%. Compare this to USA, where, in a population of around 312 million people (source: Wikipedia), dementia estimates are around 5.4 million (source:, a much higher percentage of 1.73%. To many persons, these figures provide a smugness that we in India are relatively safe from dementia, and I’ve heard people credit this to diverse reasons like our eating haldi (turmeric), having a good “culture”, caring for elders, having joint families, having some genetic protection, whatever.

Broad numbers, seen without understanding the context, can mislead, though.

Now let’s see how our view of the situation changes once we add some more data to the mix: life expectancy in various countries. (Wikipedia page here). Life expectancies are easy to glance at using this image above. (The image from Wikimedia Commons, kindly released by its creator under a Creative Commons Attribution-Share Alike 3.0 Unported license). The wikipedia page informs us that in India the average life expectancy is 64.7 years for someone born today (63.2 for males, 66.4 for females). Compare this with life expectancy of richer, “developed” countries like USA; the USA life expectancy is 78.2 years for someone born today (75.6 for males, 80.8 for females).

Combine this information with some information from the WHO report on dementia which explains that only between 2 to 10% of dementia occurs in people less than 65 years, and the bulk of the cases occur in people over 65 years of age. (The Report, Dementia: A Public Health Priority can be downloaded from this link). What’s more, as people grow older, the chances of their developing dementia increase rapidly (prevalence is said to double with every five years increase in age after the age of 65).

With all these additional pieces of information, the low figures from India start getting another possible explanation: perhaps many Indians die before they can get dementia. And even if there are differences in incidence across countries, these may not be as dramatic as people expect (hope?) they are. There is also the aspect of under-reporting/under-detection of dementia.

I don’t think that we in India can continue to feel smug about our current lower prevalence rate…

Now consider this: as a nation improves its health initiatives, life expectancy goes up. Here, play around at Gapminder graphs by selecting life expectancy and moving the year slider and seeing how the expectancy has kept going up in all countries around the world over the years. I expect that will continue (and I am sure we all want that) and that, over more years, people will start living longer in India. And as they live longer, their chance of getting dementia will go up, and the illnesses that pose threats (causing disability and death) will change.

An interesting understanding of how income of a country matters in the way people there live and die can be seen by looking at how the profile of diseases that people suffer from also change as the nation’s income changes..

Here, for example, are the WHO tables on ’causes of death’ in 2008, categorized by “income” of the country. We can see how the causes change with the income of the country. As nations manage to reduce tragedies like infant mortality, deaths from diarrhea and other infectious diseases, other diseases rear their head and become matters of concern.

  • Low income countries: Lower respiratory infections (11.3%), Diarrhoeal diseases(8.2%), HIV/AIDS (7.8%), Ischaemic heart disease(6.1%), Malaria (5.2%), Stroke and other cerebrovascular disease 4.9%), Tuberculosis(4.3%), Prematurity and low birth weight(3.2%) Birth asphyxia and birth trauma(2.9%), Neonatal infections (2.6%)
  • Middle income countries: Ischaemic heart disease(13.7%), Stroke and other cerebrovascular disease(12.8%), Chronic obstructive pulmonary disease(7.2%), Lower respiratory infections (5.4%), Diarrhoeal diseases (4.4%), HIV/AIDS (2.7%), Road traffic accidents (2.4%), Tuberculosis (2.4%), Diabetes mellitus (2.3%), Hypertensive heart disease (2.2%)
  • High income countries: Ischaemic heart disease (15.6%), Stroke and other cerebrovascular disease (8.7%), Trachea, bronchus, lung cancers (5.9%), Alzheimer and other dementias(4.1%), Lower respiratory infections (3.8%), Chronic obstructive pulmonary disease (3.5%), Colon and rectum cancers (3.3%), Diabetes mellitus (2.6%), Hypertensive heart disease (2.3%), Breast cancer (1.9%)

This further strengthens my view that we Indians should not feel smug about lower dementia prevalence rates in India yet; I think this “we don’t get dementia” comfort zone is an illusion…

Now, onwards to another set of concepts we increasingly read about: the “greying” of India. This is clearly a concern for anyone working in areas of senior care and senior health and senior abuse, and I often come across articles on numbers of how the ageing population will double or triple or whatever by year X or Y, often supplemented with numbers with strings of zeroes.

I am not sure how much these numbers hit us in ways that we remember. I think these numbers don’t fully convey the challenge awaiting us.

