Validation of self-reported occupational exposures in meatpacking workers

Objective: The ability of workers to accurately recall exposures that occur on the day of their injury is considered a potential limitation of case-crossover studies. This study assessed validity of occupational exposures reported by uninjured workers at a Midwestern meatpacking plant.

Methods: 136 workers were observed while working for 60 minutes and subsequently interviewed (within 8 days) about exposures during the observation period. Self-reported exposures were cross-tabulated with observation records using kappas to assess the level of agreement between self-reports and direct observations for binary exposures and intraclass correlation coefficients for continuous exposures.

Results: Excellent agreement was found between observed and reported work location (κ=0.97, 95% CI: 0.92-1.0), task (κ=0.83, 95% CI: 0.76-0.91), and tools (κ=0.88, 95% CI: 0.81-0.95). Personal protective equipment varied by work type and location and agreement between observed and reported usage varied from excellent to poor for various items. Excellent agreement was found for tool sharpening (κ=0.89, 95% CI: 0.82-0.97); good agreement for occurrence of break during the observation period (κ=0.60, 95% CI: 0.45-0.74); and poor agreement for the equipment malfunction, line stoppages, being tired, unusual task, unusual work method, being distracted, rushing, slipping, or falling.

Conclusions: Since self-reported exposures are utilized in many occupational injury studies, future exposure validity assessment studies should continue to improve methodology. Valid exposures will allow researchers to better understand injury etiology and ultimately prevent injuries from occurring.