Demographic factors associated with postoperative complications in primary bariatric surgery: a rapid review

Background: Bariatric surgery is highly effective for the management of severe obesity, but its safety profile is not completely understood. This review aimed to synthesise evidence linking demographic factors to postoperative complications and mortality following primary bariatric surgery. Methods: We searched Medline for observational studies of adult patients linking demographic factors to postoperative complications of primary bariatric surgery published from 2017 to 2022. Risk ratios (RR) with 95% confidence intervals (95% CI) were calculated and pooled using random effect meta-analysis. Heterogeneity was quantified using the I² statistic and tested for statistical significance using the Q-statistic. Sensitivity analyses were used to explore potential sources of heterogeneity. Results: A total of 71 observational studies (69 cohort, 2 case–control) were reviewed and appraised. Older age was consistently associated with increased risks of postoperative mortality (RR = 2.62, 95% CI 1.63–4.23, I² = 42.04%), serious complications (RR = 1.76, 95% CI 1.09–2.82, I² = 93.24%), anastomotic leak (RR = 1.64, 95% CI 1.04–2.58, I² = 61.09%), and haemorrhage (RR = 1.44, 95% CI 1.07–1.94, I² = 45.25%). Male sex was associated with increased anastomotic leak (RR = 1.39, 95% CI 1.04–1.87, I² = 72.36%). Sensitivity analyses did not identify sources of bias. Socioeconomic factors, including Black/African American race, low financial status, and marital status (mixed results), were linked to higher complication risks in some studies. Conclusions: Older age and certain demographic factors (male sex, Black/African American race, low financial status, marital status) were associated with increased risks of postoperative complications following primary bariatric surgery.