Study concept and design: Ioannides, Hennessy, Scott.
Acquisition, analysis, or interpretation of data: Ioannides, Shofer, Small, Hennessy, Abella, Scott.
Drafting of the manuscript: Ioannides, Mamtani, Scott.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Ioannides, Shofer, Small.
Administrative, technical, or material support: Small, Abella, Scott.
Study supervision: Mamtani, Abella, Scott.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Abella reported receiving grants from the National Heart, Lung, and Blood Institute, Philips Healthcare, Medtronic Foundation, and Stryker Medical; and receiving other (honoraria, stock ownership, serving on advisory boards, or serving as a consultant) from Velomedix Corp, HeartSine Corp, Ikaria Inc, Resuscor, Bard, and Stryker Medical. No other disclosures were reported.
Funding/Support: The Department of Emergency Medicine, University of Pennsylvania, provided funding for this study.
Role of the Funder/Sponsor: The Department of Emergency Medicine, University of Pennsylvania, had no role in the design and conduct of the study; had a role in the collection, management, analysis, and interpretation of the data; had no role in the preparation, review, or approval of the manuscript; and had no role in the decision to submit the manuscript for publication.
Previous Presentations: A preliminary version of these data were presented in part at a pharmacoepidemiology rounds on April 17, 2015, at the University of Pennsylvania and at an internal research-in-progress meeting on April 29, 2015.
Additional Contributions: We thank the following individuals at the University of Pennsylvania for their contributions without compensation: Carmen Farrow, MS, MBA, for special data analysis and technical assistance with EMR databases; Ari B. Friedman, PhD, for analysis and operational feedback; Jennifer R. Kogan, MD, for advising and providing feedback; and Elizabeth D. Lowenthal, MD, MSCE, and Iris M. Reyes, MD, for advising and providing assistance with the protocol.