PS3-43: Using the Electronic Health Record to Evaluate the Collateral Impact of Bariatric Surgery

Abstract

Background/AimsBariatric surgery is the only effective long-term treatment for morbid obesity. The bariatric program includes commitment to lifestyle changes that may have a collateral effect on co-inhabitants. Studies of the collateral impact are limited by small sample sizes and results have been conflicting, with studies showing both weight loss and weight gain in family members of surgery patients. This is the largest study to investigate the impact of bariatric surgery on the BMI of adults living in the same household.MethodsAdult co-inhabitants of Roux-en-Y gastric bypass patients were identified by matching addresses from an electronic health record. The sample was limited to co-inhabitants with BMI measures within the year prior and within a year after their household member’s surgery. Paired t-tests and repeated measures regression was used to determine if change in BMI from pre- to post-surgery was associated with the co-inhabitants’ age, gender, and BMI.ResultsOf 443 co-inhabitants (from 388 bariatric patients), 61% (n = 269) were male, and 21% (n = 91), 50% (n= 223), and 29% (n = 129) were aged 40kg/m2) in 12% (n = 54), 26% (n = 116), 46% (n = 205), and 15% (n = 68), respectively. The overall change in the co-inhabitants’ BMI was not significant (pre-surgery mean = 32.9, post-surgery mean = 32.8, paired t-test p-value = 0.072). Change in BMI from pre- to post-surgery was not associated with gender (P = 0.231) or pre-surgery BMI (P = 0.129). Older age was associated with significant decrease in BMI. Co-inhabitants aged ≥60 had a significant decrease in BMI (pre-surgery mean = 32.3 kg/m2, post-surgery mean = 31.9, P = 0.0002).ConclusionsOlder co-inhabitants (aged ≥60) of bariatric surgery patients had a significant reduction in BMI, while younger age, gender, and initial BMI were not associated with BMI change. The lifestyle changes required of bariatric surgery patients might have more of an impact on older co-inhabitants who are less likely to be influenced by competing lifestyle behaviors in the workplace than their younger counterparts. With more than 60 percent of co-inhabitants obese prior to surgery, it is critical to identify strategies for broadening the positive impact of bariatric surgery to co-inhabitants in all age groups.