ALTERNATIVE APPROACHES TO ANALYTICAL DESIGNS IN OCCUPATIONAL INJURY EPIDEMIOLOGY

In this paper we discuss the theoretical framework upon which observat ional studies of occupational injuries are based. Following a general description of how causal effects are estimated, the challenges faced by researchers working in this area are outlined with an emphasis on c ase-control studies. These challenges include defining the at-risk per iod for workers whose tasks change over time and whose hazard period m ay be very brief evaluating the underreporting of both exposures and i njuries, and considering the effects of multiple injuries per individu al on study design and data analysis. We review both the theoretical a nd practical considerations in the design and conduct of traditional c ase-control studies, based on the collection of individual level data, as well as other approaches, such as using information culled from ad ministrative and descriptive databases, and case-control studies in wh ich the plant or work site is the unit of analysis. The case-crossover design is also reviewed and its utility for reducing confounding due to differences between individuals by self-matching is highlighted. Wh ile this design has not yet been applied to the work setting, its pote ntial for increasing our understanding of the causes of acute-onset oc cupational injuries seems promising. Finally, a variety of hybrid desi gns are discussed, including combinations of case-control, case-crosso ver, and cohort designs. (C) 1997 Wiley-Liss, Inc.