OBJECTIVES: Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by bone fragility leading to frequent fractures and skeletal deformities. OI imposes a significant burden on people living with OI with shortened life expectancy and poor health-related quality-of-life (HRQOL), as well as payers through increased health care resource utilization. There is a significant unmet need for treatment options in OI. The objective of this study was to develop and validate a de novo health economic model that could be used for future health economic evaluations in OI.

METHODS: A health economic model was developed in Microsoft Excel to estimate patient health outcomes over a lifetime horizon in people with OI. The model utilized a discrete event simulation framework, with model cycles defined by fracture incidence. The model captured patient mobility, with capabilities defined as walking unassisted, requiring crutches, and requiring a wheelchair. The development of thoracic deformities was also considered. Mortality was modelled based on general population mortality, with additional hazards applied based on patients’ mobility status and presence of thoracic deformities. Estimated patient survival and fracture incidence were compared with published estimates in OI to validate the model.

RESULTS: The model predicted life expectancy and fracture incidence in line with published OI literature. It predicted overall survival of 69.8, 33.4, and 61.9 in people with Type I, III, and IV OI, in comparison with 73.4, 30.4, and 66.7 in the published literature (-4.9%, +9.8%, -8.5%, respectively). Similarly, fracture incidence was well aligned with published estimates, with lifetime fracture incidence of 33, 50, and 46 fractures per patient for Type I, III, and IV OI, respectively (-2.9%, +4.2%, -9.8%, versus literature-derived estimates).

CONCLUSIONS: The developed health economic model robustly captures health outcomes in people with OI and has the potential to be used for future health economic analyses in OI.