DEMOGRAPHY

1. UNIT –VI
DEMOGRAPHY
R.SRIDEVI
HOD COMMUNITY HEALTH NURSING dept

2. Demography
 Demo” means “the people” and
 “graphy” means “measurement”.
 • (Demos = population, Graphy =Picture)
Demography as the Statistical study of human population
with regard to their size And structure, their composition
by sex, age, marital status and Ethnic origin, and the
changes to these population .like changes In their birth
rates, death rates and immigration.

3. DEFINITIONS
 “” Demography is the "study of human populations in
relation to the changes brought about by the
interplay of births, deaths, and migration“
PRESSAT
 “” Demography is the ”scientific study of human
population in which includes study of changes in
population size ,composition and its distribution””

4. IMPORTANCE OF DEMOGRAPHIC DATA
Health status of a community depends upon the dynamic
relationship between number of people, their composition&
distribution
 Planning of health services can be guided by demographic
variables
example: How many health units do we need? How
to distribute them in the community in order to be accessible
to the target population? What type of manpower is
needed?

5.  Helps to Know The state of the Environment, and the pace and
quality of economic and social Development ”.
Demographic data provide a basis for predicting future
Trends and making decisions.
Demographic data are important for the formulation Implementation,
and evaluation of plans, policies, and Programs for education
housing, health, employment, Transportation ,recreational needs and
other forms of Social services.
Demographic data can guide policy makers in meeting the Needs and
of various sectors of the society, such as the Young, the adult and
aged, the unemployed, the poor, and the Various cultural groups.

6. ELEMENTS OF DEMOGRAPHY
 Size: increase or decrease
 Composition: sex and age group
 Distribution: territory

7. SCOPE OF DEMOGRAPHY
 The scope of the study is wide because demography causes slow
or rapid growth of birth rate
 Causes & changes in birth and death rates
 Population growth
 Sex & literacy ratio
 Health rates and ratio
 Dependency & independency ratio
 Calculation of population
 Size of population
 Production and consumption
 Socioeconomic status
 Standard of leaving
 Marital status, family composition etc..

8. CONCEPT OF DEMOGRAPHY
Demography is the branch of social size, structure,
which deals with the study of size, structure and
distribution of populations, along with the spatial and
temporal changes in them in response to birth,
migration, ageing and death.

9. DEMOGRAPHIC INDICATORS
• 1. Measurement of Mortality.
• 2. Measurement of Morbidity.
• 3. Measurement of disability.
• 4. Measurement of natality.
• 5. Measurement of the presence, absence or
distribution of the characteristics or attributes
of the disease.

10. • 6. Measurement of medical needs, health care
facilities, utilization of health services and other
health related events.
• 7. Measurement of the presence, absence or
distribution of the environmental and other factors
suspected of causing the disease.
8. Measurement of demographic
variables.

11. DEMOGRAPHIC INDICATORS :
• Crude Birth Rate. (CBR)
• General Fertility Rate. (GFR)
• Crude Death Rate. (CDR)
• Infant Mortality Rate. (IMR)
Life expectancy. (LE)
• Total Fertility Rate. (TFR)
• Gross Reproduction Rate.(GRR)
• Net Reproduction Rate. (NRR)

12. TOOLS OF MEASUREMENT
•
An epidemiologist usually expresses the health event as
RATES, RATIOS or PROPOTION.
RATE
• A rate measures the occurrence of some particular
event in a
population during a given period of time period.
A rate comprises the following elements.
• 1. Numerator.
• 2. Denominator.
• 3. Multiplier.

13. RATIO
• Ratio expresses a relation in size between two random
quantities.
E.g., x : y (or) x/y.
PROPORTION
• A Proportion is a ratio which indicates the relation in
magnitude of a part of the whole.
• The numerator is always included in the denominator.
• A Proportion is usually expressed as percentage.

14. RATE AND RATIO
 Rate of the vital events is defined as the ratio of the total
numbers of occurrences of the events to the total numbers
of person exposed to the risk of occurrences of that events.
 Sex ratio= Male population X 100
 Female population
 child women ratio
 Nos of child<5 yrs X 100
Total female pop 15-49 yrs

15. MEASUREMENT OF MORTALITY
 (a) Crude Death Rate (CDR)
 = Total death in a given year X 1000
 Average or mid year pop. of a year
 (b) Age-specific Death rate (ASDR)
Nos. of death at age ’a’ _X 1000
Mid-yrs pop. of a given year at age ’a’
 Crude rate is based on total population while a specific
rate is based on the basis of age, sex, cause etc

16.  FERTILITY(BIRTHS)
 -Refers to the actual number of children born to a woman or
. A simple way to measure fertility is to get the crude Birth rate;
 EQ.
 REGISTERED NUMBER OF BIRTHS IN YEAR
 CBR= --------------------------------------------------------------------- X 1000
 TOTAL MID-YEAR POPULATION
 Migration(immigration and emigration):
 -Refers to the spatial movement of person or grouped of
Persons within a country or specified territory, more or less for
Permanent residency.
 -Immigration, when one enters the country of destination.

