Definitions and Associated formulas
ANIMATED FORMULAS
This link shows formulas used to calculate rates with examples.
INFANT AND
CHILD HEALTH VARIABLES
This link lists all Infant and Child Health Variables.
LIVE BIRTH: The complete expulsion or extraction from its
mother of a product of human conception, irrespective of the duration of pregnancy,
which, after such expulsion or extraction, breathes or shows any other evidence
of life, such as beating of the heart, pulsation of the umbilical cord, or definite
movement of voluntary muscles, whether or not the umbilical cord has been cut or
the placenta is attached. (Definition recommended by World Health Organization in
1950). Heartbeats are to be distinguished from transient cardiac contractions;
respirations are to be distinguished from fleeting respiratory efforts or gasps.
CRUDE BIRTH RATE: Annual live births over total population
(see animated formulas).
95% CONFIDENCE INTERVALS CALCULATION: r ± 61.981*(r/n)1/2
Where r = live birth rate, n = number of live births or population denominator,
and 61.981=1.96*(1000)1/2
When frequencies are less than 100 then 95% confidence intervals are calculated
using the formulas provided on pages 98-102 in the NCHS 2001 Birth Report a pdf document.
RESIDENCE DATA: Data allocated to the place in South Carolina
where the person normally resided, regardless of where the event occurred.
RACE: Information on race of the mother and father is reported
on birth and fetal death certificates, and the race of the decedent is reported
on death certificates. As of 1990, Live Births are reported by race of mother instead
of race of child. This change allows South Carolina's birth data to be consistent
with the National Center for Health Statistics and other states throughout the United
States. For statistical purposes, the tables in this report are based on the broad
classifications of "white", "black", "other", and "unknown". Other race group includes
asian, pacific islander, and native americans.
ETHNICITY: Ethnicity is reported independently of race
on the birth certificate. Hispanic refers to those people whose origins are from
Spain, Mexico or the Spanish-speaking countries of Central and South America. Tabulation
categories are Hispanic, non-Hispanic, and unknown. If data is missing it is then
assigned to the unknown category.
AGE OF THE CHILD: The age of the deceased child in years
at its last birthday.
LEVEL III HOSPITAL: Hospital provides all aspects of perinatal
care, including intensive care and a range of continuously available, sub-specialty
consultation. In addition to the level II capabilities, Level III hospitals have
the staffing and technical capability to manage high-risk obstetric and complex
neonatal patients. Level III hospitals must manage at least 1500 deliveries annually,
or at least 125 admissions which weigh less than 1500 grams, require ventilatory
support, or require surgery.
CONGENITAL MALFORMATION: A physical/neurological defects
that are present at delivery.
SPINA BIFIDA/MENINGOCELE: Developmental anomaly characterized
by defective closure of the bony encasement of the spinal cord, through which the
cord and meninges may or may not protrude.
HEART MALFORMATIONS: Congenital anomalies of the heart.
DOWN'S SYNDROME: The most common chromosomal defect with
most cases resulting from an extra chromosome (trisomy 21).
CLEFT LIP/PALATE: Cleft lip is a fissure or elongated opening
of the lip; cleft palate is a fissure in the roof of the mouth. These are failures
of embryonic development.
DEATH DUE TO MOTOR VEHICLE CRASHES: Includes ICD 9 (810-825)
and ICD 10 (V02-V04, V090, V092, V12-V14, V190-V192, V194-V196, V20-V79, V803-V805,
V810-V811, V820-V821, V83-V86, V870-V878, V880-V888, V890, V892)
CAUSE SPECIFIC DEATH RATE: Annual number of deaths due
to specific cause over total population, multiplied by 100,000 (see animated formulas).
DEATHS: All deaths occurring to SC residents ages 0-14
or the age group specified.
DEATH RATE: Annual number of deaths over total population,
multiplied by 100,000 (see animated formulas).
BIRTHWEIGHT: Weight of the live birth baby at delivery
measured in grams.
GRAMS WEIGHT CONVERSION CHART
500 grams or less = 1lb. 1 oz. or less
501 - 1,000 grams = 1 lb. 2 oz. - 2 lb. 3 oz.
1,001 - 1,500 grams = 2 lb. 4 oz. - 3 lb. 4 oz.
1,501 - 2,000 grams = 3 lb. 5 oz. - 4 lb. 6 oz.
2,001 - 2,500 grams = 4 lb. 7 oz. - 5 lb. 8 oz.
2,501 - 3,000 grams = 5 lb. 9 oz. - 6 lb. 9 oz.
3,000 - 3,500 grams = 6 lb. 10 oz. - 7 lb. 11 oz.
3,501 - 4,000 grams = 7 lb. 12 oz. - 8 lb. 13 oz.
4,001 - 4,500 grams = 8 lb. 14 oz. - 9 lb. 14 oz.
4,501 - 5,000 grams = 9 lb. 15 oz. - 11 lb. 0 oz.
5,001 grams or more = 11 lb. 1 oz - or more
RATE CALCULATIONS WITH SMALL NUMBERS: There are variations
in all statistics that are the result of chance. This characteristic is of particular
importance in classifications with small numbers of events where small variations
are proportionately large in relation to the base figure. As an example, small changes
in the number of deaths or births in small population areas or in the number of
deaths from uncommon causes could result in large changes in these crude rates.
For this reason, rates for counties with small populations or other small bases
should be used cautiously.
POPULATION DATA: With the exception of population data
by race and population data for selected age groups of teens, the 2000 Census data,
provided by the Office of Research and Statistics (South Carolina Budget and Control
Board), were used to calculate the rates in this report. Population data by race
and for selected age groups were modified.
