Demography as the statistical study of human population with regard to their size & 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. 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. In demography the following three elements of population are given special attention: Change in the size of population (increase or decrease) Structure of population (on the basis of sex or age groups) Geographical distribution of population (on the basis of state or territory).

1. Presented by:
Harsh Rastogi,
Nursing Tutor,
M.S. Institute of Nursing,
Lucknow

2. Introduction
 Demography is the statistical study of human
populations.
 Demography examines the size, structure, and
movements of populations over space and time.
 Demography is useful for governments and private
businesses as a means of analyzing and predicting
social, cultural, and economic trends related to
population.

3. Etymology
 Demography (from prefix demo- from Ancient
Greek δῆμος (dēmos) meaning 'the people', and -
graphy from γράφω (graphō) meaning 'writing,
description or measurement') is the statistical
study of populations, especially human beings.
 Demo: people
 Graphy: description
 The word was coined by John Graunt in 1662.

4. Cont…
 John Graunt (24 April
1620 – 18 April 1674) has
been regarded as the
founder of demography.
 Developed early human
statistical
and census methods that
provided a framework for
modern demography.

5. Demography
 Demography as the statistical study of human
population with regard to their size & 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.
 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.

6. Definitions
 Demography is the ‘study of human populations in
relation to the changes brought about by the interplay
of births, deaths, and migration.’
 Demography is the ‘scientific study of human
population in which includes study of changes in
population size, composition and its distribution.’

7. Cont…
 Demography is the ‘statistical and mathematical
study of the size, composition and spatial
distribution of human populations, and of the
changes over time, in these aspects through the
operation of the five processes of: fertility, mortality,
marriage, migration and social mobility.’
 Demography is the statistical description and
analysis of human population.

8. Concept
 Demography is a branch of science which studies the
human population.
 In demography the following three elements of
population are given special attention:
1. Change in the size of population (increase or
decrease)
2. Structure of population (on the basis of sex or age
groups)
3. Geographical distribution of population (on the
basis of state or territory).

10. Cont…
 Some commonly used concepts are:
 Stillbirth
 Foetal death
 Family size
 Child death
 Live birth
 Parity
 Adulthood

11. Cont…
 Contraception
 Sterility
 Birth order
 Marriage
 Reproductive span
 Separation and divorce
 Fertility
 Fecundity
 Cohort

12. Cont…
 Ratio
 Migration
 Proportion
 Rates
 Percent
 Natural increase and rate of natural increase

13. Scope of demography
 It is very important for community health nurse to
know demographic aspects of their community.
 Information regarding population static: It will
help the nurses to plan and manage need based health
care services for the community at large. It includes:
 Total population
 Age and sex composition
 Median age and dependency ratio
 Socioeconomic characteristics

14. Cont…
 Family size
 Life expectancy
 Distribution and concentration
 Information regarding population
 Crude mortality rate
 Specific mortality rate
 Age specific mortality rate dynamics

15. Cont…
 Total population: This will help to determine the
bulk of services and the work load which health
workers are going to have:
 Age and sex composition: This will help to
analyze health needs, morbidity, and mortality
pattern utilization of health care services and
accordingly plan and manage health care services.

16. Cont…
 Median age and dependency ratio: This will help
to know about the ratio of young and elderly
population and adult population.
 This will help nurses to determine economic burden.

17. Cont…
 Socioeconomic characteristics: These
characteristics include education, marital status
occupation, income, etc.
 This will help not only to identify socioeconomic
status but also morbidity and mortality pattern and
fertility behaviour.

18. Cont…
 Life expectancy: Information regarding life
expectancy will help her to understand and appreciate
the impact of health care services on morbidity and
mortality among people.

19. Cont…
 Distribution and concentration: Distribution
and concentration of population in the community
will help to identify areas where services are needed
most.

20. Cont…
 Information regarding population dynamics: It
will help nurses to understand the changes that are
taking place in the population under the influence of
fertility, mortality, and migration pattern in
community.

