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Asthma Overview

Picture of a person using an inhaler Asthma is an illness that affects the respiratory tract and airways that carry oxygen into and out of the lungs. During an asthma attack, these airways constrict, resulting in wheezing and difficulty breathing. Asthma can affect people of all ages. However, it often starts in childhood and is more common in children than adults.

Asthma is a common chronic disease that continues to increase in prevalence.  It is the most common chronic disease in children. The state of Massachusetts has an elevated rate of asthma compared to the national prevalence rate. 

Causes of asthma are unknown. However, episodes of asthma (asthma attacks) can be triggered by certain environmental pollutants such as air pollution, mold, pets/pet dander, and dust mites. A number of studies have reported links between exposure to air pollution and asthma. Reducing exposure to these pollutants can help prevent symptoms. Other factors are also linked with asthma. Therefore, when comparing asthma rates across geographic areas, factors such as access to medical care and health behaviors (e.g., diet or exercise) must also be considered. The Massachusetts Department of Public Health (MDPH) participates in two programs associated with tracking asthma rates in the state.

Asthma hospitalization

Hospitalization resulting from asthma occurs regularly and often when unnecessary. Contributing factors include uncontrolled asthma conditions, limited access to health care services, and/or inadequate medical treatment practices.

Data on hospitalization visits are collected by the Massachusetts Center for Health Information and Analysis (CHIA) from all acute care hospitals and satellite emergency facilities in the state. CHIA collects information on all inpatient hospital admissions and emergency department (ED) visits.

MDPH analyzes these data and provides asthma hospitalization rates for adults and children of all ages for both inpatient hospital admissions and ED visits. Some asthma patients enter the hospital through an ED, but are later admitted to the hospital as inpatients. These patients are included in both the ED visit and inpatient hospitalization rates.

Pediatric asthma tracking in elementary and middle schools

Asthma is a chronic disease that most commonly starts during childhood. To track asthma prevalence among children in Massachusetts, a state-wide surveillance program was implemented with participation from public and private schools serving grades kindergarten through eighth grade. Beginning in 2003 and continuing through the present, the MDPH has tracked the occurrence of pediatric asthma through school health records.

To view asthma related data please click on one of the asthma outcomes in the tabs above.

Asthma Hospitalization

Picture of man wearing a nebulizer mask
Did You Know?

In the northeastern US, summer ozone pollution has been associated with contributing a substantial portion (up to 20%) of hospital visits and admissions per year for asthma and other respiratory emergencies.

Source: U.S. EPA 2006

Hospitalization for asthma occurs due to several factors including uncontrolled asthma conditions, limited access to health care services, and/or inadequate medical treatment practices.

Causes of asthma are unknown. However, episodes of asthma (asthma attacks) can be triggered by certain environmental pollutants such as air pollution, mold, pets/pet dander, and dust mites. A number of studies have reported links between being exposed to air pollution and asthma. Reducing exposure to these pollutants can help prevent symptoms. Many other factors are also linked with asthma. Therefore, when comparing rates across geographic areas, factors such as access to medical care and health behaviors (e.g., diet or exercise) must also be considered.

Data on hospitalization visits are collected by the Massachusetts Center for Health Information and Analysis (CHIA) from all acute care hospitals and satellite emergency facilities in the state. CHIA collects information on all inpatient hospital admissions and emergency department (ED) visits.

MDPH analyzes these data and provides asthma hospitalization rates for adults and children of all ages for both inpatient hospital admissions and ED visits. Some asthma patients enter the hospital through an ED, but are later admitted to the hospital as inpatients. These patients are included in both the ED visit and inpatient hospitalization rates.

