Environmental Public Health Tracking: Carbon Monoxide Poisoning Data

This page is for data users of the Wisconsin Environmental Public Health Tracking data portal.  You can find general carbon monoxide poisoning information on our carbon monoxide page.

Carbon monoxide (CO) is a toxic gas that can't be seen or smelled. CO is made whenever fuel or other materials are burned. CO is found in fires and exhaust from cars and trucks, portable generators, stoves, gas ranges, and heating systems.

The section below presents answers to frequently asked questions about our carbon monoxide data.

Access the carbon monoxide data

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Frequently asked questions

What is carbon monoxide poisoning?

Carbon monoxide (CO) is a toxic, colorless, and odorless gas. CO is given off whenever fuel or other materials are burned. CO is found in fires and exhaust from cars and trucks, portable generators, stoves, gas ranges, and heating systems.  CO fumes can build up in places that do not have a good flow of fresh air, such as a garage or a house with closed windows and doors. Breathing high levels of CO can cause severe illness or death in a matter of minutes.

Red blood cells pick up CO more easily than they pick up oxygen. If there is a lot of CO in the air, the body may replace oxygen in the blood with CO. This blocks oxygen from getting into the body, which can damage tissues and result in death.

Although carbon monoxide poisoning can almost always be prevented, more than 500 people in the United States die every year as a result of accidental, non-fire exposure to this toxic gas.  Several things can be done to prevent carbon monoxide poisoning.  Learn more by reading the carbon monoxide fact sheet.

How can tracking carbon monoxide poisoning improve public health?

Tracking carbon monoxide poisoning gives public health professionals a better understanding of the health consequences of carbon monoxide poisonings across the country.  We can monitor the impact of public health policy aimed at preventing carbon monoxide poisoning.

What is the data source?

Wisconsin Tracking provides data on carbon monoxide hospital admissions and emergency department visits. The source of these data is the Wisconsin Hospital Association Information Center, Inc.

Which measures does Wisconsin Tracking have for carbon monoxide poisoning?

What are some considerations for interpreting the data?

  • Hospital admission and emergency department visit data will not include people who experience symptoms but are not seen in the emergency room or admitted to the hospital.
  • These data do not include hospitalizations and emergency department visits among residents of Wisconsin in border states (such as Minnesota, Iowa, and Illinois).
  • These data do not include inpatient admissions or emergency department visits at hospitals owned by the federal government, such as Veterans Administration hospitals.
  • The death certificate dataset may be missing a small number of cases where the decedent is a Wisconsin resident but died in another state.
  • Cases that involve a call to the state’s poison center may or may not be treated by medical personnel, and thus it can be difficult to confirm the poisoning.
  • Data users should keep in mind that many factors contribute to a disease.  These factors should be considered when interpreting the data.  Factors include:
    • Demographics (race, gender, age)
    • Socioeconomic status (income level, education)
    • Geography (rural, urban)
    • Changes in the medical field (diagnosis patterns, reporting requirements)
    • Individual behavior (diet, smoking)

Where can I learn more about carbon monoxide poisoning?

Carbon monoxide data details

Data Details

Carbon monoxide poisoning emergency department visits

Number of emergency department visits for carbon monoxide poisoning (counts)

These data include emergency department visits for carbon monoxide poisoning and are collected from emergency room visit discharge records. This measure includes emergency department visits with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are not suppressed for this measure. Please note that counts are a statistically limited way to consider emergency department visits because they do not allow for accurate comparison between counties. Counties with higher populations, such as Milwaukee, will have more emergency department visits simply because they have more people. An age-adjusted rate is a better measure for true comparison between counties.

Crude rates per 100,000

These data include emergency department visits for carbon monoxide poisoning and are collected from emergency room visit discharge records. This measure includes emergency department visits with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed when there are fewer than five visits to improve rate stability. However, rates with zero cases are not suppressed. The crude rate is the number of emergency department visits divided by the total number of people in the area of interest (for example, a county). This is expressed as a number per unit population, such as "per 100,000 population." The crude rate does not take into account the differences in age distributions across counties and are therefore subject to bias. Use age-adjusted rates for a better standardized measure.

