topbrandingbar
corner.gif
Government Information Departments and Agencies NJ Business Portal MY New Jersey NJ people NJ Home Page

CHS Home Page CHS Data CHS Reports List of CHS tables and reports CHS topics from A-Z CHS Links CHS Frequently Asked Questions Search the CHS pages

New Jersey Health Statistics
1998

TECHNICAL NOTES

SOURCES OF DATA

Births
The chapter on natality encompasses births to New Jersey residents during the calendar year 1998. The birth certificate is the source document for data included in the analysis. New Jersey law requires that the attending physician, midwife, or person acting as midwife file a certificate of birth with the Local Registrar within five days of a birth within the state. Statistics on births to New Jersey residents which occurred in other states are also included in this report. The inclusion of these data is made possible through the auspices of the Vital Statistics Cooperative Program, which encourages the exchange of information on vital events between the states of occurrence and residence.

In January of 1996, the New Jersey Department of Health began a pilot test of its electronic birth certificate (EBC) in four maternity hospitals in the state. Upon successful completion of this test, the EBC was systematically installed in other New Jersey birthing facilities over the next two years. By the end of 1998, all New Jersey birthing facilities were reporting births to the State through the EBC system. Future reports in this series will benefit from the improved quality and timeliness of the data afforded by the EBC, as well as the enhanced array of perinatal data provided through this system.

The format of the birth certificate was revised and expanded in 1989. The position of items on the revised birth certificate led to considerable confusion between the reporting of a mother's mailing address and her residence address. In 1998, the Center for Health Statistics completed a multi-year project involving the application of address standardization software to convert mailing-label type information so that birth records could be accurately assigned to geographic areas. With the resolution of this problem, it is once again possible to display data at the municipality level. Additionally, births to residents of military bases and state institutions are now attributed to the municipality and county where the base or institution is located.

Deaths
The mortality information contained in this report covers deaths of New Jersey residents during the 1998 calendar year. The report's source document is the death certificate. New Jersey law requires the prompt filing of a death certificate by the proper authority, such as hospital personnel, physicians, medical examiners, and funeral directors, in the event of a death occurring in the state. These certificates are submitted to the office of the State Registrar, where they are recorded and filed permanently. Statistics on deaths of New Jersey residents which occurred in other states are obtained through participation in the national Vital Statistics Cooperative Program. Unless otherwise noted, the data presented in this report are for New Jersey residents.

All of the causes of deaths included in this report are underlying causes, and were coded by Bureau of Vital Statistics staff in accordance with the International Classification of Diseases, Ninth Revision, adapted for use in the United States. Additional causes of death listed on the certificates, including the immediate and intermediate causes, are not considered in the analysis. The inclusion of all listed causes of death (multiple causes of death) could lead to somewhat different results.

Infant Deaths
For the first time in this report series, infant mortality data are presented from the linked infant death-birth match file which has death certificates for infants matched with their birth certificates. This file allows analysis of maternal characteristics and newborn health information that is not on the death certificate.

It is important to note that in previous reports in this series, when infant mortality was reported by race, it was the race of the child as reported on the death certificate. Beginning with this report, the race of the mother on the birth certificate will be used. The race and ethnicity of an infant are not reported on the birth certificate and are classified for statistical purposes as the race and ethnicity of the mother. By analyzing infant deaths based on the mother's race and ethnicity, the data will be comparable with the birth data used for denominators in calculating infant mortality rates. This also allows the analysis of infant deaths by Hispanic ethnicity which was not done in the past due to poor reporting on the death certificate.

Fetal Deaths
Fetal deaths occurring after the completion of 20 or more weeks of gestation are required to be reported to the State Registrar by New Jersey law. Induced abortions of 20 weeks or more gestation are encompassed by this requirement, but are not included in the fetal death count. Fetal death figures presented in this report, therefore, include only spontaneous abortions beyond 19 weeks of gestation. Fetal deaths of unknown or unstated gestational age are also included. Only fetal deaths occurring to females who were New Jersey residents are included.

