DEMOGRAPHY in community health nursing, study about the population

this topic is very useful in community health nursing

1. DEMOGRAPHY

2. DEFINITION
“The study of the characteristics
of human populations, such as
size, growth, density,
distribution, and vital statistics.”

3. CONCEPT OF
DEMOGRAPHY
Demography is the study of the growth,
change, and structure of the human
population. Changes in a population's size
and structure are caused by changes in the
birthrate, the death rate, and the net
migration rates.

4. Demographic research focuses on why
people have the number of children they
do; on factors that affect death rates;
and on the reasons for immigration,
emigration, and geographic mobility.
Understanding a society's demography
is an essential tool in determining
current and future public health needs.

5. Demography focuses its attention
on three readily observable
human phenomena.
1.Changes in population size
2.Composition of population.
3.Distribution of population.

6. Demography indicator
1.Fertility
2.Mortality
3.Marriage
4.Migration
5.Social mobility

7. Demography cycle/stages
1. High stationary (I
st
stage)
In this stage high birth rate and
high death rate which cancel each other
and population remain stationary. India was
in this stage till 1920.

8. 2. Early expanding (II
nd
stage)
In this stage there is some
increase in population because death
rate begin to decrease and birth rate
remain same. India was in this stage
from 1920 to 1950.
3. Late expansion (III
rd
stage)
The death rate decline still
further, and birth rate tends to fall.
The population continues to grow birth
exceed death.

9. 4. Low stationary ( IV
th
stage)
Low birth and low death rate
with result that the population become
stationary.
5. Declining ( V
th
stage)
The population begin to decline
because birth rate is lower than the
death rate.

10. A pattern of steadily increasing
population growth, followed by a
period of slowing population
growth.
Generally indicated as an S-
shaped curve for population
through time.
Demographic transition
Slide
10

11. 1. High growth potential
Pre-industrial
Birth rate high (25-40/1000)
Death rate high
Life expectancy short
Population growth low but positive
Widespread misery
Slide 11

12. 2. Transitional growth
Early industrial
Birth rate remains high (or rises!)
Death rate low and falling
Life expectancy rises
Population growth “explosive”
Mortality declines beforefertility due
to better health, nutrition, and sanitation
Slide
12

13. 3. Incipient decline
Industrial
Birth rate drops due to desires to limit family size
Death rate low and stable
Life expectancy high
Population grows until birth rate = death rate
Characterized by higher levels of wealth and reduced
need for large families for labor or insurance.
Also driven by female empowerment, female
education and female labor market participation.
Slide
13

14. Slide 14
Explaining the fertility decline:
social policies
Source: K. Sundstrom. “Can governments influence population
growth?” OECD Observer, December 2001, p. 35.

15. Slide 15
Explaining the fertility decline:
infant mortality

16. Slide 16
Conclusions on population
growth and the demographic
transition
•Much popular understanding about population
growth turns out to be wrong.
•In fact, over time and across countries:
–population growth starts with a fall in child
mortality, which raises population growth
because a fertility decline happens later
–the temporary burst of population growth
involves a rise and then fall in the fraction of
people who are children
–these changes are similar in all countries, but in
today’s poor countries they occurred later and
faster, with larger magnitude over shorter time
period than occurred historically elsewhere

17. Slide 17
What happens to the
number of farmers?
•Initially, farmers are much poorer than
nonfarmers
–less capital/worker, lower skills, less
specialized
so agriculture is the residual
employer…
(opportunity cost is what ???)
annual change in the number of farmers
depends on
growth in the total population
growth in nonfarm employment

18. Slide 18
In very rich countries, the
number of farmers does not
keep falling to zero!
•In an economics model of occupational
choice, farmers would move to nonfarm
work if it offers higher incomes;
–recall the “Harris-Todaro” story…
•An equilibrium at which the number of
farmers stays constant would offer equal
farm and nonfarm earnings:
Wage
off-farm = Earnings
on-farm
= Profits/acre x acres/hour
–Thus, you can have no change in the number of

19. Conclusions on economic
growth and structural
transformation
As incomes grow…
(1)Farming declines as a fraction of the
economy
•in favor of industry and services
•even within agriculture
(2)Farmers’ incomes at first decline relative
to others
•but then farm incomes catch up
•eventually farmer incomes pass nonfarmers’
incomes
(3)The number of farmers first rises and then
falls
•speed depends on both population and income
Slide
19

20. Slide 20
•Demographic transition and structural
transformation interact, causing a rise & then fall
in the number of farmers
•Today’s developing countries have had very fast
decline in death rates, leading to unprecedented
speed of change;
•With small shares of the population in nonfarm
employment, this led to unprecedented rural
population growth and declines in land available per
farmer.
•The rural effect is compounded by shift in age
structure:
•first, more children/adult (the “demographic burden”),
•then, more child-bearing women (“population momentum”),
•then more working-age adults (the “demographic gift”)
More conclusions…

21. PICO
PROBLEM INTERVENTION COMPARISON OUTCOME
Demography,
baseline disease
characteristics,
and treatment
history of patients
with psoriasis
enrolled in a
multicenter,
prospective,
disease based
registry (PSOLAR).
POPULATION:
population from
North America,
Europe, and Latin
America.
Demographic/diseas
e characteristics,
medical histories,
life-style risk
factors, and
previous treatments
are collected at
enrollment. Efficacy
and safety data are
collected every 6
months for 8 years,
and data are
extracted annually.
Selected
parameters are
evaluated by age
quartile using post
hoc analyses.
Psoriasis is
associated with
several co
morbidities and
behavioral risk
factors
Over half of the
PSOLAR population
(54.7%) is male,
with mean age of
48.6 years and
mean body mass
index of 30.9 kg/m
at enrollment