CDC Life Tables 2012
Volume 65, Number 8 November 28, 2016
United States Life Tables, 2012
by Elizabeth Arias, Ph.D., Melonie Heron, Ph.D., and Jiaquan Xu, M.D., Division of Vital Statistics
Abstract
Objectives—This report presents complete period life tables for the United States by race, Hispanic origin, and sex, based on age- specific death rates in 2012.
Methods—Data used to prepare the 2012 life tables are 2012 final mortality statistics; July 1, 2012, population estimates based on the 2010 decennial census; and 2012 Medicare data for persons aged 66–99. The methodology used to estimate the 2012 life tables was first implemented with data year 2008. The methodology used to estimate the life tables for the Hispanic population remains unchanged from that developed for the publication of life tables by Hispanic origin for data year 2006.
Results—In 2012, the overall expectation of life at birth was
78.8 years, increasing from 78.7 years in 2011. From 2011 to 2012, life expectancy at birth increased for both males (from 76.3 to 76.4) and females (81.1 to 81.2), for the white population (79.0 to 79.1), the black population (75.3 to 75.5), the Hispanic population (81.8 to 81.9), the non-Hispanic white population (78.7 to 78.9), and the non- Hispanic black population (75.0 to 75.1).
Keywords: life expectancy • survival • death rates • race • Hispanic origin
Introduction
There are two types of life tables: the cohort (or generation) life table and the period (or current) life table. The cohort life table presents the mortality experience of a particular birth cohort—all persons born in the year 1900, for example—from the moment of birth through consecutive ages in successive calendar years. Based on age-specific death rates observed through consecutive calendar years, the cohort life table reflects the mortality experience of an actual cohort from birth until no lives remain in the group. To prepare just a single, complete cohort life table requires data over many years. It is usually not feasible to construct cohort life tables entirely on the basis of observed data for real cohorts due to data unavailability or incompleteness (1). For example, a life table representation of the mortality experience of a cohort of persons born in 1970 would require the use of data projection techniques to estimate deaths into the future (2,3).
Unlike the cohort life table, the period life table does not represent the mortality experience of an actual birth cohort. Rather, the period life table presents what would happen to a hypothetical cohort if it experienced throughout its entire life the mortality conditions of a particular period in time. For example, a period life table for 2012 assumes a hypothetical cohort that is subject throughout its lifetime to the age-specific death rates prevailing for the actual population in 2012. The period life table may thus be characterized as rendering a snapshot of current mortality experience and shows the long-range implications of a set of age-specific death rates that prevailed in a given year. In this report, the term “life table” refers only to the period life table and not to the cohort life table.
Life tables can be classified in two ways, according to the length of the age interval in which data are presented. A complete life table contains data for every single year of age. An abridged life table typically contains data by 5- or 10-year age intervals. A complete life table can easily be aggregated into 5- or 10-year age groups (see Technical Notes at the end of this report for instructions). Other than the decennial life tables, U.S. life tables based on data prior to 1997 are abridged life tables constructed by reference to a standard table (4). This report presents complete period life tables by race, Hispanic origin, and sex.
Data and Methods
The data used to prepare the U.S. life tables for 2012 are final numbers of deaths for the year 2012; July 1, 2012, population estimates based on the 2010 decennial census; and age-specific death and population counts for Medicare beneficiaries aged 66–99 for the year 2012 from the Centers for Medicare & Medicaid Services (CMS). Data from the Medicare program are used to supplement vital statistics and census data for ages 66 and over. The U.S. life tables by Hispanic origin are based on death rates that have been adjusted for race and ethnicity misclassification on death certificates using classification ratios (or correction factors) generated from an updated evaluation of race and Hispanic-origin misclassification
2 National Vital Statistics Reports, Vol. 65, No. 8, November 28, 2016
on death certificates in the United States (5). To obtain comparable estimates across years, all Hispanic-origin life tables for data years 2010 and 2011 were re-estimated using the updated classification ratios. (See Technical Notes for a detailed description of the data sets and methodology used to estimate Hispanic-origin life tables and links for the updated 2010 and 2011 life tables.)
Expectation of life
The most frequently used life table statistic is life expectancy (ex), which is the average number of years of life remaining for persons who have attained a given age (x). Life expectancy and other life table values for each age in 2012 are shown for the total population by race, Hispanic origin, and sex in Tables 1–18. Life expectancy is summarized by age, race, Hispanic origin, and sex in Table A.
