Comparative Effectiveness and Safety of Bariatric Procedures for Weight Loss: A PCORnet Cohort Study

Abstract

Background: There has been a dramatic shift in use of bariatric procedures, but little is known about their long-term comparative effectiveness.

Objective: To compare weight loss and safety among bariatric procedures.

Design: Retrospective observational cohort study, January 2005 to September 2015. (ClinicalTrials.gov: NCT02741674).

Setting: 41 health systems in the National Patient-Centered Clinical Research Network.

Participants: 65 093 patients aged 20 to 79 years with body mass index (BMI) of 35 kg/m2 or greater who had bariatric procedures.

Intervention: 32 208 Roux-en-Y gastric bypass (RYGB), 29 693 sleeve gastrectomy (SG), and 3192 adjustable gastric banding (AGB) procedures.

Measurements: Estimated percent total weight loss (TWL) at 1, 3, and 5 years; 30-day rates of major adverse events.

Results: Total numbers of eligible patients with weight measures at 1, 3, and 5 years were 44 978 (84%), 20 783 (68%), and 7159 (69%), respectively. Thirty-day rates of major adverse events were 5.0% for RYGB, 2.6% for SG, and 2.9% for AGB. One-year mean TWLs were 31.2% (95% CI, 31.1% to 31.3%) for RYGB, 25.2% (CI, 25.1% to 25.4%) for SG, and 13.7% (CI, 13.3% to 14.0%) for AGB. At 1 year, RYGB patients lost 5.9 (CI, 5.8 to 6.1) percentage points more weight than SG patients and 17.7 (CI, 17.3 to 18.1) percentage points more than AGB patients, and SG patients lost 12.0 (CI, 11.6 to 12.5) percentage points more than AGB patients. Five-year mean TWLs were 25.5% (CI, 25.1% to 25.9%) for RYGB, 18.8% (CI, 18.0% to 19.6%) for SG, and 11.7% (CI, 10.2% to 13.1%) for AGB. Patients with diabetes, those with BMI less than 50 kg/m2, those aged 65 years or older, African American patients, and Hispanic patients lost less weight than patients without those characteristics.

Limitation: Potential unobserved confounding due to nonrandomized design; electronic health record databases had missing outcome data.

Conclusion: Adults lost more weight with RYGB than with SG or AGB at 1, 3, and 5 years; however, RYGB had the highest 30-day rate of major adverse events. Small subgroup differences in weight loss outcomes were observed.

Primary funding source: Patient-Centered Outcomes Research Institute.

Figure 1.. Flow diagram for identification of the adult PCORnet Bariatric Study cohort in 11 CDRNs.

BMI = body mass index; CDRN = Clinical Data Research Network; PCORnet = National Patient-Centered Clinical Research Network. * Patients could be excluded for >1 reason.

Figure 2.. Estimated percentage of TWL through 5 y after bariatric surgery, by procedure type.

This plot shows the estimated percentage of TWL for a patient with the average baseline covariate profile using results from our sensitivity analysis, which included all follow-up weight measurements from 56 156 patients with any postsurgery weight observations. Additional details are provided in the Methods section of the text and the Statistical Appendix section of the Supplement. Shaded areas indicate pointwise 95% CIs. AGB = adjustable gastric banding; RYGB = Roux-en-Y gastric bypass; SG = sleeve gastrectomy; TWL = total weight loss.

Figure 3.. Proportions of AGB, RYGB, and SG patients with TWL >5%, >10%, >20%, and >30% at 1, 3, and 5 y.

AGB = adjustable gastric banding; RYGB = Roux-en-Y gastric bypass; SG = sleeve gastrectomy; TWL = total weight loss.