Long-term Clinical Outcomes and Health Care Utilization After Bariatric Surgery: A Population-based Study.

Objective: To determine the long-term outcomes, health care utilization, and risk factors for complications after bariatric surgery.

Background: With the burgeoning problem of obesity and the consequential rise in bariatric surgery, uncertainty remains as to whether this has been matched by a reduction in long-term health care utilization.

Methods: A population-based linked-data cohort study, utilizing a comprehensive set of data, including detailed comorbidity and complications, of each individual who had undergone bariatric surgery between 2007 and 2011 in Western Australia. Records were obtained via data linkage through the Western Australian Department of Health Data Linkage Unit. Every patient was followed for a minimum of 12-months after surgery or until death.

Results: A total of 12062 patients underwent bariatric surgery during the study period with a mean follow-up period of 41 months. Hospitalization rates after bariatric surgery were substantially reduced for all-cause (361 vs 501 per 1000 patient-years, P = 0.002) and diabetes mellitus-related (7 vs 31 per 1000 patient-years, P < 0.001) diagnoses when compared with hospitalization rates before bariatric surgery. Complications occurred in 2171 (18.0%) patients during the follow-up period. Patient age, sex, open surgical procedures, and Charlson Comorbidity Index were associated with an increased risk of complications, with age the most important and accounting for 77% of the variability in the risk of complications. Long-term all-cause mortality rate after surgery was extremely low (0.54 deaths per 1000 patient-years).

Conclusions: When measured against long-term safety outcomes, bariatric surgery has low mortality and morbidity associated with a significant reduction in subsequent hospitalizations.