Births, Deaths, and Fetal Deaths
The birth, death, and fetal death data presented in this report were generated from data files available at the time of preparation of the respective chapters. Any data pertaining to a vital event for which a certificate was filed after that time or relating to corrections or revisions made since the data were processed for this report are not included. Birth and death computer files are periodically updated by Bureau of Vital Statistics and Center for Health Statistics staff based on correction reports received from local registrars and from quarterly data quality control analyses conducted by the Center for Health Statistics. This report incorporates data from the most recently updated files. Thus, 1998 data presented in future reports of vital events may differ slightly from numbers presented in this report.

Marriages and Divorces
Information on marriages in this report was obtained from marriage certificates issued in New Jersey. Marriage certificates are filed with the State Registrar. Divorce and annulment statistics were provided by the New Jersey Superior Court, Chancery Division. Marriages are recorded by the place of issuance of the certificate and divorces and annulments are recorded by place of judgment. Since no mechanism for interstate exchange of resident marriage and divorce data exists, marriages, divorces and annulments of New Jersey residents which occur outside of the state are not included in this report, while marriages and divorces of out-of-state residents occurring in New Jersey are included.

Communicable Diseases
The chapter is derived from data on cases of reportable diseases submitted to designated programs of the New Jersey Department of Health responsible for their collection and maintenance. The New Jersey Sanitary Code and the New Jersey Administrative Code 8:57 require providing notification to the Department of Health of cases of selected communicable diseases. AIDS and AIDS-Related Complex (ARC) were added to the list of legally reportable diseases on October 6, 1986, under State Regulation 8:57-1.14. Effective May 21, 1990, State Regulation 8:57-2.1 was amended to omit ARC as a reportable condition, and to mandate anonymous reporting of HIV infections. In October, 1991, the regulations were again amended to mandate named reporting of HIV infections by providers and in April, 1992 revised to mandate laboratory reporting of HIV infections with identifiers.

AIDS and cases of HIV infection are reported to the HIV/AIDS Surveillance Program in the AIDS Epidemiological Services Unit within the Division of AIDS Prevention and Control. The Tuberculosis Control Program collects information on tuberculosis cases occurring in New Jersey through its monitoring and surveillance activities. Cases of syphilis and gonorrhea are reported to the Sexually Transmitted Disease Control Program. Data on selected vaccine-preventable childhood diseases are reported to the Vaccine Preventable Program and data on all other communicable diseases are reported to the Infectious and Zoonotic Program. These programs are coordinated by the Communicable Disease Service within the Division of Epidemiology, Environmental, & Occupational Health.

Health Status
Health objectives tracked in this report are a subset of the objectives presented in Healthy New Jersey 2000. In this report, only those based on vital statistics, communicable disease, and Behavioral Risk Factor Surveillance System data are included. The New Jersey Behavioral Risk Factor Surveillance System (BRFSS) is part of the national Behavioral Risk Factor Surveillance System, an ongoing telephone survey of adults aged 18 years and over. This survey is designed to monitor modifiable risk factors for chronic diseases and other leading causes of morbidity and death. The New Jersey Department of Health has been participating in the BRFSS since 1991, collecting approximately 125 interviews per month through 1995 and nearly double that number since 1996.

Population
Population figures for 1998 which are presented in this report and used to calculate various rates are estimates developed by the U. S. Bureau of the Census for the National Cancer Institute. Estimates were developed for each state and its counties by age, race, Hispanic ethnicity, and sex categories. These estimates may be revised by the Census Bureau, as a series of estimates for the decade is developed. The current set of estimates presented in this report has not been rounded. However, it should not be presumed that they have the degree of accuracy which such precise figures might imply.

