An examination of surgical trends before the National Emphysema Treatment trial (NETT) demonstrates the importance of nonclinical determinants of care. The number of lung volume reduction surgery (LVRS) claims increased dramatically after 1994 despite the fact that there was considerable uncertainty in the available literature.1 Favorable media reports and testimonials from patient advocacy groups influenced both patient and surgeon attitudes about LVRS.2 Some surgeons felt that investigations prior to the NETT demonstrated clear and dramatic improvements in quality of life sufficient to justify Medicare reimbursement for the procedure.3 Accordingly, they believed the NETT was a form of coercion because patients who refused to enroll in the study would not have financial coverage of their LVRS or receive the operation from a NETT surgeon. Furthermore, even if patients enrolled, the study deprived half of them of a procedure with “established” benefits. Surgeons less comfortable with this level of scientific uncertainty may have decided against performing the procedure. Nonsurgeon observers proposed that surgeons were motivated by financial gains, as the procedure was relatively inexpensive and reimbursement was generous.2 In addition to potential patient and surgeon influences, third-party coverage had an effect on decision making as evidenced by a dramatic decrease in the number of operations upon suspension of Medicare reimbursement in December 1995.4 Because many third-party payers based their coverage plans on Centers for Medicare and Medicaid Services (CMS) guidelines, this policy likely affected many non-Medicare patients and providers as well. Whether surgeons stopped performing the operation because of lack of reimbursement or as an acknowledgement of scientific uncertainty is unclear. It is clear, however, that the sharp decline in the number of procedures was temporally related to CMS intervention. Subsequent CMS policy partly limited surgical decision-making because reimbursement was limited to eligible patients and surgeons.