英和和英

Crude death rates (401-4) will depend upon the structure [particularly the age structure (325-6)] of the population as well as on the level of mortality. If the mortality of different populations is to be compared standardized mortality rates ¹ or adjusted mortality rates ¹ are sometimes computed to eliminate the effect of differences in population structure (144-4). Age is the characteristic for which mortality rates are adjusted most frequently by reference to a standard population ² with a given structure. If specific rates (134-6) for the population studied are available, it is possible to use the direct method of standardization ³ which consists of applying these rates to the corresponding groups of the standard population. If specific rates are not available, it is still possible to obtain standardized mortality rates by the indirect method of standardization ⁴. More frequently, comparative mortality indices ⁵ are computed by applying standard mortality rates ⁶ to the different groups of the population studied and summing these to obtain an expected number of deaths; the indices are then obtained by comparing the observed deaths ⁷ in the population with the expected deaths ⁸ which would have occurred had the standard rates applied.

1, Standardize, v. - standardized, adj. - standardization, n.: the process of standardizing.

• 5. If a crude death rate (401-4) is multiplied by a comparative mortality index, we obtain an indirectly standardized death rate. In British official terminology, when occupational mortality is studied, the figure obtained by direct standardization is called a comparative mortality figure and that obtained by indirect standardization a standardized mortality ratio.

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