Post on 12-Jan-2016
CHP400:Community Health Program - lI
Mohamed M. B. Alnoor
KJBKBKLJBKLB
D E M O G R A P H Y
Definition
Demography is the science that studies human population.
Demography: The study of populations, especially with reference to size and density, fertility, mortality, growth, age distribution, migration, and vital statistics, and the interaction of all these with social and economic conditions. (Oxford Dictionary)
D E M O G R A P H Y
Three main elements :1- Size of population (census) 2- Composition 3- Distribution
Elements of Demography:
D E M O G R A P H Y
Size of population
Census Estimated population
Number of all persons in the community.
Elements of Demography:
D E M O G R A P H Y
CensusA process of enumeration of all persons in the community.
• Time: 10 Years
• Procedures: Enumeration Demographic Socioeconomic
• Inter-census years: Estimation
Elements of Demography:
D E M O G R A P H Y
CensusTypes
1- De Jure Counting individuals at their legal
residence regardless of their physical presence.
• Factual• Expensive
Elements of Demography:
D E M O G R A P H Y
Census
• Easier• Economic
2- De Facto Counting individuals wherever they
actually are on day of census. regardless of their physical presence.
Types
Elements of Demography:
D E M O G R A P H Y
EstimationMethods
1- Natural increase
(Number of live births – Number of deaths) added to last census population.
(No migration in or out.)
Elements of Demography:
D E M O G R A P H Y
EstimationMethods
2- Arithmetic mean
Two consecutive censusesMean annual increaseExample:1410: 30000, 1420: 40000 Annual increase = 10000/10 =1000
(9 X 1000)
1429 = 4900040000
+
Elements of Demography:
D E M O G R A P H Y
EstimationMethods
3- Geometric method
Most accurateSpecial equation
Elements of Demography:
(compound interest formula)
D E M O G R A P H Y
Elements of Demography:
Compound Interest Formula
P = principal amount (the initial amount you borrow or deposit)
r = annual rate of interest (as a decimal)t = number of years the amount is deposited or borrowed for.A = amount of money accumulated after n years, including interest. n = number of times the interest is compounded per
year
EstimationMethods
3- Geometric method
Methods
Methods
D E M O G R A P H Y
Population (total) 27,163,977
Saudi 18.707.576
Males 9,527,173 (50.9%)
Females 9,180,403 (49.1%)
Non-Saudi 8,429,401
Males 5,932,974 (70.4%)
Females 2,496,427 (29.6%)
Last Saudi Census data (2010/1431
)
D E M O G R A P H Y
THE AGE-SEX COMPOSTION OF POPULATIONS
Saudi Population Pyramid ( 2006)
Age and sex distribution for the year 2000:
Age and sex distribution for the year 2000:
D E M O G R A P H Y
Population pyramid is the graphical presentation of the
age and sex composition of a population of an area
or country at a point in time.
The shape of the pyramid reflects the major influences
of births and deaths, in addition to any changes due
to migration.
Population Pyramid
D E M O G R A P H Y
Sex Males are shown on the left side of the pyramid Females on the right
Age young persons at the bottom, and the elderly at the top.
The pyramid consists of a series of bars, each drawn proportionately to represent the percentage contribution of each age - sex group
(often in five-year groupings) to the total population The total area of the bars represents 100 per cent of the
population.
Population Pyramid
D E M O G R A P H Y
THE AGE-SEX COMPOSTION OF POPULATIONS
1.Sex ratio: Percentage of males and females.
2.Age structure: Base denotes births (broad or narrow base) Apex denotes elderly
3.Mortality and emigration:
Shape of sides (sloping or steep).
4.Life expectancy: (Average number of years that a newborn is expected to live if current mortality rates continue to apply)
Height of the pyramid and shape of the apex.
The importance of the population pyramids
D E M O G R A P H Y
THE AGE-SEX COMPOSTION OF POPULATIONS
5.Median Age: (lower or higher)
The point in the vertical axis of age through which passes
the horizontal line that divides the surface area of the
pyramid into two equal parts (50%) younger and 50%
older).
The position of this defined point is inversely related to the
width of the base.
The wider the base, (i.e. the higher the birth rate), the lower
the median age and vice versa.
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
THE AGE-SEX COMPOSTION OF POPULATIONS
6.Dependency Ratio
The dependency ratio describes the relation between
the potentially self-supporting portion of the
population and
the dependent portions at the extreme of age (below
15 and above 65).
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
THE AGE-SEX COMPOSTION OF POPULATIONSTypes of Dependency Ratio
Young dependency: Proportion of population below 15 years of age.
Old dependency: Proportion of population above 65 years of age.
Total dependency: Proportion of population below 15 years of age plus the proportion of population above 65 years of age.
