1. Etzioni DA, Liu JH, O’Connel JB et al (2003) Elderly patients in surgical workloads: a population-based analysis. Am Surg 69:961–965
2. Liu JH, Etzioni DA, O’Connel JB et al (2004) The increasing workload of general surgery. Arch Surg 139:423–428
3. Hobbs F, Stoops N (2002) Demographic trends in the 20th century: census 2000 special report. US Dept of Commerce, Economics and Statistics Administration, US Census Bureau, Washington DC
4. Hall MJ, DeFrances C, Williams SN et al (2010) National Hospital Discharge Survey: 2007. Naz Health Stat Rep 29:1–20
5. NCEPOD (2010) National Confidential Enquiry into Patient Outcome and death. Elective and emergency surgery in the elderly: an age old problem. London.
http://www.ncepod.org.uk/2010eese.html