Data Considerations

When reviewing and interpreting asthma hospitalization data, it is important to take into consideration the following:

  • Hospitalization data, by definition, exclude discharges from specialty hospitals (e.g., psychiatric), long-term care facilities, and federal hospitals that are exempt from state reporting requirements.
  • Asthma hospitalization data do not include individuals who do not receive medical care or who are not hospitalized, including those who die in emergency rooms, in nursing homes, or at home without being admitted to a hospital, and those treated in outpatient settings.
  • Transfers from one hospital to another may be included in the dataset as separate hospitalization events.
  • Emergency department data include all asthma hospitalizations that originated in an ED, including those later admitted as inpatients. For this reason, there is overlap between the two datasets and many patients are included in both the inpatient and ED hospitalization data reported on this site. Asthma counts and rates should, therefore, not be summed across the two measures of hospitalization.
  • Numbers and rates may differ slightly from those contained in other publications. These differences may be due to file updates, differences in calculation methods (such as grouping ages differently or rounding off numbers at different points in calculations), and updates or differences in population estimates.
  • Hospitalization data are validated through a process of automated editing and report verification. In addition, each record is subjected to a series of edits that check for duplicate records, accuracy, consistency, completeness, and conformity.
  • Data will only be presented to the public if the confidentiality rules of MDPH and CHIA are met. These are rules requiring data aggregation and cell suppression to protect privacy.
  • Rates are based on the residential location of cases and not necessarily the location where incidents occur.

For additional information, please read the FAQ.

Available Data on Asthma Hospitalization

Click the Maps and Tables button on this page to access the following measures for Asthma Hospitalization in your community on the right toolbar. The most current available data will be shown.  Be sure to check the site periodically as new data are added each year. To protect privacy, no information is shown that could identify an individual.

  • Summary statistics (minimum, maximum, and average number) for monthly hospitalizations for asthma
  • Age-specific hospitalization rates for asthma
  • Crude and age-adjusted hospitalization rates for asthma
  • Explore data in tables, charts, and maps
  • All of the measures above are available by community, county, and statewide

Pediatric Asthma

Picture of child using an inhaler, which pertains to pediatric asthma.

Asthma is the most common chronic disease in children. It is an illness that affects the respiratory tract and airways that carry oxygen into and out of the lungs. During an asthma attack, these airways constrict, resulting in wheezing and difficulty breathing. Asthma can affect people of all ages, however it often starts in childhood and is more common in children than adults. Causes of asthma are unknown, however episodes of asthma (asthma attacks) can be triggered by certain environmental pollutants such as air pollution, mold, pets and pet dander, and dust mites. A number of studies have reported links between exposure to air pollution and asthma. Reducing exposure to these pollutants can help prevent symptoms.

In Massachusetts, the rate of pediatric asthma is higher than the national average. Beginning in 2002 and continuing through the present, the Massachusetts Department of Public Health/Bureau of Environmental Health (MDPH/BEH) has tracked the occurrence of pediatric asthma through school health records in students in kindergarten through 8th grade.

Did You Know?
In Massachusetts the prevalence of asthma is 12.4% among students in grades K-8.

Source: MDPH Pediatric Asthma Surveillance Program 2013-2014 school year

The number and prevalence of children with asthma can be viewed by selecting from the choices on the right toolbar.  For each year of data available, pediatric asthma prevalence estimates are compared to statewide prevalence to determine if they are statistically significantly higher, lower, or the same as the statewide pediatric asthma prevalence. In some instances, schools or communities may not be available when selecting data. This is due to the fact that MDPH does not have data available for that school or community in the year selected.  

Data Considerations

When reviewing and interpreting pediatric asthma data, it is important to take into consideration the following:

  • The data available for pediatric asthma are limited to students in grades K-8.
  • A variety of factors can impact asthma rates (e.g., socioeconomic factors). Therefore, when comparing rates across geographic areas, information such as access to medical care must also be considered.
  • Prevalence is not age-adjusted. When comparing prevalence estimates across communities, keep in mind that some of the observed differences in prevalence estimates may be due to differences in the age distribution of students in each community.

For additional information, please read the FAQ.

Available Data on Pediatric Asthma

Click the Maps and Tables button on this page to access the following measures for pediatric asthma in your community on the right toolbar. The most current available data will be shown.  Be sure to check the site periodically as new data are added each year. To protect privacy, no information is shown that could identify an individual.

  • Pediatric asthma prevalence in public and private schools
  • Pediatric asthma prevalence in communities, counties, and statewide
  • Pediatric asthma prevalence in communities, counties, and statewide (table and map)
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