maintained? In Rutkow IM (ed). Socioeconomics of Surgery . St. Louis : C.V. Mosby Company, 1989 .
36. Knox RA. Heart transplants: to pay or not to pay . Science 1980 ; 209 : 570-575 .
37. Jones EL. Evolving status of operative versus nonoperative management of coronary arterial obstruction . Cardiovascular Clinics 1987 ; 17 : 73-89 .
38. Showstack JA , Rosenfeld KE , Garnick DW , Luft HS , Schaffarzick RW , Fowles J. Association of volume with outcome of coronary artery bypass graft surgery, scheduled vs. nonscheduled operations . Journal of the American Medical Association 1987 ; 257 : 785-789 .
39. Robinson JC , Garnick DW , McPhee SJ. Market and regulatory influences on the availability of coronary angioplasty and bypass surgery in U.S. hospitals . New England Journal of Medicine 1987 ; 317 : 85-90 .
40. Hannan EL , O'Donnel JF , Kilburn H , et al. Investigation of the relationshipbetween volume and mortality for surgical procedures performed in New York state hospitals . Journal of the American Medical Association 1989 ; 262 : 503-510 , and case abstract data provided by the California Office of Statewide Health Planning and Development .
41. Evans RW.The economics of heart transplantation . Circulation 1987 ; 75 : 63-76 .
42. Renlund DG , Bristow MR , Lybbert MR , O'Connell JB , Gay WA.. New England Journal of Medicine 1987 ; 316(14) : 873-6 .
43. Luft HS. Competition and regulation . Medical Care 1985 ; 23 : 383-400 .
44. Robinson JC , Luft HS. Competition and the cost of hospital care, 1972 to1982 . Journal of the American Medical Association 1987 ; 257 : 3241-3245 .
45. Robinson JC , Luft HS . Competition, regulation, and hospital costs, 1982 to 1986 . Journal of the American Medical Association 1988 ; 260 : 2676-2681 .
46. Schaffarzick RW , Bunker JP. Regionalized surgical health care . In Rutkow IM (ed). Socioeconomics of Surgery . St. Louis : The C.V. Mosby Company, 1989 .
47. Luft HS , Garnick DW , Mark D , McPhee SJ. Volume of services in hospitals or performed by physicians . In U.S. Congress Office of Technology Assessment, The Quality of Medical Care: Information for Consumers, OTA-H-386, Washington, D.C. : US Government Printing Office , 1988 .
48. Hsiao WC , Braun P , Yntema D , Becker ER. Estimating physicians' work for a resource-based relative-value scale . New England Journal of Medicine 1988 ; 319 : 835-841 .
49. Newman D , Evans GT , Scheinman MM. Catheter ablation of cardiac arrhythmias . Current Problems in Cardiology 1989 ; 14 : 117-164.
50. Artz JS , Dinner MI , Sampliner U. Breast reconstruction with a subcutaneoustissue expander followed with a polyurethane-covered silicone breast implant . Annals of Plastic Surgery 1988 ; 20 : 517-521 .
51. Fitzgerald JF , Moore PS , Dittus RS. The care of elderly patients with hip fracture: changes since implementation of the prospective payment system . New England Journal of Medicine 1988 ; 319 : 1392-1397 .
52. Leader S , Moon M. Medicare trends in ambulatory surgery . Health Affairs 1989 ; 158-170 .
53. Kambouris AA. Ambulatory surgery: its impact on general surgical practice . The American Surgeon 1986 ; 52 : 347-350 .