Arch Intern Med. 2003;163:2146-2148

1. Updates from the Longitudinal Assessment of Bariatric SurgeryMinimally Invasive Surgery SymposiumFebruary 27th 2010

2. Arch Intern Med. 2003;163:2146-2148

3. Bariatric surgery in evolution-1990s-2002 • 3,328 gastric bypass • 1.9% 30-day mortality • High variability at different centers • Experience highly associatedto outcome

4. Bariatric Surgery Utilization and Outcomes in 1998 and 2004 Zhao. AHRQ Statistical Brief, Jan 2007 35

5. Bariatric Surgery: Insurance Claims Encinosa WE, et al. Med Care. 2009 May;47(5):531-5.

6. Motivation for LABS • Epidemic of obesity • Recognition that non-operative approaches were futile • Safety concerns were real • Process of care related to better outcomes were unclear • Mechanism of effect was in doubt • Durability unclear • Long term outcomes uncertain

7. Methodological Options • Large RCT • What question would we study? • Who would pay for the surgery? • Is there equipoise? • Prospective cohort • Framingham-like study • Credibility gap • Explore hypotheses • Look at associations • Lacks a comparison group • How would you construct this • Who would pay for this • Is it a good investment

8. What is LABS? • First large-scale NIH study on bariatrics • Approved for 5 yrs • Recently re-approved ~$20 million to date • Timeline • 1991 NIH Consensus Conference • May 2002 - NIDDK Working Group • November 2002 - RFA released • September 30, 2003 - LABS funded • January 2005 - First patient recruited • 2009-Renewed for 5 years

9. UWashington/ VMason NRI/UND OHSU/ Legacy Sacramento Bariatric GSPH Columbia/ Cornell UPMC NIDDK/ ORWH ECU Clinical Center Clinical Center Data Coordinating Center NIDDK / ORWH

10. What is LABS? • Goals • Address fundamental issues of safety, mechanism, efficacy and system impact • Structure • LABS 1 • Safety • LABS 2 • Impact • LABS 3 • Mechanism

11. LABS 1: Personnel • 33 surgeons • 70 coordinators • Data Coordinating Center • Scientists • Analysts • Administrators • NIDDK scientists

12. LABS 1: NEJM • Prospective clinical database • Adequate power • Contemporary • Rigor of data collection, analysis, and reporting

13. LABS 1: Methodology • LABS Certification - Surgeons - Research Coordinators • Data Collection and Entry • Paper forms • Entry online to DCC • Double entry • Alerts for missing or unusual data • Data Audits • Data analysis: DCC • Manuscript preparation: writing group • Final approval: Steering Committee

14. LABS 1: Data Collection • Descriptive data • Comorbidities, severity • Details of operation • Outcome day 30 • 2005-2008

15. LABS 1: Primary Outcome • Composite end point day 30 • Death • DVT/PE • Re-intervention • Percutaneous, endoscopic or operative • Failure to discharge

16. LABS 1: Statistical Analysis • Descriptive statistics • Correlations examined • Adjustment for main effects

18. Enrollment, Treatment, and Follow-up of the Patients

19. Enrollment, Treatment, and Follow-up of the Patients

20. Enrollment, Treatment, and Follow-up of the Patients

21. Enrollment, Treatment, and Follow-up of the Patients

22. LABS 1: Comorbidities (1)

23. LABS 1: Comorbidities (2)

24. LABS 1: Mortality

25. LABS 1: Serious Complications

26. LABS 1: Outcomes Associations with Adverse Outcome After Adjustment • Extremes of BMI • Inability to walk 200 feet • History of DVT/PE • History of Obstructive Sleep Apnea • Gastric bypass vs. LAGB

27. LABS 1: Outcomes Adverse Outcome • Laparoscopic gastric bypass 4.8x LAGB • Unexpected finding-lowest risk at BMI 53

28. LABS 1: Outcomes Not Associated with Adverse Outcome • Age, gender • Diabetes, hypertension • Heart disease

29. Predicted Probabilities of Adverse Outcomes, According to a History of Deep-Vein Thrombosis or Venous Thromboembolism (DVT) or Obstructive Sleep Apnea (OSA)

30. Prior Obesity or Foregut Surgery

31. Surgery Performed

32. Adverse Outcome

33. Volume-Outcome

34. Why Bariatric Surgery Safety Improved • Improved techniques • Laparoscopy • Gastric trans-section • Gastric banding • Improved technology/skills • Broadening of lower-risk patient pool • Accreditation process • Volume and expertise-based • Surgical Review Corporation • American College of Surgeons

35. Rationale for Volume-based Referral • High risk population • Technically difficult procedure • Increased financial incentive to adopt • Limited training programs • Clinical confusion about optimal approach • No regulation or surveillance • Volume-based referral has been effective for similar conditions

36. The Volume:Outcome Relationship

37. Bariatric surgery in evolution-1990s-2002 • 3,328 gastric bypass • 1.9% 30-day mortality • High variability at different centers • Experience highly associatedto outcome

38. 2005;294:1903-1908

39. The Volume:Outcome ConundrumSelection as a Confounder Flum et al JAMA 2004

40. MEDICARE EXPANDS COVERAGE FOR LIFESAVING OBESITY SURGERY Private Insurers Expected to Follow Suit  GAINESVILLE, FL – Feb. 21, 2006 -- After an extensive review of medical evidence that lasted nearly a year, the Centers for Medicare & Medicaid Services (CMS) announced today it will establish a national coverage policy for bariatric surgery to help reduce the significant health risks, including death and disability, associated with obesity.   This new policy will apply to all Medicare recipients including those over 65 and Medicare disabled who are morbidly obese (body mass index or BMI of 35 or greater) with any obesity related condition or disease and have been previously unsuccessful with the medical treatment of obesity.

41. Impact of CMS Accreditation-based Coverage Medicare 30 Day Mortality by Age and Quarter

42. Impact of CMS Accreditation-based Coverage Medicare 30 Day Mortality by Age and Quarter

43. LABS Volume-Outcome Data • 3410 RYGB procedures • Laparoscopic 87.2% • Median age 44 years • Median BMI 47.2 kg/m2 • Women 80.2% • At least 2 co-morbidities 56.2% • 31 RYGB surgeons • 1 – 49 RYGB cases/year 15 surgeons • 50+ RYGB cases/year 16 surgeons

44. Results • RYGB annual case volume inversely associated with risk of adverse outcomes • Continuous relationship without clear breakpoints • For each 10 cases per year increased volume, risk of adverse outcome decreased 10%

45. Results D C B A

46. LABS RYGB volume/yr and BMI as predictors of CAE

47. Volume:Outcome Conundrum • Volume based referrals may very well save lives BUT • Volume is a surrogate for process of care • Process of care is hard to study • Volume is often a surrogate for case-mix • Case mix is hard to study • It is unclear what would happen if high volume hospitals suddenly received patients with the same case mix of low volume hospitals • Biggest argument against volume based referral is access to care • Physician vs patient concern

48. 1-2% of eligible patients undergo surgery

49. Summary • Volume:Outcome for bariatric surgery is real • AND it’s problematic • Volume is likely a surrogate for process of care • AND very few are working on understanding this • Volume-based referrals has already and will probably continue to save lives • AND it’s a “too easy” policy intervention • Lower volume surgeons and centers will never like this • AND this is self-serving • Alternatives to improving the system are also problematic • AND critics of volume have not done a great job creating other systems