Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Graduate School of Business and Public Policy, Naval Postgraduate School, Monterey, California (Dr Shen) (firstname.lastname@example.org); and Department of Emergency Medicine, University of California, San Francisco (Dr Hsia).
In Reply: Dr Soremekun and colleagues are concerned that our analysis cannot take into account the fact that hospitals with high levels of diversion have systemic issues with quality of care and in turn worse outcomes. We believe our methodology adequately addressed this concern. We compared the percent of AMI patients who died within 7, 30, 90, 270, and 365 days when their nearest ED was in normal operation (ie, no exposure to diversion) and when the same ED was exposed to different levels of diversion. Because our comparison was within each ED, we eliminated any inherent differences across EDs, such as possible differences in baseline quality of care that might be confounded with mortality rates. We excluded EDs in which we observed fewer than 3 exposure levels so every ED in our sample was its own matched control.
Shen Y, Hsia RY. Ambulance Diversion and Survival Among Patients With Acute Myocardial Infarction—Reply. JAMA. 2011;306(12):1324-1325. doi:10.1001/jama.2011.1353