17.  Still birth:
 It is a death prior to the complete expulsion from mother irrespective of the
duration of pregnancy
 Family birth:
 Total number of persons offer family or total number of children a women or
couple born at point of time.
 Child death;
 Commonly due to social and other causes there are many deaths with a period
of 1 yr of birth from the child
 Live birth:
 It is complete expulsion of the foetus irrespective of the deviation of pregnancy
 Parity:
 In demography woman are classified according to the no of children born alive
to them parity refers to the mother.

18.  Adult hood:
 In this stage boy or girl becomes capable to produce children. the
age of puberty very much depends on food consumed are
eliminate from the body.
 Marriage:
 As legal union of person of opposite sex each individual should
be reported for vital statistics
 Contraception:
 A measure taken in order to prevent sexual intercourse from
resulting in conception.
 Reproductive span:
 Indicates child bearing period of women. Period B/w onset of
menstruation and closes it onset of menopause..

19.  Separation & divorce;
 When wife and husband don’t live together for some period in home & no
sexual relations called separation. It can be due to various reasons
 Fertility:
 It is standard of measuring the capacity of women to produce children.
Fertility can be studied in birth statistics.
 Migration:
 Its people attract to some geographical area for to stay.
 Ratio:
 It express size of one to another eg; 50;50…education ratio
 Proportion:
 It express the size of a one part of whole in relation eg;25% of old people
living with DM

20. DEMOGRAPHIC CYCLE(STAGE)
1. 1 stage---high stationary
2. 2 stage ---early expanding
3. 3 stage----Late expanding
4. 4 stage---low stationary
5. 5 stage----declining

21. DEMOGRAPHIC CYCLE(STAGE)
• High stationary (first stage ):
this stage is characterized by a high birth rate and
high death rate , population remains stationary .India
was in this stage till 1920.
Early expending (second stage ):
the death rate begins to decline while the birth rate
unchanged initial increase in population south Asia &
Africa are in this stage

22.  Late expanding (third stage):
The death rate decrease still further and birth rates
tends to fall . continue increase in population
 Low stationary (fourth stage ) :
This stage is characterized by a low birth rate &
low death rate .stability in population .
 Declining (fifth stage ):
In the declining stage birth rate is lower then the death
rate .fall in population. European, Germany and
Hungary countries present facing this stage.

23. METHODS OF DATA COLLECTION
 Primary data collection :collection is done by the
individual by using the methods such as :
 • Observation
 • Interviews
 • Questionnaires
 • Diaries
 surveys

24.  Secondary data collection :
 • census method
 Administrative records
 • Registration of vital events system
 sample registration system
 National sample survey

25. INTERVIEWS
• Interviews are undertaken on personal, one to one
basis or in a group. The advantages of interview method
are as follows.
1.It is the best means to collect an in depth information.
2.The feedback and response rate is good.
3.The information is recorded immediately and
complete.
4. Help can be provided immediately

26. DISADVANTAGES OF INTERVIEW
1. It is expensive and time consuming.
2. Training is required in case of employing many interviewers.
3. Prefixed questionnaire are required.
Types
1. STRUCTURED.
2. SEMI STRUCTURED
3. UNSTRUCTURED.

27. OBSERVATION
• Is a method to record behavioural pattern of people in a
systematic manner.
• The methods of observation include: structured, un structured,
natural, personal, mechanical, participant or non participant
observations.
• Observation method provides information on what is actually
observed.
• Bias in observation method can be eliminated by two
observers.
• Hence this method has limitations in eliciting accurate
information.

28. QUESTIONNAIRES
• Questionnaire is a common method of data collection.
• It takes time and expertise to prepare a structured questionnaire
• The questionnaire can be used to interview for a direct data
collection or a telephonic survey could be conducted.
• It can be posted, emailed or faxed.
• The main advantage of this method is that there is no bias..
The use of questionnaire is simple but requires a certain level of
education and skill from respondents.

29. DIARIES
• Diaries are used to record data obtained from the individuals.
• The data expressed in the diaries are an in-depth information and can be
used for research purposes.
CRITICAL INCIDENTS
• The critical incidents relating to health - illness event is recorded
and used for arriving decisions and policies regarding health matters.

30. II.SECONDARY DATA
• The secondary data is collected indirectly (not from inviduals) from
other sources such as hospital records, census data etc.
SOURCES OF DEMOGRAHIC DATA
census method
Administrative records
• Registration of vital events system
sample registration system
National sample survey

31. SURVEY

32. • Census is the direct method of collection of demographic data.
• Census is conducted by the government every 10 yrs.
• Census is an attempt to contact every member of the population in
a country.
• Census not only provides information regarding the number
of people, but other relevant information (age, gender, marital
status, occupation, education, employment status, migration,
language, religion etc.)
A census covers social & economic aspects of a population.
• It is conducted at the end of first quarter of each decade.
• The census commissioner of India guides, operates, and directs
the census
Census method

33.  De facto census method:
the method is to list all persons present in the household
or other living quarters at midnight of the census day .
.
 1. De jure census :
 all persons who usually live in the household are listed
on the form whether they are present or not.
 Visitors who have a usual residence else where are
excluded from the listing but are counted at their usual
residence.