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
Population 15 – 64years
Types of Dependency Ratio
Old dependency ratio
Total dependency ratio
Population above 65 years
Population below 15 yearsYoung dependency ratio =
=
=
X 100
X 100
X 100
Population 15 – 64years
Population 15 – 64years
Population below 15 years + those above 65 years
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
How can you calculate the dependency ratio.
Use the figures below to calculate the dependency ratio for Britain in 1990.
0 - 14 = 11.052 million 15 - 64 = 37.690 million 65 + = 9.156 million
Young dep=0.29 Old dep=0.24 Total dep=0.53
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
Use the figures below to calculate the dependency ratio for Egypt in 1990.
0 - 14 = 22.04 million 15 - 64 = 32.66 million 65 + = 1.99 million
Young dep=0.67 Old dep=0.06 Total dep=0.73
Population Pyramid The importance of the population pyramids
D E M O G R A P H Y
1. List factors affecting Population Dynamics
2. Define and Calculate Fertility rates
3. Define and calculate Mortality Rates
4. Define and mention types of migration
By the end of this lecture you will be able to:
ObjectivesPopulation Dynamics
D E M O G R A P H Y
Factors affecting population Dynamics
Fertility (births),
Mortality (deaths)
Migration.
Population Dynamics
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Crude Birth Rate (CBR)
General Fertility Rate (GFR)
Age Specific Fertility Rate
Total Fertility Rate (TFR)
Gross Reproduction Rate (GRR)
Fertility (Natality Rates)
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Crude Birth Rate (CBR)Fertility (Natality Rates)
Is the simplest indicator of fertility. It is defined as: the number of live births per 1000 mid-
year population in a given year and locality.
CBR=Total number of live births in a certain year and localityEstimated midyear population ( same year and locality)
X 1000
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)Crude Birth Rate (CBR)
ExampleIn a certain Country in Year 2000,live births: 325,000; population: 13,000,000
Crude birth rate= 325,000/13,000,000 x 1000= 25 live births per 1000 population per
year
=… Live Births/ 1000 population in a year.
CBR=Total number of live births in a certain year and localityEstimated midyear population ( same year and locality)
X 1000
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)General Fertility Rate (GFR)
= …Live birth/1000 female population aged 15-49.
The number of live births in a calendar year, divided by the number of women in the child bearing ages 15-49 at mid year, multiplied by 1000
GFR=Total number of live births in a certain year and localityMidyear reproductive female population( aged 15 - 49)
X 1000
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)General Fertility Rate (GFR)
ExampleIn a certain Country in Year 2000, Number of live births: 325,000; Number of women 15 – 49 : 2,600,000
Calculate GFR
General fertility rate= 325,000 /2,600,000 x 1000= 125 live births per 1000 women ages 15-49 per
year
GFR=Total number of live births in a certain year and localityMidyear reproductive female population(aged 15 - 49)
X 1000
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)Age Specific Fertility Rate
= …Live births/1000 female population in specified age group.
Total number of live births born by mothers in a specific age group in a certain year and locality
Female population in the same specific age group
X 1000 =
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)Age Specific Fertility Rate
Adolescent fertility rate It is the age-specific fertility rate for women aged 15-19. The annual number of births to women aged 15-19
years per 1,000 women in that age group.
= …Live births/1000 females in 15-19 age group.
Calculation of ASFR is important because early pregnancy is related to higher risks of maternal and infant mortality
Total number of live births born by mothers (15-19) age group in a certain year and
localityFemale population in the (15-19) age group
X 1000 =
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)Total Fertility Rate (TFR)
TFR represents the average number of births that would be born to a woman throughout her reproductive period.
It is expressed as children per woman. In Saudi Arabia, Total fertility rate (per
woman) 3.5 (2006)• In developing countries the TFR is over
6.0 children per woman. • In most developed countries the TFR is
under 2.0.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Fertility (Natality Rates)Gross Reproduction Rate (GRR) GRR represents the average number of female births that would be born to a woman throughout her reproductive period.
It is expressed as daughters per woman.
It predicts the fertility of the next generation
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality Rates
A mortality rate is a measure of the
frequency
of occurrence of death in a defined population
during a specified period of time.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCrude Death Rate (CDR)
The crude death rate is the mortality rate from all causes of death for an entire population
1000Xlocality)andyear(SamepopulationyearmidEstimated
localityandyearcertainaindeathsofnumberTotal
RateDeathCrude
= … Deaths/1000 individual in the specified year and locality.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCrude Death Rate (CDR)
Example
In a certain Country in Year 2000,Total population: 13,000,000;Deaths: 65,000Crude Death Rate = 65,000/13,000,000 x
1000= 5 deaths per 1000 per year
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates
An age-specific mortality rate is a mortality rate limited to a particular age group.