ALLOCATION OF DATA BY RESIDENCE OR OCCURRENCE

For public health planning and policy determination, the most useful population to study is usually the resident population of an area. In the case of births, deaths, and fetal deaths, the existence of resident certificate exchange agreements among the registration areas in the country permits analysis of resident birth and death statistics. Unless otherwise noted, the data presented for births, deaths, and fetal deaths represent vital events of the resident population. Morbidity data relate to New Jersey residents; reports of cases of communicable diseases diagnosed in New Jersey residents in other states are transmitted to the New Jersey Department of Health. Marriage and divorce statistics in this report represent vital events which occurred in New Jersey, regardless of the state of residence of the individuals involved.

Allocation of vital events by place of residence within the state is sometimes difficult because classification depends on the statement of the usual place of residence provided by the informant at the time the certificate is completed. For a variety of reasons, the information given may be incorrectly recorded. A common source of error is the confusion of mailing address with residence address. A major project to correctly allocate New Jersey births by municipality of mother's residence has been completed. As of the 1998 report, selected birth data will be presented for all municipalities with over 35,000 residents. The degree to which incorrect information on municipality of residence has been recorded on death certificates is not precisely known, but this issue is generally a problem only for certain minor civil divisions. Therefore, death data are only presented for municipalities with over 35,000 residents which are known to have a relatively low level of uncertainty in allocation of municipality.

QUALITY OF DATA

The reporting of births and deaths is considered to be essentially complete. According to the National Center for Health Statistics (NCHS), more than 99 percent of births and deaths are registered. Reporting of fetal deaths is believed to be somewhat less complete. For later periods of gestation, however, fetal death reporting is thought to be more complete (NCHS, 1994). The completeness of reporting by residence is dependent on the effective functioning of the interstate data exchange program for certificates which is fostered and encouraged by NCHS. Research has shown that there is some degree of slippage in receiving information on all births and deaths of New Jersey residents occurring in other states. However, the number of missing events is thought to be small, relative to the overall number of events.

The quality of the birth, death, and fetal death data included in this report is a function of the accuracy and completeness of the information recorded on the respective certificates and of the quality control procedures employed in the coding and keying processes. A query program in which the individual(s) responsible for completing the certificate is questioned about missing or conflicting information is carried out by staff of the Bureau of Vital Statistics of the New Jersey Department of Health. This process is augmented by the data quality control analyses performed by the Center for Health Statistics using all of the NCHS edit criteria.

In order to participate in the national Vital Statistics Cooperative Program, states had to achieve an error rate of two percent or less on each certificate item for three consecutive months. The error rates relate to both coding and data entry errors. New Jersey has met the error tolerance requirements for the cooperative program. After satisfying initial requirements, a monthly sample of records is used to determine that the error rate on each birth certificate item is approximately four percent or less and is no more than two percent for each death certificate item other than the medical cause-of-death information. Due to the complexity of the coding system, cause-of-death coding has a five percent error tolerance level set by NCHS. Multiple cause-of-death coding of New Jersey death records is performed by NCHS staff.

RACE AND ETHNICITY CLASSIFICATION

A race group (White, Black, American Indian/Alaska Native, Chinese, Japanese, Hawaiian, Filipino, Asian Indian, Korean, Samoan, Vietnamese, Guamian, other Asian/Pacific Islander, other race, and an unknown race category) and an ethnicity (Non-Hispanic, Mexican, Puerto Rican, Cuban, Central or South American, other Hispanic, and an unknown ethnicity category) are reported for each individual for whom a vital record is filed. The race and ethnicity of an infant are not reported on the birth certificate and are classified for statistical purposes as the race and ethnicity of the mother.

