Basic
Demographic and Epidemiologic Terms
Age: Interval of time between date of
birth and present (or time of data collection), expressed in complete years.
Age-sex pyramid: A graphic device for
depicting the age and sex distribution of a population, with relative size of
each older age group represented by ascending order of bars (males to the left
and females to the right of a center line).
Birth:
The complete delivery from the mother of a product of conception, irrespective
of duration of pregnancy, which after such delivery, breathes or shows evidence
of life.
Birth weight: The weight of an infant
at delivery, recorded in pounds and ounces or in grams. Low birth weight (LBW)
is defined as below 2500g. Very low birth weight (VLBW) is below 1500g. Ultra
low birth weight (ULBW) is below 100g. Large for gestational age (LGA) is birth
weight above 90th percentile. Average weight for gestational age (AGA) is birth
weight between 10th and 90th percentiles. Small for gestational (SGA) is birth
weight below 10th percentile.
Cause of death: Any condition that
leads to or contributes to death and is classifiable according to the tenth
revision of The International Classification of Diseases (ICD-10).
Childbearing years: The reproductive
age span of women; conventionally defined as 15 through 44 years of age for the
U.S. population.
Ethnicity: The classification of a
population that shares common characteristics, such as, religion, traditions,
culture, language, and tribal or national origin.
External cause of
death: Death caused
by Accidents and Adverse Effects (ICD-10 codes: V01-Y98).
Fecundity: The actual physiological
capacity to produce a child.
Fertility: The actual reproductive
performance of an individual, couple or a population.
Fetal death: Death of a product of conception prior to
the complete expulsion or extraction from its mother, regardless of the length
of gestation. In Texas, fetal death registration is required only for those
cases with a gestation of 20 weeks or more.
Gender: The social significance
attached to being male or female in a society.
Homicide: Death due to injury
purposefully inflicted by other individuals (ICD-10 codes: X85-Y09, Y87.1).
Household: One or more persons
residing in a separate housing unit.
ICD-10:
The International Classification of Diseases, 10th revision. A system for
classifying diseases and injuries developed by the World Health Organization
and used worldwide to improve comparability of cause of death statistics
reported from different countries. The tenth revision has been in use since
1999.
Infant: An individual less than one
year of age.
Infant death:
Death of an individual less than one year of age. Infant deaths are further
classified as neonatal deaths and post-neonatal deaths.
Life expectancy: The average number
of years that a person can anticipate living after a given age, usually birth;
most often based upon the current mortality rate of a population; a
hypothetical measurement used as an indicator of current health and mortality
conditions.
Live birth:
The complete expulsion or extraction from its mother of a product of
conception, regardless of the duration of the pregnancy, which after expulsion
shows any vital signs -- e.g. heart beat, voluntary breathing, umbilical cord
pulsation, or voluntary muscle movement.
Live birth order: The number of
children born alive to a mother, including the current child. Important in
demography because the probability of having an additional child is affected by
the number of children a woman has previously borne.
Malignant neoplasm: A tumor having
the properties of invasion and metastasis.
Maternal death: The death of a woman
resulting from pregnancy or childbearing, while pregnant or within 42 days of
termination of pregnancy.
Migration (in/out): The net migration
rate is based on the number of people who enter or exit into a defined
population location.
Morbidity: Refers to the occurrence
of diseases in a population.
Mortality: Death as a component of
population change.
Natality: Birth as a component of
population change.
Natural increase: The surplus or
deficit of births relative to deaths in a population in a given time period.
Neonate: An infant less than 28 days
of age.
Neonatal death:
Death of an individual less than 28 days of age.
Occurrence data: Data compiled by the
geographic place in which the event occurred without regard to the place of
residence of the individual(s) involved in the event.
Perinatal: Period from 20 weeks
gestation through 27 days after birth.
Population: The total numbers of
individuals in a given area.
Post-neonatal:
An infant between 28 days and less than one year of age.
Post-neonatal death: Death of an
individual between 28 days and less than one year of age.
Preterm birth: Birth at less than 37
completed weeks of gestation.
Race: Identification of a person
according to physical characteristics that are hereditarily transmissible;
formerly based on observation but now usually determined by respondent's
self-identification.
Replacement level reproduction:
Average number of children born to couples needed to replace current
population.
Residence: The geographic area of the
usual place of abode.
Residence data: Data compiled by the
usual place of residence without regard to the geographic place where the event
occurred. For births and fetal deaths the mother's usual residence is used as
the place of residence.
Underlying cause of death: The
disease or injury that initiated the train of morbid events leading directly to
death, or the circumstances of the accident or violence that produced the fatal
injury.
Vital event: An occurrence of birth,
adoption, abortion, marriage, divorce or death, together with any change in
civil status which may occur during an individual's lifetime.
Vital statistics: Demographic data on
abortions, births, deaths, fetal deaths, marriages and divorces.
Years of potential life lost (YPLL): The sum of the
years of life lost annually by persons who suffered early deaths.
References:
Alderson, Michael. An Introduction to Epidemiology.
Great
Britain
: Macmillan Press, 1976.
Haupt, Arthur and Thomas T. Kane Population Handbook.
Washington,
D.C.: Population Reference Bureau, Inc., 1991.
Last, John M. A Dictionary of Epidemiology. Second
Edition.
New
York
:
Oxford
Press, 1988.
Nam
, Charles B. Understanding Population Change.
Itasca: Peacock Publishers, Inc., 1994.
Friis, Robert H and Thomas A. Sellers.
Epidemiology for Public Health Practice (2nd ed).
Gaithersburg
:
Aspen
Publication, 1999.
Last Updated:
10/10/2006.
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