21. Cont…
 Crude mortality rate, birth rate: These rates will
help nurses to know natural increase in population
and compute growth rate.

22. Cont…
 Specific mortality rates: These include age, sex,
cause specific rates, case fatality, and proportional
mortality rate.

23. Demographic Cycle
I. Stage: High Stationary
II. Stage: Early Expanding
III. Stage: Late Expanding
IV. Stage: Low Stationary
V. Stage: Declining

24. Cont…
 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.

25. Cont…
 Late Expanding (Third Stage): The death rate
decrease still further and birth rates tends to fall,
continue increase in population. Example: China,
Singapore, India.
 Low Stationary (Fourth Stage): This stage is
characterized by a low birth rate & low death rate,
stability in population. Example: Australia in 1980-85.

26. Cont…
 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.

27. Method of data collection
 Data collection is an important aspect of any type of
research study. Inaccurate data collection can impact
the results of a study and ultimately lead to invalid
results.
 Primary Data: The data collected directly from
individuals by face to face survey is called primary
data. It is first hand information.
 For examples:
 Data collected during census
 Data related to health from an individual.
 Data related to illness from an individual.

28. Primary data
 Primary data collection is done by an individual by
using the methods such as:
1. Interview method
2. Observation
3. Questionnaire
4. Dairies
5. Surveys

29. Interview method
 Interviews are undertaken on personal, one to one
basis or in a group.
 Interviews can be conducted at work, home as well as
any fixed place (location) which was agreed by the
both parties.
 PV Young mentioned that the interview is a
systematic method by which a person enters more or
less imaginatively into the life of a comparatively
stranger.

30. Cont…
 Interviews are classified into two:
 Structured interview: In structured interview, the
questions are predetermined.
 The prefixed structured questions which an individual
has to answer by ticking off or by short answers.

31. Cont…
 Unstructured interview: In unstructured interview,
the interviewer begins by asking general questions and
encourages the person to talk freely.
 The interviewer probes for elaborations by asking why,
tell me more, how, etc.
 Interviews can be conducted telephonically, which is
an alternative form of interviewing the person.

32. Cont…
 Advantages of interview method:
 It is the way to collect in-depth information
 Feedback and respondent rate is good
 The information is recorded immediately and is
complete
 Help can be provided immediately, if required.

33. Cont…
 Disadvantages of interview method:
 It requires more money,
 It requires more time
 Training is required in case of many interviewers
 Investigator must be well-trained
 Prefixed set of questions are required.

34. Observation method
 It is a method to record behavioural pattern of people
in systematic manner:
 Observation is one of the basic method of collecting
first hand information.
 Observation method provides information what is
actually observed but bias be there.
 Observation visits can be formal, well planned and
objective based.
 Explain the purpose of making observatory visits.

35. Cont…
 Observation visits to community can help to gain
lot of information about geographical area of the
community, environmental sanitation,
socioeconomic conditions, observation of home
environment, interaction, and communication
among family members can get information about
family characteristics, health status of members and
environmental health, etc.
 Accordingly observation checklist can be prepared
to collect and record information.

36. Questionnaire
 It can set for large number of people and save
researchers time and money:
 The questionnaire can be used for the purpose of
interviewing or telephonic survey.
 It can be posted, emailed or faxed.
 The main advantages of this method is that there is no
bias
 The use of questionnaire is simple but it requires a
certain level of education and skill from respondents.
 People are more truthful while responding through
paper and pencil.

38. Diaries
 Diaries are to record the data obtained from the
individuals:
 The data from the people which was expressed in-
depth can be recorded and utilized for research
purposes.

39. Surveys
 A survey is a method of gathering information from a
sample of people, traditionally with the intention of
generalising the results to a larger population.
 Surveys provide a critical source of data and insights
for nearly everyone engaged in the information
economy, from businesses and the media to
government and academics.

41. Secondary Data
 Data collected from another source or other sources or
outside the source is called Secondary data.
 For examples:
 Data taken from hospital records
 Data taken from census.

