Epidemiology: a problem-solving journey.

As a scientific discipline, epidemiology has helped liberate the practice of public health and medicine from dogmatic thinking over the past century. This commentary highlights some integrating principles to explain why epidemiology is a problem-solving discipline. The first of these is that epidemiology is an information science. Epidemiology generates information for decision-making at all levels of the health-care system, including information for both individuals and the general public. Although all scientific disciplines produce data that may be used for decision-making, there is more immediacy for the decisions in epidemiology. The second principle is that epidemiology operates within an environment of complex systems. Etiologic factors operate in complex systems, and the use of a systems analysis approach in investigating health problems must be considered. The third principle is that epidemiology is not just a scientific discipline but a professional practice area as well. Epidemiology has a solid disciplinary scientific base, and its practice requires well-grounded academic preparation. Its objectives are very much within the public-social domain, and a well-defined, outcome-oriented, prevention-based philosophy steers its practice. In a number of universities, epidemiology is taught today as a research discipline rather than as an operational, problem-solving one. In conclusion, this commentary emphasizes the need to accept the fact that epidemiology has as much of a social role as a scientific one. Public health action, problem solving, and a sense of mission are what brings many students to epidemiology. A problem-solving, action-oriented epidemiology is consistent with that sense of mission.