A Snapshot of Population Aging Effects on Mortality and Disability
Population aging is a shift in the distribution of ages across the population from younger to older. This is a part of the great demographic transition taking place across most of the world today, accompanying the rise in wealth and overall quality of life. As we do not yet have the means to control aging through medicine, it is the case that as the older fraction of the population grows, so too does the overall incidence of age-related disease and disability. The paper noted here is one of any number of views into the sizable amount of data on this phenomenon. As the authors' scenario 3 illustrates, just to keep up with the aging of the population, just to maintain the present rates of death and disability, would require sizable improvements in the ability of medical services to extend healthy life span.
We used health-adjusted life expectancy (HALE) to measure quality of life and disability-adjusted life years (DALY) to quantify the burden of disease for the population of Guangzhou. Changes in HALE and DALY between 2010-2020 and 2020-2030 were decomposed to isolate the effects of population aging. Three scenarios were analyzed to examine the relative relationship between disease burden and population aging. In Scenarios 1 and 2, the disease burden rates in 2030 were assumed to either remain at 2020 levels or follow historical trends. In Scenario 3, it was assumed that the absolute numbers of years of life lost (YLL) and years lived with disability (YLD) in 2030 would remain unchanged from the 2020 levels.
Between 2010 and 2020, 56.24% [69.73%] of the increase in male [female, values in brackets] HALE was attributable to the mortality effects in the population aged 60 and over, while -3.74% [-9.29%] was attributable to the disability effects. The increase in DALY caused by changes in age structure accounted for 72.01% [46.68%] of the total increase in DALY. From 2020 to 2030, 61.43% [69.05%] of the increase in HALE is projected to result from the mortality effects in the population aged 60 and over, while -3.88% [4.73%] will be attributable to the disability effects.
The increase in DALY due to changes in age structure is expected to account for 102.93% [100.99%] of the total increase in DALY. In Scenario 1, YLL are projected to increase by 45.0% [54.7%], and YLD by 31.8% [33.8%], compared to 2020. In Scenario 2, YLL in 2030 is expected to decrease by -2.9% [-1.3%], while YLD will increase by 12.7% [14.7%] compared to 2020. In Scenario 3, the expected YLL rates and YLD rates in 2030 would need to be reduced by 15.3% [15.4%] and 15.4% [15.6%], respectively, compared to 2020.