Occupational
& Environmental
Medicine
College of Human Medicine

ASTHMA

Surveillance of Asthma in Michigan

Work-Related Asthma (WRA)

In 1988, the State of Michigan instituted a surveillance program for work-related asthma with financial assistance from the National Institute for Occupational Safety and Health (NIOSH). (read more)

Asthma Mortality

In response to a request for a proposal from the Centers for Disease Control and Prevention (CDC), the Michigan Department of Community Health (MDCH) in conjunction with Michigan State University (MSU) successfully competed to obtain funds to develop a rapid asthma death notification and investigation system for the State of Michigan. (read more)

Farm Asthma

Michigan State University completed a 5-year project to study asthma in farmers and their family members.
(read more)

 WORK-RELATED ASTHMA RESOURCES

Work-Related Asthma (WRA)

In 1988, the State of Michigan instituted a surveillance program for work-related asthma with financial assistance from the National Institute for Occupational Safety and Health (NIOSH). The surveillance program is a joint project of the Michigan Occupational Safety and Health Administration (MIOSHA) in the Michigan Department of Labor and Economic Opportunity (LEO), the Michigan Department of Health and Human Services (MDHHS), and Michigan State University (MSU). The goal of the surveillance program is to prevent work-related asthma through the reporting of index patients. The reporting of the index patient is regarded as a sentinel health event that may lead to the identification of other employees from the same facility who are at risk of developing asthma or who have developed similar breathing problems.

There are four major sources used to identify persons with work-related asthma:

(1) Reports from physicians (both private practice and company physicians)
(2) Reports from hospitals
(3) Respiratory claims filed with the Workers’ Compensation Agency
(4) Calls to the State's Poison Control Center

(to top)

Past Surveillance Initiative:

Asthma Mortality

In response to a request for a proposal from the Centers for Disease Control and Prevention (CDC), the Michigan Department of Community Health (MDCH) in conjunction with Michigan State University (MSU) successfully competed to obtain funds to develop a rapid asthma death notification and investigation system for the State of Michigan. This system was limited, at the request of CDC, to investigations of asthma deaths among children and young adults ages 2-34. CDC selected this age group because of the increased likelihood that deaths ascribed to asthma in the ages 2-34 were truly caused by asthma. For individuals younger than the age of two or older than the age of 34 the number of other medical conditions that may present with symptoms similar to asthma increases. The project took place from 2001-2012.

Asthma mortality rates in Michigan are slightly higher than the United State’s rate for all age groups except among adults 65 years or older. Overall asthma mortality rates in Michigan did not change significantly between 1990 and 2002 with the exception of people ages 65 and older. Asthma mortality rates in this age group dropped significantly between 1990 and 2002, with the largest reduction in rates occurring between 1998 and 1999. The mortality rate in Michigan for asthma in African-Americans of all ages (48.5 per million) was over four times that of Caucasians (11.5 per million). This racial difference in asthma mortality rates was even greater in the 5-34 year old age group (African-American vs. Caucasian, 17.5 vs. 1.8/1,000,000, ages 5-14 and 24.2 vs. 4.0/1,000,000, ages 15-34).

Next-of-kin of the deceased are interviewed and medical records, medical examiner's reports, and pharmacy records are reviewed. A two-page summary of the information is written and presented to a review panel consisting of allergists, asthma educators, emergency department physicians, family practitioners, internists, nurses, pediatricians, pharmacists, pulmonologists, respiratory technicians and social workers. There are separate panels to review the adults and children deaths. The findings from these investigations are shared with health care providers, public health personnel, health educators, and medical administrators.

