From Big Medical Encyclopedia

MORTALITY — process of decline in population owing to death. Page — social and biological process, the quantitative party to-rogo characterizes the level of health of the population. In a dignity. to statistics understand the frequency of cases of death in a certain set of the people combined by this or that sign as S. (the territory, age, sex, a social status, etc.). The concept «mortality» should not be identified with the concept «deadliness», or lethality (see), reflecting the relation of number of cases of death among patients with this or that disease to total number of such patients.

The organization of the accounting of cases of death

In all economically developed countries exists the obligatory, established by the relevant acts registration of cases of death which historically arose in connection with records of church ceremonies. Civil registration of cases of death was created in the countries of Europe in the first half of 19 century. In the majority of the countries the term of obligatory registration does not exceed 5 days, in the nek-ry countries he is limited for 24 hours. Except registration of the fact of death, record about its reason is important.

Registration of cases of death was manufactured in pre-revolutionary Russia by clergy, a cut kept special registers of births for this purpose. Soon after Great October socialist revolution decrees of the Soviet power from 18 on December (31), 1917 and on January 20 (on February 2), 1918 entered civil registration of the facts of the natural movement of the population, edges in the cities is carried out by special bodies since then — departments of civil registration (registry offices), and in villages — village and settlement Councils of People's Deputies. Registration of cases of death is made in the place of approach of an event or in the place of residence of the dead according to the statement of family members or other applicants in three-day time after death with presentation at the same time of the relevant documents confirming the fact of death. In the cities, settlements of city type and villages where not less than 2 doctors work, as such confirmation serves the medical certificate on death (see), and in other areas — the medical assistant's reference. On the basis of the specified documents in a registry office (Village Council) the statement of death including the demographic characteristic of the dead (a sex, age, a nationality, marital status, education, occupation) and nek-ry additional data on death is drawn up, from to-rykh the extreme importance the cause of death has. Record about a cause of death is made according to the international recommendations that provides the principle of selection of the main reason for death, uniform for all countries, for statistical development of mortality.

General and special mortality rates. For assessment of level C. use intensive indicators — the general and special coefficients of Page. Understand the annual number of the dead falling on average on 1000 people of the population of the country, the cities, the area, etc. as an overal coefficient of Page (t). Mathematically it is expressed as a formula: m = (M/S)*1000, where M — number of the dead in a year. S — annual average population. The size of the general indicator of S. substantially depends "on age composition of the population and therefore reflects only a tendency of process of S., but is insufficient for its profound studying. For elimination of influence on S.'s indicators of distinctions in age composition of the population resort to calculation of the so-called standardized S.'s indicators (see. Demographic statistics, Statistics sanitary), and also the special coefficients characterizing level C. in the corresponding groups of the population (age and sex, professional, on marital status, education level, etc.).

The povozrastny coefficients of S. representing the relation of number of the dead in a year in this age group to the average number of the same age group are most widely used. The overal and povozrastny coefficients of S. from the separate reasons reflecting S. from each reason calculate on average on 100 000 population.

The page depending on age has a certain pattern. The beginning of life is characterized by the increased level C.; with age S. decreases, reaching the minimum level in 10 — 14 years then again increases, at first slow, and then more and more in high gear.

A specific place among povozrastny coefficients of S. is held by child mortality, under a cut the level C. of children on the first year of life is understood. The technique of calculation of this indicator has the features (see. Child mortality).

For the characteristic of the organization and quality of medical aid, in particular obstetric and gynecologic, also indicators of maternal mortality (see) and perinatal mortality have important value (see).

Mortality of the population worldwide

In various countries, as well as at different stages of development of one country, is not identical S. and is defined by a complex of factors, are conducting from to-rykh social and economic (the material standard of living, cultural level of the population, - a way of life, the dwelling, food, traditions and customs of the population, etc.), and also a condition of health care and development of medical science.