• The numerator is the number of deaths in that age group• The denominator is the number of persons in that age group
in the population. Examples of age-specific mortality rates are infant, neonatal,
post-neonatal and under 5-years mortality rates.
1000
area same andyear same in the
group age same in thenumber Total
area andyear certain a and age
certain ain dying persons ofNumber
ratedeath specific Age x
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates
ExampleIn a certain Country in Year 2000,For age group: 25-34 yrs: population = 5,000,000; and
deaths = 20,000 within same age groupAge-specific death rate=20,000/5,000,000 x 1000= 4 deaths per 1000 population of the age group 25-34 per year
1000
area same andyear same in the
group age same in thenumber Total
area andyear certain a and age
certain ain dying persons ofNumber
ratedeath specific Age x
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Infant Mortality Rate (per 1 000 live births)
Infant mortality rate is the probability of a child born in a specific year or period dying before reaching the age of one
• Both sexes 21.0
• Females 20.0 • Males 22.0In Saudi Arabia (2006)
Total number of deaths from zero up to less than one year
during a year in a given localityTotal number of live births
in the same year and locality
Infant Mortality Rate X 1000=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Infant Mortality Rate
In a certain Country in Year 2000,Number of live births: 325,000; infant deaths: 2,750
Infant Mortality Rate = 2,750/325,000 x 1000= 8.5 infant deaths per 1000 live births per year
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Infant Mortality Rate
Infant deaths per 1000 live births
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Neonatal Mortality Rate (per 1 000 live births)
The number of deaths of neonates (infants <28 days of age) in a calendar year, divided by number of live births in that year, multiplied by 1000.
In Saudi Arabia (2004): Neonatal Mortality Rate =11 /1000 live births
Total number of deaths from zero up to less than 28 days
during a year in a given localityTotal number of live births
in the same year and locality
Neonatal Mortality Rate X 1000=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Neonatal Mortality Rate
In a certain Country in Year 2000, Number of deaths at <28 days:2,250; number of live births: 325,000Calculate Neonatal mortality rate?
Neonatal mortality rate= 2,250/325,000x1000= 6.9 neonatal deaths per 1000 live births
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Neonatal Mortality Rate
Causes of Neonatal mortality
Birth defects (the 1st leading cause ) Prematurity / low birth weight (LBW)
(the 2nd leading) Sudden infant death syndrome. Maternal pregnancy complications. Respiratory distress syndrome
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Post - neonatal Mortality Rate (per 1 000 live births)
Post-neonatal mortality rate is the number of deaths
among infants from 28 days up to 1 year of age
during a a year divided by the number of live births
during the same a year multiplied by 1,000
Total number of deaths from 28 days up to less than one year during a year in a given locality
Total number of live births in the same year and locality
Post - neonatal Mortality Rate X 1000=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates
NeonatalNeonatal Post-NeonatalPost-Neonatal
28 day(0 day) 1yearBirth
I n f a n c yI n f a n c y
NeonatalEarly
NeonatalLate
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Still birth Ratio (per 1 000 live births)
Number of fetal deaths of > 28 weeks
gestation in certain year and locality per
1000 live birthsNumber of foetal deaths from > 28 weeks of gestation in a year and in a given locality
Number of live births in the same year and locality
Still birth Ratio X 1000=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Still birth Ratio
In a certain Country in Year 2000,Still births: 1,520; live births: 325,000
Still births ratio = 1,520/325,000 x 1000= 4.69 fetal deaths per 1000 live births
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Still birth Rate (per 1 000 total births)
Number of still birth during a year and in a given locality
Total birth (live births + still birth) in the same year and locality
Still birth Rate X 1000=
For international comparison purposes, stillbirths are defined as third trimester fetal deaths (> 1000 grams or > 28 weeks).
Total births : Total births is defined as the sum of live births and still births.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Still birth Rate (per 1 000 total births)
In a certain Country in Year 2000,Still births: 1,520;live births: 325,000
Still births rate = 1,520 /(325,000+ 1,520) x 1000= 4.66 fetal deaths per 1000 total births
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Causes of Still birth
Placental problems.: Placental abruption due to pre-eclampsia and smokingsmoking.
Defects: between 5 and 10 percent of stillborn babies have chromosomal abnormalities.
Growth restriction: Small for gestational age. Infections. Bacterial infections occur between 24
and 27 weeks of gestation. They are an important cause of fetal deaths.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Perinatal Mortality Rate (per 1 000 total births)
It is expressed as the sum number of still births and
early neonatal deaths (less than 7 days of life) per
1000 total births (still births plus live births).No. of still birth + No. of early neonatal deaths
in a year and in a given locality
Total birth (live births + still birth) in the same year and locality
PMR = X 1000
It is the best indicator of MCH services
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Perinatal Mortality Rate (per 1 000 total births)
In a certain Country in Year 2000,Still birth (Fetal deaths):1,520; early neonatal deaths: 1,925;live births: 325,000Perinatal mortality rate=(1,520 + 1,925)/(325000+1,520) x 1000
= 10.6 perinatal deaths per 1000 Total births
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesAge-specific Mortality Rates Under - 5 Mortality Rate (per 1 000 live births)
Under-five mortality rate is the probability of a child born in a specific year dying before reaching the age of five.
