10.

Demography

Demography is the study of the size, composition and

distribution of human populations.

Demography studies describe the physical and social

characteristics of human populations and the changes which
occur in these characteristics.

Statistics of births, deaths, diseases, age, sex and other

characteristics of the people comprising the population are
collected and studied.

Relevance of Demography and Population Figures for the

Health Care

The statistics of births, deaths, diseases, age, sex, etc.:

 Illustrate conditions prevailing in communities which are

vital to the planning of health services
 Determine as to whether health services are meeting the
needs of the community for which they are designed.

Determinants and Measurements of Population Size

Three factors directly influence population size: births, deaths

and migration of people out of or into the population.

Changes in birth rate, mortality (or death rate) and migration

will directly affect the size of a population.

Birth rate

Compares the average annual number of births during a year per

1,000 persons in the population at midyear.

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Usually, the dominant factor in determining the rate of
population growth.

It depends on both the level of fertility and the age structure of

the population.

Death rate

Indicates the number of deaths occurring during the year, per

1,000 population estimated at midyear.

Subtracting the crude death rate from the crude birth rate
provides the rate of natural increase, which is equal to the rate
of population change in the absence of migration.

Fertility rate

It is the ratio of live births in an area to the population of that

area; expressed per 1000 population per year.

This measures the number of births in each year per 1000

women of normal reproductive age.

Mortality rate

It is the same as death rate. There are a number of different

types of mortality rates as, for examples, the following:

The fetal mortality rate: The ratio of fetal deaths to the sum of
the births (the live births + the fetal deaths) in that year.

The infant mortality rate: The number of children dying under a

year of age divided by the number of live births that year.

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The maternal mortality rate: The number of maternal deaths
related to childbearing divided by the number of live births (or
by the number of live births + fetal deaths) in that year.

Migration rate

There are 2 types of migration – immigration and emigration.

Immigration: it refers to migration of people into a country

Emigration: it refers to migration of people out of a country.

If the rate of immigration is = to rate of emigration, the size of

the population will not be affected but if one is higher than the
other the population will be increased or reduced depending on
which one is the higher.

Migration can take place under tow conditions – forced or free.

Determinants and Measurement of Population

Composition

This is measured by counting the number of people in it who

share certain biological or social characteristics, such as sex,
race, age, education, occupation, ethnic background, etc.

Importance of Knowing Composition of Population of a Country

 Government can plan for public facilities such as schools,

institutions, water, employment opportunities, health
facilities, etc.

 The sex ration and age composition of a population are

important in determining the future growth of population.

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Sex ratio

This is a way of expressing the relative numbers of males and

females in a population.

It is usually calculated by counting the number of males per

every hundred females.

Importance of sex ratio in theory

1. Forecast chances of marriage for men and women

2. It gives us insight into the migration –i.e. whether more –

women More men or women are emigrating or migrating.

3. An indication of the birth and death rate in each sex i.e.

whether more female or male babies are born and which sex
suffers the higher death rate.

Age composition

Determined by finding the median age of all its members and

then examine how many people are above or below the median.

Median age is the age which divides population exactly in half, so

that one half of the population is older than the median and one
half is younger.

Eg. 4, 6, 8, 11, 13, 16, 18, 21, 23 and 24. Median age 15 because
half under 15 and half above 15.

A well distributed population should not have a high or low

median. A young population has a low median age and a high
population of young people, whereas an old population has a
high median

Importance of age composition

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Age distribution influences the growth and economic
development of a country. It also shows whether a population
has too many dependant members and what its fertility rate is
likely to be.

E.g. high population of very young or very old members –

population too many dependants may affect economic situation of
that population or country.

Also many people in the age group 15 to 45, fertility may be very
high because this is the age when women are fertile.

Determinants of Population Distribution

Geography

People are distributed over only part of the earth’s surface which
is naturally habitable.

Urbanisation and Industrialisation

As a country become more industrially developed, people move

from rural areas to urban cities and this has an important effect
on the distribution of a population.

Effects of Urbanisation and Industrialisation

- The growth of cities can contribute to economic progress –

usually increasing amount and variety of goods and services
available to people.

- Increase people’s awareness and size of the group with which

a person can form friendships.

Consequence of Rapid Population Growth

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1. Land and natural resources

Population pressure on land and natural resources

particularly in high density areas of the country.

Increased land fragmentation, environmental degradation,

forces continuous cropping, and depletion of soil fertility
are resulting in declining productivity of agricultural land.

2. Food Security

Population growth has an impact on food self-sufficiency

and food security and hence on the nutritional status of the
population.

3. The Labour Market

Opportunities for formal wage employment are scarce –

more will be seeking employment outside the formal sector
– which unfortunately looks already constrained e.g.
smallish.

4. Social Services

The social services of education and health are already

stretched to their maximum prov. Services and facilities
such as schools, houses, health centres as well as training
teachers and health staff not easy with government limited
budget – low cash incomes.

- Increase in children and pregnant mothers needs of

maternal and child health services put strain negative
effect.

- Problem arise when urbanisation occurs so rapidly that it

strains the ability of urban government to provide

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 housing, sanitation, public safety and other necessary
services and when there are not enough jobs.

- The rising number of unemployed urban youth appear to

be contributing to rising rates of crime and violence,
particularly in the mega cities of the developing world.

Current Demographic Trends

Causes of population growth

There has been a decline in death rate combined with high birth
rates in developing countries and the following are some of the
reasons:

- Increase in food production and distribution

- Improvement in water and sanitation
- Introduction of medical technology such as vaccines and
antibiotics
- Advances in health care

The Demographic Transition Theory

The old balance

With its very high death rate, high birth rate and
consequent slow growth or stability in the total population
increase.

The transitional period

Characterised by its declining death rate, high birth rate

and consequent high rate of natural increase, leading to an
explosion in the population numbers.

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The new balance

Which will hopefully have not only a low death rate, but also
a controlled, low birth rate so that there is only limited
population increase.

The aim of most demographic health planners is ultimately

to achieve a nil population growth.

Population Momentum

With a large number of people moving into their childbearing

years, the total number of births continue to rise even though
individual couples have fewer children than their earlier
generations.

National Population Policy

The overall goal of the Policy is

“to improve the standard of living and quality of life of the

Malawian people”

In order to attain this goal, the Policy proposes to lower fertility

and infant, child and maternal mortality rates.

As early pregnancy has been identified as a major contributing

factor to high infant and maternal mortality, the Policy focuses
on reducing adolescent marriages and teenage pregnancies

Overall Goal

To improve the standard of living and quality of life of the

Malawian people.

The policy’s central feature is to ensure that the future growth of

the country’s population is kept under manageable and

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sustainable boundaries, while still maintaining the right of each
individual and couple to decide the number of children they wish
to bear.