Comparison of Long-term Mortality (>8 years) of 7,862 Bariatric Patients to the General Population in New York State

Dana A Telem, MD, Maria Altieri, MD, Jie Yang, PhD, Qiao Zhang, MS, Wendy L Patterson, MPH, Brittany D Peoples, MS, Gerald Gracia, MD, A. Laurie Shroyer, PhD, MSHA, Aurora D Pryor, MD. Stony Brook Medicine, New York State Department of Health Office of Quality and Patient Safety.

Introduction: Obesity is a well-established risk factor for mortality. Sparse data is available on long-term patient mortality following bariatric surgery compared to the US general population. The purpose of this study is to assess patient long-term mortality rates and risk factors for all-cause mortality following the 3 most commonly performed bariatric procedures: laparoscopic Roux-en-Y gastric bypass, laparoscopic adjustable gastric band (AGB), and laparoscopic sleeve gastrectomy (SG).

Methods: Following IRB approval, New York Statewide Planning and Research Cooperative System (SPARCS) administrative data was used to identify 7,862 adult patients who underwent bariatric surgery from 1999-2005. SPARCS is a comprehensive data reporting system which collects patient-level risk characteristics, treatments, and outcomes for all New York State (NYS) hospital discharges. Bariatric surgery was identified by discharges with a primary diagnosis of overweight or obesity and a primary procedure code for RYGB, AGB, or SG. For study records, the Social Security Death Index database was used to identify post-hospital mortalities through July 2013. Risk factors for mortality were univariately screened using a Cox proportional hazard (PH) model and analyzed using a multiple PH model. Based on age, gender, and race/ethnicity, actuarial projections for mortality rates in the general population were compared to the actual post-bariatric surgery mortality rates observed. For this study, the actuarial NYS death rates were obtained from Centers of Disease Control’s annual reports published through 2010; with actuarial projections for 2011-July 2013 based on the 2010 report.

Results: Of the 7,862 obese patients evaluated, the average post-surgery mortality rate was 2.5% with 8-14 years of follow-up. Mortality rates declined from 4-7% for the period from 1999-2002 to 1.4-2.9% for 2003-2005. Mean time to death following a bariatric procedure ranged from 4-6 year and did not differ between operations (p=0.073). From 1999-2010, the actuarial mortality rate predicted was 2.21% versus the observed 1.5% for the bariatric  population. Extrapolating actuarial projections to 2013, demonstrated the actuarial mortality predictions for the general NY State population at 3.2% versus the bariatric surgery patients’ observed morality rate of 2.5%. No difference in the risk of long-term mortality was observed among different operative procedures or for 30-day operative complications. Significant risk factors for mortality following multiple PH regression analysis included (hazard ration(HR) with 95% confidence interval): Male gender (HR 2.2[1.6-3.0],p<0.001), Medicare (HR 2.49[1.65-3.77],p<0.0001), Medicaid (HR 2.85[1.71-4.76],p<0.0001), congestive heart failure (HR 3.2[2.0-4.9],p<0.0001), rheumatoid arthritis (HR1.9[1.0-3.4],p=0.03), chronic pulmonary disease (HR 1.7[1.3-2.3],p=0.0007) and diabetes (HR1.44 [1.2-2.0],p=0.02).

Conclusion: Long-term mortality rate following bariatric surgery normalizes to the actuarial rates predicted for the general population. This result did not vary by procedure choice. Additionally, perioperative complications do not increase the risk of long-term mortality. This study did identify specific patient risk factors for long-term mortality. Risk factors included: male gender, Medicaid/Medicare as primary insurance and presence of comorbidities including congestive heart failure, chronic pulmonary disease, rheumatoid arthritis and diabetes. Special attention and consideration should be given to these “at risk” patient sub-populations.

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