The etiology of epidemiologic perseveration: when enough is enough.

The inspiration to undertake epidemiologic research comes from many sources, but little has been written about when it is time to quit pursuing a given topic. Perseveration of research beyond that point may result from: (1) hope that our intuition about risks and benefits can be proven empirically correct, despite repeated failures, (2) ideological commitment to public health policy for which epidemiologic corroboration is desirable but not forthcoming, (3) biologically compelling pathways with epidemiologic implications that cannot be confirmed, (4) topics with low quality or contradictory epidemiologic findings that are not worthy of the refinement in research methods necessary for a resolution, (5) continuation past the point at which the best methods that epidemiology can offer on a topic fail to provide a satisfactory resolution, and (6) opportunism driven by the availability of research funds for unproductive activities. To more optimally allocate our efforts, we would benefit from a steadfast focus on the goal of advancing science and public health. We should draw on outside evaluators to judge the merits of continued investigation, anticipate the need to explain succinctly in future publications how this work represents an advancement on a worthy topic, and acknowledge openly when we have come to an impasse.