Incidence of bariatric surgery and postoperative outcomes: a population‐based analysis in Western Australia

Objective: To investigate the incidence of bariatric surgery and postoperative outcomes in a population‐based cohort of patients in Western Australia over a 17‐year period. Design and setting: A population‐based incidence study of all bariatric procedures (n = 1403) performed in WA hospitals over the period 1988–2004, based on hospital morbidity and death data from the WA Data Linkage System. Main outcome measures: Changes in incidence of bariatric procedures over time; mortality and complications within 30 days after surgery; survival rates after surgery relative to age‐, sex‐, and period‐matched survival rates in the general population; factors predictive of re‐admission to hospital. Results: The incidence of bariatric surgery increased from 1.2 procedures per 100 000 person‐years in 1988 to 24.2 procedures per 100 000 person‐years in 2004. Although some of this was ascribed to a rising prevalence of obesity generally, there was a 13‐fold increase in the bariatric procedure rate within the obese population itself. At 5 years, the relative survival rate in bariatric patients was the same as the survival rate in the general population. Within the 30‐day postoperative period, mortality was low (0.07%) and 9.6% of patients experienced complications. Those who had bypass‐type procedures were more likely to be re‐admitted within 30 days than those who had gastric reduction procedures (adjusted hazard ratio, 5.80 [95% CI, 3.42–9.84]). Conclusion: The use of bariatric surgery increased 20‐fold over the study period. Relative survival after surgery was in line with population norms. The observed low mortality rates and moderate level of complications are similar to findings in other studies in which the proportion of reduction procedures has been high.