Study finds the effects of population aging have been exaggerated

September 09, 2010

Laxenburg, Austria - 9th September 2010. Due to increasing life-spans and improved health many populations are 'aging' more slowly than conventional measures indicate.

In a new study, to be published in Science, (10 September) scientists from the International Institute for Applied Systems Analysis (IIASA) in Austria, Stony Brook University, US, (SBU), and the Vienna Institute of Demography (VID) have developed new measures of aging that take changes in disability status and longevity into account.

The results give policymakers faced with growing numbers of elderly new tools to more accurately determine the cost of an aging population and to determine more appropriate retirement ages. Currently, assessments are frequently based on United Nations aging forecasts that include the proportion of the population that is 65 years and older, and the "old age dependency ratio" (OADR), which considers the number of people dependent on others when they reach age 65.

"Those measures are based on fixed chronological ages, and this can generate misleading results," says Dr Warren Sanderson, from IIASA and SBU. "When using indicators that assume fixed chronological ages, it's assumed that there will be no progress in factors such as remaining life expectancies and in disability rates. But many age-specific characteristics have not remained fixed and are not expected to remain constant in the future."

However, many people over 65 are not in need of the care of others, and, on the contrary, may be caregivers themselves. The authors provide a new dependency measure based on disabilities that reflect the relationship between those who need care and those who are capable of providing care, it is called the adult disability dependency ratio (ADDR). The paper shows that when aging is measured based on the ratio of those who need care to those who can give care, the speed of aging is reduced by four-fifths compared to the conventional old-age dependency ratio.

Co-author Dr Sergei Scherbov, from IIASA and the VID, states that "if we apply new measures of aging that take into account increasing life-spans and declining disability rates, then many populations are aging slower compared to what is predicted using conventional measures based purely on chronological age."

The new work looks at "disability-free life expectancies," which describe how many years of life are spent in good health. It also explores the traditional measure of old age dependency, and another measure that looks specifically at the ratio of disabilities in adults over the age of 20 in a population. Their calculations show that in the United Kingdom, for example, while the old age dependency ratio is increasing, the disability ratio is remaining constant. What that means, according to the authors, is that, "although the British population is getting older, it is also likely to be getting healthier, and these two effects offset one another."

New measures of aging that include not just changes in longevity, but accurate numbers about disability rates, "can help educate the public about the likely consequences of improvements in health and longevity," the authors say. And such measures have policy implications because, "slow and predictable changes in pension [retirement] age justified by an increased number of years of healthy life at older ages, may be more politically acceptable than large, abrupt changes justified on the basis of budget stringency."
-end-
Reference: Sanderson W. C. and Scherbov S. Remeasuring Aging: Science Policy Forum. September 10 2010.

For more information or interviews contact: Professor Warren Sanderson: International Institute for Applied Systems Analysis (IIASA) Austria and Stony Brook University, USA. Tel: + 1-631-681-2778 Warren.Sanderson@stonybrook.edu

Dr Sergei Scherbov: International Institute for Applied Systems Analysis (IIASA) Austria and the Vienna Institute of Demography. Tel. +43 2236 807 280 or +43 1 515 817 707 mob. +43 676 930 87 13 (from September 5-16 in Moscow, mob: +7 926 704 96 08) sergei.scherbov@oeaw.ac.at. scherbov@iiasa.ac.at,

Leane Regan: International Institute for Applied Systems Analysis (IIASA) Tel: +43 2236 807 316, Mob: +43 664 443 0368; regan@iiasa.ac.at

About IIASA:

IIASA is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policy makers to shape the future of our changing world.

IIASA is independent and funded by scientific institutions in Africa, the Americas, Asia, and Europe. www.iiasa.ac.at

International Institute for Applied Systems Analysis

Related Aging Articles from Brightsurf:

Surprises in 'active' aging
Aging is a process that affects not only living beings.

Aging-US: 'From Causes of Aging to Death from COVID-19' by Mikhail V. Blagosklonny
Aging-US recently published ''From Causes of Aging to Death from COVID-19'' by Blagosklonny et al. which reported that COVID-19 is not deadly early in life, but mortality increases exponentially with age - which is the strongest predictor of mortality.

Understanding the effect of aging on the genome
EPFL scientists have measured the molecular footprint that aging leaves on various mouse and human tissues.

Muscle aging: Stronger for longer
With life expectancy increasing, age-related diseases are also on the rise, including sarcopenia, the loss of muscle mass due to aging.

Aging memories may not be 'worse, 'just 'different'
A study from the Department of Psychological & Brain Sciences in Arts & Sciences adds nuance to the idea that an aging memory is a poor one and finds a potential correlation between the way people process the boundaries of events and episodic memory.

A new biomarker for the aging brain
Researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan have identified changes in the aging brain related to blood circulation.

Scientists invented an aging vaccine
A new way to prevent autoimmune diseases associated with aging like atherosclerosis, Alzheimer's disease, and Parkinson's disease was described in the article.

The first roadmap for ovarian aging
Infertility likely stems from age-related decline of the ovaries, but the molecular mechanisms that lead to this decline have been unclear.

Researchers discover new cause of cell aging
New research from the USC Viterbi School of Engineering could be key to our understanding of how the aging process works.

Deep Aging Clocks: The emergence of AI-based biomarkers of aging and longevity
The advent of deep biomarkers of aging, longevity and mortality presents a range of non-obvious applications.

Read More: Aging News and Aging Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.