Excess mortality ratio with reference to the lowest age-sex-specific death rates among countries

Indicators based on mortality data have long been used to measure the level of health status and to monitor and evaluate the progress and achievements of health programmes. Their usefulness is particularly obvious when dealing with preventable deaths. This article proposes the use of the lowest death rate recorded among industrialized countries for each age/sex group as an achievable target and as a reference for assessing the amount of excess mortality. The resulting indicator, excess mortality ratio (EMR), reveals some features of the mortality pattern which may not be easily noticed by means of other mortality indicators. Two sets of the lowest age-sex-specific death rates are considered, namely one comprising the lowest rates recorded in each calendar year (the current minimum) and the other comprising the lowest rates ever recorded since 1950 (the historical minimum). The former may be used for monitoring whether a country is moving ahead in mortality reduction in pace with low mortality countries, while the latter may be considered as a realistic goal for a country's mortality reduction. In computing the EMR, the lowest death rates are first applied to the age-sex composition of the population of a given country for a given calendar year to obtain the number of deaths which would have been expected under the lowest mortality pattern; the expected number is then subtracted from the actual number of deaths recorded in the country during the calendar year to yield the "excess". The indicator is finally calculated by taking the ratio of the excess to the expected minimum. The historical minimum death rates found from the records maintained in WHO's mortality data base are shown in Table 2 (for country codes used, see Table 1). The minimum rates have themselves declined with time as seen in Table 4, especially in young age groups, and the declining trend has been more marked in females. These trends are seen also in individual countries' data (Table 3). A comparison of the cause-of-death pattern of a country with that of the world's lowest death rate will reveal the causes to which the country's excess mortality is attributable, as seen in Table 5. At the same time, the table also shows that even the lowest rates are made up of causes which are largely preventable. The world's lowest rate therefore may be regarded as conservative targets for mortality reduction.(ABSTRACT TRUNCATED AT 400 WORDS)