Does Bariatric Surgery Reduce Health Care Costs?: Weighing the Evidence

Bariatric surgery is by far themost effective therapy formorbid obesity and obesity-related conditions, especially type 2 diabetesmellitus.Numerouswell-designedobservational studies and randomized clinical trials showprofoundweight loss, high rates of comorbidity resolution, improvedquality of life, and decreased mortality after bariatric surgery.1-3 Despite these well-known clinical benefits, there is debate about the impact of bariatric surgery on health care expenditures. Bariatric surgery itself is a relatively expensive intervention.Besides the surgical episode itself, there are substantial preoperative costs fromtesting and referrals to specialists, as well as increased postsurgical costs owing to shortand longer-term complications. Studies evaluating the longer-term health care costs have shownmixed results.4-6 The study in this issue of JAMA Surgery by Lewis et al7 brings important newdata to this debate. Using a uniquedata source, privatepayer claims fromacross theUnitedStates, the authorswere able tomeasure health care expenditures (from thepayer perspective) over time for patients undergoing laparoscopic adjustable gastric banding and laparoscopic gastric bypass procedures. Importantly, theauthorsusedarigorous longitudinal study design—evaluatinghealth care costs over time inpatientswho had surgery—that allows patients to serve as their own controls. Inmanyways, this is superior to using a nonsurgical cohort of control individuals, as there is no way of knowing whether patientswho do not have surgery are truly similar to those who do have surgery. The study design used by Lewis et al7 assumes that an individual’s health care spending trend will continue on a similar trajectory (a slow upward trend) if they do not have surgery, which seems quite reasonable. This study has 2 very important findings.7 First, at 3 years after surgery, there was a significant change in trajectory of health care expenditures,with a flatteningof the trend in total health care costs and prescription drug costs. Without surgery, it is most likely that this trend would have followed the upward trend demonstrated in the preoperative period. This finding implies that bariatric surgery is certainly not increasing costs as many worry about, and it very well may result in net cost savings in the long term. Second, this studyprovides important informationon the comparative effectiveness of the laparoscopic band vs laparoscopic gastric bypass. Although the laparoscopic band was associated with lower costs and fewer emergency department visits early postoperatively (which has clinical face validity), by 3 years, the laparoscopic gastric bypass was associatedwith lower total andprescription costs. This conclusively demonstrates that the superior clinical efficacy of laparoscopic gastric bypass demonstrated in clinical trials translates into greater longer-term health care cost savings. This study does leave some important questions to answer. Namely, what happens to health care expenditures beyond 3 years? As the authors pointed out, if this flattening of the cost trend continues, bariatric surgery may be a costsaving procedure,7 which has important implications for expanding insurance coverage.Moreover, howdo expenditures for laparoscopic sleeve gastrectomy comparewith gastric bypass? Because laparoscopic sleeve gastrectomy is rapidly becoming the most common bariatric procedure subsequent evaluations of this procedure will be essential.