Occupational asthma is common, yet little is known about long-term outcomes in the United States. A case series of 55 (of 72) occupational asthma patients were interviewed in follow-up 31 (± 15) months after removal from the cause to evaluate asthma severity and employment outcomes. Standard criteria were used to rate severity. At follow-up, 54 subjects (98%) had active asthma, of which 26 cases (47%) were "severe." Multivariate analysis showed increased risk of "severe" asthma for women (odds ratio [OR]= 13.8; 95% confidence interval [95% CI] = 1.3 to 151.7) and industrial sector workers (OR = 11.9; 95% CI = 1.3 to 109.8). Thirty-eight subjects(69%) were unemployed, risk being greater for those with "severe" asthma (OR= 20.9; 95% CI = 1.9 to 229.8) and for those without a college degree(OR = 7.3; 95% CI = 1.2 to 43.4). These results indicate that occupational asthma is disabling and probably irreversible for most patients referred to a specialty clinic, despite prolonged removal from causative agents. Women, industrial workers, and those with severe asthma or lack of a college degree appear to be at risk for worse outcomes. Greater efforts at primary and secondary prevention should lessen the burden of long-term illness and unemployment due to occupational asthma.
From the Occupational Health Program, Department of Environmental Health, Harvard School of Public Health, Boston, Mass. (Dr Gassert, Dr Hu, Dr Kelsey, Dr Christiani); the Center for Occupational and Environmental Medicine, Massachusetts Respiratory Hospital, Braintree, Mass. (Dr Gassert, Dr Hu, Dr Kelsey, Dr Christiani); and the Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.(Dr Hu, Dr Kelsey).
Address correspondence to: Thomas H. Gassert, MD, MSc, Occupational Health Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115.