The term "bariatric surgery" refers to a collective group of procedures that involve modifications to the digestive system that promote weight loss. As the Washington State Health Care Authority reviews its coverage policy for bariatric surgery, it is therefore timely to assess the evidence on the clinical benefits and cost-effectiveness of common weight loss procedures across all relevant populations, including those defined by level of obesity, age, and levels of comorbidity.
Status: Decision completed
Primary criteria ranking
- Safety = High
- Efficacy = High
- Cost = High
- Documents (all assessments)
- Draft key questions: comment and response
- Final key questions
- Draft evidence report: comment and response
- Final evidence report
- Final evidence report: appendices
- Final findings and decision
Assessment timeline (2015)
- Draft key questions published: October 8, 2014
- Public comment period: October 8 to 22, 2014
- Final key questions published: November 7, 2014
- Draft report published: February 9, 2015
- Public comment period: February 9 to March 13, 2015
- Final report published: April 12, 2015
- HTCC public meeting: May 15, 2015
About 93 million Americans are classified as obese (Obesity Action Coalition, 2014). While the number of obese individuals has remained stable in recent years, obesity continues to be one of the most prevalent public health issues in the U.S. (Ogden, 2014). In June 2012, the American Medical Association officially recognized obesity as a chronic disease, believing it would more effectively address the issue; however, the new classification remains controversial among advocates, policymakers, and the medical community, who feel that such a designation may distance patients from responsibility for their condition (Pollack, 2012).
Compounding the problem is the lack of viable treatment alternatives. Success rates from lifestyle modifications alone have been modest at best, and the risk-benefit tradeoffs for weight-loss medications are questionable. Clinical interest in expanding the use of bariatric surgery is therefore justifiably high, but there are uncertainties regarding the relative performance of each type of procedure in specific patient populations (e.g., adult versus pediatric patients, moderately versus severely/moderately obese, etc.). There are also conflicting data on long-term benefit. Earlier findings from retrospective chart review as well as prospective observational study suggested a sustained reduction in all-cause mortality at 7-11 years of follow-up (Adams, 2007; Sjostrom, 2007), but data from a more recently-published study of a cohort of U.S. veterans indicated no mortality benefit at a mean of 6.7 years of follow-up (Maciejewski, 2011).
It is estimated that more than one-third of adults and about 17% of adolescents are obese (Ogden, 2014). The health effects of obesity are myriad, and include the development of Type 2 diabetes, hypertension, cardiovascular disease, high blood pressure, and sleep apnea. Obesity and its sequelae are estimated to generate $147 billion in health care costs in the U.S. alone (Finkelstein, 2009).
Historically, options for treating obesity have been limited to lifestyle modifications such as dietary changes and exercise as well as the use of weight-loss medications and dietary supplements, many of which have been shown to pose significant health risks of their own (National Institutes of Health, 2013). More recently, options for surgical intervention have become more widespread. The term "bariatric surgery" refers to a collective group of procedures that involve modifications to the digestive system that promote weight loss, and include gastric bypass, gastric banding, sleeve gastrectomy, and biliopancreatic diversion (with or without duodenal switch) (National Institutes of Health, 2009). Procedures can be performed via open or laparoscopic surgery; the choice of procedure and method primarily depends on the severity of obesity, the presence of comorbid conditions, the experience of the surgeon, and the patient's individual preferences or other contraindications (Colquitt, 2009).
In certain settings and populations, bariatric surgical procedures have shown reductions in body weight and reduced risks of obesity-related conditions. Early use of the procedures focused on individuals meeting criteria for severe or morbid obesity (body mass index [BMI] ≥35.0 kg/m2) who had at least one obesity-related condition (e.g., diabetes). Subsequent studies have been conducted in individuals at lower levels of BMI, which has led to regulatory approval specific to this population: in 2011, the FDA approved the use of a laparoscopic adjustable gastric banding device (LAP-BAND®, Apollo Endosurgery, Inc.) for use in patients with lower levels of obesity (BMI 30.0-34.9) and at least one obesity-linked condition (U.S. Food and Drug Administration, 2011). The most common application of bariatric surgery in less obese individuals has been in patients with Type 2 diabetes. Clinical interest in expanding the use of bariatric surgery to individuals with lower levels of obesity is high; questions remain, however, regarding the performance of these procedures in these patients versus those with higher levels of obesity, the health-system impact given the higher prevalence of moderate obesity versus severe/morbid obesity, and the durability of clinical benefit in all populations.
There are also specific risks associated with bariatric procedures, which may include bowel obstruction, development of gallstones or hernias, stomach perforation and ulcer, "dumping syndrome" (diarrhea and other related symptoms caused by rapid movement of undigested food to the small bowel), and in some cases, death (Mayo Clinic, 2014). Additional surgeries may be required as part of a multiphase procedure (as with biliopancreatic diversion), to implement an entirely new treatment modality, remedy a complication, or reverse the procedure altogether if complications are life-threatening (Brethauer, 2014). Surgical revisions comprise about 6% of all weight loss surgeries performed annually in the U.S. (American Society for Metabolic and Bariatric Surgery, 2014). Also, as with any surgical procedure, there are general surgical risks, including hemorrhage, wound infection, deep vein thrombosis and/or pulmonary embolism, and anesthesia reactions (Mayo Clinic, 2014).