Epidemiology and public health: Is a new paradigm needed or a new ethic?

Public health militancy has been increasingly frustrated by what many perceive as the marginally fertile studies of risk factors operating at the individual level, whose causal underpinnings are often and inevitably weakened in multifactorial situations. As a remedy, leading advocates propose a refocusing of epidemiology and public health on socioeconomic, cultural, and political studies, and on broad interventions at population level. This new "paradigm" would be aided by a relaxation of evidentiary standards of causality, away from scientific criteria and more toward dialectic (rhetorical) precepts derived in a humanistic and sociologic tradition. It is countered here that such proposals would further reduce the objectivity and thus likely weaken rather than strengthen epidemiology and the justification of public health action. Instead, a realistic appraisal finds that multifactorial epidemiology raises warning signals of varying influence, and that the usefulness of epidemiology and public health could be enhanced by conceiving of methods to score the relative strength and priority of such warnings. (C) 1998 Elsevier Science Inc.