Center for Health Statistics Information for Local Health Officers

• What is the Center for Health Statistics?
  
• Publications produced by CHS
  
• Hard copy reports
  
• Web only reports
  
• Data produced by CHS
  
• Data listed by subject
  
• Data listed by geographical level
  
• Other data sources outside of CHS
  
• Data quality
  
• Municipality-level deaths
  
• Asian/Pacific Islander and Hispanic deaths
  
• Small numbers and confidentiality
  
• Rates based on small numbers
  
• Methods
  
• Crude rates
  
• Age-adjusting
  
• YPLL
  
• Life expectancy
  

What is the Center for Health Statistics?
The Center for Health Statistics (CHS) collects, analyzes, and disseminates New Jersey health data and information and serves as a resource to the Department in development of health data policy.  Functions of CHS include

• annual reporting of vital events: births, deaths, fetal deaths, and marriages.
  
• collecting data and preparing reports on health-related behaviors (BRFS), and induced terminations of pregnancy (abortions).
  
• maintaining the NJSHAD state data query system.
  
• providing baseline and trend data to measure the impact of public health strategies for disease prevention and health promotion (Healthy New Jersey).
  
• disseminating health insurance coverage data.
  
• houses the Office of Injury Surveillance and Prevention (OISP) which is the central source for injury statistics and information on injury prevention and control efforts in New Jersey. OISP is also home to several special injury projects such as a central nervous system injury registry and a violent death reporting system.
  
• responding to requests for New Jersey vital statistics and other health data.

• New Jersey Health Statistics – an annual report of vital events and other selected data at the state level, including some tables of county-level data and some data for selected large municipalities.  Reports are available on the Web back to 1993.  Starting in 1999, the full report is Web-only.
  
• Healthy New Jersey – State health objectives for 2000 and 2010.  Healthy NJ 2000 publications since 1999 and all Healthy New Jersey 2010 publications are available online. The 2005 Update is only available online.
  
• Topics in Health Statistics – a report series on various topics related to data maintained by CHS.  All reports are available on the Web.
  
• New Jersey Behavioral Risk Factor Survey – results from a survey of health-related behaviors.  All reports are available online.
  
• Central Nervous System Injury Surveillance in New Jersey – based on CDC-funded TBI and Spinal Cord Injury (SCI) surveillance.  All reports are available on the Web.

Web Only Reports

• New Jersey Health Statistics – Starting in 1999, the full report is only available online.
  
• Healthy New Jersey 2010: Update 2005 - This first data update of 2010 health objectives is only available online.
  
• Health Data Fact Sheets - Data and information briefs related to selected national health observances and other seasonal topics.
  
• Then and Now in New Jersey - Health profiles for the State now and 100 years ago.
  
• A Profile of New Jersey Older Adults Aged 60+ Years

• Data are listed by subject – births, deaths, infant deaths, fetal deaths, abortions, marriages, morbidity, health-related risk factors, population, and geographic information – in the Subject Index on our website.

Data listed by geographic level

• Data are listed by geographic level – state, county, municipality, census tract – in our Geographic Index.

 Other data sources outside CHS

While we occasionally report some of the following types of data in our reports, CHS does not collect, analyze, or maintain these databases.  To get the most up-to-date data and answers to questions about these data, please visit their sources:

• NJDOH AIDS Prevention and Control for HIV and AIDS incidence and prevalence data
  
• NJDOH Cancer Resources for cancer incidence data
  
• NJDOH Communicable Disease Service for STD, TB, vaccine-preventable, infectious, and zoonotic disease incidence data
  
• NJDOH Family Health Services for asthma and diabetes prevalence and hospitalization data
  
• NJDOH Health Care Systems Analysis Division for hospitalizations and cardiac surgery data
  
• NJ Department of Education for Youth Risk Behavior Survey (YRBS) data
  
• NJ Department of Human Services for addictions (smoking and substance abuse), mental health, disability, and Medicaid data
  
• NJ State Data Center for Census data and population estimates
  
• CDC for all national-level health data
  
• Health.gov for all other national-level health information

This list is not exhaustive, but covers most of the types of data for which we get requests.

There are certain variables in some of our datasets that are of substandard quality.  For this reason, we do not publish these items.  They are available to local health officers in our public use files or by request.

•   Municipality-level death data
  Data for 211 of New Jersey’s municipalities are overcounted or undercounted by more than 10%.  Because street addresses are available on the electronic files of births, infant deaths, and fetal deaths, CHS geocodes addresses to correct the discrepancies.  Therefore, birth, infant death, and fetal death data for all municipalities are accurate.  Street addresses are not currently included in the electronic death file, however; therefore inaccurate residence codes cannot be corrected.  For this reason those municipalities with an overcount or undercount greater than 10% are not displayed in our tabulations of death data.  The implementation of the Electronic Death Registry System (scheduled for mid-2005) will alleviate this problem.  For more information and a table of overcounts and undercounts by municipality, go to Overcounts and Undercounts in New Jersey Municipality-Level Data.
  
