An Evaluation of Employer-Reported Data in the Nation’s Occupational Injury Surveillance System

The Bureau of Labor Statistics’ (BLS) Survey of Occupational Injuries and Illnesses (SOII) is a key source of occupational injury surveillance data, providing both national and state-level estimates of work-related injuries and illnesses. While there is growing evidence that employers underreport injuries in SOII, there is little consensus about the magnitude of underreporting. Moreover, little empirical data exist to explain the reasons for underreporting. By linking SOII injury case data to Washington State workers’ compensation claims data, this study estimated the number of unreported workers’ compensation claims, identified establishment characteristics associated with unreported claims, and assessed the impact of injury classification differences on case estimates. Occupational injury and illness record-keepers were interviewed to explore record-keeping and business practices that may explain SOII’s incomplete case capture. An estimated 70% of Washington State workers’ compensation claims were captured in SOII. Claims among state and local government establishments were most likely to be reported. Unreported claims were more than twice as prevalent among small education services establishments and large construction establishments compared to large manufacturing establishments. Workers’ compensation-assigned injury codes estimated 94% more amputations than SOII-assigned codes while SOII-assigned codes estimated 34% more cases of work-related musculoskeletal disorders. Among interviewed participants, record-keeping noncompliance was wide-spread and did not differ by underreporting. Other factors including using workplace injury data to evaluate supervisors’ or SOII respondent’s job performance, recording injuries for a worksite that operates multiple shifts, and failing to follow SOII instructions were more common among establishments with unreported workers’ compensation claims. Underreporting of workers’ compensation claims to SOII varies by establishment characteristics, obscuring true differences in work injury incidence and hindering the use of SOII to identify and prioritize groups at greatest risk of occupational injury and illness. Increased education and outreach to help participants comply with recordkeeping requirements may improve the accuracy of SOII data, but business practices that incentivize low injury rates will continue to confound establishment-based injury data. Surveillance efforts should explore the development and use of alternate data sources including healthcare and worker-based data to better understand the true burden of occupational injuries and illnesses.