Download - Demography and Health
Demography and Health
Dr.Rajkumar PatilAsstt. Prof., Community Medicine
AVMCH, Pondicherry
Demos + graphein
Demography is scientific study of human population
Community Medicine and Demography
Community medicine is vitally concerned with population as the health of the people depends upon:
the number of people the space they occupy the skill that they have acquired
Major sources of demographic data
• Census
• Registration of vital events
• NFHS
Three phenomena in Demography
• Changes in population size• Composition of population• Population distribution in space
Five demographic processes
• Fertility• Mortality• Marriage• Migration• Social mobility
There are four ways in which the number of people
in an area can change during two time periods
Population Growth
Natural Increase (Births-Deaths) + Net Migration (Immigration-emigration)
Demographic cycle
Demographic cycle
Phase/Stage
BR DR Natural Increase
Examples
High Stationary
0-very slow India was in this stage till 1920
Early Expanding
+ Slow South Asia & Africa
Late Expanding
Rapid India, China,Singapore
Low Stationary
Slow UK, Denmark, Sweden, Belgium
Declining Declining Germany & Hungary
Distribution of world population
World Population Trend
Year Population
1800 978 million
1900 1650 million
1950 2.5 billion
1970 3.6 billion
1980 4.4 billion
1985 4.8 billion
2000 6 billion
Trend-Population of world
(2001 estimates)
1. China – 20.43%2. India – 17.01%3. U.S.A. – 4.61% 4. Indonesia – 3.42%5. Brazil – 2.81%6. Pakistan – 2.39%7. Russia – 2.25% 8. Bangladesh – 2.21%9. Nigeria – 2.20%10.Japan – 2.01%
10 most populous countries of the world
On 2.4% of world’s land area,17% of the world’s population (2004-1080 million)
1921-Year of “big divide”, India’s population has been steadily increasing since 1921
India will become the most populous country by the year 2050 (1.53 billion)
Population trend in India
1901-2001 Population trend in India
Year Total popu. (millions)
Average annual
Growth rate (%)
Decadal Growth rate
(%)
1901 238.4 - -
1911 252.1 0.56 0.75
1921 251.3 -0.03 -0.31
1931 279.0 1.04 11.00
1941 318.7 1.33 14.22
1951 361.1 1.25 13.31
1961 439.2 1.96 21.64
1971 548.2 2.20 24.80
1981 683.3 2.22 24.66
1991 843.9 2.14 23.86
2001 1027.0 1.93 21.34
Population trend in India
Most populous states of India
Rank
State Population (million)
Percentage(%)
1 Uttar Pradesh 166.1 16.2
2 Maharashtra 96.8 9.4
3 Bihar 82.9 8.1
4 West Bengal 80.2 7.8
5 Andhra Pradesh 75.7 7.4
6 Tamil Nadu 62.1 6.6
7 Madhya Pradesh 60.4 5.9
8 Rajasthan 56.5 5.5
9 Karnataka 52.7 5.1
10 Gujarat 50.6 4.9
Proportion of males & females in different age-groups
Direct bearing on social, economic, health needs of communities
In an “old” population, for example, the society has to arrange for
the care of the elderly, & the country’s health system must be
organized accordingly.
Age & Sex composition
Table-Distribution of population by age & sex (SRS–2003)
Age group (yr)
Male (%) Female (%) Total (%)
0-4 11.3 10.8 11.0
5-9 10.6 10.3 10.5
10-14 11.0 10.7 10.9
15-19 11.0 10.4 10.7
20-24 9.5 9.7 9.6
25-29 8.4 8.3 8.3
30-34 7.4 7.5 7.5
35-39 6.6 7.0 6.8
40-44 5.8 5.7 5.7
45-49 4.9 5.0 4.9
50-54 3.9 3.7 3.8
55-59 3.1 3.2 3.2
60-64 2.3 2.5 2.4
65-69 1.9 2.2 2.0
70+ 2.5 3.1 2.8
Total 100 100 100
It is a pictorial presentation (double histogram) of the age-sex composition of a population
Male & Female are compared for age
Under-developed/developing country: Broad base & tapering top (pyramid shape)
Developed countries: Bulge in the middle and has a narrow base (spindle shape)
Age pyramid
Population/age pyramid of India, SRS estimates1996
Spindle shape
Age pyramid, World Population Prospects 1998 (UN)
Dependency Ratio is the ratio of economically dependant population to economically independent population
Total Dependency Ratio = Children (<15 yr) + Elderly (>65 yr) X 100
Working Age(15-64)
Young age dependency ratio
Old age dependency ratio
Dependency Ratio
Trends in Dependency ratio in India (per 100 persons)
Year Total(Societal)Dependency
Young age dependency
Old age dependency
1990 68 61 7
2000 62 54 8
2004 64 56 8
2010 54 45 9
Ratio of males to females in the population
Sex Ratio = Number of Males X 1000 Number of Females
Sex ratio of:
India : 933 females/1000 males Kerala : 1058 females/1000 males Punjab : 874 females/1000 males
Factors affecting sex ratio: 1. Difference in mortality conditions of males &
females 2. Female foeticide and infanticide
Sex Ratio
Sex ratio trend in India
CBR & CDR of selected countries (2004)
Country CBR(per1000 mid yr pop.)
