About Substance-Involved Mortality Data

Tracking substance-involved mortality involves collecting data about the number of deaths that involve substance use and misuse.

This page provides general information about substance-involved mortality data and measures developed by the Iowa Department of Public Health (IDPH). Contact Us for more information about these data.

Information on this page:

What do these data tell us?
How can we use this data?
What can these data not tell us?
What is the source of the data?
What time period of data is available?
How are substance-involved deaths identified?
How are rural-urban counties defined?
What is the difference between a number, rate, age-adjusted rate, and age-specific rate?
What are the limitations of the data?
Where can I find more technical information about the data?

What do these data tell us?

The number and rates of substance-involved deaths in Iowa by year and gender.
If the number or rates of substance-involved deaths are going up or down over time.
If a segment of a population is at higher risk for substance-involved deaths.

How can we use this data?

To inform the public about substance-involved deaths.
For program planning and evaluation by state and local partners.

What can these data not tell us?

What leads to a substance-involved death.
The total burden of substance-involved mortality in a given population.

What is the source of the data?

Mortality data are collected along with other vital events such as births and marriages. In Iowa, official registration of all vital events are recorded and maintained by local registrars located in county recorders offices and with the IDPH Bureau of Vital Statistics.

What time period of data is available?

Substance-Involved Mortality data on the Iowa Public Health Tracking (IPHT) portal displays mortality data from the year 2011 through the most recent year of data available.
Mortality measures are published on the IPHT portal annually following the release of population estimates. This creates a six-month lag before data are available.

How are substance-involved deaths identified?

The National Center for Health Statistics (NCHS) captures causes of deaths from death certificates using ICD-10 codes. All death certificates include a primary, or underlying, cause of death and up to 20 non-primary, or contributing, causes of deaths. Each code includes a letter followed by a number.

For chronic and acute alcohol-related deaths, the following ICD-10 codes are listed as the primary cause of death:

F10.0-F10.9
G62.1, G31.2, G72.1, I42.6
K29.2, K70-K70.4, K70.9
Q86.0, P04.3, O35.4
K86.0, K85, K86.1
G40, G41
I85, I98.2
K22.6, K74.3-K74.6, K76.0, K76.9, K76.6
O03
X45
Y15
T51.0, T51.1, T51.9
X65
R78.058

For opioids and methamphetamine, all primary causes of death include:

Accidental poisoning by drugs: X40-X44
Intentional self-poisoning by drugs: X60-X64
Assault by drug poisoning: X85
Drug poisoning of undetermined intent: Y10-Y14

For opioids, the secondary cause(s) of death include:

All opioid-involved deaths: T40.0-T40.4, T40.6
Prescription opioids: T40.2, T40.3, T40.4
Other opioids and methadone: T40.2, T40.3
Other synthetic opioids: T40.4
Heroin: T40.1
Cocaine: T40.5
Other and unspecified narcotics: T40.6

For methamphetamine, the secondary cause of death includes the code:

Psychostimulants with abuse potential (includes methamphetamine): T43.6
Methamphetamines do not have its own ICD-10 code, and is included in T43.6 (Psychostimulants with abuse potential).

How are rural-urban counties defined?

Urban-Rural designations are based on the National Center for Health Statistics designations. Counties were grouped based on population estimates from the American Communities Survey. More information can be found at: https://www.cdc.gov/nchs/data/series/sr_02/sr02_166.pdf.

What is the difference between a number, rate, age-adjusted rate, and age-specific rate?

Number:

If you want to understand the magnitude or how big the overall burden is, then use the number.
The number indicates the total number of deaths.
To protect an individual's privacy, counts of 5 or less are suppressed.

Crude Rate:

If you want to understand the probability or what is the underlying risk in a population, then use a rate.
In our analysis a rate is calculated using a numerator, the number of substance-involved deaths during a period of time, divided by a denominator, the number of people in a population during the same period of time. This fraction is then multiplied by 100,000 to provide a more recognizable value.
To protect an individual's privacy, rates based on counts of 5 or less are suppressed.

Age-adjusted rate:

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 less are suppressed.

Age-specific rate:

A rate of an event (such as disease or death) measured within a particular age group. It is similar to a crude rate but is calculated within an age group (e.g. an age-specific rate of substance-involved deaths in adults 35-44 years of age).
To protect an individual's privacy, rates based on counts of 5 or less are suppressed.

What are the limitations of the data?

Data are not appropriate for estimating the total burden of substance-involved health issues.
Data is not provided for Iowa residents who die outside the state so rates may be underestimated.

Where can I find more technical information about the data?

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