Race/ethnicity designations used in the natality chapter of this report are white (non-Hispanic), black (non-Hispanic), Hispanic, Asian/Pacific Islander (non-Hispanic), and other (non-Hispanic) races. The Hispanic category includes persons of Mexican, Puerto Rican, Cuban, Central/South American, or other Hispanic ethnicity, regardless of race. The Asian/Pacific Islander (non-Hispanic) category includes persons of Chinese, Japanese, Hawaiian, Filipino, Asian Indian, Korean, Samoan, Vietnamese, Guamian, and other Asian and Pacific Islander descent who were not reported as Hispanic. The other (non-Hispanic) race category includes all race groups other than white, black, and Asian/Pacific Islander who were not reported as Hispanic.

Race and ethnicity classifications are based on self-reports, or in the case of death records, on reports from respondents, usually a family member, or from persons responsible for preparing the death certificates. Race and ethnicity reporting on birth certificates has been found to be virtually complete, therefore birth data for Asian/Pacific Islanders and Hispanics are presented in the natality chapter. However, race reporting for races other than white and black and reporting of Hispanic ethnicity on death certificates is incomplete; therefore, data presented in the mortality chapter are only given for white and black races, regardless of ethnicity. Persons who are identified as Hispanic have been included in the analysis of mortality data by race based on the race reported on the decedent's death certificate. Asians and Pacific Islanders are included in the other race category.

 

 

 

 

DEFINITIONS

Natality
Abnormal Conditions of the Newborn (Ventura, et al., 2000):
Birth Injury: impairment of the infant's body function or structure due to adverse influences which occurred at birth.
Hyaline Membrane Disease/RDS: a disorder primarily of prematurity, manifested clinically by respiratory distress and pathologically by pulmonary hyaline membranes and incomplete expansion of the lungs at birth.
Meconium Aspiration Syndrome: aspiration of meconium by the fetus or newborn, affecting the lower respiratory system.
Assisted Ventilation: a mechanical method of assisting respiration for newborns with respiratory failure.

Apgar Score: a summary measure of an infant's clinical condition based on heart rate, respiratory effort, muscle tone, reflex irritability, and color taken at one and five minutes after delivery. Each of the factors is given a score of 0, 1, or 2; the sum of these five values is the Apgar score which can range from 0 to 10. A score of 10 is optimal and a low score (usually considered to be less than 7) is considered an indication of potential health problems and raises concerns about the subsequent health and survival of the infant.

Birth Weight: the first weight of the fetus or newborn obtained after delivery. Birth weight is recorded in grams.

Complications of Labor and/or Delivery (Ventura, et al., 2000):
Febrile: a fever greater than 100 degrees F or 38 C occurring during labor and/or delivery.
Moderate or Heavy Meconium: meconium consists of undigested debris from swallowed amniotic fluid, various products of secretion, excretion, and shedding by the gastrointestinal tract; moderate to heavy amounts of meconium in the amniotic fluid noted during labor and/or delivery.
Premature Rupture of Membranes (More than 12 Hours): rupture of the membranes at any time during pregnancy and more than 12 hours before the onset of labor.
Abruptio Placenta: premature separation of a normally implanted placenta from the uterus.
Placenta Previa: implantation of the placenta over or near the internal opening of the cervix.
Other Excessive Bleeding: the loss of a significant amount of blood from conditions other than abruptio placenta or placenta previa. An EBC software cross-edit does not allow this complication to be selected unless blood loss greater than or equal to 750 cc for vaginal deliveries and 1,200 cc for cesarean deliveries is entered.
Precipitous Labor (Less than 3 Hours): extremely rapid labor and delivery lasting less then 3 hours.
Prolonged Labor (More than 20 Hours): abnormally slow progress of labor lasting more than 20 hours.
Dysfunctional Labor: failure to progress in a normal pattern of labor.
Breech/Malpresentation: at birth, the presentation of the fetal buttocks rather than the head, or other malpresentation.
Cephalopelvic Disproportion: the relationship of the size, presentation, and position of the fetal head to the maternal pelvis which prevents dilation of the cervix and/or descent of the fetal head.
Cord Prolapse: premature expulsion of the umbilical cord in labor before the fetus is delivered.
Fetal Distress: signs indicating fetal hypoxia (deficiency in amount of oxygen reaching fetal tissues).

