What patient factors influence bariatric surgery outcomes? A multiple regression analysis of Ontario Bariatric Registry data

Background: As bariatric surgery evolves and gains popularity, statistical analysis of its outcomes could improve the process of decision-making and risk assessment. This study aimed to evaluate the influence of age and other factors on bariatric surgery outcomes in order to improve patient selection and outcomes. Methods: We analyzed data from the Ontario Bariatric Registry to evaluate the influence of age and 10 other factors on early (< 90 d) and 1-year surgical outcomes among patients aged 18 years or older who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) between January 2010 and May 2013. Early outcomes included composite adverse events and readmission. The 1-year outcomes included percent excess body weight loss (%EBWL), and remission of diabetes mellitus and hypertension. We performed multiple regression analysis to identify independent variables that influenced these outcomes. Results: We identified 3166 patients (2655 women [83.9%] and 511 men [16.1%], mean age 44.8 yr, mean body mass index [BMI] 48.4) who underwent LRYGB (2839 [89.7%]) or LSG (327 [10.3%]) over the study period and completed their 1-year follow-up. Preoperative American Society of Anesthesiologists (ASA) score and history of angina were independent variables that influenced the composite adverse event outcome. Obstructive sleep apnea was the only factor that influenced early readmission. The independent factors that influenced %EBWL were age, type of surgery, BMI and baseline glycosylated hemoglobin (HbA(1c)) level: age was found to influence hypertension remission, and HbA(1c) level and obstructive sleep apnea were found to influence diabetes remission. Conclusion: Complications after bariatric surgery can be predicted by preoperative ASA score and history of angina; patient age was not related to an increase in postoperative complications. These factors could help both surgeon and patient make appropriate surgical decisions.