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The Roger C. Lipitz Center for Integrated Health Care

Posted date: October 8, 2013

Good Intentions and Unintended Consequences: Policy Challenges of Patient Safety

Lauren Nicholas

            Decades of medical research suggest that patients have better surgical outcomes when they are treated in high-volume hospitals.1,2,3 Researchers and payers have claimed that many lives could be saved if elective surgeries were regionalized to a small number of high-volume centers.  This claim has rarely been tested in practice.  In 2006, the Centers for Medicare and Medicaid Services issued a National Coverage Decision restricting reimbursement for Medicare-covered bariatric surgeries to high-volume hospitals designated as Centers of Excellence (COE).  Hospitals become COEs by meeting structural requirements for morbidly obese patients, reporting data to a registry, and performing a minimum of 125 procedures per year with at least 2 surgeons performing 100 operations over a two-year period. 

            Since the policy change only affected Medicare bariatric surgery patients, it created treatment and control groups that were and were not restricted to high-volume hospitals.  This enabled us to examine the effect of the policy on intended outcomes- measures of patient safety and quality of care, and unintended outcomes, particularly racial disparities and access challenges.  4, 5 

            Surgical outcomes including complications, reoperations, and mortality improved for Medicare patients following the policy change. However, these trends were observed for non-Medicare patients as well, and pre-dated the policy change.  Greater experience with bariatric surgery and increased use of laparoscopic techniques contributed to improved patient safety across settings of care.

Bariatric Surgery Complications

Source: Bariatric Surgery Complications Before vs After Implementation of a National Policy Restricting Coverage to Centers of Excellence, JAMA. 2013;309(8):792-799. doi:10.1001/jama.2013.755.Bariatric Surgery Complications

            When we compared trends in patient outcomes before (January 2004 – March 2006) and after (April 2006 – December 2009) the Medicare National Coverage Decision, we found no statistically significant evidence that the policy restricting Medicare patients to high-volume hospitals was associated with improved outcomes with bariatric surgery. 

            Regionalization policies come at a cost to some patients, who lose access to their closest or preferred hospitals.  Researchers generally assume that these restrictions cause patients to increase distance traveled, but do not influence the overall decision to have surgery.  We found that this was not true for bariatric surgery.  After the coverage decision, racial and ethnic minority patients accounted for a smaller share of Medicare patients, while use increased among non-Medicare minority patients.

National Coverage Decision on Bariatric Surgery

Source: Bariatric Surgery in Minority Patients Before and After Implementation of a Centers of Excellence Program, JAMA. 2013;310(13):1399-1400. doi:10.1001/jama.2013.277915

            Overall, the policy change was associated with a 17% decrease in the share of Medicare bariatric surgery patients from minority groups.  We hypothesize that patients may have chosen not to have surgery when they could not use preferred hospitals and providers.  Since bariatric surgery is one of the few effective treatments for morbid obesity, a health condition with significant implications for length and quality of life as well as health care spending, the selective referral policy appeared to have a significant harmful public health impact that was not outweighed by safety gains. 

            In light of growing research suggesting that bariatric surgery COEs are not safer for patients than other hospitals and new concerns about the unintended harms of restrictions on hospital choice, the Centers for Medicare and Medicaid Services recently reversed the COE policy.  Medicare beneficiaries can now use any hospital for bariatric surgery. 

            The bariatric surgery case offers several lessons for payer and policymaker efforts to improve the quality of health care.  Designing policies with limited clinical evidence remains a challenging area.  Bariatric COE criteria were chosen without information about whether higher bariatric surgery volume would cause improved patient outcomes.  It was also unknown whether this type of policy might create access problems for vulnerable patients.  Similar concerns will apply to decisions to implement selective referral policies for other elective procedures.   Whenever possible, these policy changes should be implemented in ways that facilitate ongoing monitoring of the costs and benefits, dialogue between researchers and regulators, and modifications as appropriate.  The recent CMS decision memorandum summarizing available research to justify reversing the bariatric surgery coverage decision is a model for this approach.


Birkmeyer JD, Siewers AE, Finlayson EVA, et al. Hospital Volume and Surgical Mortality in the United States. New England Journal of Medicine. 2002;346(15):1128-1137.

Dudley RA, Johansen KL, Brand R, Rennie DJ, Milstein A. Selective Referral to High-Volume Hospitals. JAMA: The Journal of the American Medical Association. March 1, 2000 2000;283(9):1159-1166.

Gaynor M, Seider H, Vogt WB. The Volume-Outcome Effect, Scale Economies, and Learning-by-Doing. American Economic Review. 2005;95(2):243-247.

Dimick JB, Nicholas LH, Ryan AM, Thumma JR, Birkmeyer JD. Bariatric surgery complications before vs after implementation of a national policy restricting coverage to centers of excellence. JAMA. 2013;309(8):792-799.

Nicholas LH, Dimick JB. Bariatric surgery in minority patients before and after implementation of a centers of excellence program. JAMA. 2013;310(13):1399-1400.