1 / 30

Denominators - PowerPoint PPT Presentation

  • Updated On :

Denominators. Demography in epidemiology FETP India. Competency to be gained from this lecture. Use demographic methods and data in applied epidemiology . Key elements . Demography Sources of information Demographic processes. Demography . Definition

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Denominators' - mira

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Denominators l.jpg


Demography in epidemiologyFETP India

Competency to be gained from this lecture l.jpg
Competency to be gained from this lecture

Use demographic methods and data in applied epidemiology

Key elements l.jpg
Key elements

  • Demography

  • Sources of information

  • Demographic processes

Demography l.jpg

  • Definition

    • Study of the size and distribution of human populations

    • Study of processes that bring about changes in these populations

      • Fertility and mortality (Biological)

      • Migrations

  • Objective

    • Study trends over time and variation across regions or subgroups in population processes


Factors affecting fertility and mortality l.jpg
Factors affecting fertility and mortality

  • Proximate determinants

    • Ability to use contraception

  • Exogenous factors

    • Social, cultural, economic, psychological, environmental

    • Behavioural or life style factors

      • In some cases, access to or use of health services


Consequences of change in population processes example of ageing l.jpg
Consequences of change in population processes: Example of ageing

  • Labour force and the economy

  • Child bearing in the adolescent and older ages

  • Women’s and children’s health and well-being

  • Population movements

  • Epidemiology of diseases


Sources of demographic data l.jpg
Sources of demographic data ageing

  • Censuses

  • Vital registration systems

  • Sample surveys

  • Sample registration system (India)

Source of data

Sample registration system srs in india l.jpg
Sample registration system (SRS) in India ageing

  • 1964-5

    • Pilot basis

  • 1969-70

    • Full scale

  • Dual reporting system

  • Provides estimates of birth and death rates at state and national levels

    • Regular publication of annual vital rates


Srs dual reporting system l.jpg
SRS’ dual reporting system ageing

  • Each event (birth or death) captured by two independent procedures

    • Continuous enumeration in population

    • Sample survey every 6 months

  • Events matched

    • Missing in both systems estimated

  • Evaluation of SRS

    • Under-enumeration does not exceed 5%


Sample design for srs l.jpg
Sample design for SRS ageing

  • Rural areas

    • Each district divided in two strata

      • Villages > 1500 population

      • Villages < 1500 population

    • Simple random sampling of villages and segments from the two strata without replacement

  • Urban areas

    • Sampling unit: Census enumeration block


Half yearly survey for srs by full time supervisor from census directorate l.jpg
Half yearly survey for SRS by full time supervisor from census directorate

  • Collects information on births and deaths from residents and visitors

  • Reference period:

    • Six month

    • 12 month to capture events missed during the last survey

  • Updates

    • House, household members and pregnant women list

  • Matching of events

  • Field verifications

    • Unmatched

    • Partially matched events


Sources of information on causes of death l.jpg
Sources of information on census directoratecauses of death

  • Urban areas

    • Under SRS

    • Collection of information on medically certified deaths

  • Rural areas

    • Collection of data by paramedical staff using verbal autopsy techniques


Demographic processes l.jpg
Demographic processes census directorate

  • Number of people in an area at a given time:

    • Pt = Po + B - D +I -O

      • B= Births

      • D= Deaths

      • I= Immigrations

      • O= Out-migrations

  • From age structure to age composition


Rates and ratios of mortality and pregnancy wastage l.jpg

CDR census directorate

Crude death rate


Age specific death rate


Infant mortality rate


Neonatal mortality rate


Post-neonatal mortality rate


Perinatal mortality rate

Expectation of life at age x


Cause-specific death rate


Maternal mortality rate

Rates and ratios of mortality and pregnancy wastage


Age pyramid india 1961 and 2001 l.jpg
Age pyramid, India, 1961 and 2001 census directorate

Influences risk of various illnesses and conditions as well as the health risk behaviours


