Injury classification agreement in linked Bureau of Labor Statistics and Workers' Compensation data

BACKGROUND Estimates of select occupational injuries and illnesses often differ across data sources. We explored agreement in injury classifications and the impact of differences on case estimates among records reported to multiple data sources. METHODS We linked cases reported in the Bureau of Labor Statistics (BLS) annual Survey of Occupational Injuries and Illnesses (SOII) to Washington State workers' compensation (WC) claims and evaluated agreement in injury characteristics coded in each data source according to the same occupational injury and illness classification system. RESULTS Agreement between data sources was greatest for body part and lowest for event or exposure. Agreement on nature of injury varied by condition. WC-assigned injury codes estimated 94% more amputations than SOII-assigned codes while SOII-assigned codes estimated 34% more work-related MSD cases. CONCLUSIONS Accounting for classification differences may improve case ascertainment within individual data sources and help align injury and illness estimates derived from different data sources.