Overview of Demography, Vital Statistics, and

Population Dynamics

K11&1221 Sept 2015

To understand the how demographic data and vital statistics are used in Public Health

To understand the measures of mortality, fertility, morbidity that are based on vital statistics

To understand the determinants of population size and the demographics transition

Learning Objectives

Basic understand the demography of population: size, distribution, composition and factors that determine demographic changes

Basic understanding of how to use the most commonly available health statistics to quantify disease in Public Health Practice

Basic understanding of the most common vital statistical measures encountered in Practice

Basic understanding of population dynamics and carrying capacity

Performance Objectives

•Is the scientific study of human population•Size, distribution, composition and the factors that determine their changes •Demography Covers 5 aspects of human population;

1. Size 2. Distribution 3. Composition 4. Population dynamic 5. Socio-economic determinants and

consequences of population change

Demography

Demographic data include those variables that describe the characteristics of a population

person, place, & time

Characteristics= Population Profiles:(i.e., population size in an area and how it

changes over time)

Demographic Data

Population composition and Vital Statistics

Population composition include:AgeSex or gender

EthnicityIncomeOccupationHealth services useGeographic locationGeographic density

Vital statistics (Events)include:

Births

DeathsMarriagesDivorces

Environment more resources are needed for more people

Demographic data and vital statistics are useful tools in: Determining a community’s health

status Deciding what’s the best way for

providing health services Planning a public health program Evaluating a program’s effectiveness

Why demographic data and vital statistics are

important?

CensusRegistration of Vital Events

Morbidity Surveys

Sources of Vital Statistics & Demographic Data

Malaysia conducts a 5 year census in the National Health and Morbidity Survey. Each household and resident is enumerated (counted).

Person info: sex,age,race,marital status, place of residence, and relationship to or position as head of household

A systematic sample of households provides: income, housing, number of children born, education, employment status, means of transportation to work, and occupation.

Demographic Data:NHMS Census

Department of statistics Statistical Releases Social and Demography

Abridged Life Tables, Malaysia ( 1 Article ) Household Expenditure ( 1 Article ) Household Income ( 2 Articles ) Labour Force Survey Report ( 1 Article ) Migration Survey Report ( 1 Article ) Monthly Principal Statistics of Labour Force, Malaysia ( 1 Article ) Population and Housing Census, Malaysia 2010 ( 5 Articles ) Population Projection, Malaysia ( 1 Article )

States Census: tables are published for the entire Malaysia by each state

Statistics on Demographic Data

In the Malaysia that all vital events must be registered.

Birth certificates serve as proof of citizenship, age, birthplace and parentage.

Death Certificates - required as burial documents and in settlement of estates and insurance claims.

Demographic Data:Annual Registration of Vital Events

Vital Statistics

Annual - detailed tables of vital events by various demographic characteristics and major geographic subdivision. Vital_Statistics_Malaysia_2012.pdf

Data on marriages and divorces are collected and published in a separate volume.

Demographic Data:

Vital Statistics Data

• Prepared by Statistics Department- a nationwide, computerized index of death records compiled from each state’s vital statistics offices.

• Mortality measures provide an indirect means to assess a community’s health, underlying causes of death are necessarily useful in capturing the many diseases and illnesses that exist within any given community.

• Allows researchers to decide if persons in their studies have died. Includes death certificate number, state person died in and date of death.

Demographic Data:

National Death Index

Morbidity data (i.e., prevalence of disease) Communicable disease reports are shared

through CDC’s Morbidity and Mortality Weekly Reports (MMWR) and CDCIS

More serious diseases are well reported (i.e., cholera,plague,yellow fever, rabies, paralytic polio)

Morbidity measures are useful for program planning and evaluation.

Demographic Data: Morbidity Surveys

Reportable/ Notifiable diseases National Health Morbidity Survey Hospital records data Industrial hygiene records School health records Medical care subgroups (i.e.,prepaid health

insurance plans) Chronic Disease Registries (i.e., tumor registries) Insurance industry data

Demographic Data:

Sources of Morbidity Data

Three rates used in vital statistics:Crude rates - computed for an entire populationSpecific rates - consider differences among subgroups, computed by age, race, sex or other variables.Adjusted (standardized) rates - to make valid summary comparisons between two or more groups with different age (or other) distributions.

Vital Statistics Rates, Ratios, and Proportions

Each rate is a measure of the relative frequency of deaths that occurred in a given population over a specific time period (time at risk).

Population size is usually defined as the population at midyear (July 1).

These measures estimate the population at risk (a+b)/time(t) of one year.

If this convention cannot be met, then the calculation should really be considered a “proportion” rather than a rate.

Measures of Mortality

Universally used as generalized indicator of a population’s health.

May not be truly reflective without accounting for age, race, or sex.

Example:State, Yr - population: 5000; deaths: 25Crude Death Rate = 25/5000 x 1000

5 deaths per 1000 per year

Measure of Mortality: Annual Crude Death Rate

Defined as the number of deaths in a specific age group in a calendar year, divided by the population of the same age group on July 1 of that year, the quotient multiplied by 1000.

