Recent improvements in bariatric surgery outcomes.

OBJECTIVE Bariatric surgery is one of the fastest growing hospital procedures, but with a 40% complication rate in 2001. Between 2001 and 2005 bariatric surgeries grew by 113%. Our objective is to examine how 6-month complications improved between 2001 and 2006, using a nationwide, population-based sample. DATA/DESIGN: We examined insurance claims in 2001-2002 and 2005-2006 for 9582 bariatric surgeries, at 652 hospitals, among a population of 16 million non-elderly people. Outcomes and costs were risk-adjusted using multivariate regression methods with hospital fixed effects. PRINCIPAL FINDINGS Between 2001 and 2006, while older and sicker patients underwent the surgery, the 180-day risk-adjusted complication rate declined 21% from 41.7% to 32.8%. Most of the improvement was in the initial hospital stay, where the risk-adjusted inpatient complication rate declined 37%, from 23.6% to 14.8%. Risk-adjusted rates of readmissions with complications declined 31%, from 9.8% to 6.8%. Risk-adjusted hospital days declined from 6 to 3.7 days, and risk-adjusted and inflation-adjusted payments declined 6%.Improvements in complication rates and readmission rates were associated with a within-hospital 30% increase in hospital volume. Volume had no impact on costs. The use of laparoscopy, which increased from 9% to 71%, reduced costs by 12%, while gastric banding decreased costs by 20%. Laparoscopy had no impact on readmissions, but the increase in banding without bypass reduced readmissions. CONCLUSIONS Improvements in bariatric outcomes and costs were due to a mix of within-hospital volume increases, a move to a laparoscopic technique, and an increase in banding without bypass.