Raising the Standard: Raising the Standards with MBSAQIP: Part 2

| July 1, 2022

by Wayne J. English, MD, FACS, FASMBS; David Provost, MD, FACS, FASMBS; Teresa LaMasters, MD, FACS, FASMBS; Richard Peterson, MD, MPH, FACS, FASMBS; and Paul Jeffers, BS, BA

Dr. English is Co-Chair of the MBSAQIP Standards/Verification Subcommittee and Associate Professor of Surgery at Vanderbilt University Medical Center in Nashville, Tennessee. Dr. Provost is Co-Chair of the MBSAQIP Standards/Verification Subcommittee and Professor of Surgery at Baylor Scott & White Medical Center – Temple in Temple, Texas. Dr. LaMasters is a member of the MBSAQIP Standards/Verification Subcommittee, MBSAQIP Site Reviewer, President-Elect of the American Society for Metabolic and Bariatric Surgery, Medical Director at UnityPoint Clinic Weight Loss and Des Moines, Iowa, and Clinical Associate Professor at University of Iowa. Dr. Peterson is Professor of Surgery, UT Health San Antonio; Chief, Bariatric and Metabolic Surgery UT Health San Antonio in San Antonio, Texas. Mr. Jeffers was the MBSAQIP Verification Specialist from July 2015 to April 2022 and is currently the Commission on Cancer Standards Development Manager.

Funding: No funding was provided for this article.

Disclosures: The authors report no conflicts of interest relevant to the content of this article.

Bariatric Times. 2022;19(7):16–17.

This article is the second of a series of articles discussing the upcoming revised version of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) standards. The article will review volume, low-acuity center, and ambulatory surgery center criteria within Standard 2.

Standard 2: Program Scope and Governance 

Standard 2.1: Volume criteria. The volume criteria standard has been one of the more controversial standards. Prior to the MBSAQIP, the annual volume requirement for accreditation recognized by the Centers for Medicare and Medicaid Services (CMS) was 125 procedures. This was based on data showing that bariatric surgery performed at hospitals performing more than 100 cases annually demonstrated shorter length of stay, lower morbidity and mortality, and decreased costs.1

However, one study looking at over 32,000 patients revealed a definite volume-outcomes relationship, but no inflection point could justify selecting a specific volume threshold.2 Additional studies looking at CMS’s policy found no statistical differences in the risk-adjusted complication and reoperation rates prior to and after CMS’s national coverage decision.3,4 This would eventually lead to a policy change in which patients were no longer required to seek care only at programs participating in the American Society for Metabolic and Bariatric Surgery (ASMBS) or American College of Surgeons (ACS) accreditation programs.

It is uncertain how the MBSAQIP will evolve regarding the volume criteria. For now, best evidence supports a comprehensive center annual volume of at least 50 stapled cases. However, low-volume center outcomes have been shown to rival their high-volume counterparts. Proposals to consider for future changes in the MBSAQIP volume criteria include reducing the annual volume requirement or providing a performance-based accreditation status, but more data is needed to justify these changes. 

One change being made in the revised standards is clarification of the definition of adolescence. Previously, the adolescent age was limited to patients 18 years of age and younger. This was overly restrictive, as continuity of care was being compromised for select patient populations that routinely follow up long-term at children’s hospitals. Adolescent centers are now approved to operate on patients over the age of 18 years, but patients over the age of 21 years need to be reviewed by the Metabolic and Bariatric Surgery (MBS) Committee to determine if the patient should be maintained at the adolescent center for continuity of care or deferred to an accredited adult center. 

Frequently asked questions (FAQs) received by MBSAQIP staff regarding Standard 2.1 are listed below. 

Q: We are an Initial Center applying for accreditation. Do we need to meet the volume requirement before applying? 

A: Yes. All applicant centers must meet the volume criterion for the designation level for which they intend to apply before submitting their application. This volume criterion must be met within the most recent 12 months prior to application. 

Q: We are an Initial Center applying for accreditation. We do not have access to the MBSAQIP Registry. How do we capture our initial case volume in the registry? 

A: Initial applicants will receive MBSAQIP Registry access once the Pre-review Questionnaire (PRQ) has been approved. When registry access is granted, the MBS clinical reviewer will retroactively capture case volume from the first day of that month, and all future cases performed at the center. The MBS clinical reviewer may choose to capture additional cases as far back as the MBSAQIP Registry’s 90-day lock date will allow.

Q: We are a Renewal Center with an upcoming reaccreditation site visit. How is our data review period determined? 

A: Your center will complete the Application Data Template (ADT) as part of the PRQ. The ADT will automatically generate your 36-month data review period based on the month and year you begin completing the ADT. Here is the formula for calculation: Start date=(current month–1 month)–36 months.

