1. US Census Bureau Current Population Survey; Annual Social and Economic Supplement, 2011 http://www.census.gov/population/age/data/2011.html
2. US Census Bureau, Population Division Percent Distribution of the Projected Population by Selected Age Groups and Sex for the United States: 2015 to 2060 http://www.census.gov/population/projections/data/national/2012/summarytables.html
3. Centers for Medicare and Medicaid Services (CMS) Online Survey Certification and Reporting (OSCAR) database http://www.cdc.gov/nchs/hus/contents2011.htm#120
4. Centers for Disease Control and Prevention, (CDC), National Health Care Survey (NCHS) 2010 National Ambulatory Medical Care Survey (NAMCS); United States, 2010 http://www.cdc.gov/nchs/dhcs.htm
5. Mental illness surveillance among adults in the United States;Reeves;Morb Mortal Wkly Rep Suppl,2011