Comparing the Benefits and Harms of Three Types of Weight Loss Surgery -- The PCORnet® Bariatric Study
Condition: Obesity; Bariatrics; Body Weight; Diabetes Mellitus; Weight Loss; Roux-en-Y Gastric Bypass; Gastric Bypass
MeSH terms: Body Weight; Weight Loss
Study type: Observational

Summary: 
      The main goal of this research project is to conduct a comparative effectiveness research
      study involving existing data in the PCORnet Common Data Model to provide accurate estimates
      of the 1-, 3-, and 5-year benefits and risks of the three most common bariatric procedures -
      Roux-en-y gastric bypass, adjustable gastric banding, and sleeve gastrectomy - with a focus
      on outcomes that are important to adults and adolescents with severe obesity: 1) changes in
      weight, 2) rates of remission and relapse of diabetes, and 3) major adverse events.
    

Detailed description: 
      The main aims of this study will compare the effectiveness and safety of the three most
      common bariatric surgical procedures: Roux-en-y gastric bypass (RYGB), adjustable gastric
      banding (AGB), and sleeve gastrectomy (SG).

      Question (Aim) 1: To what extent does weight loss and weight regain differ across the three
      bariatric surgical procedures at 1, 3, and 5 years? This aim addresses the primary outcome of
      interest among most patients seeking bariatric surgery - the differential impact of these
      procedures on maximum weight loss as well as the extent of longer-term weight regain. We will
      also explore the heterogeneity in weight loss and regain across several key subgroups that
      may have differential response to surgical treatment, specifically groups defined by age,
      race/ethnicity, baseline BMI, smoking status, and pre-operative comorbidities.

      Question (Aim) 2: To what extent do these bariatric procedures differ on improvements in
      diabetes risk at 1, 3, and 5 years? Among patients with diabetes, remission or "cure" of
      their disease (defined as HbA1c <6.5% off diabetes medications) has been cited as the most
      important outcome of bariatric surgery. Thus, we will examine the comparative effect of these
      procedures on rates of diabetes remission as well as relapse (recurrence). Secondary analyses
      will examine the comparative impact of the procedures on glycemic control independent of
      diabetes remission.

      Question (Aim) 3: What is the frequency of major adverse events following these three
      different bariatric surgical procedures at 1, 3, and 5 years? We will examine four important
      adverse event outcome categories across the three procedures: 1) short- and long-term (1, 3,
      and 5 year) mortality rates, 2) a composite end point of 30-day major adverse outcomes: based
      on the definition used in the Longitudinal Assessment of Bariatric Surgery (LABS) study that
      included death; venous thromboembolism; percutaneous, endoscopic, or operative subsequent
      intervention; and failure to be discharged from the hospital; 3) subsequent hospitalization
      (any hospitalization following initial surgery); and 4) subsequent
      reoperation/reintervention: defined as any additional bariatric procedure and other
      procedures related to device removals, gastric revisions, abdominal or incisional hernia
      repair, laparoscopy or laparotomy, and percutaneous endoscopic gastrostomy tube placements.

      Question (Aim) 4: To what extent do bariatric surgery outcomes explored in Aims 1-3 differ
      with respect to baseline depression diagnosis at 1, 3, and 5 years after surgery?

      Question (Aim) 5: To what extent do bariatric surgery outcomes explored in Aims 1-3 differ
      with respect to race and ethnicity at 1, 3, and 5 years after surgery?
    

Intervention name(s): Roux-en-y gastric bypass (RYGB) - historical; Adjustable gastric banding (AGB) - historical; Sleeve gastrectomy (SG) - historical
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): Participant has had RYGB, as identified using existing data; Participant has had AGB, as identified using existing data; Participant has had SG, as identified using existing data
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        The study population are children and adults (aged 12 through 79 years of age) who have
        undergone one of the three most common bariatric procedures performed in the United Sates -
        Roux-en-y gastric bypass, adjustable gastric banding, and sleeve gastrectomy. The
        population will be identified using participating sites' PCORnet Common Data Model (CDM).
      
Keywords: Observational Study; Comparative Effectiveness Research