Demography

LEARNING OBJECTIVES:
• To define demography and recognize its importance.
• To differentiate between rate, ratio, proportion, and index
• To describe population estimations in the census and inter-
census years.
• To describe and interpret different profiles of the
population pyramid.
• To define data sources for vital indices.
• To calculate rates/indicators for birth, death, morbidity
and fertility.
• Recognize the relationship between SDGS & vital indices

DEMOGRAPHY
4
Demography: to describe population characteristics, size or
number, distribution and to study the change of these
determinants over time.

• Distribution of the population by age,
sex, occupation, education, religion,
marital status, race, etc.
Population
characteristics
• No. of persons in the populationPopulation size
• Population arrangement in space at a
given time; geographically (Upper &
Lower Egypt) or among various types
(Urban or Rural).
Population
distribution
• Growth or decline of the total
population or one of its structural units
over time.
Population
change

IMPORTANCE OF DEMOGRAPHY
• Basic information for health services planning.
• It provides the No. of population to be covered by health
services,
• It provides the amount of vaccines or drugs needed every year.
• It provides the characteristics of population in different
geographical areas that can affect health.
• To calculate health indicators for the community
• Used in comparison & evaluation of health services

HEALTH INDICATORS
Rate
• Frequency of an event in a population in relation to time (birth rate).
• Usually multiplied by a constant as 100 or 1000 to get integer
number.
Ratio
• Occurrence of an event in relation to other unrelated event.
(male to female ratio is 1:2).
Proportion
• Ratio that compares a part with the whole.
• When the base is 100 a proportion is called a percent “%”.
Index
• Used when the true denominator can’t/or difficult to be
calculated so a related accurate denominator is used instead.

METHODS OF STUDYING DEMOGRAPHY
Calculate population size using census & inter
census methods.
Study population growth using rate of natural
increase.
Study population composition by age & sex using
population pyramid.
Study population distribution by using maps.
Calculate health related indicators (birth, death,
fertility & disease rates).

The census is to enumerate people in certain area
(country) at certain time.
It collects data about the no. of population,
characteristics as age, sex, and socio-economic data
as income, crowding index, occupation, education
level etc..

 Census is done every 10 years since it is time,
effort and cost consuming.
 Mid-year population is the no. of population
calculated from census at the 1st of July (it was
chosen as a standard for any census).

IMPORTANCE OF CENSUS
Calculate the actual no. of population living in a country at the year of the
census.
For planning for future health care programs.
Provides general characteristics of the population used in
comparison over periods of time, or comparison with other foreign
populations.
To estimate population in years between censuses.
Calculate vital statistical rates.

DRAWBACKS OF CENSUS
Expensive, needs time, money
and personnel.
If it consumes long time in
data collection & analysis the
results will be irrelevant
Data may be inaccurate “ages
& income”
There are some areas where
people are moving as seasonal
& temporary hired workers
“Missed or under-estimated”.
Lack of co-operation between
people & census data
collectors.
Data collectors may fill
questionnaire by themselves
when houses are empty.

 1st population census in Egypt was at 1882 “The total
population was 6.7 millions”
 Last population census at 2017 (14th census & 1st
electronic census) “The total population was 104.2
millions; 94.8 million are living in the country & 9.4
million are abroad”

INTER-CENSUS ESTIMATION
Since census is done
every 10 years, certain
methods are used to
calculate the no. of
population at years in
between.
Arithmetic
method
Rate of
natural
increase (RNI)
Total growth
rate
Graphic
method
Geometric
method

Arithmetic method
Calculating difference between 2
subsequent censuses
Dividing that difference by 10 (to find
the annual increase of population)
Multiplying this annual increase by no.
of difference years
Add the result to population number in
the 1st census
This method assumes that the population increases yearly
with the same amount which is not true.

Census 2000 - census 1990= 80 - 60 = 20 millions
Annual increase of pop.= 20 / 10 = 2 millions
Pop. Increase in 4 years = 2 x 4 = 8 millions
Pop. No. in 1994 = 8 + 60 (pop. 1990) = 68 millions
Census
1990 = 60 millions
2000 = 80 millions
1994 ?