POPULATION DATA BY RACE: The U.S. Census Bureau Population
data contains data for both "multiple race", and single race categories. This presents
problems for calculating vital statistical rates. The following methodology was
developed jointly by Office of Research and Statistics, South Carolina State Budget
and Control Board and the Division of Biostatistics and Health GIS, Public Health
Statistics and Information Services, SCDHEC.
The populations of these two race categories were allocated to the standard single
race categories by age, gender and county. This allocation was based on the proportional
distribution of the population of the standard single race categories within each
of these age, gender, county groups.
POPULATION DATA FOR SELECTED AGEGROUPS: For inter-census
years, ORS provides estimated population data for South Carolina by age for five-year
age groups. It is assumed that the population within each of these age categories
is distributed uniformly through out the age interval. Based on this assumption,
the population for females 14-17, 15-17 and 18-19 years is derived, consecutively,
as follows - (20% of the female population 10-14 years plus 60% of the female population
15-19 years), (60% of the female population 15-19), and (40% of the female population
15-19). Pregnancy data for these teenagers are published annually in the South Carolina
Vital and Morbidity Statistics reports and also in the South Carolina Teen Pregnancy
Data Book(s).
COMPARABILITY: In order that disease classifications may
be consistent with advances in medical science and changes in diagnostic practice,
any system for categorizing causes of death must periodically be revised. Major
revisions in the International Classification of Diseases (ICD), by which causes
of death are classified, occur approximately every ten years, and each decennial
revision of the ICD has produced some break in comparability of cause of death statistics.
In South Carolina, the Sixth Revision of the ICD was used from 1949-1957; the Seventh
Revision for 1958-1968; the Eighth 1969-1978; and the Ninth Revision went 1979-1998;and
the Tenth Revision went into effect in 1999.
Prior to 1949, under the first five revisions, cause of death was selected on the
basis of priority tables for multiple causes, as set forth in The Manual For Joint
Causes of Death. Under the Sixth, Seventh, Eighth, and Ninth Revisions of the International
Lists, the cause selected for tabulation has been the "underlying" cause, defined
as the "disease or injury which initiated the train of morbid events, leading directly
to death." (ICDA, Eighth Revision, 1968, Vol. 1, page xxix).
The introduction of the concept of "underlying" cause in 1949, with the Sixth Revision,
resulted in a basic change in classification of death which seriously affects the
interpretation of mortality trends before and after 1949. The Seventh Revision was
essentially a clarification of the Sixth Revision, but the Eighth Revision introduced
some major modifications in classification lists and coding procedures. The Ninth
Revision also brought some major changes in classification and coding. However,
the Tenth Revision introduced some of the most dramatic changes so far.
In order to make valid comparisons of mortality by cause for events classified by
different revisions of the ICD, comparability ratios were developed. Comparability
ratios are computed by the National Center for Health Statistics from the results
of dual coding of certificates according to the old and the new procedures. Taking
the number of deaths classified to a given cause by the Tenth Revision and dividing
the result by the number of deaths classified to that cause by the Eighth Revision
derived the comparability ratios used with the Tenth Revision. Provisional comparability
ratios for the United States as a whole, based on the Ninth and Tenth Revisions,
have been developed for a limited number of causes published by the National Center
for Health Statistics.
IMPLEMENTATION OF THE INTERNATIONAL CLASSIFICATION OF DISEASES (ICD
)10TH REVISION: The ICD is a classification system developed collaboratively
between the World Health Organization (WHO) and 10 international centers so that
the medical terms reported by physicians, medical examiners, and coroners on death
certificates can be grouped together for statistical purposes. ICD-10 replaces the
ICD-9, used with 1979-1998 data.
The purpose of the ICD and of WHO sponsorship is to promote international comparability
in the collection, classification, processing and presentation of mortality statistics.
New revisions of the ICD are implemented periodically so that the classification
reflects advances in medical science.
ICD-10 affects the classification, processing, and presentation of mortality data.
Some titles have changed. The total number of categories has doubled as a result
of the addition or deletion of terms used to describe diseases or conditions. The
transfer of certain diseases from one section to another reflects new discoveries
and advances in knowledge on the nature or causes of particular diseases. The addition
of separate categories identifies specific diseases or particular complications
of diseases that are of growing interest. Additionally, the codes associated with
each title have been converted from numeric to alphanumeric entities. The ICD rules
for processing mortality data are generally similar but account for some changes
observed in mortality statistics.
HOW ICD-10 COMPARES TO ICD-9: The intent of developing
new revisions is to incorporate changes in medical knowledge. Compared with ICD-9,
the ICD-10 has: ·Expanded detail for many conditions (e.g., viral hepatitis has
been expanded from ICD-9 code 070, a single 3-digit category, to ICD-10 codes B15-B19,
five 3-digit categories)
·Transferred conditions around the classification (e.g., hemorrhage has been moved
from the circulatory chapter to the symptoms and signs chapter)
·Used alphanumeric codes instead of numeric codes (e.g., code for diabetes mellitus
was 250 in ICD-9 and is E10-E14 in ICD-10)
·Modified coding rules (e.g., the "Old pneumonia, influenza, and maternal conditions"
and "Error and accidents in medical care" coding rules have been eliminated)
·Modified the tabulations lists (e.g., the US' ICD-10 113-cause list replaces the
US' ICD-9 72-cause list)
Assistance in using the ICD-10 can be obtained by contacting the National Center
for Health Statistics, Data Dissemination Branch, 6525 Belcrest Road, Room 1064
Hyattsville, Maryland 20782-2003
(301) 458-4636 (voice) (301) 458-4027 (fax)
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