Bariatric surgery volume by hospital and long-term survival: population-based NordOSCo data

Background It is unclear whether annual hospital volume of bariatric surgery influences the long-term survival of individuals who undergo surgery for severe obesity. The hypothesis that higher annual hospital volume of bariatric surgery is associated with better long-term survival was evaluated. Methods This retrospective population-based study included patients who underwent bariatric surgery in Sweden and Finland between 1989 and 2020. Annual hospital volume was analysed for risk of all-cause mortality. Multivariable Cox regression provided HRs with 95 per cent confidence intervals adjusted for age, sex, co-morbidity, country, and type of bariatric procedure. Results Weight loss surgery was performed in 77 870 patients with a 0.5 per cent risk of postoperative death (mortality rate (MR) per 100 000 people 592.7, 95 per cent c.i. 575.0 to 610.9). Higher annual hospital volume of bariatric surgery was associated with a lower risk of all-cause mortality. The adjusted HRs were slightly more reduced for each quartile of annual hospital volume compared with the lowest quartile (MR per 100 000 people for lowest quartile 815.1, 95 per cent c.i. 781.7 to 849.9; for quartile II: HR 0.88, 95 per cent c.i. 0.81 to 0.96 (MR per 100 000 people 545.0, 512.0 to 580.1); for quartile III: HR 0.87, 0.78 to 0.97 (MR per 100 000 people 428.8, 395.5 to 465.0); for quartile IV: HR 0.82, 0.73 to 0.93 (MR per 100 000 people 356.0, 324.1 to 391.1)). In analyses restricted to laparoscopic surgery, volume and mortality were related only in the crude model (HR 0.86, 0.75 to 0.98), but not in the multivariable model (HR 0.97, 0.84 to 1.13) that compared highest and lowest quartiles. Conclusion If there was a survival benefit associated with hospital volume, it may have been due to a faster uptake of laparoscopic surgery in the busier hospitals. Currently there is a paucity of evidence concerning the influence of hospital volume on prognosis after bariatric surgery. This population-based cohort study, which included over 75 000 patients from Sweden and Finland who underwent bariatric surgery, suggests that higher annual hospital volume improves long-term survival.

Automated summary

This study evaluated the association between annual hospital volume of bariatric surgery and long-term survival in patients with severe obesity. The results showed that higher annual hospital volume was associated with a lower risk of all-cause mortality.