Congenital Anomalies of the Child (Ventura, et al., 2000):
Central Nervous System Anomaly: includes anencephalus, spina bifida/meningocele, hydrocephalus, microcephalus, or other anomaly of the brain, spinal cord, or nervous system.
Heart Malformation: congenital anomaly of the heart.
Other Circulatory/Respiratory Anomaly: other specified anomalies of the circulatory or respiratory systems.
Gastrointestinal Anomaly: includes rectal atresia/stenosis, tracheo-esophageal fistula/esophageal atresia, omphalocele/gastroschisis, or other anomaly of the gastrointestinal system.
Urogenital Anomaly: malformed genitalia, renal agenesis, or other anomaly of the organs concerned in the production and excretion of urine, together with organs of reproduction.
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.
Polydactyly/Syndactyly/Adactyly: polydactyly is the presence of more than five digits on either hands and/or feet; syndactyly is having fused or webbed fingers and/or toes; adactyly is the absence of fingers and/or toes.
Club Foot: deformities of the foot, which is twisted out of shape or position.
Other Musculoskeletal/Integumental Anomaly: includes diaphragmatic hernia or other anomaly of the muscles, skeleton, or skin.
Down's Syndrome: the most common chromosomal defect with most cases resulting from an extra chromosome.
Other Chromosomal Anomaly: any other chromosomal aberration.

Live Birth: the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy, which, after such separation, breathes or shows any evidence of life, such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles.

Low Birth Weight: birth weight of less than 2,500 grams or approximately 5 pounds, 8 ounces. Prior to 1989, New Jersey defined low birth weight as 2,500 grams or less.

Marital Status: the marital status of the mother for statistical purposes is determined for data years after 1988 by the response to the birth certificate item, "Mother married? (At birth, conception, or any time between)".

Medical Risk Factors for This Pregnancy (Ventura, et al., 2000):
Anemia: hemoglobin level of less than 10.0 g/dL during pregnancy or a hematocrit of less than 30 percent during pregnancy.
Cardiac Disease: disease of the heart.
Acute or Chronic Lung Disease: disease of the lungs during pregnancy.
Diabetes: metabolic disorder characterized by excessive discharge of urine and persistent thirst; includes juvenile onset, adult onset, and gestational diabetes during pregnancy.
Genital Herpes: infection of the skin of the genital area by herpes simplex virus.
Hydramnios/Oligohydramnios: any noticeable excess (hydramnios) or lack (oligohydramnios) of amniotic fluid.
Hemoglobinopathy: a blood disorder caused by alteration in the genetically determined molecular structure of hemoglobin (example: sickle cell anemia).
Chronic Hypertension: blood pressure persistently greater than 140/90, diagnosed prior to onset of pregnancy or before the 20th week of gestation.
Pregnancy-Associated Hypertension: an increase in blood pressure of at least 30mm Hg systolic or 15mm Hg diastolic on two measurements taken 6 hours apart after the 20th week of gestation.
Eclampsia: the occurrence of convulsions and/or coma unrelated to other cerebral conditions in women with signs and symptoms of preeclampsia.
Incompetent Cervix: characterized by painless dilation of the cervix in the second trimester or early in the third trimester of pregnancy, with premature expulsion of membranes through the cervix and ballooning of the membranes into the vagina, followed by rupture of the membranes and subsequent expulsion of the fetus.
Previous Infant 4,000+ grams: the birth weight of a previous live-born child was over 4,000 grams (8 pounds, 14 ounces).
Previous Preterm or Small-for-Gestational Age Infant: previous birth of an infant prior to term (before 37 completed weeks of gestation) or of an infant weighing less than the tenth percentile for gestational age using a standard weight-for-age chart.
Renal Disease: kidney disease.
Rh Sensitization: the process or state of becoming sensitized to the Rh factor as when an Rh-negative woman is pregnant with an Rh-positive fetus.
Uterine Bleeding: any clinically significant bleeding during the pregnancy taking into consideration the stage of pregnancy; any second or third trimester bleeding of the uterus prior to the onset of labor.