For a long time S. of world's population was on a high level. At the end of 19 — the beginning of 20 century thanks to achievements of medical science and holding effective anti-epidemic actions S. in the European countries began to decrease quickly, having reached rather low level. In other countries it remained high to the middle of 20 century. By this time significant progress of medicine, hl. obr. successful fight with inf., went. - kish. and other acute diseases, caused S.'s decrease around the world, especially in developing countries. At the same time for economically developed countries there was characteristic an increase in distinctions in levels C. of men and women: Page of women decreased more considerably, than men. Along with it in a number of the countries there was S.'s increase in separate age groups, especially at men that reduced growth rates of an indicator of average life expectancy (see), and in the nek-ry countries caused its reduction.

Dynamics of povozrastny indicators of S. in a number of the countries demonstrates that decrease in its level happened hl. obr. due to reduction of number of premature death (among children and persons of young and middle age). Comparison of povozrastny indicators of S. of the population which are economically developed and developing countries indicates more high level of S. among children and persons of young age in developing countries.

Dynamics of mortality of the population in the USSR.

pre-revolutionary Russia S. was on very high level. In 1913 an overal coefficient of S. in Russia (in sovr. borders of the USSR) made 29,1 per milles, exceeding the corresponding coefficients of the majority of the European countries.

Social and economic transformations in our country, development of the Soviet health care and medical science promoted considerable decrease in S.: the overal coefficient for 1000 of the population decreased to 18,0 in 1940 and to 6,9 in 1964. However in the subsequent the tendency to increase in an overal coefficient of mortality was outlined (from 7,3 in 1965 to 10,3 in 1981) that is caused generally by increase as a part of the population of a share of persons of advanced ages. S.'s increase in separate age groups (tab. 1) is noted also a nek-swarm. In 1982 the overal coefficient of mortality decreased to 10,1 °/00.

The reasons of death

Considerable decrease in S. from inf. diseases, and also the postareniye of the population brought in economically developed countries to structural change of causes of death. So, if in 1900 in the USA infectious diseases among all causes of death occupied 18,3%, diseases of the blood circulatory system — 16,8%, malignant new growths — 3,6%, then in 1978 these indicators respectively made 0,9%, 51,0% and 20,6%. Similar changes happened also in other economically developed countries. Now in such countries first place among causes of death was won by diseases of the blood circulatory system and malignant new growths. The subsequent places belong to accidents, poisonings and injuries, diseases of a respiratory organs. The dead for all these reasons make more than 80% of all dead (tab. 2). In developing countries infectious and other acute diseases remained the main reasons for death.

The number of patients and dead from diseases of the blood circulatory system continues to increase in the majority of economically developed countries. Throughout a century S.'s indicator from these reasons in Austria and Norway increased more than by 3 times, in England and Wales, Denmark and the Netherlands — twice. In the USSR S.'s indicator from diseases of the blood circulatory system from 1960 for 1981 increased with 247,2 to 536,4 by 100 000 population. This growth is caused mainly by a postareniye of the population. Since 1981 in the USSR decline in mortality from this form of pathology is noted a nek-swarm.

S.'s indicator from malignant new growths made in the USSR 115,5 in 1960, 123,4 in 1965 and 142,1 in 1981 on 100 000 population (S. from oncological diseases in the majority of the developed countries is lower). Growth of this indicator is caused by a postareniye of the population what the standardized indicators eliminating influence of an age factor and allowing to state the actual tendency to S.'s decrease from this reason testify to. Against the background of the general decrease in S. from oncological diseases S.'s increase from tumors of separate localizations is noted (tracheas, bronchial tubes, lungs, a mammary gland, a rectum, leukemias).

Accidents, poisonings and injuries are the main reason for death of children since 3 years and adult population at able-bodied age (up to 40 years at women and to 50 at men). In the majority of the countries die of the injuries got at transport incidents in nek-ry more often — owing to suicides (Sweden, Japan, Denmark, Switzerland). In 1980 from 100 000 population died from accidents, poisonings and injuries in the Netherlands — 44, in England and Wales — 41.

