Author Affiliations: Capital Medical University, Beijing, People's Republic of China, Beijing, China (Dr Y. Wang); and Graduate University of Chinese Academy of Sciences, Beijing (Dr W. Wang) (email@example.com).
To the Editor: The study by Dr Hsia and colleagues1 demonstrated that the number of hospital emergency departments (EDs) in nonrural areas declined by 27% from 1990 to 2009, with for-profit ownership, location in a competitive market, safety-net status, and low profit margin associated with increased risk of ED closure.
The majority (66%) of the 1041 ED closures were due to the closure of an entire hospital that operated an ED. However, the closure of an entire hospital was not entered into the model as a confounding factor. The risk factors identified in the study might be associated with increased risk of hospital closure but not ED closure. In other studies, for-profit ownership was correlated with the closure of rural community hospitals and urban hospitals.2,3 If ED closures due to hospital closure were excluded from the analysis, or the model was adjusted for hospital closure, the factors associated with ED closure might lose statistical significance. Moreover, factors other than for-profit ownership, location in a competitive market, safety-net status, and low profit margin, such as overcrowding, might account for ED closure.4,5
Wang Y, Wang W. Emergency Department Closures in the United States. JAMA. 2011;306(9):929-930. doi:10.1001/jama.2011.1257