Multiple Births: individual births in twin, triplet, quadruplet, and higher order multiple deliveries.

Obstetric Procedures (Ventura, et al., 2000):
Amniocentesis: surgical transabdominal perforation of the uterus to obtain amniotic fluid to be used in the detection of genetic disorders, fetal abnormalities, and fetal lung maturity.
Electronic Fetal Monitoring: monitoring with external devices applied to the maternal abdomen or with internal devices with an electrode attached to the fetal scalp and a catheter through the cervix into the uterus, to detect and record fetal heart tones and uterine contractions.
Induction of Labor: the initiation of uterine contractions before the spontaneous onset of labor by medical and/or surgical means for the purpose of delivery.
Stimulation of Labor: augmentation of previously established labor by use of oxytocin.
Tocolysis: use of medications to inhibit preterm uterine contractions to extend the length of pregnancy and, therefore, avoid a preterm birth.
Ultrasound: visualization of the fetus and the placenta by means of sound waves.

Plurality: singleton, twin, triplet, quadruplet, etc.

Previous Pregnancy Terminations: from the mother's pregnancy history on the certificate of live birth, a previous spontaneous or induced termination of pregnancy at any time after conception that did not result in a live birth.

Teen Birth: birth to a mother under 20 years of age.

Tobacco, alcohol, and drug use during pregnancy: use of these substances self-reported by mother.

Trimester of Pregnancy: the first trimester includes the first 12 weeks of pregnancy, the second trimester encompasses the thirteenth through twenty-fourth weeks and the third trimester is the period after the twenty-fourth week through delivery.

Very Low Birth Weight: birth weight of less than 1,500 grams or approximately 3 pounds, 5 ounces.

Mortality
Cause of Death Classification: a system of specification of the diseases and/or injuries which led to death and the sequential order of their occurrence. The version of the system in use in 1998 was the International Classification of Diseases, Ninth Revision (1977), sponsored by the World Health Organization.

Fetal Death: death prior to the complete expulsion or extraction from its mother of a product of conception; the fetus shows no signs of life such as breathing or beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles. Fetal deaths are also referred to as stillbirths, miscarriages, or abortions.

Infant Death: death within the first year of life.

Maternal Death: a death in which the certifying physician has designated a maternal condition as the underlying cause of death. In the Ninth Revision of the International Classification of Diseases, (1977), the World Health Organization defined a maternal death as "the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes".

Neonatal Death: death of an infant within the first 27 days of life.

Perinatal Mortality: for purposes of this report, includes fetal deaths of 20 or more weeks of gestation and neonatal deaths.

Postneonatal Mortality: death of an infant from 28 days to one year of life.

Underlying Cause of Death: the disease or injury which initiated the train of events leading directly to death or the circumstances of the unintentional injury or violence which produced the fatal injury. All cause-of-death data in this report relate to the underlying cause of death coded from the death certificate.

Years of Potential Life Lost (YPLL): a measure of the number of years of life not lived by each individual who died before reaching a predetermined age. For purposes of this report, the predetermined age is 65. This measure weights deaths at younger ages more heavily than deaths at older ages; the younger the age at death, the greater the number of years of potential life lost. The YPLL for a population is computed as the sum of all the individual YPLL for individuals who died during a specific time period.

