Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
[Report of the Medical Officer of Health for London County Council]
Report of the County Medical Officer—General.
The population at risk for the purposes of the life-table is arrived at by adding to the total intercensal population estimated for the last four census, by the method explained above, the institutional population shown in the preceding table, and is as follows:—
|Age group.||Population at risk, ten years 1901-1910.|
The deaths in the population during the ten years, fully corrected for institutions, were specially abstracted for the Council by arrangement with the Registrar-General:—
|Age group.||Total deaths in population at risk, 1901-1910.|
The construction of the life-table from these data then proceeded upon the same lines as were
followed in the calculation of the life-table for 1891-1900.
Reference deserves to be made here to methods of life-table construction from census returns which
have been advocated since the first life-table was issued, especially to that proposed by Mr. George King
(see Inst. Actuaries Jnl., vol. xlii., part III., p. 225), who applies Dr. Sprague's method of osculatory
interpolation with advancing differences, and to that of Dr. Buchanan (ibid., p. 359), who illustrates
the application of Dr. Sprague's method, and of Dr. Karup's process of continuous summation, to
central difference formula}. The work is somewhat shortened by both these methods, even when, as
is here the case, the populations and deaths in years of life are also required. On the other hand it
is clear from both the papers referred to that the method of construction used affects the results
to some extent; and it has appeared to be desirable to retain comparativity between this and the
former life-table so far as possible by adhering to the method already used.
The interpolated populations and deaths in each year of life, and the mortality-rates, are shown
in the following table :—