Life expectancy at birth (e0) for 2012 for the total population was 78.8 years. This represents the average number of years that the members of the hypothetical life table cohort can expect to live at the time of birth (Table A).
Survivors to specified ages
Another way of assessing the longevity of the period life table cohort is by determining the proportion that survives to specified ages. The lx column of the life table provides the data for computing this proportion. Table B summarizes the number of survivors by age, race, Hispanic origin, and sex. To illustrate, 57,855 persons out of the original 2012 hypothetical life table cohort of 100,000 (or 57.9 %) were alive at exact age 80. In other words, the probability that a person will survive from birth to age 80, given 2012 age-specific mortality, is 57.9%. Probabilities of survival can be calculated at any age by dividing the number of survivors at the terminal age by the number at the beginning age. For example, to calculate the probability of surviving from age 20 to age 85, divide the number of survivors at age 85 (42,169) by the number of survivors at age 20 (98,940), which results in a 42.6% probability of survival.
Explanation of the life table columns
Column 1. Age (between x and x + 1)—Shows the age interval between the two exact ages indicated. For instance, “20–21” means the 1-year interval between the 20th and 21st birthdays.
Column 2. Probability of dying (qx )—For example, for males in the age interval 20–21, the probability of dying is 0.001053 (Table 2). This column forms the basis of the life table; all subsequent columns are derived from it.
Column 3. Number surviving (lx )—Shows the number of persons from the original hypothetical cohort of 100,000 live births who survive to the beginning of each age interval. The lx values are computed from the qx values, which are successively applied to the remainder of the original 100,000 persons still alive at the beginning of each age interval. Thus, out of 100,000 female babies born alive, 99,457 will complete the first year of life and enter the second; 99,314 will reach age 10; 99,122 will reach age 20; and 48,874 will live to age 85 (Table 3).
Column 4. Number dying (dx )—Shows the number dying in each successive age interval out of the original 100,000 live births.
For example, out of 100,000 males born alive, 650 will die in the first year of life; 104 between ages 20 and 21; and 1,001 after reaching age 100 (Table 2). Each figure in column 4 is the difference between two successive figures in column 3.
Column 5. Person-years lived (Lx )—Shows the number of person-years lived by the hypothetical life table cohort within an age interval x to x + 1. Each figure in column 5 represents the total time (in years) lived between two indicated birthdays by all those reaching the earlier birthday. Thus, the figure 98,714 for males in the age interval 20–21 is the total number of years lived between the 20th and 21st birthdays by the 98,766 males (column 3) who reached their 20th birthday out of 100,000 males born alive (Table 2).
Column 6. Total number of person-years lived (Tx )—Shows the total number of person-years that would be lived after the beginning of the age interval x to x + 1 by the hypothetical life table cohort. For example, the figure 5,658,735 is the total number of years lived after attaining age 20 by the 98,766 males reaching that age (Table 2).
Column 7. Expectation of life (ex )—The expectation of life at any given age is the average number of years remaining to be lived by those surviving to that age, based on a given set of age-specific rates of dying. It is derived by dividing the total person-years that would be lived beyond age x by the number of persons who survived to that age interval (Tx / lx). Thus, the average remaining lifetime for males who reach age 20 is 57.3 years (5,658,735 divided by 98,766)
(Table 2).
Results
Life expectancy in the United States
Tables 1–18 show complete life tables for 2012 by race (white and black), Hispanic origin, and sex. Table A summarizes life expectancy by age, race, Hispanic origin, and sex. Life expectancy at birth for 2012 represents the average number of years that a group of infants would live if they were to experience throughout life the age-specific death rates prevailing in 2012. In 2012, life expectancy at birth was 78.8 years, increasing by 0.1 year from 2011.
Changes in mortality levels by age and cause of death can have a major effect on changes in life expectancy. Life expectancy at birth increased 0.1 year in 2012 from 2011 primarily because of decreases in mortality from heart disease, cancer, Influenza and pneumonia, stroke, and Chronic lower respiratory diseases (CLRD) (6). Increases in life expectancy in 2012 from 2011 for the total population were slightly offset by increases in mortality from suicide and Chronic liver disease and cirrhosis. Decreases in mortality from cancer, heart disease, Influenza and pneumonia, CLRD, and unintentional injuries generated an increase in life expectancy among the male population. This increase in life expectancy for males was offset somewhat by increases in mortality from Chronic liver disease and cirrhosis, homicide, and suicide. Similarly, the increase in life expectancy for the female population was mainly brought about by decreases in mortality for heart disease, cancer, Influenza and pneumonia, stroke, and Alzheimer’s disease. For females, however, the increase in life expectancy was offset by an increase in mortality from suicide (6).
