Exposure assessment for fespiratory sensitizers and irritants: expert assessment versus subject assessment of exposure based on telephone questionnaire responses in an HMO-based study of occupational asthma.
Hunt-P; Herrick-R; Marx-A; Sama-S; Milton-D; Hallock-M; Pechter-E; Boylstein-R; Dieffenbach-A
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :37
Occupational exposures to respiratory sensitizers and irritants were assessed based on telephone questionnaire responses in an ongoing case-control study of adult onset asthma. An expert panel of six industrial hygienists evaluated exposures using text descriptions of job title, industry, job tasks, tools and chemicals used, and workplace conditions elicited in open-ended questions during the telephone interview. Job descriptions were elicited for jobs held in the past year only, minimizing bias due to subject recall. Six hundred eleven jobs held by 93 cases and 372 controls were evaluated. Each job description was evaluated by two experts for three sub-scores (probability, intensity, and frequency of exposure) and an overall exposure score on a three-point scale (0 - none, low; 1 - moderate; 2 - high). Exposure prevalence across all jobs was 16% to 29% for sensitizers and 15% to 33% for irritants using strict and lenient exposure definitions, respectively. Agreement on the three- point scale among the experts was moderate, with weighted kappa's for main and sub-scores ranging from 0.40 to 0.55. For dichotomized exposure measures simple kappa's ranged from 0.37 to 0.58. Agreement on positive exposure ranged from 40% to 75% using strict and lenient definitions; agreement on unexposed ranged from 75% to 95%. Subject assessment of exposure was measured with questions on the presence, intensity, and frequency of exposure to "dusts" and "gas or chemical fumes." Agreement between experts and subjects was poor, with kappa's ranging from 0.0 to 0.20. Subjects' assessment of dust exposure greatly over-estimated sensitizer and irritant exposure (Sensitivity: 0.75 to 0.78; specificity: 0.30 to 0.32). Subject assessment of chemical exposure and dust exposure based on secondary question responses (e.g., expo- sure intensity) showed improved specificity, but agreement with experts was still poor. Agreement among experts and subjects was generally better for cases.
Irritants; Occupational-diseases; Occupational-exposure; Exposure-levels; Workplace-monitoring; Dusts; Fumes
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California