Abstract
To prevent workplace injuries, epidemiologic research must continue to progress beyond methods originally used for acute or chronic diseases. For injury research, exposure assessment requires increased sophistication because exposures comprise multiple, transient factors and complex work activities. Frequently reported risk factors such as age, gender, seniority, or prior injury are often confounders or effect-modifiers of unknown exposures. Injury rate calculations across nominal categories, e.g., department or job classification, identify where hazards are concentrated but provide little insight into their nature; injury counts often perform almost as well. Calculation of rates in relation to time actually spent in plausible etiologic exposure conditions usually is not feasible. Generalization of the Haddon approach for individual injury events to systematically analyze injury case series can identify both the mechanism of injury and the relative occurrences of high-risk conditions. In some contexts, case-crossover designs may elucidate injury causation. National databases and information systems of employers, insurers, and equipment suppliers could contribute case series for injury hazard identification. Byenhancing exposure assessment through a focus on case series, epidemiologic research can expand its contribution to preventing workplace injuries.