Minimum volume standards
While efforts to regionalize surgical care have gradually evolved, calls have been growing to formalize policies that limit the performance of some procedures to surgeons and centers that meet a minimum volume threshold or standard.21 One such effort, based on consensus from 3 academic hospital systems, was a campaign for hospitals to “Take the Volume Pledge.”21 The campaign’s goal is to encourage health care systems to restrict the performance of 10 procedures to surgeons and hospitals within their systems that meet a minimum volume standard for the given operations.21 In essence, procedures would be restricted for low-volume providers and centers and triaged to higher-volume surgeons and hospitals within a given health care system.21
Proponents of the Volume Pledge argue that it is a relatively straightforward way to align patients and providers to optimize outcomes. The Volume Pledge focuses on larger hospital systems and encourages referral within the given system, thus mitigating competitive and financial concerns about referring patients to outside providers. Those who have argued against the Volume Pledge point out that the volume cut points chosen are somewhat arbitrary, that these policies have the potential to negatively impact rural hospitals and those serving smaller communities, and that quality is a more appropriate metric than volume.22 The Volume Pledge does not include any gynecologic procedures, and to date it has met with only limited success.23
Perhaps more directly applicable to gynecologic surgeons are ongoing national trends to base hospital credentialing on surgical volume. In essence, individual surgeons must demonstrate that they have performed a minimum number of procedures to obtain or retain privileges.24,25 While there is strong evidence of the association between volume and outcomes for some complex surgical procedures, linking volume to credentialing has a number of potential pitfalls. Studies of surgical outcomes based on volume represent average performance, and many low-volume providers have better-than-expected outcomes. Volume measures typically represent recent performance; it is difficult to measure the overall experience of individual surgeons. Similarly, surgical outcomes depend on both the surgeon and the system in which the surgeon operates. It is difficult, if not impossible, to account for differences in the environment in which a surgeon works.25
A study of gynecologic surgeons who performed hysterectomy in New York State demonstrates many of the complexities of volume-based credentialing.26 In a cohort of more than55,000 patients who underwent abdominal hysterectomy, there was a strong association between low surgeon volume and a higher-than-expected rate of complications. If one were to consider limiting privileges to even the lowest-volume providers, there would be a significant impact on the surgical workforce. In this cohort, limiting credentialing to the lowest-volume providers, those who performed only 1 abdominal hysterectomy in the prior year would restrict the privileges of 17.5% of the surgeons in the cohort. Further, in this low-volume cohort that performed only 1 abdominal hysterectomy in the prior year, 69% of the surgeons actually had outcomes that were better than predicted.26 These data highlight not only the difficulty of applying averages to individual surgeons but also the profound impact that policy changes could have on the practice of gynecologic surgery.
Volume-outcomes paradigm discussions continue
The association between higher surgeon and hospital procedural volume for gynecologic surgeries and improved outcomes now has been convincingly demonstrated. With this knowledge, over the last decade the patterns of care for patients undergoing gynecologic surgery have clearly shifted, and these operations are now more commonly being performed by a smaller number of physicians and at fewer hospitals.
While efforts to improve quality are clearly important, many policy interventions, such as regionalization of care, have untoward consequences that must be considered. As we move forward, it will be essential to ensure that there is a robust debate among patients, providers, and policymakers on the merits of public health policies based on the volume-outcomes paradigm. ●