“Expenditures for the Top Five Therapeutic Classes of Outpatient Prescription Drugs, Medicare Beneficiaries, Age 65 and Older, U.S. Civilian Noninstitutionalized Population, 2010,” by Anita Soni and Marc Roemer (Statistical Brief No. 411, May 2013, .pdf and HTML format, 6p.).
meps.ahrq.gov/mepsweb/data_stats/Pub_ProdResults_Details.jsp?pt=Statistical+Brief&opt=2&id=1109