This method neglects the immigration factor that
can increase/decrease population number.
Rate of natural increase (RNI)
Calculate RNI = CBR – CDR
“the number of population added per year”
Multiply this increase by the number of
years
Added to the 1st census

TGR= (birth rate + immigrants to the country) -
(death rate + emigrants outside).
Then the estimated population is calculated by the
arithmetic way as previously described
Total growth rate

Plotting a straight line connecting population
numbers in all previous censuses (x-axis represents
years of censuses) & (y-axis represents population
number in million).
We can know from that graph the estimated
population number in years between 2 censuses also
we can predict the number of population in the
future by extending the line.
Graphic method

120
100
80
60
40
20
0
1990 2000
Graphic method
No.ofPop.
20101994
y
X1996

It is calculated by certain equation that depends on
the last 2 population censuses, the no. of years in
between the censuses & the annual rate of increase.
Geometric method
This method assumes that population growth is not
linear (or steady every year).

Changing population growth pattern (transition) is
mainly affected by:
Births Deaths
Migration Life expectancy
Population
growth

Countries are classified into the following patterns in
relation to the rate of natural increase (RNI):
Stationary
Low births & low
deaths.
RNI <1.5%.
Long life
expectancy
As in Sweden
Transitional
High births but
decreasing deaths.
RNI 1.5 - ≤ 2.5% As in Egypt.
High potential
High births &
high deaths.
RNI > 2.5%.
Short life
expectancy
As in Pakistan.

LIFE EXPECTANCY
The average no. of years that can be expected to be lived by
any individual at certain age.
Life expectancy is directly proportional to country
development, socio-economic level, health services
standard, use of new technology, good nutrition, healthy
environment, literacy etc.

In developed countries the life expectancy of new borne is
85 ys while in under developed countries it reaches 40 ys.
In Egypt, life expectancy of new borne increased recently to
reach 73 & 69 ys (for females & males).

POPULATION PYRAMID
Graphical presentation of population by age & sex.
Vertical axis represents age groups (in fives)
Horizontal axis represents the % of population of these
age groups in relation to sex.

• Base of the pyramid represents the birth rate.
• Height represents the no. of years to be lived at specific age (life
expectancy).
• Top represents the % of elderly.
• Slope of the pyramid represents age specific death rates.
• Dependency ratio: is the No. of young ages <15 years old plus the No. of old ages >65
(who are dependent groups) per 100 persons aged from 15-64 years (who is an
independent group).
• It represents the % of males & females at each age group.
Characteristics of population pyramid

Birth rate
Lifeexpectancy
Old age group
Dependency ratio=
No of dependents/
No. independents
% of males
&females at
each age group

Expansive model:
Wide base (rapid
population growth
& high birth rate).
Strong tapering &
short height of
pyramid (high
death rate).
Constrictive
model:
Narrow base (low
birth rate)
Slow tapering
slope (decreased
death rate).
Stationary model:
Almost equal no.
in all stages (low
birth rate & low
death rate)
Narrow base
Very slow tapering
Models of population pyramids

In 1950: It follows the expansive model:
1. The base is wide due to high birth rate.
2. Strong tapering: high specific death rates especially from 0-5 ys old.
3. The top is narrow due to small % of elderly.
4. The height is short due to short life expectancy.

In 2000: it shows a constrictive model:
1. The base is narrower than that of the 1950 “decreased birth rate”.
2. The fertility declines where the proportion aged between 0-4 years
& between 5-9 years are less than those aged between 10-14 years.
3. More decrease in the different age specific death rates is noticed
(slow tapering slope).
4. Life expectancy has increased (Height of the pyramid is increased).
5. Increased no. of the elderly (wider top of the pyramid).

In 2016 (CAPMAS, 2016)
1. Base is broader than that of the 2000 “slight increase in birth rate”.
2. More decrease in the different age specific death rates is noticed
(slow tapering slope).
3. Life expectancy has increased (Height of the pyramid is increased).
5. Increased No. of the elderly (slightly wider top of the pyramid).

