Survival Among High-Risk Patients After Bariatric Surgery

Study Questions:

What is the association of bariatric surgery and survival for older men?

Methods:

This was a retrospective cohort study of bariatric surgery programs in Veterans Affairs medical centers. Mortality was examined for 850 veterans who had bariatric surgery in January 2000 to December 2006 (mean age 49.5 years, standard deviation [SD] 8.3; mean body mass index [BMI] 47.4, SD 7.8) and 41,244 nonsurgical controls (mean age 54.7 years, SD 10.2; mean BMI 42.0, SD 5.0) from the same 12 Veteran Integrated Service Networks; the mean follow-up was 6.7 years. Four Cox proportional hazards models were assessed: unadjusted and controlled for baseline covariates on unmatched and propensity-matched cohorts. The main outcome measure was all-cause mortality.

Results:

Among patients who had bariatric surgery, the 1-, 2-, and 6-year crude mortality rates were, respectively, 1.5%, 2.2%, and 6.8% compared with 2.2%, 4.6%, and 15.2% for nonsurgical controls. In unadjusted Cox regression, bariatric surgery was associated with reduced mortality (hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.51-0.80). After covariate adjustment, bariatric surgery remained associated with reduced mortality (HR, 0.80; 95% CI, 0.63-0.995). In analysis of 1,694 propensity-matched patients, bariatric surgery was no longer significantly associated with reduced mortality in unadjusted (HR, 0.83; 95% CI, 0.61-1.14) and time-adjusted (HR, 0.94; 95% CI, 0.64-1.39) Cox regressions.

Conclusions:

The authors concluded that the use of bariatric surgery compared with usual care was not associated with decreased mortality in severely obese older patients.

Perspective:

In this propensity-matched cohort of obese high-risk primarily male patients, bariatric surgery was not significantly associated with survival during a mean of 6.7 years of follow-up. The survival benefit with bariatric surgery in the Swedish Obese Subjects (SOS) trial was not observed until a median of 13 years of follow-up; therefore, additional observation time may be required to see benefit in this older predominantly male cohort. Even though bariatric surgery may not be associated with reduced mortality among older male patients, many patients may still choose to undergo bariatric surgery, given the strong evidence for significant reductions in body weight and comorbidities such as diabetes and improved quality of life. Additional prospective studies with longer-term follow-up and careful selection of surgical and nonsurgical cohorts are needed to ascertain the true survival advantage of bariatric surgery.

Keywords: Outcome Assessment (Health Care), Bariatric Surgery, Follow-Up Studies, Body Mass Index, Veterans, Body Weight, Obesity, Diabetes Mellitus


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