====== United States Population ======

As the US [[population]] continues to age, an increasing percentage of neurosurgical patients are elderly. Geriatric populations already account for over 25% of US hospitalizations
((Polanczyk CA, Marcantonio E, Goldman L, Rohde LE, Orav J,
Mangione CM, Lee TH (2001) Impact of age on perioperative
complications and length of stay in patients undergoing noncardiac
surgery. Ann Intern Med 134(8):637–643. https://doi.org/10.7326/
0003-4819-134-8-200104170-00008))
and by 2030, 5% of the US population is predicted to be octogenarians
((Yancik R (2005) Population aging and cancer: a cross-national
concern. Cancer J 11(6):437–441)).
Additionally, the population over the age of 65 is expected to double by 2040
((Wroe PC, Finkelstein JA, Ray GT, Linder JA, Johnson KM, RifasShiman S, Moore MR, Huang SS (2012) Aging population and future burden of pneumococcal pneumonia in the United States. J
Infect Dis 205(10):1589–1592. https://doi.org/10.1093/infdis/
jis240)).