CDR( per1000 mid yr pop.)
India 24.1 7.5
Bangladesh 27 8
Pakistan 31 8
Sri Lanka 16 6
Thailand 16 7
Nepal 30 8
China 13 7
Japan 9 8
Singapore 9 5
UK 11 10
USA 14 8
World’s average birth rate is 21/1000 population
Source: SRS 1998
CBR
Rate at which a given population is expected to increase in a given period of time
CBR-CDR = GR (in %, excluding migration) 10
Approximately 95% of population growth occurs in developing countries
Growth RateGrowth Rate
Relation between growth rate & population
Rating Annual rate of growth %
Population doubling time in years
Stationary Population
No growth -
Slow growth Less than 0.5 More than 139
Moderate growth 0.5 to 1.0 139-70
Rapid growth 1.0 to 1.5 70-47
Very rapid growth 1.5 to 2.0 47-35
Explosive growth 2.0 to 2.5 35-28
Explosive growth 2.5 to 3.0 28-23
Explosive growth 3.0 to 3.5 23-20
Total number of children borne by a women during
her child bearing age (15 to 45 years)
Total fertility rate (TFR) gives an idea of total family size
TFR in India: 2.68 (NFHS-3)
Family size depends upon –
Duration of marriage
Education of couple
No. of live births
No. of living children
Preference of male child
Family Size
Mass migration of rural population into urban
centers resulting in increasing the urban population & growth of cities
Cause of urbanization: Better employment and social services
MEGA CITY: City with population of 10 million or more
Urbanization
Number of persons living per square kilometer
Density in India:
Year 1901 – 77 persons/km2
Year 2001 – 324 persons/km2
Year 2004 – 363 persons/km2
Density of Density of populationpopulation
A person (7 yr or more) is considered as literate if he or she can read & write with understanding in any language.
State Male lit.(%)
Female lit.(%)
Totallit.(%)
Tamil Nadu
82 65 73
Kerala 94 88 91
India 76 54 65.38
Literacy & education
Literacy rates
Female literacy
Expectation of life at a given age is the average number of years which a person of that age may expect to live, according to the mortality pattern prevalent at that age
Indicator of country development & overall health
Expectation of life at birth – World 1950 : 46.5 years
2002 : 63 years
Expectation of life at birth – India
Year Males Females Total
1901 23.63 23.96 23.8
2001 63.90 66.90 65.4
Life expectancyLife expectancy
Approximately 95% of population growth is in developing countries
Currently,1/3 of the world population is under 15yr, & will soon enter the reproductive bracket, giving more potential for population growth
The expected number of births per woman, at current fertility rate is:
– Africa 6.1
– Asia 3.2
– Latin America 3.4
– North America 2.0
– Europe 1.6
Population Explosion
•Economic implications •Demographic Implications
In population with low birth and death rate, 9-13% is 65yr or more. There is increased demand for senior citizen
•Environmental / Ecological Implications
•Social / Political Implications
Fertility Actual bearing of child
Factors affecting fertility
1. Age at marriage
2. Duration of married life
3. Spacing of children
4. Education
5. Economic status
6. Caste & religion
7. Nutrition
8. Family planning
9. Others – biological, physical, social, cultural, housing, breast feeding, industrialization, urbanization, health conditions etc.