Communicable Diseases
Stages of Syphilis (Larsen, et. al., 1990):
Primary Syphilis: begins within approximately 30 hours after infection; a primary chancre usually forms within two through six weeks of infection. Both treponemal and nontreponemal antibodies appear one through four weeks after the lesion has formed. Even without treatment, the lesion usually resolves within two months.
Secondary Syphilis: occurs within six weeks of healing of the primary lesion. Disseminated lesions appear that are attributable to systemic infection. Virtually every organ and tissue of the body are affected. Whether treated or untreated, the lesions of secondary syphilis usually resolve within 2 through 10 weeks.
Latent Syphilis: this stage represents a conversion from an acute to a chronic infection. After the first year, the host's immune response suppresses the infection to the point where lesions are not clinically apparent. A patient with reactive nontreponemal or treponemal tests in the absence of clinical symptoms is said to have latent syphilis. A patient is categorized as having early latent syphilis if the serologic tests of that patient have been nonreactive within the preceding year or if symptoms suggestive of primary or secondary syphilis were present during that time. Other patients are considered to have late latent syphilis and should be evaluated for potential asymptomatic neurosyphilis.

Verified Case of Tuberculosis: is also referred to as a new active case of tuberculosis. These cases are characterized by (1) any bacteriological confirmation of the presence of Mycobacterium tuberculosis or (2) in the absence of bacteriological confirmation, for a diagnosis of active pulmonary tuberculosis the patient must present a positive purified protein derivative (PPD), or must exhibit a positive chest x-ray, or in the case of children, must be epidemiologically linked to another active case of tuberculosis. In the case of extrapulmonary tuberculosis, the patient must show signs of clinical improvement while taking tuberculosis medication (K. Shilkret, personal communication, 1992).

All Tables in the Report
Not Stated: an inclusive term used to represent data which are missing, unknown, not available, or not classifiable.

RATES AND RATIOS

The presentation of vital statistics in the form of rates and ratios facilitates comparisons between political subdivisions with populations of different sizes or between subgroups of a population. Crude rates are calculated by dividing the number of events of a type that occur to the residents of an area (e.g., births, deaths) by the resident population of an area or subgroup. The events are limited to those that occur within a specific time period, usually a year, and the population is, in general, the mid-year estimate of the resident population of the area, although census counts as of April 1 may be used in decennial census years. Crude rates are expressed in terms of occurrences within a standard, rounded population, usually 1,000 or 100,000.

While the denominators for rates consist of the population at risk of the events included in the numerator (e.g., births, deaths), ratios are designed to indicate the relationship between two counts in which the denominator population is not at risk of the events included in the numerator. An example of a ratio contained in this report is the maternal mortality ratio in which the number of deaths due to maternal causes forms the numerator and the number of live births provides the denominator.

In order to compare natality and mortality experience among various ages and races or between the sexes, rates may be computed for subgroups of the population. These are referred to as age-, race-, or sex-specific rates and are calculated by dividing the relevant events within a subgroup by the population in the subgroup. Death rates from specific causes may also be calculated, with the numerator consisting of the deaths from the particular cause in an area and the denominator comprised of the population at risk of the disease or condition.

The numbers of births and deaths in an area are directly related to the demographic characteristics of the area's population. In comparing rates over time or among geographic areas, it is helpful to eliminate the effects of the differences in the populations' demographic characteristics on the comparison. This can be accomplished through adjustments of the rates for the particular characteristics of interest. Since age is the variable that has the greatest effect on the magnitude of rates (Shryock, Siegel, et al., 1976), the most common type of adjustment of rates is for age. Direct adjustment of vital statistics rates involves application of existing rates (age-, race-, or sex-specific) to a standard population to arrive at the theoretical number of events that would occur in the standard population, at the rates prevailing in the actual population. These events are then divided by the total number of persons in the standard population to arrive at an adjusted rate. Adjusted rates are index numbers and cannot be compared to crude or other actual rates. The use of adjusted rates is limited to comparison with other adjusted rates, based on the same standard population. The standard population used in this report is the United States 1940 standard million, derived from the counts of the 1940 decennial census.