42.  Secondary data collection is done by using the
methods such as:
 1. Census
 2. National survey
 3. Registration of vital events
 4. Record review method.

43. Census
 Census is defined as the simultaneous recording of
demographic, social, and economic data of a countries
population on a specified day.
 Census is conducted by national government every 10
years.
 The first census conducted on 1881
 The last census was conducted in Feb-March-2011.

45. Cont…
 The census is providing information includes age, sex,
marital status, language, education, occupation,
economic status, place of birth and employment status
number of children's, number of death, etc.
 The Census Commissioner of India is an overall in-
charge of conducting census in India.
 The Census Commissioner of India guides, operates,
and directs the census.

46. Registration of vital events
 It is an important source for getting information about
vital events such as births, death, marriages, etc.
 In this system every important event about population
is registered.
 It is done by varies agencies like panchayath,
corporation, municipality, police, hospital, and
revenue system.
 In order to improve the civil registration system,
Central Birth and Death Registration Act was
passed on 1 April 1969-70 by Government of India.

48. Cont…
 The Act makes it compulsory for the registration of
birth and deaths throughout India.
 The time limit for registration of birth is 14 days and
the time limit for registration of death is within 7
days.
 In case of failure of doing so, a fine up to 50 will be
imposed.
 In some countries births and deaths are recorded by
the first time health workers such as village health
guides.

49. National survey
 Survey conducted at central level to collect the
information related to population from various states.

50. Record review method
 Much of community identification information such
as housing conditions, socioeconomic status,
demographic information, vital events, health services,
etc. are available in the records maintained in health
agencies.

51. Analysis of Data
 The data collected needs to be arranged in tables,
charts, diagrams, graphs, pictures and curves to stress
important points.
 The data presented should be based on the principles
designed to meet the criteria.

52. Interpretation of Data
 Interpretation maybe defined as the process of making
the sense of the result and examine their implications.
 The data collected is analyzed and then interpreted.
The values interpreted should be in simple way so as to
make these understandable.
 While interpreting, the maximum and minimum
values should be should be shown so to have an
estimation of in between values.
 The demographic data can also be analyzed and
interpreted by tables, charts, diagrams, pie charts,
pictograms, etc.

53. Demographic rates & ratios
 Population dynamics: Population dynamic refers to
the study and measurement of population change and
components of change overtime.
 The population change is influenced by three factors
that is:
 Birth
 Death
 Migration
 This is thus influences the population size,
composition, and its distributions.

54. Cont…
 Measurement Tools for Population Dynamics:
 Population is not static
 Population changes with time
 The changes are due to births, deaths, and
migration process
 Commonly the rate and ratios are tools used to
analyze the influences of these process.

56. Rate
 The large rates are calculated from total number of
events which occur in a defined geographical area
during a calendar year.
 The rate can be:
1. Crude Rate
2. Specific Rate
3. Birth & Fertility Rate
4. Death Rate

57. Crude Rate
 It is based on midyear population.
 Crude Rate = (Number of total events in an area
during the year/Estimated midyear population of the
same area during the same year) × 1000.

58. Specific Rate
 It is based on the specified population by age, sex, etc.
 Specific Rate = (Number of total events in specified
population an area during the year/Estimated midyear
specified population of the same area during the same
year) * 1000.

59. Birth and fertility rates
 The number of babies born in a particular group of
people during a particular period of time.
 The fertility rate at a given age is the number of
children born alive to women of that age during the
year as a proportion of the average annual population
of women of the same age.

60. Crude Birth Rate (CBR)
 CBR= (Number of live births/Estimated midyear
population) * 1000.

61. Fertility rate
 The fertility rates are completed on the bases of
women population in reproductive age, i.e. 15-45/49
years.

62. General Fertility Rate (GFR)
 GFR = (Number of live births/Women aged 15-45
years) * 1000.

63. General Marital Fertility Rate
(GMFR)
 GMFR = (Number of live births/Married women aged
15-45 in a year) * 1000.

64. Age Specific Fertility Rate (ASFR)
 The calculation of ASFR for every age group of five year
interval during the reproductive age group.
 ASFR = (Number of live births/Women in any
specified age group during the reproductive period) *
1000.