• Great impact on fertility
• Early marriages- increased births
• Age of marriage:• In 1930’s:13 years• In 2001: 21years
YEARS AFTER MARRIAGE
% OF BIRTHS
1-5 10-25 %
5-15 50-55 %
25 very few
• Well fed society- low fertility
• Poorly fed society- high fertility
• Education is inversely proportional to fertility
• “economic status is inversely proportional to fertility”
• Economic development is the best contraceptive
• Total fertility rate1. Muslims ---3.592. Hindus ---2.783. Christians ---2.44
• MBC/SC/ST-higher fertility rate
• Physical, social, and cultural factors
Place of women in society Opportunities for women and
local community involvement Value of children in society Widow remarriage
Breast feedingCustoms and beliefsIndustrialization and
urbanizationBetter health conditions
Replacement Level Fertility When a couple has two births during their reproductive
life, just enough to replace themselves.
Replacement level is considered when there are, on the
average, 2.1 births per woman (TFR), to compensate for
child deaths
Fertility Indicatorsa. Original rates
1.Crude Birth rate (CBR)
CBR=Live Births x 1000/mid year population
2.General fertility rate (GFR)
GFR = Live Births x 1000/mid year female pop. (15-49yr)
3.General marital fertility rate (GMFR)
GMFR= Live Births x 1000
mid year married female pop.(15-49yr)
4. Age specific fertility rates (ASFR)
Indicator of Fertility pattern & family planning
Live births in specific age group x 1000 Midyear population of women in that age group
5. Age specific marital fertility rate (ASMFR)
Live births in specific age group x 1000 Midyear population of married women in that age
group
b. Derived rates
6. Total fertility rate (TFR)
Average number of live births a woman is expected
to undergo during her reproductive life.
TFR = 5 x ƩASFR
1000
7. Total marital fertility rate (TMFR)
TFR = 5 x ƩASMFR 1000
8. Gross reproduction rate (GRR)
Average number of girls born to a woman during her reproductive life, if she experiences the current fertility pattern throughout the reproductive life (15-49) assuming no mortality
GRR = 5 x ƩASFR for female Live Births 1000
GRR = TFR x newborn sex ratio
9. Net reproduction rate (NRR)
Average number of girls born (and survived) to a woman during her reproductive life, if she experiences the current fertility pattern throughout the reproductive life (15-49) and assuming current mortality pattern
NRR = Number of girls born and survived Number of the women survived after the end of reproductive life
c. Related rates and ratios
10. Child-woman ratio
Number of children < 4 yrs of age per 1000 women of child bearing age.
11. Pregnancy rate
Ratio of no. of pregnancy in a year to married women in the ages (15 – 49)
12. Abortion rate No. of abortions per 1000 women of child bearing age group.
13. Abortion ratio No. of abortions performed/ no. of live births
14. Marriage rate
Crude MR = Number of marriages in a yr x 1000
Mid Year Population
General MR = Number of marriages in a yr x 1000
Number of unmarried persons in 15–49 age gp.
Exercise-I
In a PHC with a population of 28000,the age wise break up of women population in reproductive age group and the live births in these age groups are given below.Age (yr) Women
populationLive births
15-25 1850 140
25-35 3210 352
35-45 1400 72
Calculate:1.Age specific fertility rates2.General fertility rate3.Crude birth rate
Following are the age specific fertility rates among reproductive age group women in 1991 and 2001 in a country. a. Calculate Total Fertility Rate (TFR) for 1991and 2001yr. b. Whether this country has achieved replacement level fertility in the year 2001?
Age group (years)
ASFR (1991)
ASFR(2001)
15-19 70.1 58.2
20-24 220.0 188.2
25-29 179.0 165.5
30-34 112.0 98.0
35-39 64.5 52.1
40-44 28.7 18.9
45-49 12.4 6.3
Exercise-II
Fertility trends
TFR and CBR in Indian states(2003-04)
universality of marriage early marriage early puberty low standard of living low rate of literacy additional customs and
habits absence of family planning
habit
Reasons for High Birth Rate in India
1. Absence of natural checks2. Mass control of diseases3. Advance in medical science4. Better health facility5. Impact of national
programmes6. Improvements in food supply7. International aid8. Development of social
consciousness among masses
Reasons for declining Death Rate