Asthma Metadata: Emergency Department (ED) Visits


ED visit data are from the Maine Health Data Organization (MHDO).  Population data are from the U.S. Census Bureau.

Dates Available:

2001 – 2014, 2016 – 2020

Geographic Resolution:

State, Public Health District, County, Town


The Maine EPHT program receives ED data annually, based on discharge date, from MHDO.  Asthma ED visits (ICD9-CM 493.0 - 493.9; ICD10-CM J45) among Maine residents are analyzed, stratified by admission date, geographic resolution, age group, and sex.

The dataset contains the following measures:

  1. Crude rate of ED visits for asthma per 10,000 population.
  2. Age-adjusted rate of ED visits for asthma per 10,000 population.
  3. Number of ED visits for asthma.


This data set supports efforts to improve public health in Maine and contributes to the U.S. CDC’s National Environmental Public Health Tracking (EPHT) Network. A key activity of participants in this network is to track and make available environmental health measures on state and national data portals. Measures derived from the data set described here can be used to compare Asthma ED visits across the state, between groups of people, over time, and in relation to risk factors, exposures, and health outcomes.

The Maine Tracking Network, a member of the National EPHT Network, connects communities, public health professionals, policy makers, state agencies, and others to the data they need to monitor public health, respond to health concerns, prioritize resources for public health action, and evaluate prevention activities. Maine tracks certain health effects, exposures, and environmental hazards that have known relationships, as well as some health effects and environmental hazards that have suspected relationships. By making health and environmental data available through the Maine Tracking Network, more people have access to data they need to think critically and hypothesize about health outcomes and their relationships to conditions in the environment.

Supplemental Information:

The Maine EPHT program analyzes asthma ED visits by admission date. Admission date is more closely associated with the timing of an environmental exposure while discharge date is more commonly used for chronic disease measures.  Analyses allow for only one ED visit per patient per day.

Entity and Attribute Overview:

This dataset contains the following fields: admission year, geographic resolution, measure, sex, age group, count, population, rate per 10,000, 95% confidence intervals for rate, age-adjusted rate, 95% confidence intervals for age-adjusted rate.

Data Limitations:

  • Data represent the number of ED visits, by admission date, for asthma. The data do not represent the number of individual people who visited the ED, nor the burden of disease in Maine.
  • Only Maine residents admitted to Maine hospitals are included in the analysis; the total number of asthma ED visits, especially in areas served by hospitals in neighboring states or provinces, may be undercounted.
  • Asthma ED data, by definition, do not include asthma occurrences among individuals who do not receive medical care, are treated in outpatient settings, or die without being admitted to a hospital.
  • When comparing rates across geographic areas, a variety of non-environmental factors, including socio-demographic characteristics and access to medical care, can impact the likelihood of persons with asthma seeking treatment from an ED.
  • These data do not include patients served by Veterans Affairs, Indian Health Services, or patients who are institutionalized.

Access Constraints:

Publicly available data are suppressed in accordance with the Maine CDC Privacy Policy to protect confidentiality.

More Information:

Suggested Citation for Data Displays:

Maine Center for Disease Control and Prevention, Maine Tracking Network. Asthma: Emergency Department Visits. Available online:  Accessed on [date accessed].