Mortality

Mortality or death is affected by a variety of factors. They may be biological, physiological, environmental, etc. From the demographic view point, mortality is related to the age and sex of an individual. There is infant mortality, mortality of woman at the time of delivery, mortality of man due to cancer of the prostate, etc.

In its Manual on the International Statistical Classification of Causes of Death, the World Health Organisation (WHO) places them under the following five categories:

  • 1. Infectious, parasitic and respiratory diseases
  • 2. Cancer
  • 3. Diseases of the circulatory system
  • 4. Violence and accidents
  • 5. All other causes such as diseases of the digestive system.

With the exception of category 4 when deaths occur due to violence and accidents, deaths in the remaining categories are being reduced with the advancement of medical science in both developed and developing countries. In the past, the mortality rate was high because of food shortages and famines, spread of epidemics, insanitary conditions, and long and recurrent wars.

After the Second World War, the mortality rates have declined so much in developed countries along with birth rates that the problem of extremely small growth rate of population has arisen in a number of countries like France, Germany, Japan, etc. This has been due to rapid advancement in medical sciences in controlling all types of diseases through life saving drugs and surgery.

Other factors responsible for low mortality rates in developed countries have been cleanliness of person and home, hygienic surroundings, pollution control, social security measures, balanced food, health consciousness, etc.

Causes of Decline in Mortality Rates in Developing Countries:

Mortality rates have declined considerably in developing countries in recent years due to the following reasons:

  • (1) Disease Control Medicines: By importing drugs from developed countries, the developing countries have been able to control such mass killers as typhoid, malaria, small pox, pneumonia, plague, etc. The World Health Organisation, in particular, has been helpful in eradicating malaria, small pox, polio, TB, etc. to a considerable extent.
  • (2) Public Health Programmes: Developing countries with the assistance of WHO have been adopting public health programmes for keeping the environment clean and free of pollution. Governments have been following strict pollution control measures. Consequently, deaths due to respiratory diseases have declined.
  • (3) Medical Facilities: Medical facilities have not only increased but also improved in such countries. The number of doctors and trained nurses has increased considerably. Besides the spread of government hospitals in urban centres and primary health centres in rural areas, private hospitals and nursing homes are fast coming up which provide the best of medical facilities comparable to those in advanced countries. As a result, the number of deaths are on the decline.
  • (4) Spread of Education: With the spread of education, people are becoming rational. They are giving up superstitious and fatalist attitude towards life. They have started taking keen interest in their own health and that of their children. They have become health conscious. They take nutritive and balanced diet, do exercise, go for a walk and even to a gym. All these have brought down the death rate.
  • (5) Status of Women: In almost all the developing countries, the status of women in society has increased with spread of literacy among them. Women now understand the importance of cleanliness and hygiene and take better care of their children’s health. Consequently, the infant mortality rate is on the decline. Early marriage of girls has been banned in the majority of developing countries, thereby reducing the death rate at the time of the first child.
  • (6) Food Supply: With the increase in food supply in the majority of developing countries and through imports of food grains from developed countries like the USA and Australia, famines have been controlled. This has resulted in reduction of death rates in such countries.
  • (7) Life Expectancy: Over the years, life expectancy has increased in developing countries due to increase in economic growth rates, rise in per capita incomes, improved health, medical, sanitation facilities, etc. Consequently, the death rate is on the decline and the percentage of population in 60 plus age group is on the increase.

IGNOU SOURCE:

Causes of Death

The World Health Organisation has prepared a Manual on the International Statistical Classification of Diseases, Injuries and Causes of Death. According to this Manual (WHO, 1955), one thousand groups of diseases have been
identified, and these are re-grouped into an intermediate list of 150 causes numbered A1, A2, A3, etc. These, in turn, are regrouped into an abbreviated list of 50 causes numbered as B 1, B2, B3, etc. This last list of 50 groups of causes is used for computing deaths and death rates on the basis of the causes of death. Again, from this list of 50 groups of causes, various diseases have been grouped according to their response to various health measures, resulting in five groups. These are:

  • 1) Infectious and parasitic diseases of the respiratory system,
  • 2) Cancer,
  • 3) Diseases of the circulatory system,
  • 4) Deaths by violence, and ,
  • 5) All other causes.

