Safety and Effectiveness of the Most Common Bariatric Procedures Examined

bariatric surgery
bariatric surgery
Smaller studies have suggested little or no difference in short-term weight loss between Roux-En-Y gastric bypass and sleeve gastrectomy.

Adult patients lost more weight with Roux-En-Y gastric bypass (RYGB) than with sleeve gastrectomy (SG) and adjustable gastric banding (AGB) procedure at years 1, 3, and 5 of follow-up, according to a cohort study published in the Annals of Internal Medicine.

Researchers sought to compare weight loss and safety among the 3 most common bariatric procedures in the United States.

A retrospective observational cohort study was conducted that included adult patients (age 20 to 79 years) who had a primary bariatric procedure at health systems affiliated with participating PCORnet Clinical Data Research Networks from January 1, 2005, to September 30, 2015. The primary bariatric procedure had to have occurred during inpatient or ambulatory encounters, and the body mass index (BMI) of participants had to be at least 35 kg/m2 or greater.

The primary outcome of the study was the percentage of total weight loss at 1, 3, and 5 years. In addition, investigators examined 30-day rates of major adverse events. Linear mixed-effects model framework was used to calculate mean adjusted weight with each procedure at all 3 follow-up points. To control for potential confounding variables, researchers constructed a propensity score model for each time cohort and pairwise analysis.

Of the 65,093 participants who had complete baseline information, 46,510 patients met inclusion criteria.

At baseline, RYGB patients had the highest mean BMI (49.6 kg/m2) and had a greater prevalence of comorbid conditions than SG or ABG patients. RYGB patients also had the greatest total percentage weight loss at each point, whereas AGB had the lowest. Furthermore, rates of adverse events were highest (5.0%; n = 32,208) for RYGB patients, whereas rates did not differ significantly between SG and AGB patients (2.6% [n = 29,693] and 2.9% [n = 3192], respectively). Researchers also noted that sleep apnea was the most common overall adverse event reported in each of the study groups.

Investigators reported that weight loss was lower among patients who had diabetes, were aged ≥65 years, had a BMI <50 kg/m2, or classified themselves as Hispanic or African American compared with patients without these characteristics.

Researchers addressed several limitations during the study. Weight measurements in the study were model-estimated predictions at each point, as opposed to systematically collected measurements. Also, administrative censoring prevented researchers from identifying patients who had missing follow-up data, and there was also a risk for unobserved confounding that may have persisted despite the propensity score adjustment, as patients were not randomly assigned. Further, BMI data were missing from a substantial portion of the cohort in the electronic health records both at baseline and at follow-up, potentially introducing biased data. Finally, researchers were unable to examine the heterogeneity of treatment effects by site because of resource constraints.

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The researchers noted that “the data presented [in this study] are probably more broadly representative of the typical experience of patients having bariatric surgery in most major surgical centers in the United States. The magnitude of weight loss differences we observed will likely be meaningful to patients and providers as they consider treatment options for severe obesity.”

“These analyses demonstrate that RYGB is associated with greater weight loss than SG and that AGB is associated with the least weight loss in a large and geographically and racially diverse population. Health care providers, patients, and policymakers can use these data to inform treatment and insurance coverage decisions,” concluded the investigators.

Disclosures: Multiple authors declare affiliations with the pharmaceutical industry. Please refer to reference for a complete list of authors’ disclosures. This study was funded by the Patient-Centered Outcomes Research Institute via contract OBS-1505-30683.

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Arterburn D, Wellman R, Emiliano A, et al. Comparative effectiveness and safety of bariatric procedures for weight loss: A PCOR cohort study [published online October 30, 2018]. Ann Intern Med. doi:10.7326/M17-2786