1. Centers for Disease Control and Prevention 2013 http://www.cdc.gov/brfss/about/index.htm
2. Arthritis: its prevalence, risk factors, and association with cardiovascular diseases in the United States, 1999 to 2008;Ong;Ann Epidemiol,2013
3. Centers for Disease Control and Prevention 2013 http://www.cdc.gov/nchs/nhanes.htm
4. Centers for Disease Control and Prevention 2013 http://www.cdc.gov/nchs/nhis.htm
5. Prevalence of doctor-diagnosed arthritis and arthritis-attributable activity limitation: United States, 2010-2012;Barbour;MMWR,2013