Just looking at the number of seniors (and how they increase over years) does not convey the gravity of the challenges ahead. Of course, we want more seniors to be there (and I hope to remain alive and be one of them). The questions are related to the quality of life of these added years and more seniors, and the structure of society and its ability to look after them.

A graphic way of considering the ageing situation and how it impacts entire societies is looking at a “population pyramid” which depicts how a population divided between various age groups (see page explaining it here).

population pyramid This sort of pyramid may take different shapes depending on various situations; some examples of classic shapes of the pyramid, as available in Wikipedia uploads, are shown here.

It can be pretty interesting to see how this population pyramid is expected to change over the years (or has changed over the years) for various countries. Here, if you like some fun, go to this Census site that allows you to see multiple representations. Select “population pyramid graph” from the drop down “Select Report” (it’s the last option). Select “India” from the “select country” dropdown, and then select some “year” and click the button “submit”; I suggest trying years across a range, such as 1995, 2012, 2035…or whatever hits your fancy. Note how the distribution of age groups across the population changes over the years. Have a look, too, at the population pyramid graph of some developed country, too, say Norway 2050.

Now combine this way of viewing a population with another concept: that of an economic factor called dependency ratio. Essentially, this looks at the proportion of the section of the population that is likely to be dependent and the section of the population that will support this section. The implication is that if a population has many old persons (who are dependent) and children (again a dependent section) compared to people in the “productive years”, the society will face a challenge in being able to support the dependent sections of the population while also trying to remain economically prosperous.

It is obvious, too, that it is not enough to have health schemes and policy frameworks such that people reach riper ages; older people need to remain healthy and productive and happy to the extent possible. There also need to be systems to support those who need support without soaking up all the energies of the immediate family and friends. Only then can society still have enough persons free to remain productive and prosperous. If everyone is busy looking after elders and kids, who remains available to provide services or produce goods, run administration, manage infrastructure, handle the country, do research, qualify for various professions, and all that?

(An aside: a quote from the WHO report: By 2050 people aged 60 and over will account for 22% of the world’s population, four-fifths living in Africa, Asia or Latin America.)

Okay, so now, back to dementia.

Most reports focus on the total numbers of persons with dementia in a country, stuff that is useful for policy makers allocating resources. For individuals, though, a more emotionally charged aspect is: what is the possibility/ probability for the individual and persons around that individual to be affected by dementia? Or, the possibility that the individual will have to provide care for someone with dementia. That elderly person I know, will she develop dementia? What about me? Numbers like 37 lakhs (or a doubling of that) may not impinge on their minds much as statements on the incidence of dementia as found with age, or on the impact of dementia in terms of disability and early death.

Incidence is not really well understood across countries. Studies throw up different figures, and have not been done in many locations. Dementia prevalence and projection numbers depend on combining eligible studies and on consensus figures of experts, along with demographics, changes expected across years, and plenty of assumptions. There’s a lot of scope for variation, not just between countries and genetic profiles, but also because incidence will change depending on how well people control (or slip on) risk factors, such as cardiovascular risk factors and others. Even so, available tidbits confirm to me that dementia is something to be concerned about at a personal level for any of us who want to age well. And that suitable policies and support for dementia are important to ensure that dementia patients and their caregivers be supported.

My mother had dementia. For well over a decade of my life, as I tried to support her (sometimes succeeding, sometimes only making things worse), I had plenty of first-hand experience of the challenges that dementia and its care bring to patients and their families. But when I am discussing this topic here, I am not thinking of myself as an ex-caregiver; what I am expressing are thoughts that would apply even if I had no prior experience of dementia.

Take a person who has never actually seen dementia up close. What sort of information would make that person pause to think whether dementia is a concern area? Or affect life choices in terms of risk factor mitigation or planning for future care of elders in the family? Here are some random sentences from published reports that, I think, would help the person understand and consider dementia as a possible concern area:

  • Compared to other chronic medical conditions (heart diseases, cancer and stroke), AD is the fourth leading cause of death in the Asia Pacific region (quote from Dementia India Report 2010)
  • According to different estimates, between 2% and 10% of all cases of dementia start before the age of 65. The prevalence doubles with every five-year increment in age after 65. (WHO report: Dementia: A Public Health Priority)
  • Dementia is one of the major causes of disability in later life. It accounts for 11.9% of the years lived with disability due to a noncommunicable disease. It is the leading cause of dependency (i.e. need for care) and disability among older persons in both high-income countries and LMIC. (WHO report: Dementia: A Public Health Priority)
  • One in eight people aged 65 and older (13 percent) has Alzheimer’s disease. Nearly half of people aged 85 and older (43 percent) have Alzheimer’s disease. (Alzheimer’s Report 2011, USA).
  • Alzheimer’s disease is the sixth-leading cause of death across all ages in the United States. It is the fifth-leading cause of death for those aged 65 and older. (. (Alzheimer’s Report 2011, USA).
  • One In Seven Americans Over Age 70 Has Dementia (Report of a study, quoted here:

Pause, re-read these. For example, One in eight persons aged 65 and older has Alzheimer’s. Ouch!

