Conflicting results exist about the relationship between bariatric surgery and fracture risk. Also, prediction of who is at increased risk of fracture post bariatric surgery is not currently available. Hence, we used a combination of a self-controlled case series (SCCS) study to establish the association between bariatric surgery and fracture, and develop a prediction model for post-operative fracture risk estimation using a cohort study. Patients from UK Primary care records from the Clinical Practice Research Datalink GOLD linked to Hospital Episode Statistics undergoing bariatric surgery with BMI≥30kg/m2 between 1997 and 2018 were included in the cohort. Those sustaining 1+ fracture/s in the 5 years before or after surgery were included in the SCCS. Fractures were considered in 3 categories: 1) Any except skull and digits (primary outcome), 2) major (hip, vertebrae, wrist/forearm and humerus) and 3) peripheral (forearm and lower leg). Of 5487 participants, 252 (4.6%) experienced 272 fractures (of which 80 were major and 135 peripheral) and were included in the SCCS analyses. Major fracture risk increased after surgery, incidence rate ratios (IRRs [95% CIs]) 2.77 (1.34, 5.75) and 3.78 (1.42, 10.08) at ≤3 years and 3.1-5 years post-surgery when compared to 5 years prior to surgery, respectively. Any fracture risk was higher only in the 2.1-5 years following surgery (IRR 1.73 (1.08, 2.77)) when compared to 5 years prior to surgery. No excess risk of peripheral fracture after surgery was identified. A prediction tool for major fracture was developed using 5487 participants included in the cohort study. It was also internally validated (AUC ROC 0.70) with anxiolytics/sedatives/hypnotics use and female as major predictors. Hence, major fractures are nearly three-fold more likely after bariatric surgery. A simple prediction tool with 5 variables identifies high risk patients for major fracture.
|Journal||Journal of Bone and Mineral Research|
|Early online date||25 Jun 2021|
|Publication status||E-pub ahead of print - 25 Jun 2021|
- general population studies
- fracture risk assessment
- statistical methods