Reliability and validity of an asthma questionnaire for healthcare workers.
Delclos-GL; Arii-A; Aday-LA; Bartholomew-K; Carson-A; Lai-D; Lusk-C; Stock-T; Symanski-E; Whitehead-LW
Working Partnerships: Applying Research to Practice, NORA Symposium 2003, June 23-24, 2003, Arlington, Virginia. Washington, DC: National Institute for Occupational Safety and Health, 2003 Jun; :128-129
Background: Attention has focused on respiratory hazards among healthcare workers (HCWs), partly because of reports of asthma linked to latex, glutaraldehyde and other airborne exposures in hospital settings. Our group is conducting a study to develop, validate and field test a new survey instrument for work-related asthma in HCWs (Phase I) that will then be streamlined for use in a population-based survey (Phase II) of occupational exposures and asthma in healthcare settings. The Phase I questionnaire was designed to be completed in under 30 minutes and consisted of four general sections: asthma symptoms (12 questions, with subquestions); nonoccupational exposures and family history (9 questions), job exposure history (focused on current and longest held jobs); and demographics (8 questions). Initial results are presented on validation of the asthma section of the questionnaire. Questions on asthma were originally derived from the IUATLD questionnaire, supplemented with additional items in consultation with pulmonary, occupational health and survey design experts. After pretesting in a small pilot study, a cross-sectional study was conducted in a convenience sample of 102 nonsmoking, employed HCWs (with and without asthma). Participants completed the questionnaire, a methacholine bronchial challenge test, a detailed interview with an industrial hygienist and provided a blood sample for measurement of specific IgE antibodies to common aeroallergens. Two weeks later, they completed and returned a second questionnaire containing selected items from the original questionnaire, to assess test-retest reliability (% agreement between the two questionnaires). Lacking a universal "gold standard" for asthma for use in epidemiology studies, the questions on asthma were validated against two frequently used measures, methacholine PC20 and a previous physician diagnosis of asthma (MD asthma). Performance of these questions was also compared to that of a 5-question discriminant function predictor (DFP), previously validated by Burney et al (1). Results: Time to completion of the questionnaire ranged from 13 to 25 minutes. Internal consistency for respiratory symptoms (Cronbach alpha=0.86) and allergic symptoms when near animals or trees (Cronbach alpha=0.86) was excellent. Test-retest reliability of questionnaire items related to asthma-like symptoms ranged from 78% to 94%. Based on analysis of receiver operating curve characteristics, a subset of 8 questions was identified (related to wheezing, difficulty breathing, nocturnal symptoms, and symptoms near animals, feathers or trees) that offered the best combination of sensitivity and specificity, while retaining good internal consistency (Cronbach alpha=0.75). Conclusions: Initial evaluation of the asthma section of this questionnaire indicates good validity and reliability for the 8-question predictor, in preparation for further field testing and cross-validation in the Phase II population based survey.
Questionnaires; Bronchial-asthma; Health-care-personnel; Epidemiology; Occupational-exposure; Exposure-assessment; Allergies; Dusts; Dust-particles; Dust-exposure; Statistical-analysis; Respiratory-system-disorders; Pulmonary-system-disorders
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
Working Partnerships: Applying Research to Practice, NORA Symposium 2003, June 23-24, 2003, Arlington, Virginia
University of Texas Health Science Center, Houston