The pattern of mortality on the basis of causes of death in the developing regions is quite different from that in the developed regions, though this pattern too has undergone changes over the years as mentioned above. For those countries for which data on causes of death are available, it is possible to study the changes in the causes of death along with the changes in mortality.

i) Reasons for high mortality in the past: It has already been pointed out that, up to the nineteenth century, death rates all over the world were very high and fluctuating. The main reasons for such high mortality rates were:

  • Acute and chronic food-shortages causing famines and conditions of malnutrition;
  • Epidemics;
  • Recurrent wars; and
  • Poor sanitary conditions.

The study of infant mortality gains importance, specially because mortality during the first year of life is invariably high for all countries, irrespective of whether the overall levels of mortality are high or low. Further, level of infant
mortality acts as an indicator of the medical and health facilities, expectation of life at birth, age structure of population and fertility change in a population.

ii) Factors aflecting infant mortality: A variety of factors affecting infant mortality are customarily classified as biological/endogenous and exogenous (socio-economic and environmental) factors. These categories should not
be treated as watertight compartmentsfor there is a great deal of interaction between them. At times, it is even possible to modify biological factors by introducing changes in socio-economic factors or environmental factors.

  • Endogenous/BiologicaI factors: Most of the endogenous factors related to the formation of the foetus in the womb are biological in nature. Among the biological factors affecting foetal and neo-natal infant mortality rates, the important ones are the age of the mother, the birth order, the period of spacing between births, prematurity birth, weight at birth and the fact of multiple births. Based on in-depth studies done on the age of the mother, the parity of the mother or the order of pregnancy andlor of birth it has been generally observed that foetal and neo-natal mortality rates are higher at the younger ages of the mother (that is, below the age of 19), at first parity and for the first birth order. These mortality rates start declining up to the age of 29 of the mother, and at the second and third parity and then again increases with higher age of the mother, higher parities, and high birth orders. It is now an established fact the causes of foetal and neo-natal deaths arise mainly out of genetic factors, and may be traced back to the intrauterine life of the feotus and to the damage occurring during the process of birth.
  • Exogenous Causes: Social, cultural, economic and environmental factors are also found to affect infant mortality, specially during the post-neonatal period. However, post-neo-natal deaths are mainly due to various epidemics caused by communicable diseases, both of the digestive system such as diarrhoea and enteritis, and of the respiratory system such as bronchitis and pneumonia as well as by faulty feeding patterns and poor hygiene. The important environmental factors include crowding and congestion, insanitary surroundings, lack of proper sunshine and fresh air, etc. Changing patterns of lifestyle impacting on culture producing illegitimate births and consequent effects leading to infant mortality is also contributing to a high infant mortality rate.

One interesting feature of the role of endogenous and exogenous factors in determining infant mortality rates is worth noting. In developed countries where infant mortality rates are very low, a higher proportion (that is, more
than two-thirds) of infant deaths occur during the neo-natal stage only, because, being developed they have been successful in almost completely eliminating the environmental factors responsible for such deaths. The main causes of infant mortality in these countries are, therefore, mainly genetic or biological in nature. On the other hand, in countries where infant mortality rates are high, the majority of infant deaths occur after the neo-natal stage and are mainly due to environmental factors (United Nations, 1973). International comparisons of the causes of death by regions, continents or countries is made difficult because of diffeqences in terminology, method certification, diagnostic techniques and the interpretation of death certificates by the coders.

iii) Causes of mortality decline in developed countries: In Europe, North America and Oceania continuous economic progress resulting from Agricultural and Industrial Revolutions have been the main reasons for the reduction in mortality rates, which first began to decline rather weakly in the seventeenth century and then with an increasing tempo throughout the eighteenth and nineteenth centuries.

Important developments that affected morality in European countries since the eighteenth century have been the increase in the supply of food, advances in technology, extension of the benefits of medical research, development of immunology, advances in chemotherapy (use of drugs to cure or inhibit the progress of diseases) and other improved health services, improvements in sanitary conditions and public health measures, and heavy and better
clothing to combat severe winters, social reforms, etc. All these have collectively led to improvements in the standards of living and fall in morality in many ways. Similar developments over a period in other countries also have gradually contributed to the decline of their mortality rates.

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