The primary causal factor identified in the first two years of investigation was the lack of compliance by patients with good asthma management including regular use of inhaled steroids rather than dependence on ß agonists and elimination of asthma triggers such as cigarette smoke and pets. Some of the deficiencies noted in asthma management were from inadequate prescription of inhaled steroids particularly in emergency departments. The low percentage of asthmatics with asthma management plans (only 9%) would suggest that more can be done by the health care system to encourage patient compliance. Particular recommendations were made for:

  • Case Managers for high risk patients (patients with a Emergency Department visit and/or a hospitalization for asthma).
  • Case Managers for asthmatics with psychiatric conditions and education on asthma for psychiatric health care providers.
  • Pharmacy notification to doctors for patients who repeatedly fill ß agonist prescriptions or possibly placing a limitation on the number of refills allowed.
  • Provision of more comprehensive asthma care in Emergency Department – Education and inhaled steroids.
  • Referral to specialists for patients with a hospitalization and/or Emergency Department visit for asthma.
  • Need for health insurance for asthmatics, (more of a problem in adults than children).

     

(to top)

Past Surveillance Initiative:


Farm Asthma

Michigan State University completed a 5-year project from 2001-2006 to study asthma in farmers and their family members.

A consensus document on Respiratory Health Hazards in Agriculture was published by the American Thoracic Society. One of the conclusions of the document is that “Agents in the agricultural environment clearly aggravate and may cause asthma”. Table I shows a list of known allergens related to farming. In addition, there are a number of chemicals used on farms which have been associated with the form of asthma which occurs after an acute spill or leak without a latency period of exposure, Reactive Airways Dysfunction Syndrome (RADS). Substances reported to cause RADS include anhydrous ammonia used as a fertilizer, the herbicide Metam, disinfectants, and cleaners containing acids, ammonia, chlorine and glutaraldehyde. 

 

Table I. Known Allergens Related to Farming

Plant

   Grain dust (all types of grain)

 

Animal

   Grain mites

   Grain weevil

   Cow dander

   Cow urine

   Pig dander

   Pig urine

 

Poultry dander

Poultry mites

Egg yolk proteins

Meal worm

Fungi

 (Alternaria, Aspergillus, Cladosporium)

Chemicals

   Antibiotics used in feed

      (spiramycin, amprolium)

   Formaldehyde

   Glutaraldehyde

 

 



There is limited data on the frequency of occurrence of asthma among farmers and even less information on the percentage of asthma in farmers which is work related.

Asthma from farmers becoming allergic to cow dander is the most common cause of work-related asthma in Finland. The highest risk for asthma in the European Community Respiratory Health Survey was for farmers. In France, asthma prevalence was reported to be increased among farmers; in New Zealand, wheezing and airway hyperresponsiveness was significantly increased in farmers; in Canada, grain farming was a significant risk factor for asthma, in Norway, farmers in animal production had an increased prevalence of asthma; in the United States, wheezing was associated with pesticide use by farmers; and in Sweden, farmers were reported to have increased mortality from asthma.

On the other hand there have been an increasing number of articles on the “Hygiene Hypothesis” of asthma suggesting a lower prevalence of asthma among individuals brought up on a farm particularly those exposed to animals. A possible explanation for a decreased risk of asthma in the farming population would be that children exposed to the varied blend of irritant, allergic and infectious agents on a farm will have promotion of TH1 type T helper cells as opposed to Th2 type helper cells, the latter type cells which are associated with allergic and asthmatic conditions. A number of recent studies have reported a reduced prevalence of asthma or atopy in children brought up on a farm. Since children brought up on farms are the primary labor pool for future farmers, this would lead to a reduced incidence of asthma among farmers.

The specific aims of the MSU project were:

A.1 To estimate the prevalence of asthma in the adult farm population that was farm-related.

A.2 To estimate the proportion of farm-related asthma in the farm population that occured after a latency period from onset of exposure, that occured without a latency period from onset of exposure [Reactive Airways Dysfunction Syndrome (RADS)], or that occured from aggravation of pre-existing asthma.

A.3 To determine how the estimated proportion of types of farm-related asthma and incidence of farm-related asthma changes when the subjects with asthma have objective testing to confirm both the diagnosis of asthma and farm-related asthma.

A.4 To determine how the proportion and incidence generated from active case ascertainment differs from the ongoing more passive case ascertainment of the Sentinel Event Notification System for Occupational Risks (SENSOR) surveillance system.

 (to top)