About Death Data

about death data

Iowa Public Health Tracking uses vital records collected by the IDPH Bureau of Health Statistics. Vital records are information about human life, such as birth and death.

This page provides general information about the death data and measures developed by the Iowa Public Health Tracking program. Contact Us for more information about these data.

Information on this page:

What do these data tell us?

  • If certain causes of death are going up or down over time.
  • If certain causes of death vary by location and gender.
  • If select causes of death are going up or down over time in a specific location.

Back to top

How can we use these data?

  • To inform the public about what diseases and conditions should be of public health concern.
  • For program planning and evaluation by state and local partners.

Back to top

What can these data not tell us?

  • The social, environmental and other factors that influence a cause of death.
  • Environmental exposure-related causes of death are only one piece of a puzzle that includes many other factors such as access to and quality of healthcare, individual and community characteristics, genetic factors, behavioral factors, social support, and injury prevention. Many of these factors are not included in death records. Variables that are included are often difficult to interpret without additional information on social and behavioral factors.

Back to top

What is the source of the data?

  • Death certificates filed with the Iowa Department of Public Health Vital Records program is the data source for the death measures.
  • Measures are computed using data on deaths of Iowa residents, with residency determined by address at time of death as listed on the death certificate. Cause of death is based on the primary cause listed on the death certificate.

Back to top

What time period of data is available?

  • The Iowa Public Health Tracking portal displays death data from the year 2000 through the most recent year of data available.

Back to top

How is cause of death identified?

  • Cause of death is identified from death certificates filed with the IDPH Vital Records program.
  • Cause of death is the disease or injury that initiated the sequence of events leading directly to death, or the circumstances of the accident or violence, which produced fatal injury.

Back to top

What is the difference between a number and rate? How would I use them?


  • The number indicates the total number of a death outcome.
  • To understand the magnitude or what the overall burden is, use the number.
  • If there are fewer than 5 cases, Iowa Public Health Tracking program suppresses those numbers to preserve data privacy.


  • In our analysis, a percentage is calculated using the number of events as the numerator (the number of a death outcome during a period of time) divided by the number of total deaths during a period of time. This fraction is then multiplied by 100 (percent) to provide a more recognizable value.
  • To understand the probability or what the underlying risk in a population is, use a percentage.
  • To protect an individual's privacy, rates based on counts under 5 are suppressed.

Age-adjusted rate:

  • A rate is a ratio between two measures with different units. In our analysis a rate is calculated using a numerator, the number of deaths with a certain cause of death during a period of time, divided by a denominator, the number of people at risk in a population during the same period of time. This fraction is then multiplied by a constant (in this case 10,000) to provide a more recognizable value.
  • Age-adjusted rates are useful when comparing the rates of two population groups that have different age distributions.
  • A weighted average, called the direct method, is used to adjust for age in this analysis. Age specific rates in a given population are adjusted to the age distribution in a standard population by applying a weight. The U.S. 2000 Standard population is used as the basis for weight calculations.
  • To protect an individual's privacy, rates based on counts of 5 or fewer are suppressed.

Back to top

What are the limitations of the data?

  • The quality of vital statistics data is directly related to the completeness and accuracy of the information contained in the source documents.
  • Timeliness is a limitation of the vital records system. It is not unusual for a death record to be amended weeks or months after it was originally processed due to autopsy results, or out-of-state death. Because of the time it takes to correct and amend death records, the final death file for a particular calendar year can take many months after the end of the calendar year to close and be made available for epidemiological use. Data on some causes of deaths, such as homicide and poisonings takes even longer to be ready for analysis because of the time it takes to conduct toxicology and other medical examinations.
  • Residential information is very important when examining environmental exposures and other risk factors that may occur before death. A limitation of the data source is that the place of residence during life when risk factors occur may not be represented by residence at time of death.

Back to top

Where can I find more technical information about the data?

Contact Us to learn more about death data, or any of the measures displayed on the Iowa Public Health Tracking Portal.

Back to top