Three basic principles for improving epidemiology: an industry view.

Three principles are presented that will improve the quality of epidemiologic studies now being done. These principles are: (1) that outcome foreknowledge should be disclosed and discussed; (2) that key data in the study should be well understood to include what influences it and its inherent variability; and (3) that detailed exposure characterization, whether it be occupational or personal risk factors, should be an integral part of all studies. The quality of epidemiologic studies resides in meticulous planning and execution, because not considering important confounders or poorly measuring an effect can mask or magnify associations.