When I look around myself, I find enough persons over 65 years,over 70 years, and I know of persons who are on their way to celebrating their 85th birthday. I am sure all of you know dozens of people in these age groups. Think of the faces of these persons who you meet and know yourself, or who you hear about as parents or grandparents of friends and acquaintances. Think of the incidence figures I mention above, and see how they hit harder now.

Remember, too, that poor awareness exacerbates the tragedy, because dementia remains unrecognized.

If you meet these persons with dementia, you may not figure out the nature of the problem in your interactions. So, well-meaning though you are, you may end up talking in ways that hurt or stress these persons. You may even believe some critical comments they make about their family members without knowing these are driven by poor memory and delusions. (It is normal and acceptable to criticize children and call them greedy and abusers and believe that elders are being mistreated, because isn’t that what all soap operas tell us?)

And this dementia may even be unrecognized by the families till it is in a really advanced stage, or not even then. Family members may get frustrated because this elder is acting strangely or wandering, and they don’t know how to handle it or what to expect. They don’t realize how this will require an increasing amount of adjustments around the elders. In spite of all the love and respect they have, and the hard work they may be willing to do for these seniors, they may end up doing things that are ineffective, or even make the situation worse.

Spreading awareness about dementia aims to avoid such human costs to patients and persons around them…

These are my scattered and initial ponderings. Prevalence or incidence of dementia, and how the incidence of dementia can impact people and society, and how it can be changed by addressing risk factors is just too vast a topic, an entire field of study by itself. I am definitely nowhere near getting even a perspective of the problem, regardless of my attempts to pore over various published reports.

But I have pored over enough to acknowledge that dementia and its care are definitely areas of concern. This blog post and its scattered data presentation was prompted by what I saw as an oversimplification and misrepresentation of a situation. Perhaps later I will muster up energy to read up and learn about related issues like disability, morbidity, and mortality of various diseases, and their various underlying assumptions….

Just one more small aside as I close…

I read an interview somewhere where someone said that people would not be so dismissive of dementia if this disease was hitting younger people. This statement struck me as a very acute observation. Possibly diseases associated with elderly, with ageing, seem less urgent to solve. In spite of our cultural respect for white-haired wisdom of elders whom we respect, we perhaps are okay with them to fade out, and to face problems well beyond normal ageing problems. We say, anyway they are old. But if we do not die off before that (and who wants to die!), we will get old, too. We will then be at the receiving end of this indifference to diseases that affect the elderly more than they affect the younger people. We may not be too happy with such indifference in the twilight years of our own lives.

That’s something worth pondering over, no?

Oh, and I would love to hear what you think about this.

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About Swapna Kishore
I'm a writer, blogger, and resource person for dementia/ caregiving in India, and deeply concerned about dementia care in India. On this blog I share my own caregiving journey, my experiences as a resource person for dementia care, and musings on life, aging, dementia in India, and such sundries. More about me and the work I do for dementia care in this set of pages:

4 Responses to Dementia prevalence, life expectancy, population pyramids, and playing around with graphs and scattered numbers; also, some sundry thoughts

  1. Vijaya says:

    Hi Swapna, Though you call this scattered and initial ponderings, you have really shown how to put things in perspective. Your articles are very nicely researched. Thank you.

  2. garfield12 says:

    Hi Swapna, as a medical professional who has recently started working with dementia patients, I often wonder the effect the disease has, not just on the patient, but on the family as a whole. While a few caregivers open up and share the challenges they face, giving us a window of opportunity to help them, others prefer a more passive approach. Their mantra is “as long as the patient is not disruptive, all is well”.They overlook the fact that by ignoring the problem, they are only worsening the patient’s cognitive impairment.

    Reading your blog helped me gain an insight into the issue from a caregiver’s point of view and helped me visualize a new dimension in patient care. Kudos for the fantastic job you are doing with your blog. Your “sundry thoughts” raise some very important points which are aptly augmented with hard-hitting statistics. I enjoyed the read – thank you for sharing your story and thoughts with us!

    – Shivika

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