Fig. 1. (A ) Ecology of care, with the site of U.S. healthcare utilization for each 1,000 persons in the year 2000. Reprinted with permission from Green LA, Fryer GE Jr, Yawn BP, Lanier D, Dovey SM: The ecology of medical care revisited. N Engl J Med 2001; 344:2021–5. (B ) Analogous spatial distribution of U.S. surgical care, with different types of surgical sites reflecting different strata (not to scale) of patient acuity and surgical complexity. Reprinted with permission from Orkin FK, Longnecker DE. Anesthesia risk, Anesthesiology (edited by Longnecker DE, Brown DL, Newman MF, Zapol WM). New York, McGraw-Hill, 2008.