Causes of death l.jpg
Causes of death census directorate

  • Study the process of mortality

  • Stratified for

    • Still birth

    • Neonatal deaths

    • Infant deaths

    • Child deaths

    • Maternal deaths

    • Adult deaths


Determinants of mortality l.jpg
Determinants of mortality census directorate

  • Demographic factors

    • Age, sex, marital status and family size

  • Socio-economic variables

    • E.g., Income, education, religion

  • Health related behaviours

    • E.g., Smoking, alcohol and drug use

  • Disabilities and diseases

  • Type of death

    • Still birth, neonatal, infant, child, maternal and adult


Cause of death by verbal autopsy among 5 years of age tamil nadu india 2004 icd 10 l.jpg
Cause of death by verbal autopsy among > 5 years of age, Tamil Nadu, India, 2004(ICD 10)


Life tables l.jpg
Life tables Tamil Nadu, India, 2004

  • Study longevity, success rates and hazards

  • Ordinary life tables

    • Studies attrition from a cohort resulting from a single factor

  • Multiple decrement life tables

    • Attrition due to more than one factor

  • Multi-state life tables

    • Move through different states


Cause elimination using life tables l.jpg
Cause elimination using life tables Tamil Nadu, India, 2004

  • Objective

    • To eliminate the effects of competing risks of dying from various causes on the risk of dying from a given cause

    • To measure the ‘pure’ severity of the cause

  • Example

    • To study the mortality of HBV infection acquired at birth, one has to subtract, year by year, the mortality from other causes since there is a long delay between infection (at birth) and death (during adulthood)

  • Method

    • Construct life table in which all causes are eliminated except one particular cause


Population distribution size and density of the population by geographic subdivision l.jpg
Population distribution: Size and density of the population by geographic subdivision

  • GIS (Geographic information system)

    • Organized collection of computer hardware, software, geographic data and personnel designed to efficiently capture, store, update, manipulate, analyze and display all forms of geographically referenced information

  • Useful to study trends and spatial pattern of population processes

  • Provide insights into the location and distribution of public health needs and resources


Fecundity and fertility l.jpg
Fecundity and fertility by geographic subdivision

  • Frequency of live births in a population

  • Fecundity

    • Ability to produce live offspring

    • Cannot be measured

    • Can be assessed clinically

  • Fertility

    • Actual production of live offspring


Measures of fertility l.jpg

CBR by geographic subdivision

Crude birth rate


General fertility rate


Age-specific fertility rate


Total fertility rate


Gross reproduction rate


Not reproductive rate


Parity progression ratio


Mean birth Interval

Measures of fertility


Determinants of fertility l.jpg
Determinants of fertility by geographic subdivision

  • Focus on proximate determinants

  • Include

    • Exposure to sexual intercourse

    • Exposure to conception

    • Gestation and successful parturition


Contraception l.jpg
Contraception by geographic subdivision

  • Conventional

  • Permanent

  • Abortion to unwanted pregnancies

  • Failure


Adolescent pregnancies l.jpg
Adolescent pregnancies by geographic subdivision

  • May cause sexually related problems including sexually transmitted diseases

  • Induced abortion

  • Improper child development

  • High mortality risk for mother and babies


Migration l.jpg
Migration by geographic subdivision

  • Definition

    • Movement of people from usual (primary) residence to another

    • Involves crossing an administrative or political boundary

  • Most difficult to measure


Nuptiality marriage and marital dissolution l.jpg
Nuptiality: by geographic subdivisionMarriage and marital dissolution

  • Frequency of marriages

  • Characteristics of persons joining

  • Dissolution

    • Separation

    • Divorce

    • Death

  • Crude marriage rate

  • Age and sex specific marriage rate

  • General marriage rate

  • Median or mean age at marriage


Estimations and projections on the basis of census data l.jpg
Estimations and projections on the basis of census data by geographic subdivision

  • Inter-censal

  • Post-censal

  • Future (Projection)


Take home messages l.jpg
Take home messages by geographic subdivision

  • Demography is closely related to epidemiology

  • Sources of information are diverse and cross validate each other

  • Demographic processes are studied by time, place and person