麻豆传媒

Sleeve gastrectomy jumped in popularity after Medicare began covering the bariatric procedure in 2012, a serial cross-sectional study showed.

Among over 76,000 Medicare beneficiaries with obesity who underwent bariatric surgery, sleeve gastrectomy jumped from 515 procedures performed in 2012 to 9,955 procedures performed in 2017, reported Ryan Howard, MD, of the University of Michigan in Ann Arbor, and colleagues.

In this study, "initiation of insurance coverage for sleeve gastrectomy in 2012 was associated with significant temporal and regional practice variation that was associated with treatment and balanced characteristics between treatment arms, making it a strong instrumental variable," they explained in .

Among a representative sample of the 10 largest states, utilization of sleeve gastrectomy jumped from 7.9% in 2012 to 92.8% in 2017 in New Jersey, which was the highest increase, and from 10.9% to 63.2%, respectively, in Ohio, which was the smallest increase.

State-level utilization of sleeve gastrectomy in the prior year was highly associated with choosing this procedure (Kleibergen-Paap Wald F statistic 910.3), Howard's team pointed out.

"CMS decided that 'effective for services performed on and after June 27, 2012, Medicare Administrative Contractors (MAC) acting within their respective jurisdictions may determine coverage of standalone laparoscopic sleeve gastrectomy for the treatment of comorbid conditions related to obesity in Medicare beneficiaries,'" they wrote, adding that "large-scale policy decisions often create significant geographic variation."

They noted that since this was a Medicare patient population, "the older age and increased prevalence of comorbidities such as kidney failure among patients undergoing sleeve gastrectomy reflect the preferential use of this procedure in high-risk patients, because it is more well-tolerated than gastric bypass."

Patients who underwent sleeve gastrectomy did see better 1-year post-surgical outcomes than those who opted for gastric bypass:

• Mortality: 0.9% vs 1.7%
• Complications: 11.6% vs 14.1%
• Emergency department visits: 48.3% vs 53.6%
• Hospitalizations: 23.4% vs 26.5%
• Reinterventions: 8.7% vs 12.2%

The risk of surgical revision was not different between groups (0.6% vs 0.4%).

In an , Laura F. Garabedian, PhD, MPH, of Harvard Medical School in Boston, noted that the researchers weren't able to measure the exact insurance coverage across the states and therefore "their data suggest that all regions elected to cover sleeve gastrectomy (i.e., there was no variability in coverage)."

"An ideal insurance coverage policy for quasi-experimental evaluation is one that creates variation in treatment coverage across groups of patients over time (e.g., state-level differences in coverage, which would be conducive to a difference-in-difference design [i.e., pre-post with control]) or creates a cutoff that induces treatment variation among a group of patients (e.g., age of eligibility for Medicare coverage, which would be conducive to a regression discontinuity design)," Garabedian pointed out.

For this study, Howard and colleagues included 76,077 patients who underwent bariatric surgery -- 44,367 underwent sleeve gastrectomy (mean age 56.9, 73.5% women) and 31,710 underwent gastric bypass (mean age 55.9, 74.9% women). Most patients were white.

The primary outcome was the association of the instrumental variable with treatment (i.e., undergoing sleeve gastrectomy), in addition to outcomes, including mortality, complications, emergency department visits, hospitalizations, reinterventions, and surgical revisions.

All but two patient characteristics (race and diagnosis of depression) were well-balanced between the top and bottom quartiles of the instrumental variable, the authors noted.

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