Hypersensitivity Pneumonitis in Workers Exposed to Metalworking Fluids

BACKGROUND: This study used data from a large UK outbreak investigation, to develop and validate a new case definition for hypersensitivity pneumonitis due to metalworking fluid exposure (MWF-HP). METHODS: The clinical data from all workers with suspected MWF-HP were reviewed by an experienced panel of clinicians. A new MWF-HP Score was then developed to match the “gold standard” clinical opinion as closely as possible, using standard diagnostic criteria that were relatively weighted by their positive predictive value. RESULTS: The new case definition was reproducible, and agreed with expert panel opinion in 30/37 cases. This level of agreement was greater than with any of the three previously utilized case definitions (agreement in 16–24 cases). Where it was possible to calculate, the MWF-HP Score also performed well when applied to 50 unrelated MWF-HP cases. CONCLUSIONS: The MWF-HP Score offers a new case definition for use in future outbreaks. Am. J. Ind. Med. 57:872–880, 2014. © 2014 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc.