Five-Year CT Follow-Up of Vertebral Fracture Risk Using Opportunistic Osteoporosis Screening

Primary objective: To assess the predictive performance of opportunistic volumetric bone mineral density (vBMD) from routine thoracoabdominal CT scans for incident vertebral fractures over 5 years or longer.

Secondary objectives:

• To compare the performance of vBMD to predict incident vertebral fractures with other predictors, including demographic and clinical risk factors, FRAX algorithm scores for 5-year risk of major osteoporotic fractures (MOF), prevalent vertebral fractures, and prevalent clinical fractures, as well as combinations of these predictors.
• To stratify the analyses based on age decades and sex.
• To compare the predictive performance between CT scans with and without administration of i.v. contrast medium.
• To compare the predictive performance of vBMD (using asynchronous calibration) with Hounsfield units
• To describe the prevalence and incidence (in fractures per person-years) of the study population
• Assessment of the impact of a preventive treatment of patients at high risk of fracture in terms of the number of avoided fractures (simulation study)

Inclusion criteria

• Baseline CT and 5 years follow-up CT including parts of the lumbar spine

Exclusion criteria

• CT: No sagittal reformations or axial slices ≤3 mm
• CT: No inclusion of at least T6 to L4
• No BMI data available