34. USES OF CENSUS
 Is the primary sources of basic national population
 data required for administrative purposes and
many aspects of economic and social planning and research.
 Provides information on:
 trends in population growth.
 change in age and sex structure cause of fertility, mortality,
migration and urbanization.
 Useful for estimating, calculating birth and death rates
 Changes in the national occupational and industrial
composition
 Levels of literacy and educational attainments

35.  Religion, languages and caste/ethnic composition
 Analysis of economic development.
 Future trends of population growth.
 National, local, public and private planning.
 Estimating school going population, military and economic
manpower.
 Future growth of cities and requirement of food,
water, housing and health services.
 Number of voters- present and future and many
more

36. ADMINISTRATIVE RECORDS
 Used in almost every country and a common example of such are
health statistics from hospitals.
 their reliability in providing accurate demographic data depends upon
the completeness of the record.
 administrative recording process and the competence of reporting
(Suharto, 2011).
 Administrative recorded are a very cost effective
 data source in developing countries but unfortunately in most of the
departments have not yet fully developed their administrative
recording systems.

37. VITAL REGISTRATION SYSTEMS•
Registration of vital events is the basis of vital statistics.
• Vital events refers to births, death, migration, marriages, divorces, foetal
deaths are registration in India.
• In 1873, Govt of India passed the Birth, Deaths & Marriage
Registration Act.
• Indian states such as Karnataka, Tamil Nadu etc have passed their own
policies related to registration of vital events.
• The main drawback in this registration process is that it has
the provision only for voluntary registration.
• So data is not accurate and complete as people do not voluntarily get the
birth, death or marriages registered.
• The data tends to be unreliable

38. The other reasons for incompleteness include :
1. Illiteracy.
2. Ignorance.
3. Lack of concern.
4. Lack of motivation.
5. Lack of uniformity.
6. Multiple registration agencies.

39. SAMPLE REGISTRATION SYSTEM (SRS)
 Initiated in 1969-70 for want of complete
registration from CRS.
 • Provide reliable annual estimates of birth, death
and infant mortality rates at the State and National
levels separately for rural and urban areas.
 • Also provides Child Mortality Rate (CMR), Total
Fertility Rate (TFR), Sex Ratio at Birth and 0-4 age,
Institutional deliveries, Medical Attention before
death, etc.

40. SRS
 One of the largest demographic household sample
survey in the world
 • Only panel survey with dual recording
 • Panel revised once in 10 years based on the latest
available Census frame

41. NATIONAL SAMPLE SURVEYS
ORGANIZATION(NSSO)
 • National Sample Survey Organisation (NSSO),
now known as National Sample Survey Office, is
an organization under
the Ministry of Statistics of the Government of India.
 • Largest organization in India conducting regular
socioeconomic surveys (like household consumer
expenditure, employment and unemployment,
health and medical services etc).
 • Established in 1950

42. NSSO
 Topics to be decides in a particular survey round.
 • NSSO every year brings out reports on status of
estimation of agricultural production in India.

43. ANALYSIS & INTERPRETATION OF DATA
• The data thus collected should be arranged in tables, charts,
diagrams, graphs, picture & curves to stress important points.
• The data presented should be based on the principles designed
to meet the criteria.
TABLE

44. CHARTS
• The data collected could be represented in the form of a chart.
• The data contained in a chart is more easy to understand and
retained easily than a table.
TYPES OF CHARTS :
1. BAR CHARTS. (simple. Compound, Histogram)
2. LINE DIAGRAMS.
3. PIE CHARTS.
4. PICTOGRAM.
6. STATISTICAL MAP.
7. STATISTICAL AVERAGES & DISPERSION OF MEASURES OF
VARIATION

45. BAR CHART

46. TYPES OF BAR CHARTS
1. Simple Bar Chart.
2. Component Bar Chart.
3. Histogram.

47. SIMPLE BAR CHART.

48. COMPONENT BAR CHART
1. The component bar chart represents
many components.
2. The representation could be either as vertical or as
horizontal bars.

49. HISTOGRAM
1.Histogram is a pictorial diagram which consists of series of blocks.
2.If the mid point of histograms blocks is joined, then a line with
fluctuation is seen.
3.frequency polygon is obtained by joining the mid points of histogram
blocks.

50. LINE DIAGRAM
A line graph is usually used to show the change of information over a
period of time. This means that the horizontal axis is usually a time
scale, for example minutes, days, months or years. Example: The
table shows the daily earnings of a store for five days.

51. PIE CHART
• Pie charts are diagrammatically represented in circles with the
radius "O". and at radius angle 360 degree.

52. PICTOGRAM
• In pictogram, small pictures or symbols are used to present the
data.