Regional differences in EpiPen prescriptions in the United States: The potential role of vitamin D
Received 5 September 2006; received in revised form 26 March 2007; accepted 26 March 2007. published online 13 June 2007.
Background
The epidemiology of anaphylaxis is uncertain, especially its geographic distribution.
Objective
To address this deficit, we examined regional rates of EpiPen prescriptions in the United States.
Methods
EpiPen prescriptions in 2004 were obtained for all 50 states and Washington, DC, from NDCHealth, Pharmaceutical Audit Suite (Alpharetta, Ga). Data included the number of total filled prescriptions, including refills, and the actual number of EpiPens prescribed. Several data sets were used to obtain state-specific populations, as well as multiple demographic, health, and weather characteristics. State population was used to calculate the average number of prescriptions written per person.
Results
Overall, there were 1,511,534 EpiPen prescriptions filled during 2004. These prescriptions accounted for 2,495,188 EpiPens. On average, there were 5.71 EpiPens prescribed per 1000 persons. Massachusetts had the highest number of prescriptions per 1000 persons (11.8), whereas Hawaii had the lowest (2.7). In addition to state-to-state variation, there was an obvious regional difference: New England (Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, Maine) had the highest values, with 8 to 12 EpiPen prescriptions per 1000 persons, whereas the southern states (between and including California and Mississippi) had only 3 prescriptions per 1000 persons. The New England finding persisted even when controlling for all available factors (eg, population demographic characteristics, number of health care providers, prescriptions for other medications).
Conclusion
A strong north-south gradient was observed for the prescription of EpiPens in the United States, with the highest rates found in New England.
Clinical implications
The regional differences in EpiPen prescribing may provide important etiologic clues (vitamin D status) and merit further investigation.
Boston, Mass, Los Angeles, Calif, Memphis, Tenn, and Baltimore, Md
aFrom the Center for D-receptor Activation Research
bDepartment of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston
cDepartment of Allergy, Kaiser Permanente, Los Angeles
dUniversity of Tennessee College of Medicine, Memphis
eDivision of Pediatric Allergy and Immunology, Department of Pediatrics, Johns Hopkins Medical Center, Baltimore
Reprint requests: Carlos A. Camargo, Jr, MD, DrPH, EMNet Coordinating Center, Massachusetts General Hospital, 326 Cambridge Street, Suite 410, Boston, MA 02114.
The NDCHealth prescription data were purchased by Dey (Napa, Calif).
Disclosure of potential conflict of interest: C. A. Camargo, Jr, has consulting arrangements with Dey and has received grant support from Dey and Verus. M. S. Kaplan has consulting arrangements with Dey and the EpiPen Advisory Committee and has received grant support from Genentech and the Childhood Asthma Research and Education Network. P. Lieberman has consulting arrangements with Dey and Verus; is on the speakers' bureau for Dey, Verus, Sanofi-Aventis, Genentech, Medpointe, and GlaxoSmithKline; and has served as an expert witness for Medpointe. R. A. Wood has consulting arrangements with Dey and has received grant support from Merck and Genentech. The rest of the authors have declared that they have no conflict of interest.
ABSTRACT