The difference in life expectancy between the sexes was 4.8 years in 2012, unchanged from the difference in 2011. From 1900 to 1975, the difference in life expectancy between the sexes increased from 2.0 years to 7.8 years (Table 19). The increasing gap during these years is attributed to increases in male mortality due to ischemic heart disease and lung cancer, both of which increased largely as the result of men’s early and widespread adoption of cigarette smoking (7,8). Between 1979 and 2010, the difference in life expectancy between the sexes narrowed from 7.8 years to 4.8 years (Table 19). The general decline in the sex difference since 1979 reflects proportionately greater increases in lung cancer mortality for women than for men and proportionately larger decreases in heart disease mortality among men (7,8).
The 2012 life table may be used to compare life expectancy at any age from birth onward. On the basis of mortality experienced in 2012, a person aged 65 could expect to live an average of 19.3 more years for a total of 84.3 years; a person aged 85 could expect to live an additional 6.6 years for a total of 91.6 years; and a person aged 100 could expect to live an additional 2.3 years, on average (Table A).
Life expectancy by race
From 2011 to 2012, life expectancy increased by 0.2 year to 75.5 years for the black population, and by 0.1 year to 79.1 years for the white population. The difference in life expectancy between the white and black populations was 3.6 years in 2012, a historically record low level. The white/black difference in life expectancy narrowed from 14.6 years in 1900 to 5.7 years in 1982, but increased to 7.1 years in 1993 before beginning to decline again in 1994 (Table 19). The increase in the gap from 1983 to 1993 was largely the result of increases in mortality among the black male population due to HIV infection and homicide (8).
Among the four race/sex groups (Figure 1), white females continued to have the highest life expectancy at birth (81.4 years), followed by black females (78.4), white males (76.7), and black males (72.3). From 2011 to 2012, life expectancy increased by 0.1 year for black males (from 72.2 to 72.3) and by 0.2 year for black females (from 78.2 to 78.4). Black males experienced a decline in life expectancy every year during 1984–1989 (8), followed by annual increases in 1990–1992 and 1994–2012. From 2011 to 2012, life expectancy increased by 0.1 year for both white males (from 76.6 to 76.7) and white females (from 81.3 to 81.4). Overall, gains in life expectancy between 1980 and 2012 were 8.5 years for black males,
6.0 years for white males, 5.9 years for black females, and 3.3 years for white females (Table 19).
Life expectancy by Hispanic origin
From 2011 to 2012, life expectancy increased by 0.1 year for the non-Hispanic black population (from 75.0 to 75.1) and for the Hispanic population (from 81.8 to 81.9). It increased by 0.2 year for the non-Hispanic white population (from 78.7 to 78.9) (Table A). In 2012, the Hispanic population had a life expectancy advantage at birth of 3.0 years over the non-Hispanic white population and 6.8 years over the non-Hispanic black population. The U.S. life tables by Hispanic origin are based on death rates that have been adjusted for race and ethnicity misclassification on death certificates (see Technical Notes for a detailed description of the methodology). Among the six Hispanic-origin race/sex groups (Figure 2), Hispanic females continued to have the highest life expectancy at birth (84.3 years), followed by non-Hispanic white females (81.2), Hispanic males (79.3), non-Hispanic black females (78.1), non-Hispanic white males (76.5), and non-Hispanic black males (71.9). The smallest difference is between Hispanic males and non-Hispanic black females, with Hispanic males having an advantage of 1.2 years. The largest difference is between Hispanic females and non-Hispanic black males, with Hispanic females having a life expectancy at birth that is 12.4 years greater.