Standards 2.2 and 2.3: Low-acuity and ambulatory center patient selection. The MBSAQIP standards outline that more complex procedures should only be performed at centers performing at least 50 stapling procedures annually. If a center is performing fewer cases, then patient selection must be restricted to lower-risk patients.

There was no separate ambulatory surgery center (ASC) standard in the first version of the standards; an ASC was considered a comprehensive center, provided all the core standards were met. However, resources are clearly different between an inpatient and outpatient facility. Payors strongly felt there was no clear way, based on MBSAQIP designation, for the public to determine whether a center had comprehensive inpatient services. Some insurers were already in the process of developing their own separate ASC designation, despite centers being accredited as MBSAQIP “comprehensive” centers. As a result, a new ASC standard was developed for Version 2 of the standards. 

The MBSAQIP is continuously monitoring outcomes at low-acuity centers and ASCs. Changes made from 2016 to 2019 standards included removing some restrictions on revisional procedures. There are no major changes for the upcoming revised standards, except for clarification of the acceptable revisional procedure list. 

A systematic review looking at patients with obesity undergoing ambulatory surgery concluded that insufficient data was available to make strong recommendations regarding appropriate patient selection of the patient with obesity scheduled for ambulatory surgery.5 These data subsequently make it challenging for the MBSAQIP to impose restriction at ASCs. Interestingly, ASCs had already demonstrated the tendency to self-select lower-risk patients without imposing a low-acuity criteria restriction.6 

Based on internal MBSAQIP ASC data, by complying with the low-acuity definition, ASCs could still operate on 95 percent of their patients according to age criteria and 98 percent of their patients according to sex and body mass index (BMI) criteria. Almost all female patients, who comprised over 80 percent of the patient population, would meet the criteria, but only 84 percent of male patients would be included.It was estimated that only five fewer cases would be performed at MBSAQIP-accredited ASCs. The MBSAQIP completed an additional comprehensive internal review of its data using propensity score matching for over 2,800 similar patients in comprehensive and ambulatory centers. Accredited ASCs were shown to deliver comparable care to accredited comprehensive centers. No significant differences in outcomes were noted when looking at patients with less than one day length of stay, compared to greater than one day length of stay.

It is estimated that approximately 40,000 ambulatory procedures in the United States (US) are not captured by MBSAQIP accredited centers,7,8 thus making it difficult to obtain sufficient data to justify revising the volume and patient selection criteria at ASCs. More data should be forthcoming from the coronavirus disease 2019 (COVID-19) pandemic era, as many facilities implemented inpatient MBS moratoriums. As a result, many surgeons started performing increasing number of procedures at ASCs to maintain the flow of their clinical practices.

This concludes the second article of Raising the Standards with MBSAQIP. The next article will review additional components of Standard 2. 


  1. Nguyen NT, Paya M, Stevens CM, et al. The relationship between hospital volume and outcome in bariatric surgery at academic medical centers. Ann Surg. 2004;240(4):586–593; discussion 593–594. 
  2. Gould JC, Kent KC, Wan Y, et al. Perioperative safety and volume: outcomes relationships in bariatric surgery: a study of 32,000 patients. J Am Coll Surg. 2011;213(6):771–777. 
  3. Dimick JB, Nicholas LH, Ryan AM, et al. Bariatric surgery complications before vs after implementation of a national policy restricting coverage to centers of excellence. JAMA. 2013;309(8):792–799. 
  4. Scally CP, Shih T, Thumma JR, Dimick JB. Impact of a national bariatric surgery center of excellence program on Medicare expenditures. J Gastrointest Surg. 2016;20(4):708–714.
  5. Joshi GP, Ahmad S, Riad W, et al. Selection of obese patients undergoing ambulatory surgery: a systematic review of the literature. Anesth Analg. 2013;117(5):1082–1091. 
  6. Abraham A, Ikramuddin S, Jahansouz C, et al. Trends in bariatric surgery: procedure selection, revisional surgeries, and readmissions. Obes Surg. 2016;26(7):1371–1377. 
  7. English WJ, DeMaria EJ, Brethauer SA, et al. American Society for Metabolic and Bariatric Surgery estimation of metabolic and bariatric procedures performed in the United States in 2016. Surg Obes Relat Dis. 2018;14(3):259–263. 
  8. Clapp B, Harper B, Cutshall M, et al. How many sleeve gastrectomies are done at nonaccredited centers in Texas? Surg Obes Relat Dis. 2020;16(5):658–662. 

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Category: Past Articles, Raising the Standard

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