The definition of rates and ratios used in this report follows. It should be noted that alternative forms exist for some of these statistics. Some other states and the federal government may employ different formulae for the computation of selected rates, in particular, the perinatal and fetal death rates.

Crude Birth Rate: the number of resident live births per 1,000 population.

General Fertility Rate: the number of resident live births per 1,000 females aged 15-44 years.

Total Fertility Rate: age-specific birth rates of women in five-year age groups multiplied by five and summed to form a total for all ages. This rate indicates the number of children a cohort of 1,000 women would bear if they experienced the existing age-specific birth rates throughout their childbearing years.

Age-Specific Birth Rate: the number of resident live births to females in a specific age group per 1,000 females in the age group.

Crude Death Rate: the number of resident deaths per 100,000 population.

Age-Adjusted Death Rate: Direct Method-the elimination of the effect of age on the crude death rates for purposes of comparison with other rates by applying actual age-specific rates to a standard population. The resulting death rate in the standard population is age-adjusted and can be compared to other death rates age-adjusted to the same standard population.

Cause-Specific Death Rate: the number of resident deaths from a specific cause per 100,000 population.

Infant Death Rate: the number of resident deaths under one year of age per 1,000 population.

Infant Mortality Rate: the ratio of the number of deaths to children less than one year of age in a given year per 1,000 births in the same year.

Neonatal Death Rate: the number of resident infant deaths within the first 27 days of life per 1,000 live births.

Postneonatal Death Rate: the number of resident infant deaths from 28 days to one year of life per 1,000 live births.

Perinatal Death Rate: the number of resident neonatal deaths plus resident fetal deaths of 20 or more weeks gestation per 1,000 resident live births plus fetal deaths of 20 or more weeks gestation.

Fetal Death Rate: the number of resident fetal deaths of 20 or more weeks gestation per 1,000 resident live births plus fetal deaths of 20 or more weeks of gestation.

Maternal Mortality Ratio: the number of resident deaths from complications of pregnancy, childbirth, and the puerperium per 100,000 resident live births.

Marriage Rate: the number of marriage certificates issued in an area per 1,000 population.

Divorce Rate: the number of divorces occurring in an area per 1,000 population.

Caution should be exercised in the interpretation of rates and ratios based on small numbers. Chance variations in the number of vital events occurring in sparsely populated areas can cause rates to fluctuate widely over time. In accordance with NCHS standards, percentages or rates based on fewer than 20 cases are considered unreliable for analysis purposes. Therefore, these percentages and rates are not displayed and are indicated by ** in the appropriate cell. For purposes of analyzing vital statistics rates for small areas, calculation of three- or five-year average rates and other statistical methodologies for analyzing small numbers may provide more meaningful measures.

CAUSE-OF-DEATH RANKINGS

The cause-of-death rankings found in this report are based on distinct causes of death from the list of 35 cause groups and a residual category employed in the cause-of-death distributions by race-sex groups and age and by county in the report. The one exception is that the cause groups Motor Vehicle Fatalities and Other Unintentional Injuries are combined into a single category, Unintentional Injuries, for purposes of ranking leading causes of death. As of the publication of New Jersey Health Statistics, 1992, a minor change was made in the grouping of certain infectious and parasitic diseases which transferred a few ICD-9 codes that had previously been included in the "Residual" category and to the "Other Infectious and Parasitic Disease" grouping. This was done to make the groupings more consistent with NCHS' presentation of mortality data.

The cause-of-death ranking of infant deaths is based on the NCHS List of 61 Selected Causes of Infant Death (Murphy, S.L., 2000).


Return to Health Statistics 1998

Previous Section

Next Section

 
State Privacy Notice legal statement DOH Feedback Page New Jersey Home

 
department: njdhss home | index by topic | programs/services
statewide: njhome | my new jersey | people | business | government | departments | search

Copyright © State of New Jersey, 1996-2004
Department of Health
P. O. Box 360
Trenton, NJ 08625-0360

Last Updated: