Importance: Little is known about comorbidity remission after bariatric surgery during typical clinical care across diverse and geographically distributed populations.
Objective: To estimate the improvement in obesity-related comorbidities after bariatric surgery and to identify clinical factors associated with these responses using a large representative population of patients.
Design, setting, and participants: This retrospective cohort study included all patients (N = 33,718) with a recorded Current Procedural Terminology code for Roux-en-Y gastric bypass (RYGB) or adjustable gastric banding (AGB) in the MarketScan Commercial Claims and Encounters Medicare Supplemental Databases from January 1, 2005, to June 30, 2010, and who had continuous enrollment from 6 months or more before to 12 months after surgery.
Main outcomes and measures: Comorbidities before and after surgery were identified using both diagnoses (from International Classification of Diseases, Ninth Revision [ICD-9] codes) and prescription drug fills. Remission was based on a record of the comorbidity within 6 months before surgery, without record of the condition 18 months after surgery, using both ICD-9 codes and medication fills, as applicable. Multivariable logistic regression models were developed to identify factors associated with remission of diabetes and hypertension.
Results: Among the 33,718 patients, 13 comorbidities with at least 1% prevalence before surgery were identified. Both RYGB and AGB led to statistically and clinically significant reductions in these comorbidities; remission rates for all comorbidities were higher after RYGB than AGB. For comorbidities that could be defined using both ICD-9 and prescription drug fill codes, prevalence was higher before and lower after surgery when measured by fill codes. Diagnoses using ICD-9 codes, but not prescription fill codes, increased in the 3 months before surgery. In multivariable logistic regression models for remission of diabetes mellitus after RYGB and AGB, age (RYGB: odds ratio [OR], 0.976; 95% CI, 0.965-0.988 and AGB: OR, 0.982; 95% CI, 0.971-0.933), procedure year (RYGB: OR, 1.11; 95% CI, 1.012-1.218 and AGB: OR, 1.185; 95% CI, 1.039-1.351), preoperative insulin use (RYGB: OR, 0.14; 95% CI, 0.114-0.171; AGB: OR, 0.174; 95% CI, 0.131-0.230), preoperative sulfonylurea use (RYGB: OR, 0.616; 95% CI, 0.505-0.752 and AGB: OR, 0.449; 95% CI, 0.357-0.566), and other antidiabetic medication use (RYGB: OR, 0.747; 95% CI, 0.568-0.981 and AGB: OR, 0.506; 95% CI, 0.359-0.715) were significantly associated with response after both procedures. For remission of hypertension, age (RYGB: OR, 0.964; 95% CI, 0.957-0.972 and AGB: OR, 0.968; 95% CI, 0.959-0.977), number of preoperative antihypertensive medications (RYGB: OR, 0.104; 95% CI, 0.067-0.161 and AGB: OR, 0.239; 95% CI, 0.140-0.408), and preoperative diuretic use (RYGB: OR, 1.729; 95% CI, 1.462-2.045 and AGB: OR, 1.648; 95% CI, 1.380-1.967) were significantly associated with response after both procedures.
Conclusions and relevance: Analysis of a large, representative administrative database confirmed established predictors and revealed novel variables associated with comorbidity remission after bariatric surgery. Incorporating these factors into clinical tools to assess an individual patient's risk-to-benefit profile for these procedures could enhance patient selection and the overall use of surgery for the treatment of obesity and metabolic disease.