Patterns of visits to hospital-based emergency rooms.

What are the functions of hospital emergency care in our society? How are these functions associated with the characteristics of emergency room users, their environment and with other available medical resources? To answer these questions, an ecological conceptual framework has been developed, along with a procedure which clearly distinguishes between the sources of individual variation (user characteristics) and ecological variation (the users' environment and available medical resources). Four different functions have been identified: (1) care of critical or urgent cases requiring treatment only available in a hospital, (2) care of urgent cases requiring treatment also available elsewhere than in a hospital, (3) care of non-urgent cases requiring treatment only available in a hospital and (4) care of non-urgent cases requiring treatment also available elsewhere than in a hospital. The ecological units selected for this study do not differ statistically with regard to the frequency with which emergency rooms are used for these four functions. However, certain individual factors predicting frequency of utilization do differ depending on the unit; for example, patient health status is not uniformly related to the use of emergency rooms for non-urgent reasons in all units. This association is particularly weak in socio-economically deprived units and more significant at higher socio-economic levels.