Question

The discussion 2 topic is "The National Center for Health Statistics had change the Standard Population for Age Standardization of Death Rates from 1940 to 2000. Discuss how it affected the age-adjusted rates of mortality. Discuss any one method of adjusted rate (direct / indirect). "

Discuss (direct) 150 to 200 words

Data of 1940 to 2000

Answer 1

1)The purpose of this report is to provide the rationale for and the
implications of implementing a new population standard for age-
adjusting death rates.

2)Based on the year 2000 population, the new
standard replaces the existing 1940 standard million population that
has been used for over 50 years.

3)The change will be implemented by
the National Center for Health Statistics (NCHS), effective with deaths
occurring in 1999.

4)This report also includes a technical discussion of
direct and indirect standardization and statistical variability in age-
adjusted death rates ,
5)The crude death rate is a widely used measure of mortality.
6)However, crude death rates are influenced by the age composition of
the population. As such, comparisons of crude death rates over time
or between groups may be misleading if the populations being com-
pared differ in age composition. This is relevant, for example, in trend
comparisons of U.S. mortality given the aging of the U.S. population (1).
The crude death rate for the United States rose from 852.2 per 100,000
population to 880.0 during 1979–95. This increase in the crude death
rate was due to the increasing proportion of the U.S. population in older
age groups that have higher death rates. Age standardization, often
called ‘‘age adjustment,’’ is one of the key tools used to control for the
changing age distribution of the population, and thereby to make
meaningful comparisons of vital rates over time and between groups.
In contrast to the rising crude death rate, the age-adjusted death rate
for the United States dropped from 577.0 per 100,000 U.S. standard
population to 503.9 during 1979–95. This age-adjusted comparison is
free from the confounding effect of changing age distribution and
therefore, better reflects the trend in U.S. mortality. To use age
adjustment requires a ‘‘standard precise methods direct and indirect,

Direct standardisation Method :

By the middle of the nineteenth century, public health practitioners in England had began to recognize that simple crude rates were inappropriate summary measures for comparing population health when the age distribution of the geographic areas were markedly different. Discussions centered around the development of a summary mortality index free from the effect of age differences. In a paper he read to the Statistical Society of London, Sir Edwin Chadwick, one of the early public health reformers in England, proposed the use of “the mean age at death” as a summary measure for comparing the health condition of the various “sanitary districts” around London (Finer, 1952; Lewis, 1991). This index, he argued, represented a true summary of the age-specific risks of dying. In response, Neison, a practicing actuary, disagreed with Chadwick’s underlying logic. He argued that since mortality increased with age, Chadwick’s mean age at death for geographic areas with a relatively older population would tend to overstate excess mortality. In a subsequent article, Neison demonstrated the fallacy in Chadwick’s argument by comparing the crude mean age at death with the mean age computed by a method of direct standardization (Neison 1844). Neison was, thus, the first to introduced both the concepts of direct and indirect standardization, as well as the term standard population.
The Registrar General’s report of 1883 was the first reported use of Neison’s direct standardization method, using the 1881 population census of England and Wales as the standard (most current at the time). In subsequent reports, the standard was changed each time there was a new census, i.e., every ten years (Woolsey, et al., 1959; Benjamin, et al., 1980). These frequent changes of the standard were cumbersome since historical rates had to be recalculated each time in order to assess current trends. As a solution, the 1901 population census was eventually adopted as a general standard in England and Wales, and remained unchanged even when a new census became available.
In order to facilitate comparison with mortality rates in England and Wales, the United States adopted the 1901 British standard. This practice continued until the early 1940s when it was decided that the difference between the US population at the time and the 1901 English population was significant enough to warrant a change in standard. As a result, the US adopted its 1940 census population (the most current at the time) as the new standard. Recently, however, there has been growing concern that the 1940 standard no longer reflects the increasingly older US age structure. In response, the National Center for Health Statistics sponsored two national workshops in 1991 and 1997 on the issue of a new US standard. The final report of these workshops recommended the adoption of a new standard based on the projected 2000 population age distribution. Data of 1940 to 2000:

the data mainly by the implication of mostly 15 causes, these are based on percentage based on between 1979 to 1995.

