Community Based Study of Adult Onset Asthma

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00005544
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: May 2005
  Purpose

To identify the role of irritant exposure in adult-onset asthma by simultaneously using both clinical and case control methods in a community-based perspective study of asthma incidence.


Condition
Asthma
Lung Diseases

Study Type: Observational
Study Design: Observational Model: Defined Population

Resource links provided by NLM:


Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: February 1999
Estimated Study Completion Date: January 2005
Detailed Description:

BACKGROUND:

Asthma incidence is increasing, and in adults work-related exposures may be an important factor-occupational asthma (OA) incidence increased 70 percent over the last decade according to a recent registry based study. The true contribution of occupational exposures to adult-onset asthma is unknown because the methods for measuring OA give conflicting results. Methods based on surveillance of clinically diagnosed OA account for less than one to five percent of adult-onset asthma. However, case-control methods of measuring asthma risk by industry suggest that six to 33 percent of adult-onset asthma is caused by workplace exposures. The conflict may occur because of two factors: physicians often fail to diagnose and report OA, and irritant exposures may increase the risk the risk of asthma without causing cases that meet the clinical definition. Both factors have important implications for proper treatment and prevention of asthma in adults.

DESIGN NARRATIVE:

Clinical and case control methods were used to identify the role of irritant exposure in adult-onset asthma in a community-based prospective study of asthma incidence. The study cohort was a typical US working population enrolled in an HMO. Additional benefits of the study design were the opportunities to validate a questionnaire for exposure assessment and for detection of work-related asthma. Specifically, the study: 1) Investigated incident cases in a cohort of over 80,000 adults over three years and determined the proportion that met a clinical definition of occupational asthma (OA); 2) Used a nested case-control study to determine the incidence of all asthma by occupation and workplace exposure; 3) Determined whether clinical OA accounted for the excess incidence of adult-onset asthma associated with workplace exposure to sensitizers and irritants; 4) Prospectively followed asthmatics for two years after diagnosis to determine the impact of adult-onset asthma on lung function, employment, income, and quality of life, and to determine whether prognosis differed for clinical OA and for asthma associated with workplace irritant exposure; 5) Tested an intervention designed to increase appropriate clinical diagnosis, and thus secondary prevention of OA.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

No eligibility criteria

  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00005544

Sponsors and Collaborators
Investigators
Investigator: Donald Milton Harvard University School of Public Health
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00005544     History of Changes
Other Study ID Numbers: 5087
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Asthma
Lung Diseases
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Hypersensitivity
Immune System Diseases

ClinicalTrials.gov processed this record on September 16, 2014