demographic yearbook annuaire demographique 1951

There has been considerable improvement over the years
in the reporting of specific diagnoses. The relative decline
in the percentage of deaths attributed to the group of illdefined
or unknown causes has been significantly large in
many areas of the world. This factor needs to be taken into
consideration in the interpretation of mortality trends for
specific causes of death. However, the quality of medical
certification is still so poor in many areas as to make data
concerning specific causes of death of questionable value.
Another important consideration is the increasing accuracy
of diagnoses that has come about through the advancement
of medical knowledge and the development of
new diagnostic tests and procedures. Certain diseases and
conditions that were seldom recognized in the past are now
being recognized and reported with much greater frequency,
with the result that death rates from these causes may show
a rising trend which did not in fact occur.
On the whole, the most that statistics on causes of death
can be expected to do is to reflect average medical opinion
concerning the causes of death in a population. Despite the
many factors that complicate the interpretation of these
data, they furnish a useful, if not a wholly accurate and
consistent, record of changing patterns of mortality. In the
field of demographic analysis, they are of great value for
the interpretation of population trends and prospects.
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