Example:Country, Yr - age group: 25-34 yrs; population: 5,000,000;

deaths: 200,000Age-specific death rate= 200,000/5,000,000 x 1000

= 40 deaths per 1000 population per year for age group 25-34

Measure of Mortality: Age-Specific Death Rate

Defined as the number of deaths assigned to a specific cause in a calendar year, divided by the population on July of that year, the quotient multiplied by 100,000

Example:Country, Yr - cause: accidents;

population: 5,000,000; deaths: 4,000Cause-specific death rate= 4,000/5,000,000 x 100,000

= 80 accidental deaths per 100,000 population per year

Measure of Mortality:

Cause-Specific Death Rate

Defined as the number of deaths assigned to a specific cause in a calendar year, divided by the total number of deaths in that year, the quotient multiplied by 100

Proportional mortality is very useful in occupational studies for measuring the relative importance of a specific cause of death.

Example:Country, Yr - total deaths from all causes: 1,500,000;

deaths from cancer: 675,000Proportional mortality ratio= 675,000/1,500,000 x 100

= 45% of total deaths per year from cancer

Measure of Mortality:

Proportional Mortality Ratio

Defined as the number of deaths of persons age 0-1 in a calendar year, divided by the number of live births in that year, quotient multiplied by 1000

Example:State, Yr - live births: 325,000; infant deaths:

1,750Infant mortality= 1,750/325,000 x 1000

= 5.4 infant deaths per 1000 live births per year

Measure of Mortality: Infant Mortality Rate

Defined as the number of deaths assigned to puerperal causes (i.e., childbearing) in a calendar year divided by the number of live births in that year, the quotient multiplied by 100,000.

Example:Country, Yr - deaths due to puerperal causes: 275; live births: 1,750,000.Maternal mortality ratio: 275/1,750,000 x 100,000

= 15.71 maternal deaths per 100,000 live births per year

Measure of Mortality: Maternal Mortality Ratio*

Defined as the number of deaths of neonates (infants <28 days of age) in a calendar year, divided by number of live births in that year, the quotient multiplied by 1000

Neonatal mortality is an important measure because the majority of infant deaths occur during the short time period following birth (first 28 days).

Example:State, Yr -: deaths at <28 days=2,750;

live births: 325,000Neonatal mortality proportion= 2,750/325,000 x 1000= 8.5 neonatal deaths per 1000 live births

Measure of Mortality: Neonatal Mortality Proportion

Defined as the delivery of a fetus that shows no evidence of life (no heart action, breathing, voluntary muscle movement) if the 20th week of gestation has been completed or if the period of gestation was unstated.

Defined as the number of fetal deaths in a calendar years, divided by the number of live deaths in that year, the quotient multiplied by 1000.

Example: State, Yr - fetal deaths: 2,450; live births: 525,000 Fetal death ratio = 2,450/525,000 x 1000

= 4.7 fetal deaths per 1000 live births

Measure of Mortality: Fetal Death Ratio

Defined as the number of fetal plus neonatal deaths, divided by the number of live births plus fetal deaths, the quotient multiplied by 1000

Example:State, Yr - fetal deaths: 3,250; neonatal deaths: 5,750;

live births: 475,000Perinatal mortality proportion= 3,250+5,750/475,000+

3,250 x 1000= 18.8 perinatal deaths per 1000 fetal deaths plus live births

Measure of Mortality: Perinatal Mortality Proportion

Defined as the number of live births in a calendar year, divided by the population at July 1 of that year, the quotient multiplied by 1000

Example:State, Yr - live births: 250,000; population:

30,000,000Crude birthrate= 250,000/30,000,000 x 1000

= 8.3 live births per 1000 population per year

Measure of Fertility: Crude Birthrate

Defined as the number of live births in a calendar year, divided by the number of women ages 15-44 at midyear, quotient multiplied by 1000

Example:Country, Yr - live births: 7,500,000; number of

women ages 15-44: 35,000,000General fertility rate= 7,500,000/35,000,000 x 1000

= 214.3 live births per 1000 women ages 15-44 per year

Measure of Fertility: General Fertility Rate

Defined as the number of newly reported cases of a given disease in a calendar year, divided by the population on July 1 of that year, the quotient multiplied by either 1000, 100,000, or 1,000,000 (whatever’s convenient).

Example:State, Yr - new cases of AIDS reported: 5,250;

population: 35,000,000Incidence rate: 5,250/35,000,000 x 100,000

= 15 new AIDS cases per 100,000

Measure of Morbidity: Incidence Rate

Defined as the number of existing cases of a given disease at a given time, divided by the population at that time, the quotient multiplied by 1000, 100,000, or 1,000,000 (whatever’s convenient)

Example:Country, Yr - number of men alive with AIDS: 3,750;

population: 15,000,000 menPrevalence proportion= 3,750/15,000,000 x 100,000

= 25 AIDS cases per 100,000 men

Measure of Morbidity: Prevalence Proportion

Defined as the number of deaths assigned to a given cause in a certain period, divided by number of cases of the disease reported during the same period, the quotient multiplied by 100.

Example:Country, Yr - report number of male AIDS cases: 45,000;

deaths from the disease: 37,000.Case-fatality proportion: 37,000/45,000 x 100

= 82.2% mortality among reported cases of AIDS

Measure of Morbidity: Case-Fatality Proportion

Adjusting, or standardizing, rates is used to make valid comparisons between populations that may differ in some significant way (i.e., age distribution).

Standardized rates have no meaning in isolation, since adjusted rates are artificial.

Depending on type of data - there are two methods to adjust rates - direct (preferred) and indirect.

The numerical values of the adjusted rates depend on the choice of the standard population.

Adjustment of Rates (or, Rate Adjustment)