• Race and ethnicity data on death certificates
  Asian and Pacific Islander race and Hispanic ethnicity are known to be undermeasured on death certificates. This is a nationwide problem.  Due to the manner in which the data are collected, race and ethnicity are believed to be complete on birth and fetal death certificates.  Race and ethnicity of the mother from the birth certificate is used in infant death reporting.  An estimated 13% Asian/Pacific Islander undercount and 7% Hispanic undercount exists among death records.  Besides miscoding on death certificates, there is believed to be a selection bias in that the sick do not immigrate to the U.S. but sick and elderly foreign-born U.S. residents do emigrate back home to die contributing to the very low death rates seen for Hispanics and Asian/Pacific Islanders.  For this reason, Asian and Pacific Islander and Hispanic mortality data have been reported separately.  In the majority of our death reports, we have used three race categories – White, Black, and Other (includes Asians and Pacific Islanders as well as American Indians and Alaska Natives and those who are not identified in any of the above mentioned groups) – and we report Hispanics in the race category indicated on their death certificates.  Beginning with 2003 death data, the same race/ethnicity categories used for our birth, infant death, and fetal death reports will be used for deaths: White (non-Hispanic), Black (non-Hispanic), Hispanic (of any race), Asian/Pacific Islander (non-Hispanic), and Other Races (non-Hispanic).  For more information, go to Asian And Pacific Islander Mortality In New Jersey and Hispanic Mortality in New Jersey.
  
• Small numbers
  We do not publish municipality-level data if the value is less than 5 because it could lead to the identification of individuals.  Small numbers are available to local health officers in our public use files or by request, with the understanding that they will not be published.
  
• Rates based on small numbers
  In keeping with NCHS guidelines regarding statistical reliability, we do not publish rates based on fewer than 20 events (births, deaths, etc.) for any geographic level.  See the Random Variation section of the Technical Notes of Deaths: Final Data for 2000 on the NCHS website for a full explanation.  Multiple years of data may be combined to compute rates when a single year of data yields fewer than 20 events.

Visit NCHS’s website for definitions of various types of crude rates.

Age-adjusted death rates are computed to eliminate the effect of age on crude death rates for purposes of comparison with other rates.  This is done by applying 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.  Since 1999, all age-adjusted rates have been calculated using the 2000 standard population.  Other common standards that have been in use in the past are the 1940 and 1970 standards.  In the following age-adjustment Excel worksheets, enter the appropriate age-specific deaths and population for the year, geographic area, race, sex, and/or cause of death of interest in the gray cells and the resulting age-adjusted rate will appear in the red cell.

How to calculate YPLL (years of potential life lost)

Years of potential life lost (YPLL) is a measure of the number of years not lived by each individual who died before reaching a predetermined age, usually 65 or 75.  (NCHS switched to YPLL before 75 in 1996 and CHS switched in 2000.)  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.  In the following YPLL Excel worksheets, enter the appropriate age-specific numbers of deaths and the population under age 65 or 75 for the year, geographic area, race, sex, and/or cause of death of interest in the gray cells and the resulting YPLL rate will appear in the red cell.

Life expectancy is the average number of years of life remaining to a person at a particular age and is often used as a summary measure of the health status of a population.  The most commonly used life expectancy measure is life expectancy at birth, the number of years a person born in a given year is expected to live.  Calculation of life expectancy requires birth, death, and population data.  It is recommended that there be at least 700 deaths in a given geographic area/race/sex group when calculating life expectancy.  If there are fewer than 700 deaths, multiple years of data may be combined to give life expectancy for a range of years.  Life expectancy does not change much from year to year and random variation can cause life expectancy to decrease slightly on occasion, therefore the overall trend is key. 

In the following life expectancy Excel workbook, there are separate worksheets for all races and both sexes, males, females, whites, blacks, white males, white females, black males, and black females.  The k-values in gray in the Qx column (column F) differ for each race and sex as does the value of s (cell D129), therefore the appropriate worksheet must be used for each race/sex combination.  These values change annually and are available in the Methodology section of the Technical Notes of the annual United States Life Tables publications on the NCHS website.

In the worksheets, input the appropriate age-specific number of deaths (column B) and population (column E) for the geographic area, race, and/or sex of interest in the gray cells.  Note that cell B85 is the number of deaths of those aged 85 and over.  The worksheet takes into account deaths of unknown age, so enter those in B121.  In cells D124-D127, enter the geographic area/race/sex-specific numbers of infant deaths this year, infant deaths born last year, births this year, and births last year, respectively.  The resulting life expectancy will appear in the red cell. 

If single year of age population data are not available for the geographic area of interest, an abridged life table may be used.  The abridged life table uses deaths and population in 5-year age groups.  Unlike the complete life table, it does not require separate factors for each race and sex, nor does it take into account unknown age, births, or infant deaths.  It does, however, require at least one death in each age group and at least 700 total deaths are recommended for accuracy.  If there are fewer than 700 deaths or there are no deaths in at least one age group, multiple years of data may be combined to give life expectancy for a range of years.  In the following abridged life expectancy Excel worksheet, input the appropriate age-specific number of deaths (column B) and population (column C) for the geographic area, race, and/or sex of interest in the gray cells.  The resulting life expectancy will appear in the red cell.

Abridged Life Table