In 2050: It will show a stationary model:
1. Different age groups proportions are almost equal due to almost
equal birth & death rates.
2. Slow tapering at old age groups due to expected low age specific
death rates. More flat top due to expected increase in No. of elderly.
3. Longer life expectancy which may reach up to 80 ys. (Height of the
pyramid is increased).

STUDY POPULATION
DISTRIBUTION BY USING MAPS

Some health & socio-economic indicators are used to
facilitate evaluation & comparison of population
characteristics
Annual economic
growth rate: Average
annual growth rate
(AAGR)
Per capita income Literacy percentage
Total dependency
ratio
Life expectancy
Health indices (vital
rates)

The average increase in the value of an individual
investment, portfolio, asset, or cash stream over the period
of a year.
It is calculated by taking the arithmetic mean of a series of
growth rates.
Annual economic growth rate
Average annual growth rate (AAGR)
Economic Growth Rate: the rate at which a nation's Gross
Domestic product (GDP) changes/grows from one year to
another.
GDP is the market value of all the goods & services
produced in a country in a particular time period.

‫المحلي‬ ‫الناتج‬ ‫إجمالي‬

Measures the average income earned per person in a given
area (city, region, country, etc.) in a specified year.
It is calculated by dividing the area's total income by its total
population.
Per capita income
‫نسمة‬ ‫لكل‬ ‫القومي‬ ‫الدخل‬

Literacy % = No. of literate persons x 100
Total population
Literacy percentage
73.8% in Egypt 2016

Total dependency ratio =
No. of children (0-14 ys) + old people (>65 ys) X 100
No. of population (15-65 ys)
Total dependency ratio
61.8% in Egypt 2016

Life expectancy means the average no. of years
which the person of a given age may expect to live
according to mortality rates of that country.
Life expectancy

Health indices (vital rates)
Mortality
Morbidity
Fertility
Birth

Vital indices are quantitative measures that
describe various aspects of health status of a
defined community & summarize the vital events in
the human life.
Births Marriage Fertility Diseases Deaths

Birth
Crude Birth Rate
(CBR)
Fertility
CBR
General Fertility
Age-specific
Fertility
Total Fertility
Fecundity
Gross
Reproduction
Net Reproduction
Morbidity
Incidence
Prevalence
Attack
Case Fatality
Mortality
Crude Death
Age specific
Mortality
Age-Sex specific
Mortality
Proportional
(Relative)
Mortality

CBR in Egypt was 33.5/1000 in 1990, decreased to
23/1000 in 2010, raised to 27.8 in 2014 and in the
last census reached 30.3/1000 in 2016

Although CBR describes the increase in population
over time, yet it is not specific for comparison
between countries because the denominator is the
whole population.
The rate must exclude young girls, unmarried and
menopausal women who are infertile.
Yet, this rate is used for its simplicity, easy to know
birth number because of legal registration in health
office & population number at any time (from
census and inter censuses methods).

Birth
Crude Birth
Fertility
CBR
General Fertility
Age-specific
Fertility
Total Fertility
Fecundity
Gross
Reproduction
Net Reproduction
Morbidity
Incidence
Prevalence
Attack
Case Fatality
Mortality
Crude Death
Age specific
Mortality
Age-Sex specific
Mortality
Proportional
(Relative)
Mortality

FERTILITY
The reproduction performance of a population

GENERAL FERTILITY RATE (GFR)
GFR=
No. of live births X1000
No. of women (15- 49ys) in the same locality & year.
Since, women in the reproductive age constitutes
about 25% (1/4) of the population, therefore the
GFR is considered to be about 4 times the CBR.

Advantages
• GFR is a more accurate
index than CBR because:
• It is related only to
females in the
reproductive age.
• It is more suitable for
comparison between
countries since it
eliminates the difference
in sex composition.
Disadvantages
• It doesn’t consider that
not all females in the
reproductive age are
married & fertile.
• It doesn’t consider the
difference in females’ age
distribution in different
countries.

