This blog is intended to go along with Population: An Introduction to Concepts and Issues, by John R. Weeks, published by Cengage Learning. The latest edition is the 12th (it came out in 2015), but this blog is meant to complement any edition of the book by showing the way in which demographic issues are regularly in the news.

If you are a user of my textbook and would like to suggest a blog post idea, please email me at: john.weeks@sdsu.edu

Wednesday, April 1, 2015

World's Oldest Person Dies at 117--Will You Make it?

At any given moment, the world's oldest person is a moving target (figuratively, not literally, of course). We know that the oldest authenticated age at death is 122 years and 164 days. This was older than Moses who reportedly died at 120, but I have had several students over the years point out that the Bible says that Abraham lived to be 175... Anyway, Misao Okawa died yesterday in a rest home in Osaka, Japan, of heart failure at age 117 years and 26 days. USA Today noted that:
Okawa, the daughter of a kimono maker, was born on March 5, 1898, in Osaka and was recognized as the oldest person in the world by Guiness World Records in 2013.
Okada [of the rest home] said Okawa lost her appetite about 10 days ago. She celebrated her birthday in March at her nursing home, wearing a pink kimono with cherry blossom prints. During her birthday, she was quoted as saying she was "very happy" to be that age.
Very happy and very lucky, in the sense that an incredibly small number of humans have ever come even close to that age. And that reminds to thank Lynnda Jordan for pointing me to an article suggesting various ways by which you might try to determine your own likely age at death. This is really an article that should be read from the bottom up, because at the end of the article it has links to a variety of websites on which you can evaluate your likely death day, as I point out in Chapter 5 of my text. The key to all of these is your age and sex, with a few obvious caveats thrown in--the "real causes of death"--smoking, alcohol abuse, and not wearing seat belts, for example. These numbers come largely from life tables generated by the U.S. Centers for Disease Control. If you live outside the U.S. you can adjust your age at death upward if you live in Japan or most places in western and northern Europe, and adjust it down for most other places in the world.

The first part of the article, however, seems like it is telling a different story because it discusses the use of a treadmill index to estimate a person's likely number of years left. The research is reported as follows:
Want to know if you'll survive the decade? Hop on a treadmill. Johns Hopkins researchers analyzed more than 58,000 stress tests and concluded that the results of a treadmill test can predict survival over the next 10 years. They came up with a formula, called the FIT Treadmill Score, which helps use fitness to predict mortality.
But if you follow the link in that paragraph to the original article, the real results are a bit different:
After age and sex, peak metabolic equivalents of task and percentage of maximum predicted heart rate achieved were most highly predictive of survival (P<.001).
The research article is behind a subscription not covered by the SDSU library, and no longer available in NIH's PubMed Central (not sure why not), so I can't get to the entire article, but my guess is that "after age and sex" there is very little left to explain. There may be a tiny bit of influence from the treadmill test (note that given the large sample size, almost any effect will show up as statistically significant), but not enough to do you very much good in improving your guess once you put in your age and sex. So, my advice is that if you want to know how long you are likely to live, just look up a life table and find the answer. It really is that simple, but remember not to bet too much money on dying at an exact age--a lot of stuff can happen between now and then. 

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