In KSA (2006): deaths per 1 000 live births: • both sexes
26 • female 23 • male 28
Total number of deaths among children under-5 years of age
during a year and in a given localityThe under – 5
mortality Rate X 1000=
Total number of live births in the same year and locality
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCurrent Situation
Each year nearly 11 million children die before the age of five, 30,000 every day, largely from preventable causes.largely from preventable causes.
41% of these deaths occur in Africa, which has only 10 % of the world’s under-five population.
33% of all child deaths occur in the first month of life.
Under - 5 Mortality
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesMaternal Mortality Ratio (per 100 000 live births)
but not from accidental or incidental causes.
The death of a woman while pregnant or
within 42 days of end of
pregnancy
irrespective of the duration or site of pregnancyfrom any
cause • related to • or aggravated by
pregnancy or its management
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesMaternal Mortality Ratio (per 100 000 live births) The number of maternal deaths per 100 000 live
births during a specified time period (usually 1 year). In Saudi Arabia (2005) MMR= 18/100 000 live birth
Maternal mortality ratio
Number of Maternal deaths assigned to causes related to pregnancy
in a given year and locality X 100 000=
Total number of live births in the same year and locality
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesMaternal Mortality Ratio (per 100 000 live births)
Abruptio Placenta
Eclampsia
Postpartum Hemorrhage
Retained Place
nta
Hypertension in Pregnancy
Uterine Atony
Puerperal Sepsis
Placenta Previa
Rheumatic Heart Disease Amniotic Fluid Embolism
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesMaternal Mortality Ratio (per 100 000 live births) In a certain Country in Year 2000,number of deaths due to maternal causes: 51,Number of live births: 325,000Calculate Maternal mortality ratio
Maternal mortality ratio = 51/325,000 x 100,000= 15.7maternal deaths per 100,000 live births per
year
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCause-specific mortality rate
The number of deaths attributed to a specific
cause divided by the population at the midpoint
of the time period multiply by 100,000.
Deaths of a specific cause in a given year and locality
Estimated mid – year populationin the same year and locality
Cause – specificMortality Rate X 100 000=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCause-specific mortality rate
Deaths due to tuberculosis (per 100 000 population) In Saudi Arabia (2006) =5.0
No. of deaths of tuberculosisin a given year and locality
Estimated mid – year populationin the same year and locality
Specific death rate
due to tuberculosis
X 100 000=
Example of Cause-specific mortality rates
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCause-specific mortality rate
In a certain Country in Year 2000,Total population: 13,000,000; Deaths due to (cause) accidents: 5,200
Cause-specific death rate= 4,000/5,000,000 x 100,000
= 40 accidental deaths per 100,000 population per year
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesProportionate mortality rate
Defined as the number of deaths assigned to a
specific cause in a calendar year, divided by the
total number of deaths in that year, the quotient
multiplied by 100
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesProportionate mortality rate In a certain Country in Year 2000,total deaths from all causes: 65 000; deaths from cancer: 29 250
CancerProportionate mortality rate
= 45% of total deaths per year are from cancer
29 250/ 65 000 x 100=
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Mortality RatesCase Fatality Rate
(Death to case ratio)
Case Fatality Rate ( CFR )
Total number of deaths froma certain disease
in a year in a given locality
Total number of cases having the same disease
in the same year and locality
= X 100
It reflects severity (virulence) of It reflects severity (virulence) of diseasesdiseases
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Migration
Migration is the movement of populations across a
specified boundary for the purpose of residing.
Migration is the change of residence of a person or
group of persons for better life and higher
standard of living.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
Migration The terms immigration and emigration are used
to refer to moves between countries (international
migration).
The parallel terms: in-migration and out-migration
are used for internal movement between
different areas within a country (internal migration).
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
MigrationTypes of migration Internal migration
It is the movement within the boundaries of a
given country.
Examples of internal migration:
1 - Rural - Urban migration.
2 - Movement of nomads.
3 - Movement of temporary and seasonal nature.
4 - Movement between and within urban areas.
D E M O G R A P H Y
Population DynamicsFactors affecting population Dynamics
MigrationTypes of migration
a) Permanent migration:
eg. Arabs to the U.S.A., Australia and Canada.
b) Temporary migration:
The intent is return to the motherland after few years.
e.g. Professionals and laborers to Gulf Countries.
In many countries, the effect of migration is minimal when compared to fertility and
mortality.