AGE-SPECIFIC FERTILITY RATE (ASFR)
It is calculated for every 5 years of the reproductive age of a woman.
It is important for differentiating between fertility behaviors at
different age groups.
Therefore there are “7” ASFRs (every 5 years) for all women in the
reproductive period.
ASFR=
No. of live births born to mothers aged 15 -20 years old X 1000
No. of women of the same age group (15-20 years) in a certain locality & year.
It is a better index than the GFR as it takes into account the
difference in age distribution of females in different areas & the
degree of fertility in each age group.

TOTAL FERTILITY RATE (TFR)
It is the average no. of live children that would be born to a
woman if she passes through her child bearing period
following the ASFR in a given year & locality.
TFR in Egypt: 3.2 (2006) & 3.5 (2016) children / woman.
It equals the average of the 7 ASFRs.
TFR = 5 Σ ASFR (for 5-year age for 7 groups)
TFR in 2016= 5 (SFR 15-19ys + SFR 20-24 +SFR 25-29 +
SFR 30-34 + SFR 35-39+ SFR 40-44 + SFR 45-49)

FECUNDITY RATE (FR)
FR =
No. of live births X 1000
Married women in a certain locality & year.
It is a better index than the GFR as it includes only
married women.

GROSS REPRODUCTION RATE (GRR)
 In Egypt, it is estimated to be 1.5, which means that every
woman is expected to give birth to 1 to 2 women during
her childbearing period.
 However, it does not consider the possibility of deaths of
women during their child bearing period.
GRR =
Only born females, (expected to be future mothers) X 1000
Women in the childbearing period.
= TFR X Proportion of females in relation to the total births.

NET REPRODUCTION RATE (NRR)
It takes into consideration the deaths of women
during their childbearing period using life tables of
females.
NRR = GRR X Life expectancy of females during
childbearing period from life tables.
The best measure of fertility.

FACTORS AFFECTING FERTILITY:
• The greater the no. of women in
childbearing period in a certain pop. the
higher fertility level.
• The younger the age of marriage the
higher is the fertility.
• Higher economic status & higher level
of education of women are associated
with low fertility rates.
• Physiological capability of couples to
reproduce is affected by their health
conditions.
• Reasons that motivate a couple to
increase or decrease No. of children they
will have.

High Fertility Motives Low Fertility Motives
• Economic motives: Children as
a source of income to the family.
• Health motives: High infant &
preschool death rates.
• Cultural & religious motives:
- Traditions & community “large
family is considered as a source of
power & social status”.
- Some wives “large no. of children
ensure security& prevent divorce”.
- Family planning is prohibited in
Islam.
• Economic motives: large
expenses for good education &
health.
• Health motives:
- Mother & Children Health are
better with suitable spacing of
pregnancies.
- Large family:
*Bad effect on physical, mental,
social & spiritual health of the family.
*Hazards of deprivation, child abuse,
delinquency.

 Dimensions of the population problem in Egypt are
summarized in insufficient resources in relation to no. of
people.
 Aspects related to demography include:
Population
growth
Population
characteristics
Population
distribution.

Improvement in the health conditions in the last few years
has lead to a decrease in the death rate & a proportion of the
birth rate & thus the RNI has remained high.
Recently a decrease in the birth rate has started & thus the
RNI began to decrease.
But, due to past experience of high birth rate a large no. of
the population is entering the fertile age group and therefore
the population growth will remain high for years before
starting to decline.
Population Growth

Rate 2006 2016
Total Dependency ratio 58% 62.3%
CBR 25.5/1000 30.3/1000
CDR 6.4/1000 4.7/1000
RNI 1.94/1000 2.51/1000
Life expectancy for male
Life expectancy for females
69 ys
73 ys
71.4 ys
74.2 ys
Infant mortality rate 26.2/1000 19.7/1000
Maternal mortality rate 84/100000 33/100000
TFR children/woman 3.2 3.5
Population characteristics in 2006 & 2016

About 95% of population lives around the Nile in a
very narrow area representing 5% of Egypt land, so
population density is very high.
Population distribution:

SOLUTIONS
Long term
solution
• Increasing resources
• Investment in industry
• Increasing land cultivation & productivity
• Exportation
• Building new factories
• Reclaiming desert
• Female education
Short term
solution
• Decreasing birth rate
• Empower low fertility motives
• Try to decrease high motives

MORBIDITY RATES
They are disease occurrence data that are used in disease
surveillance.
The most widely used measures of illness in a population are
incidence & prevalence rates.

