Objective: To evaluate methods for determining excessive short-term decline in forced expiratory volume in one second (FEV1) in diacetyl-exposed workers.
Methods: We evaluated five methods of determining excessive longitudinal FEV1 decline in diacetyl-exposed workers and workers from a comparative cohort: American Thoracic Society (ATS), ACOEM an 8% limit, and a relative and absolute longitudinal limit on the basis of spirometry data variability. Relative risk and incidence of excess decline were evaluated.
Results: Incidence of excessive FEV1 decline was 1% in the comparative cohort using ATS and ACOEM criteria, 4.1% using relative limit of longitudinal decline, 4.4% with absolute longitudinal limit of decline, and 5.6% by using the 8% limit. Relative risk of abnormal FEV1 decline in diacetyl-exposed workers was elevated in all evaluated methods.
Conclusion: Alternative methods for respiratory surveillance in diacetyl-exposed workers may be preferable to ATS or ACOEM.