deaths from diseases of the circulatory and urinary systems show greater increase
than would be accounted for by the increase in population, while deaths attributed
to old age remain practically stationary. The figures suggest that with progressive
improvement in diagnosis and certification there has been an increasing transfer
from the indefinite heading "old age" to the more definite headings "heart disease"
and " nephritis."
Returning to the question of the increase in valvular disease and endocarditis,
it is found that the large proportion of deaths attributed to heart disease, but not
allocated to any of the specified headings comprising the heart group, has decreased
continually since 1880, and it is thus evident that there has been a transfer of deaths
from these undefined heart diseases to the definite heading of valvular disease and
endocarditis. Further confirmation of this view is found in the fact that the increase
in valvular disease is greatest at ages over 65 years ; for it will be appreciated that
the diagnosis, in deaths from this cause occurring at ages below 65 years, when
complications are less frequent, is more definite than at high ages when, owing to
general functional decay, valvular disease is apt to be associated with diseases of
the respiratory or nervous systems.
With regard to cancer, on reference to the annual report or tne medical officer
for 1923 (page 38) it will be seen that when the changes in the age-constitution of
the population have been allowed for, as far as practicable, the cancer mortality
per thousand living still shows increase, although among females the rate of increase
has recently fallen, while at ages below 65 years the mortality has actually decreased.
The view is still defensible that the increase in the mortality from cancer is very
largely, at any rate, accounted for by increase in the population at high ages upon
which the maximum mortality falls and by the great improvement in accuracy of
certification. More than 30 years ago this hypothesis was maintained by Mr.
George King, F.I.A., and Dr. (now Sir) Arthur Newsholme, in a paper read before
the Royal Society (proceedings of the Royal Society, volume 54). At that time the
amount of reliable statistical records of the incidence of cancer was limited. Since
then, however. Dr. T. H. C. Stevenson has made detailed analysis of the records of
cancer mortality in England and Wales and discussions bearing upon the question
of the movement of the mortality rate in recent years will be found in the annual
reports of the Registrar-General, notably those for 1911 (page lxxvi), 1913 (page Ivii),
1917 (page lxx) and 1922 (page 74). It should be borne in mind that cancer includes
all malignant growths, growths which differ histologically as well as in age-incidence.
The deaths from cancer cannot, therefore, be taken as exactly comparable in different
districts and at different times.
The diseases of the urinary system consist principally of acute and chronic
nephritis, and it will be seen from the Supplement to the Registrar-General's 75th
Annual Report, Part III., p. ccxi. that, when full correction has been made for
differences in the age- and sex-constitution of the population of England and Wales,
the death-rate from these causes has increased continuously since 1841-50, though
at ages below forty-five years some decrease has occurred since the "nineties."
The course of mortality from diseases of the brain and nervous system
is probably not accurately represented by the curve given in the diagram. Many
changes have occurred both in nomenclature and classification of the diseases contained
in the group so that it cannot be said with any degree of certainty that the
deaths comprised in this group in the early years precisely correspond as to cause
with those of more recent years. In the "list of causes of death," drawn up in
1837, cephalitis and hydrocephalus were both included in the group of brain diseases;
subsequently, in 1847, hydrocephalus, which was mostly tubercular meningitis,
was transferred to the group of tubercular diseases. The term "cephalitis" gave
place in 1881 to the heading "inflammation of the brain "and this was replaced in
1901 by " meningitis (not tubercular)". As, however, in the early years cephalitis