Emergency department visits: the cost of trauma centers.

Crowded emergency departments (EDs) have become a serious problem in the current U.S. healthcare system. Patient wait times and periods of ED diversion have increased, raising concerns about the timeliness, efficiency, and quality of ED treatment. This study addresses the question of whether there are economies of scale (EOS) in ED care, and the extent to which such economies vary across different types of EDs. A hospital cost function approach is taken to evaluate average and marginal costs of EDs designated as trauma centers. Data comes from acute care hospitals in Texas for the period 1998-2004. Cost functions corresponding to four different levels of ED trauma care are estimated using a translog panel data model with hospital fixed effects. The marginal costs (in 2004 dollars) of each trauma center level are: $53 (Level I), $177 (Level II), $119 (Level III), and $258 (Level IV). Average cost per ED visit for trauma centers exceeds marginal cost at all Levels, indicating the presence of EOS. The results support a possible expansion of ED size policy in order to improve the cost efficiency of ED services.