Age-adjusted rates per 100,000

These data include emergency department visits for carbon monoxide poisoning and are collected from emergency room visit discharge records. This measure includes emergency department visits with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed when there are fewer than five visits to improve rate stability. However, rates with zero cases are not suppressed. An age-adjusted rate is a rate that is statistically modified to eliminate the potential biasing effect of different age distributions across different populations. In other words, the age-adjusted rate accounts for the possibility that emergency department visits for carbon monoxide may be more frequent among younger individuals and some counties have more younger individuals than others. Direct age-adjustment is conducted using the 2000 U.S. standard population.

Carbon monoxide poisoning hospitalizations

Number of hospitalizations for carbon monoxide poisoning (counts)

These data include hospitalizations for carbon monoxide poisoning and are collected from inpatient hospital discharge records. This measure includes hospitalizations with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are not suppressed for this measure. Please note that counts are a statistically-limited way to consider hospitalizations because they do not allow for accurate comparison between counties. Counties with higher populations, such as Milwaukee, will have more hospitalizations simply because they have more people. An age-adjusted rate is a better measure for true comparison between counties.

Crude rates per 100,000

These data include hospitalizations for carbon monoxide poisoning and are collected from inpatient hospital discharge records. This measure includes hospitalizations with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded.. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed when there are fewer than five visits to improve rate stability. However, rates with zero cases are not suppressed. The crude rate is the number of hospitalizations divided by the total number of people in the population of interest (for example, a county). This is expressed as a number per unit population such as "per 10,000 population." A crude rate does not take into account the differences in age distributions across counties and are therefore subject to bias. Use age-adjusted rates for a better standardized measure.

Age-adjusted rates per 100,000

These data include hospitalizations for carbon monoxide poisoning and are collected from inpatient hospital discharge records. This measure includes emergency department visits with an ICD-9 code of 986, E868.2, E868.3, E868.8, E868.9, E982.0, or E982.1 or an ICD-10 code of T58.01, T58.04, T58.11, T58.14, T58.2X1, T58.2X4, T58.8X1, T58.8X4, T58.91 or T58.94 in the principal or other diagnosis fields. Records of intentional or purposeful CO poisoning are excluded. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed when there are fewer than five visits to improve rate stability. However, rates with zero cases are not suppressed. An age-adjusted rate is a rate that is statistically modified to eliminate the potential biasing effect of different age distributions across different populations. In other words, the age-adjusted rate accounts for the possibility that hospitalizations for asthma may be more frequent among younger individuals and some counties have more younger individuals than others. Direct age-adjustment is conducted using the 2000 U.S. standard population.

Carbon monoxide poisoning mortality

Number of deaths from carbon monoxide poisoning (counts)

These data include deaths from carbon monoxide poisoning and are collected from the National Vital Statistics System from the National Center for Health Statistics. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed for counties with nine or fewer (including zero) per 100,000 to protect confidentiality. Please note that counts are a statistically limited way to consider deaths because they do not allow for accurate comparison between counties. Counties with higher populations, such as Milwaukee, will have more deaths simply because they have more people. An age-adjusted rate is a better measure for true comparison between counties.

Crude rates per 100,000

These data include deaths from carbon monoxide poisoning and are collected from the National Vital Statistics System from the National Center for Health Statistics. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed for counties with nine or fewer (including zero) per 100,000 to protect confidentiality. The crude rate is the number of deaths divided by the total number of people in the population of interest (for example, a county). This is expressed as a number per unit population, such as "per 10,000 population." A crude rate does not take into account the differences in age distributions across counties and are therefore subject to bias. Use age-adjusted rates for a better standardized measure.

Age-adjusted rates per 100,000

These data include deaths from carbon monoxide poisoning and are collected from the National Vital Statistics System from the National Center for Health Statistics. These data include three categories of carbon monoxide poisoning causes:

  1. Unintentional, non-fire related;
  2. Unintentional, fire-related; and
  3. Unknown intent.

Data are suppressed for counties with nine or fewer (including zero) per 100,000 to protect confidentiality. An age-adjusted rate is a rate that is statistically modified to eliminate the potential biasing effect of different age distributions across different populations. In other words, the age-adjusted rate accounts for the possibility that carbon monoxide poisoning deaths may be more frequent among younger individuals and some counties have more younger individuals than others. Direct age-adjustment is conducted using the 2000 U.S. standard population.

Glossary and definitions of terms

Explore definitions and explanations of terminology found on the portal, like age-adjusted rate and confidence intervals.

Last Revised: June 16, 2022