In general, the commonly-used period life expectancies tend to be lower than the cohort life expectancies, because mortality rates were falling over the course of modern development. Whenever mortality rates are falling then the period life expectancy is lower than the life expectancy of the cohort born then. An important point to bear in mind when interpreting life expectancy estimates is that very few people will die at precisely the age indicated by life expectancy, even if mortality patterns stay constant.
For example, very few of the infants born in South Africa in will die at Most will die much earlier or much later, since the risk of death is not uniform across the lifetime. Life expectancy is the average.
In societies with high infant mortality rates many people die in the first few years of life; but once they survive childhood, people often live much longer. Indeed, this is a common source of confusion in the interpretation of life expectancy figures: It is perfectly possible that a given population has a low life expectancy at birth, and yet has a large proportion of old people.
Given that life expectancy at birth is highly sensitive to the rate of death in the first few years of life, it is common to report life expectancy figures at different ages, both under the period and cohort approaches. For example, the UN estimates that the period global life expectancy at age 10 in was This means that the group of year-old children alive around the world in could expect to live another Finally, another point to bear in mind is that period and cohort life expectancy estimates are statistical measures, and they do not take into account any person-specific factors such as lifestyle choices.
Clearly, the length of life for an average person is not very informative about the predicted length of life for a person living a particularly unhealthy lifestyle. In practical terms, estimating life expectancy entails predicting the probability of surviving successive years of life, based on observed age-specific mortality rates.
How is this actually done? Age-specific mortality rates are usually estimated by counting or projecting the number of age-specific deaths in a time interval e. To ensure that the resulting estimates of the probabilities of death within each age interval are smooth across the lifetime, it is common to use mathematical formulas, to model how the force of mortality changes within and across age intervals.
For some countries and for some time intervals, it is only possible to reconstruct life tables from either period or cohort mortality data. As a consequence, in some instances—for example in obtaining historical estimates of life expectancy across world regions —it is necessary to combine period and cohort data.
Life tables are not just instrumental to the production of life expectancy figures as noted above , they also provide many other perspectives on the mortality of a population. This chart provides an example, plotting survival curves for individuals born at different points in time, using cohort life tables from England and Wales.
At any age level in the horizontal axis, the curves in this visualization mark the estimated proportion of individuals who are expected to survive that age. As we can see, less than half of the people born in in England and Wales made it past their 50th birthday. Since life expectancy estimates only describe averages, these indicators are complementary, and help us understand how health is distributed across time and space.
In our entry on Life Expectancy you can read more about related complementary indicators, such as the median age of a population. In practice, however, things are often more complicated: One important distinction and clarification is the difference between cohort and period life expectancy. HALE increased by 5. This can be attributed to public health policies aimed at:. HALE takes into consideration several different data points, like mortality rates and health status information, to estimate healthy life expectancy.
HALE represents the expected number of remaining years of life spent in good health from a particular age typically birth or 65 years , assuming the rates of mortality and morbidity remain unchanged. HALE data is often also separated out by gender and race. The available data can vary from country to country but commonly includes objective and subjective health status indicators that measure physical health, mental health, and functional status, along with self-perceived health scores based on national health surveys.
The most commonly used method to determine HALE is the Sullivan method, which is computed by subtracting the probable duration of disability or inability to perform important activities from the life expectancy. Also known as disability-free life expectancy DFLE , Sullivan's index results in prevalence-based life tables that studies show provide a clear and consistent population health outcome measure for evaluating the success of investments in healthcare.
Another method of formulating HALE, the multistate life table method allows individuals to move between different health states over time. These can include things like smoking status, hypertension, and diabetes. A study comparing the Sullivan's index to the multistate tables found they both produce similar results at ages 60 and 70, but the multistate tables provide higher HALE estimates at age 90 and over.
Globally, the average healthy life expectancy for someone age 60 was Regionally, people living in North, South, and Central America have the longest healthy life expectancy at In the United States, the average life expectancy is Women, live 2.
Race also contributes to longevity: Whites live an average of It is too soon to determine how the global pandemic of COVID will impact health-adjusted life expectancy across the globe. Researchers at the Social Science Research Council suspect countries that are hard hit by COVID may see a temporary decline in overall life expectancy similar to the dip observed following the pandemic flu. Total life expectancy in the U. How this will translate to years in good health remain to be seen as the long-term effects of COVID are not yet understood.
Coronavirus has lead to blood clots, blood vessel problems, and damage to the heart, lungs, and brain leading to potential chronic health problems that can impact an individual's quality of life. Health-adjusted life expectancy estimates are used to make predictions about specific populations.
While it can provide hints about how long you can expect to live in good health, it won't give you a definitive answer. Take steps to increase your years in good health, such as getting regular exercise, eating more plant-based foods , and keeping routine doctor appointments and regular physicals. Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life.
World Health Organization. Healthy life expectancy HALE. WHO methods and data sources for life tables Updated March State-specific healthy life expectancy at age 65 years--United States, Contribution of specific diseases and injuries to changes in health adjusted life expectancy in countries from to retrospective observational study.
A healthy bottom line: healthy life expectancy as an outcome measure for health improvement efforts. Milbank Q. Obtaining multistate life table distributions for highly refined subpopulations from cross-sectional data: A Bayesian extension of Sullivan's method.
Comparison of methods for calculating healthy life expectancy in a Japanese population: An analysis of Nippon Data Rev Epidemiol Sante Publique. Update June 4, Social Science Research Council. Updated June 25, Mayo Clinic. Updated August 18, Your Privacy Rights. To change or withdraw your consent choices for VerywellHealth.
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