Design and validation of a questionnaire for asbestos exposure for clinical practice

Introduction: Exposure’s knowledge is fundamental for diagnosing asbestos related diseases, but it is often difficult to determine in clinical practice. The objective of this study was to design a short, valid and reliable questionnaire to determine such exposure. Methods: A multidisciplinary expert committee designed a short questionnaire (7 questions, 2 annexes), covering occupational, domestic and environmental asbestos exposure. It was administered to a sample of patients, with and without asbestos disease, on 2 occasions with an interval of 2-3 weeks. The 2 interviewers were not aware of the patient’s illness. We evaluated: applicability and comprehensibility; validity of content (according to expert committee criteria) and construct (using validity analysis techniques for known groups, by contrast of hypotheses); test-retest and interobserver reliability using Cohen’s Kappa coefficients (κ) (acceptable if κ> 0.31, considerable if κ> 0.61). Results: Validation was performed in 90 patients, mostly men (88.9%), with a mean age of 70.8 years old (SD=8.4), 47.8% had asbestos disease. The experts and users considered the questionnaire understandable and viable (mean time of administration of 9’25’’). Validity of content was considered appropriate according to the experts’ criteria, the conceptual framework and the ability to detect different areas of exposure. 5 hypotheses were contrasted and confirmed. κ values were κ=0.93 and κ=0.50 for test-retest and interobserver reliability, respectively. Conclusions: The designed questionnaire can be considered understandable and viable according to experts and users, as well as valid and reliable for the detection of exposure to asbestos in clinical practice.