65. Age specific marital fertility rate
(ASMFR)
 ASMFR = (Number of live births/Number of married
women in specified age group in a year) * 1000.

66. Total Fertility Rate (TFR)
 It refers to the average number of children that would
be born alive to women if she experiences through all
her child bearing years conforming to the age specific
fertility rates currently prevalent in community.

67. Death rates and ratios
 Mortality rate, or death rate, is a measure of the
number of deaths (in general, or due to a specific
cause) in a particular population, scaled to the size of
that population, per unit of time.

68. Cont…
 Mortality rate is typically expressed in units of deaths
per 1,000 individuals per year; thus, a mortality rate of
9.5 (out of 1,000) in a population of 1,000 would mean
9.5 deaths per year in that entire population, or 0.95%
out of the total.
1. Crude Death Rate
2. Specific Death Rate

69. Crude Death Rate (CDR)
 CDR= (Number of deaths/Midyear population in a
year in defined area) * 1000.

70. Specific death rate
 The cause-specific mortality rate is the mortality
rate from a specified cause for a population.
 The numerator is the number of deaths attributed to
a specific cause.
 The denominator remains the size of the population at
the midpoint of the time period.
 The fraction is usually expressed per 100,000
population.

71. Age Specific Death Rates
 ASDR= (Number of deaths in a particular age
group/Number of deaths in a mid-year population of
that age group) * 1000.

72. Sex Specific Mortality Rate
 SSMR = (Number of deaths by particular sex/Midyear
population of particular sex) * 1000.

73. Age Sex Specific Mortality Rate
 ASSMR = (Number of deaths by particular age and
sex/Midyear population of the same age and sex) *
1000.

74. Other Variables
 In addition to age and sex specific death rates, there
can be many other variables such as occupation,
income, religion, etc.

75. Cause Specific Death Rate
 CSDR = (Number of deaths due to particular
disease/Midyear population) * 1000.

76. Maternal Mortality Rate
 It refers to number of deaths of pregnant women due
to any pregnancy related cause within 42 days of
termination of pregnancy per 1000 live births.

77. Case Fatality Rate
 CFR = (Total number of deaths due to disease/Total
number of cases due to same disease) * 1000.

78. Ratio
 The ratio manifests the relative size of the quantities of
two variable: For example, The relative number of
females to males, Doctor-nurse ratio.
 Ratio is result of dividing quantity of one variable with
the quantity of another variable.
1. Pregnancy Ratio
2. Abortion Ratio
3. Child Woman Ratio

79. Pregnancy ratio
 Number of pregnancies in a year: Married women in
reproductive age.
 The number of pregnancies means all the pregnancies.
(Live births, stillbirths abortions, and present
pregnancy).

80. Abortion ratio
 Number of all types of abortion: Number of live births.
 All types of abortions means the abortions which have
occurred either as threatened inevitable or abortions
due to medical reasons.

81. Child woman ratio
 Number of children 0-4 years of age: Women of child
bearing age, i.e. 15-44 years.

82. Migration
 It refers to spatial or geographical movement of
population involving a change of usual residence
between clearly defined geographical units.
 Demographers distinguish the international and
internal migration as follows:
1. International Migration
2. Internal Migration
3. Immigration Rate
4. Emigration Rate
5. Net Migration Rate

83. International migration
 It refers to movement of people involving permanent
change of residence from one country to another.
 It is designated as emigrants from the nation left and
as immigration to the receiving nation.

84. Internal migration
 It refers to movement of people involving change
residence from one area to other within a country.

85. Immigration rate
 IR = (Number of immigrants in a year/Total midyear
population of destination) * 1000.

86. Emigration rate
 ER = (Number of Emigrants in a year/Total midyear
population of area of origin) * 1000.

87. Net migration rate
 NMR = ((Number of immigrant-Number of
Emigrants)/Total midyear population) * 1000.