The Hispanic mortality advantage is also evident in the effect produced on life expectancy at birth when race and Hispanic origin are considered separately. Until 2006, U.S. life tables were produced only by race (white and black), regardless of Hispanic origin. When the Hispanic population is excluded from the two race groups and only the non-Hispanic black and non-Hispanic white populations are included, life expectancy at birth declines. For example, for the black population, regardless of Hispanic origin, life expectancy at birth was 75.5 years in 2012, but it was 75.1 years when only the non- Hispanic segment of the black population was included. Similarly, life expectancy for the white population, regardless of Hispanic origin, was 79.1 years in 2012, but was 78.9 years when only the non- Hispanic segment of the white population was included. The effect of the Hispanic mortality advantage on race-specific life expectancy was also observed for each race/sex group. (See Technical Notes for a detailed description of the methodology used to estimate the Hispanic-origin life tables.)
Survivorship in the United States
Table B summarizes the number of survivors out of 100,000 persons born alive (lx) by age, race, Hispanic origin, and sex for 2012. Table 20 shows trends in survivorship from 1900 to 2012. In 2012, 99.4% of all infants born in the United States survived the first year of life. In contrast, 87.6% of infants born in 1900 survived the first year. Of the 2012 period life table cohort, 57.9% survived to age 80 and 2.0% survived to age 100. In 1900, 13.5% of the life table cohort survived to age 80 and 0.03% survived to age 100 (Table 20). The U.S. life tables by Hispanic origin are based on death rates that have been adjusted for race and ethnicity misclassification on death certificates (see Technical Notes for a detailed description of the methodology).
Survivorship by race
Among the four race/sex groups, white females have the highest median age at death, with about 52.7% surviving to age 84 (Tables 4–9). Of the original hypothetical cohort of 100,000 infant white females, 99.2% survive to age 20, 88.5% survive to age 65, and 49.1% survive to age 85. White males have slightly higher survival rates than black females at the younger ages, with 98.9% surviving to age 20 compared with 98.6% of black females (Tables 5 and 9).
At the older ages, however, black female survival surpasses white male survival. By age 85, white male survival is 35.6% compared with 41.6% for black females. The median age at death for black males is close to 76 years, about 9 years less than that for white females (Table 8). Among black males, 97.9% survive to age 20, 72.7% to age 65, and 25.5% to age 85. By age 100, very little difference is seen between the white and black populations in terms of survival. Around 1% of white males and black males, and around 3% of white females and black females, survive to age 100.
Survivorship by Hispanic origin
In 2012, 99.5% of both Hispanic and non-Hispanic white infants survived the first year of life, compared with 98.9% of non- Hispanic black infants (Tables 10–19). In adulthood, 99.1% of both the Hispanic and non-Hispanic white populations survived to age 20, while 98.2% of the non-Hispanic black population survived to age 20. By age 65, the Hispanic population has a clear survival advantage compared with the other two populations. Overall, 87.9% of the Hispanic population survived to age 65, compared with 84.5% of the non-Hispanic white and 77.3% of the non-Hispanic black populations. The Hispanic survival advantage increases with age, so that by age 85, 51.8% of the Hispanic population has survived compared with 42.1% of the non-Hispanic white and 33.3% of the non-Hispanic black populations. Among the six Hispanic-origin race/sex groups, Hispanic females have the highest median age at death, with 48.2% surviving to age 88 (Figure 3). The group with the next highest median age at death is non-Hispanic white females, with 48.7% surviving to age 85. Among Hispanic males, 50.2% survived to age 83, followed by non-Hispanic black females with 49.9% surviving to age 82, non-Hispanic white males with 48.5% surviving to age 81, and non-Hispanic black males with 49.2% surviving to age 76 (see Technical Notes).
Effects of updated corrections of race and Hispanic-origin misclassification on U.S. death certificates
A new study about misclassification of race and Hispanic origin on U.S. death certificates revealed that classification improved significantly for the Hispanic population, where the proportion of Hispanic decedents incorrectly classified as non-Hispanic declined from 5% to 3% (5). Classification for the non-Hispanic white and non-Hispanic black populations remained very good. The life tables by Hispanic origin shown in this report are based on death rates that were corrected for misclassification of Hispanic origin (and race for the non-Hispanic white and black populations) on death certificates, using correction factors from the new study (5). To provide accurate comparisons across years, the Hispanic-origin life tables for 2010
and 2011 were re-estimated using the updated correction factors. Table C shows life expectancy at selected ages for 2010 and 2011 that are based on the previous and revised life tables. As expected, life expectancy at birth for the Hispanic population in 2010 and 2011 is higher than that based on the previous correction factors.
See the attached file for Technical Notes
