The probable longevity is very different to the possible longevity that we read in headlines. We are not all going to reach age 100 any time soon. At the end of 2012, the Institute for Health Metrics and Evaluation presented a study on longevity, sponsored by the Bill & Melinda Gates Foundation, across 187 countries for the period between 1990 and 2010. The study seeks to determine healthy life expectancy at birth across nations and across time.
The National Geographic Magazine (Amanda Fiegl, Ladies Last, April 2013) has used the data to highlight some trends and some geographical differences across the US (available on the digital edition). Between 1989 and 2009, the longevity differential between women and men has decreased from 7 years to 5.1 years. Over this 20 year period there have been improvements to life expectancy (defined as healthy life expectancy at birth), but not as universally as the casual observer may believe.
In 1989, the lowest female life expectancy (at birth) was 73.2 years (Baltimore, MD), and the highest was 81.9 years (Kauai, HI). 20 years later, in 2009, we are seeing 74.1 years (McDowell County, WV) and 85.8 years (Collier County, FL). For men, the corresponding numbers are 62.3 years (Washington, DC) and 76.2 years (Fairfax County, VA) in 1989. In 2009, it is 66.1 years (Quitman County, MS) and 81.6 years (Marin County, CA).
There are three important facts:
- We are not on a super-charged ride to age 100. The above numbers refer to a time period of 20 years in which life expectancy at birth improved – but while the improvements are more pronounced in the male cohort, they are less so with women. The gap between men and women is closing.
- The gap between poor and rich is opening up. The lowest female life expectancies hardly improved over a 20 year period.
- Geography matters. The areas that had the greatest difference between male and female life expectancy still show the greatest differential.
We would fully expect the trends of the last 20, economically benign years, to have come to a halt, and quite possibly reverse.