Introduction to Demography, Sources of Population Data, Health and Vital Statistics

Vocabulary practice flashcards covering fundamental concepts in demography, demographic formulas, vital statistics, population pyramids, census methodologies, and Nigerian health reporting systems.

Demography

The statistical study of human populations with respect to size, structure, distribution, growth, density, migration, vital statistics, and the effect of these factors on social and economic conditions.

John Graunt

A London citizen who established demographic analysis and descriptive statistics in 1662 through his book, 'Natural and Political Observations upon the Bills of Mortality', by developing techniques to quantify mortality patterns.

Population Structure

The composition and static characteristics of a population at a specific point in time, encompassing age, sex, educational attainment, income, households, urbanization, and ethnicity.

Population Dynamism

The ongoing processes that cause population size and structure to change over time, driven by vital events (natality, fertility, mortality, marital changes) and migration.

Live Birth (WHO 1950)

A natality event occurring when a foetus exits the maternal body and subsequently exhibits any sign of life, such as a heartbeat, pulsation of the umbilical cord, or voluntary movement.

Complete Birth

The complete separation of an infant from the maternal body by severance of the umbilical cord after $42$ completed weeks ($294\,\text{days}$) of gestation.

Preterm Birth (PTB)

The birth of an infant before $37$ completed weeks ($259\,\text{days}$) of gestation.

Low Birth Weight (LBW)

An infant weight at birth that is substandard, defined as strictly less than $2500\,\text{g}$.

Crude Birth Rate (CBR)

The ratio of live births in a year to the mid-year population of that territory, expressed per $1000$ individuals: $\text{CBR} = \frac{\text{Number of live births}}{\text{Mid-year population}} \times 1000$.

Preterm Birth (PTB) Rate

The proportion of preterm born infants per $100$ live births occurring in a given year: $\text{PTB rate} = \frac{\text{N of preterm births}}{\text{N of all live births}} \times 100$.

Low Birth Weight (LBW) Rate

The proportion of substandard weight infants ($<2500\,\text{g}$) per $100$ live births occurring in a given year: $\text{LBW rate} = \frac{\text{N of substandard weight infants}}{\text{N of all live births}} \times 100$.

General Fertility Rate (GFR)

The number of live births occurring within a year per $1000$ women of childbearing capacity, defined as women aged $15\text{--}49\,\text{years}$: $\text{GFR} = \frac{\text{N of live births}}{\text{Mid-year female population aged } 15\text{--}49} \times 1000$.

Age-Specific Fertility Rate (ASFR)

The number of live births delivered by women belonging to a specific age cohort (e.g., $20\text{--}24\,\text{years}$) per $1000$ women in that exact cohort during a given year.

Total Fertility Rate (TFR)

The average number of children a woman would bear across her reproductive lifetime ($15\text{--}49\,\text{years}$) assuming her childbearing conforms to age-specific fertility rates each year.

Replacement Level Fertility

A Total Fertility Rate threshold value of $2$, representing the exact number of children needed for a mother and father to be replaced in a population under stable mortality and zero net migration.

Crude Mortality Rate (CMR)

The total number of deaths occurring in a year per $1000$ individuals of the mid-year population: $\text{CMR} = \frac{\text{N of death cases}}{\text{Mid-year population}} \times 1000$.

Infant Mortality Rate (IMR)

The number of infant deaths under one year ($365\,\text{days}$) of age in a given year per $1000$ live births occurring in the same year, serving as a key indicator of a nation's health level.

Perinatal Mortality Rate

The number of infant deaths occurring within the first $24\,\text{hours}$ of life per $1000$ live births in a given year.

Postnatal Mortality Rate

The number of infant deaths occurring within the first week of life (days $0\text{--}6$) per $1000$ live births in a given year.

Neonatal Mortality Rate

The number of infant deaths occurring between $7$ and $27\,\text{days}$ of life per $1000$ live births in a given year.

Postneonatal Mortality Rate

The number of infant deaths occurring between $28$ and $365\,\text{days}$ of life per $1000$ live births in a given year.

Maternal Mortality Rate

The number of deaths of women during pregnancy, childbirth, and within the first $42\,\text{days}$ post-delivery per $100,000$ live births in a given year.

Life Expectancy at Birth

The average number of years a newborn infant is expected to live if prevailing age- and sex-specific mortality structures persist throughout their life.

Natural Population Growth

The balance of natural demographic change calculated by subtracting the crude death rate from the crude birth rate: $\text{PG} = \text{CBR} - \text{CDR}$.

Descriptive Demography

The branch of demography focusing on portraying the structural characteristics ('what') of a population—such as size, ages, and geographic distribution—rather than explaining underlying causes.

Analytical Demography

The branch of demography analyzing population dynamics, structural changes, and societal influences through demographic indices such as the total fertility rate and life expectancy.

Population Pyramid

A graphical representation of the age and sex distribution of a population displayed as back-to-back horizontal histograms, traditionally featuring males on the left and females on the right.

Expansive Population Pyramid

A triangular population pyramid with a broad base and narrow top, characteristic of developing nations like Nigeria with high birth rates and high death rates.

Constrictive Population Pyramid

A beehive-shaped or inverted triangular population pyramid featuring a narrow base and bulging middle, reflecting low birth rates, low death rates, and an aging population (e.g., the United States).

Stationary Population Pyramid

A rectangular or barrel-shaped population pyramid with relatively equal proportions across age groups, reflecting stable birth and mortality rates.

Census

The total process of collecting, compiling, evaluating, analyzing, and publishing demographic, economic, and social data for all individuals in a country or territory at a specified time, typically conducted every $10\,\text{years}$.

De Jure Census Count

A census enumeration method where individuals are recorded according to their legal, usual place of residence regardless of where they are physically present on enumeration day.

De Facto Census Count

A census enumeration method where individuals are counted where they are physically found on the day of enumeration; this is the method utilized in Nigeria.

Post-Censal Population Estimate

The recalculation of population counts following a census using the balancing equation: $\text{Population estimate} = \text{Population base} + \text{Births} - \text{Deaths} + (\text{Immigration} - \text{Emigration})$.

Coverage Errors

Census errors arising from the complete omission of individuals or hamlets (under-enumeration) or counting people multiple times (over-enumeration).

Content Errors

Census errors resulting from inaccurate recording of personal attributes, particularly age misstatements.

Multi-Round Demographic Survey

A demographic survey method where field interviewers make repeated follow-up visits to selected households over time to track and verify events occurring between rounds.

Vital Statistics Registration System

A continuous, compulsory system of recording vital demographic events—including births, deaths, marriages, and divorces—for an entire population or subgroup.

Passive Vital Statistics Registration

A registration framework where legislation requires individuals experiencing vital events to initiate registration themselves, keeping operating costs low but resulting in delayed completeness.

Active Vital Statistics Registration

A registration framework where authorities actively pursue data collection through home visitors and incentives, achieving high completeness quickly at a higher operational cost.

Compulsory Registration Act, No. 69 (1992)

Nigerian legislation charging the National Population Commission with mandatory civil registration, specifying birth registration within $60\,\text{days}$ and death reporting within $48\,\text{hours}$.

Morbidity Statistics

Systematic statistical data tracking the amount, types, and presentation of illnesses and diseases occurring across a community or population.