The causes are mainly

1. Diseases of heart percentage of change 1940 was -30.7,2000 was -26.2,

2. Malignant neoplasms ( -0.7 and 3.8)

3. Cerebrovascular disease ( -35.8 and -34.7)

4. COPD ( -42.9 & 58.7),

5. Accidents and adverse effects ( - 28.8 & -24.8),

6. Pneumonia and influenza ( 15.6 & 29.4),

7. DM ( 36.1 & 33.8),

8) HIV (184.2 & 189.2),

9) suicide ( -3.9 & 4.6),

10) chronic liver diseases ( -37.0 & -32.8),

11) Nephritis ( -1.1 & 10.0),

12) Homicide (-7.8 & -13.6),

13) septicaemia ( 76.0 & 94.7),

14) Alzheimer's (980.0 & 1862.8),

15) Atherosclerosis ( -59.4 & -61.5).

to the year 2000 standard affects age-adjusted death
rates for specific causes of death largely in terms of the magnitude of
the rate and much less in terms of the trend. However, the effect
varies greatly among the leading causes of death. It shows
trends from 1979 to 1995 in age-adjusted death rates using the 1940
and year 2000 standards for each of the 15 leading causes of death
in the United States in 1995. For those causes where risk increases
sharply with age, chronic diseases in particular, the change in
magnitude is up threefold. For cerebrovascular diseases (stroke), for
standard population using the 1940 standard but is 63.9 using the
year 2000 standard, a 2.4-fold difference. Large differences also occur
for heart disease, malignant neoplasms (cancer), chronic obstructive
pulmonary disease, pneumonia and influenza, diabetes, nephritis
(kidney disease), septicemia, Alzheimer’s disease, and atheroscle-
rosis. Age-specific death rates for all of these causes of death are
higher in older age groups, and, as a result, these causes are more
affected by the larger weights of the year 2000 standard.
In contrast for those causes where risk is more uniform among the
age groups, the differences in rates based on the two standards are
much smaller. These causes include accidents, Human immunodefi-
ciency virus (HIV) infection, suicide, chronic liver disease, and homicide,
which are more concentrated in the younger and middle-age groups and
consequently are much less affected by the disparity in weights between
the two population standards.
Choice of the age standard does affect trends in some of the
leading causes of death. The effect is least when changes in age-
specific rates are parallel and is greater when age-specific trends
diverge over time. For most of the leading causes, trends in age-
adjusted death rates are virtually parallel regardless of the standard.
Thus, trends for heart disease, stroke, diabetes, HIV infection, suicide,
chronic liver disease, homicide, and atherosclerosis are approximately
the same using the year 2000 standard and the 1940 standard. For
example, for heart disease the age-adjusted death rate based on the
1940 standard declined by 30 percent from 1979 to 1995 and by
26 percent based on the year 2000 standard. The difference reflects the
greater emphasis that the year 2000 standard weights give to rapid decline heart disease at younger age,

the decline among those older than 65 years was only 19 percent

For other leading causes of death, trends using the two different
standards are less consistent. The previously described case of cancer
is illustrative because of the clear pattern of divergent age-
specific trends. Based on either standard, the trend in age-adjusted
death rate for cancer increased gradually from 1979 reaching a peak
in 1990 and declining steadily thereafter,However, based on
the 1940 standard, the 1995 rate is 0.7 percent below the rate for 1979;
while using the year 2000 standard, the 1995 rate is 3.8 percent above
that for 1979. The relatively higher 1995 rate based on the year 2000
standard reflects the greater emphasis that the year 2000 standard
gives to increases in age-specific death rates at the older ages than the
decreases at the younger ages; while the 1940 standard gives more
emphasis to the decreases at the younger ages

.