One of methods of profound studying of S. is the analysis of its multiple reasons considering unlike traditional statistics of S. based on the principle of selection only of the main reason for death, all diagnoses specified in the conclusion about a cause of death. The number of the conclusions about a cause of death with multiple diagnoses on materials of a number of the countries fluctuates from 38 to 76% and depends (if certificates on death are completed correctly) first of all on age composition of the dead. Development of multiple causes of death allows to establish interdependence of individual diseases, and also the most important combinations of diseases, a part to-rykh remains to the unknown if S.'s development is made only for the main reason. Development of multiple causes of death is labor-consuming and difficult, however supplies with a number of the additional information valuable in the practical relation.

Tables of mortality or survivorship represent system of the interconnected indicators characterizing the sequence of extinction of the population at this level C. at separate age. Modern tables C. are under construction the demographic, or indirect method based on the principle of the hypothetical assumption of stationary type of the population i.e. about lack of migration and changes in processes of birth rate and mortality throughout life of generation. The tables of mortality constructed by this method show an order of consecutive extinction not of the real, really existing generation, and some conditional number which were born (accepted usually for 100 000), mortality to-rykh is equal to povozrastny mortality that calendar year in various age, in Krom calculation was made.

Methods of receiving the specified elements of tables of mortality are stated in the guides to demographic and sanitary statistics. As an illustration serves the table of mortality of the population of the USSR in 1958 — 1959, the made TsSU USSR (tab. 3).

From tables of mortality receive one of the major indicators for the characteristic of health of the population — an indicator of average duration of the forthcoming life (see. Life expectancy ).

There are concepts of probable and modal life expectancy. Understand age up to which a half of all number of been born lives as probable life expectancy. Understand age of which the greatest number of the dead are the share as modal life expectancy. Modal life expectancy shows the most typical age of death in senile years. Tables of mortality give also the chance to receive the most exact povozrastny mortality rates (tabular mortality rates) received by division of 1000 into the corresponding indicator of average duration of the forthcoming life and used for comparison on this indicator of the population of various territories.

The same tables made for the persons who died of the separate reasons (the table of mortality for the reasons), allow to define by similar tabular mortality rates death rate from the specific reason and extent of influence of mortality from the separate reasons on the average duration of the forthcoming life. The technique of creation of tables of mortality in the latter case is based on a hypothesis of elimination of mortality from this disease.

The technique of creation of tables of mortality finds application, besides, during the studying of the long-term results of treatment of patients with nek-ry chronic diseases and for comparison of efficiency of treatment of these patients with various methods. About success of treatment of chronic patients generally judge by its long-term results and first of all by longevity after treatment. Information about all patients continuing to live during the studied period about the dead with the indication of date of death and on the persons who left from under observation of medical institution is necessary for measurement of survival of patients with method of creation of tables of mortality (change of the residence, death from another, but not from the main disease and so forth). Such tables show number of the patients who stayed under observation completely the years first, second, third etc. after treatment and number of the dead within each studied year after treatment. The ratio of these data allows to receive rates of mortality and survival for each next year after treatment. Comparison of indicators of survival of homogeneous patients, treated by various methods, gives the chance to reveal the most effective from their number.


Table 1. POVOZRASTNY MORTALITY RATES of the POPULATION In the USSR In 1938 — 1976 for 1000 persons. The corresponding AGE GROUP (The National economy of the USSR in 60 years, 1977, page 73)



The Table 2 STRUCTURE of CAUSES OF DEATH in a number of the STATES B of % To the RESULT ( WORLD HEALTH STATISTICS ANNUAL; 1981, 1982)


Bibliography: Poor M. S. medico-demographic studying of the population, M., 1979; Bystrova V. A. Experience of studying of multiple causes of death, Owls. zdravookhr., No. 11, page 52, 1972; The Natural movement of the population of the modern world, under the editorship of E. Yu. Burnashev, M., 1974; R. Narodonaseleniye's Press and his studying. (The demographic analysis), the lane with fr., M., 1966; At r l of An and with B. Ts. Evolution of life expectancy, M., 19 78; Manual of mortality analyis, Geneva, WHO, 1980; Ovcarov V. K. a. Bystrova V. A. Present trends in mortality in the age group 35—64 in selected developed countries between 1950 — 1973, Wld Hlth Stat. Quart., v. 31, p. 208, 1978.

V. K. Ovcharov, V. A. Bystrova.