S1 Evidence-based case definition for EAA due to metalworking fluid exposure

Introduction and objectivesAlthough a number of case definitions for MWF EAA have been used in previous outbreaks, none has emerged as an evidence-based standard. This study used data from a large UK MWF outbreak investigation, to develop and validate a new case definition for MWF EAA.MethodsDemographic and clinical data from the 37 workers with suspected EAA during a large outbreak were reviewed by an Expert Panel. A new case definition for MWF EAA was developed using significant differences between workers with and without definite clinical EAA. This MWF EAA Score was modelled to match Expert Panel opinion as closely as possible, and used clinical criteria relatively weighted by their positive predictive value for EAA in the outbreak. The performance of the new scoring system was compared with other existing case definitions, and applied to 50 cases of MWF-EAA from nine published US outbreaks.ResultsThe MWF EAA Score is shown in Abstract S1 table 1, where the highest score is applied in each section. A score of >26 represents definite EAA, 19–26 possible EAA, and