Reference

Tarlo SM, Liss G, Corey P et al, A workers' compensation claim population for occupational asthma. Comparison of subgroups, Chest, 1995;107:634-641,

BOHRF Original Authors' Main Conclusions

The original authors' main conclusions are taken from Abstract, Results and Discussion. They are decided upon by the authors of the BOHRF occupational asthma guidelines and form part of the guidelines.

Retrospective study of 609 claims submitted to Ontario Workers Compensation Board (WCB, 1984-1988). Study to assess determinants of outcome of WCB accepted claims at permanent disability assessments. The WCB decision reached was occupational asthma in 39% of claims (57% of these attributed to isocyanates). A further 39% were accepted for aggravation of asthma from irritant exposures (AA). Exposure to a known sensitiser occurred in 91% with occupational asthma and to an irritant in 67% with AA. Of 200 occupational asthma accepted claims reviewed at a mean of 1.9 years later, clearing of asthma occurred in 19% and milder asthma in 47%. At follow-up 54% were unemployed. Outcome was best with early diagnosis and milder impairment of pulmonary function at initial assessment.

BOHRF Associated Evidence Statements

The BOHRF occupational asthma guidelines state that this reference is associated with the following evidence statements

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2+

The symptoms and functional impairment of occupational asthma caused by various agents may persist for many years after avoidance of further exposure to the causative agent.

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The likelihood of improvement or resolution of symptoms or of preventing deterioration is greater in workers who have relatively normal lung function at the time of diagnosis.

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The likelihood of improvement or resolution of symptoms or of preventing deterioration is greater in workers who have shorter duration of symptoms prior to diagnosis.