INCIDENCE RATE
The population at risk can be the entire population in a specified
area, or specific group of people “people of certain age, sex etc”.

It is very important parameter in
epidemiology.
It tells us about new cases & thus we can
associate this event of illness with the
possible causal factors.
It can be calculated for both chronic &
acute diseases.
It measures the relative importance of one
illness over the other.
Importance

PREVALENCE RATE
• The no. of current cases of an illness (old & new) at a
point of time / Population examined at same point of
time X Constant.
• Point of time is a short period (hours, days…).
Point prevalence
• The no. of current cases of an illness (old & new)
over a period of time / midyear population of the
same period X Constant.
• Period of time is longer (months, years).
Period Prevalence

It is an indicator of the burden of a disease on a
population since it reflects the no. of cases
whether old or new.
It measures the relative importance of one
illness over the other.
It can be used for evaluation of health services.
Importance

ATTACK RATE
It is an incidence rate estimated in an epidemic (or
outbreaks) when observation of population at risk is
for short period.
Attack rate =
No. of new cases of specific disease during an epidemic X 100
Total no. of persons at risk during the same time.

CASE FATALITY RATE
It measures the virulence of an agent & the severity of a
disease.
Therefore is considered as a morbidity measure although it
involves deaths.
CFR =
No. of deaths of cases from specific illness X constant.
No. of cases of the same illness in the same time and place

DEATH INDICES (MEASURES OF MORTALITY)
Although not effective as the morbidity indices but
sometimes they are the only available data.
• Death rates are important indicators of the health status in
a community.
• They can indicate the impact of a particular cause on the
population.
• They can study the relation of a certain cause to the
disease occurrence.

CRUDE DEATH RATE (CDR)
CDR in Egypt has decreased in 2016 to reach 4.7%.
This improvement can be attributed to: community
development, better health services, application of
modern techniques, new drugs, and health education etc.
CDR is not specific rate as it includes all deaths in a
population irrespective of its age, sex distribution or cause
of death.

STANDARDIZATION OF DEATH RATE
In order to compare death rates across countries, we
need to standardize the death rates to neutralize the
difference in age & sex composition of the
population by using:
Direct
method
Indirect
method

Use arbitrary population age groups to which we apply the age
specific mortality rates of each one of the two countries that we
want to compare.
By this way we get the expected no. of deaths in the arbitrary
population if it has the same age composition of country 1 & 2.
If we use this calculated expected no. of deaths as the numerator
& the total population as a denominator we will get the adjusted
death rate for each country that eliminated the difference in age
composition.
Direct Method

Indirect Method
Apply age specific mortality rate of an arbitrary population to
the two population age groups that we want to compare. Thus
we will have the expected no. of deaths for each population.
The proportion of true deaths to the expected deaths for each
community will give the proportional mortality rate for each
community. When we multiply this proportional mortality of
each community by total expected no. of deaths we will get
the specific mortality rate for each community.

AGE SPECIFIC MORTALITY RATE (ASMR)
ASMR =
No. of deaths in a specified age group & specific time X constant
Population of the same age group & at the same time period
ASMR describe the rate of deaths in each age group.
The causes of deaths among age groups are different and
therefore by using this rate we can prioritize these causes to
be solved.

AGE-SEX SPECIFIC MORTALITY RATE (ASSMR)
No. of deaths of males at certain age group X 1000
No. of males of the same age group in the same area and time

CAUSE SPECIFIC MORTALITY RATE
No. of deaths from a specific cause X constant
Population at the same time period
Cause specific MR describes the severity of the disease to
cause deaths.
Cancer has high cause specific MR.

PROPORTIONAL (RELATIVE) MORTALITY RATE
No. of deaths from a specific cause X constant
Total deaths from all causes in the same area & time
It describes the relative importance of a specific disease as
a cause of mortality in relation to other causes

Demography

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