1. Kaufman DW, Kelly JP, Rosenberg L, et al. Recent patterns of medication use in the ambulatory adult population of the U.S.: the Slone survey. JAMA 2002;287:337–344.
2. Lidell E, Luepker R, Baigi A, Lagiou A, Hildingh C. Medication usage among young adult women: a comparison between Sweden, the USA, and Greece. Nurs Health Sci 2008;10:4–10.
3. IMS Health, Inc. Global pharmaceutical sales by region, 2007. Available from: http://www.imshealth.com . Accessed July 2008.
4. Nutrition Business Journal. NBJ’s supplement business report 2007: an analysis of markets, trends, competition and strategy in the U.S. dietary supplement industry. October 2007. Available from: http://www.nbj.stores.yahoo.net/nbjsubure20.html . Accessed July 2008.
5. Centers for Medicare & Medicaid Services, Office of the Actuary. National health expenditure projections. Available from: http://www.cms.hhs.gov/NationalHealthExpendData/Downloads/proj2007.pdf . Accessed July 2008.