PMS43 - AN ECONOMIC VALUE FRAMEWORK TO ASSESS THE COST EFFECTIVENESS OF FRACTURE PREVENTION TREATMENTS IN PATIENTS WITH OSTEOPOROSIS AT IMMINENT RISK OF FRACTURE

Abstract

Osteoporotic fractures increase the risk of subsequent fracture. This risk is distinctly elevated immediately after the fragility fracture (‘imminent risk’) and can remain elevated for 10 years, highlighting the importance of early identification and treatment. Treatment sequences for new bone-forming agents are being assessed for use in patients at imminent risk of fracture. Here, we describe a new cost-effectiveness model framework relevant to the use of bone-forming agents. We developed a Markov-microsimulation model to simulate the projected treatment pathway, quality adjusted life years (QALYs) and lifetime costs of a patient with a fragility fracture, with treatment sequencing and time since fracture as factors. The patient could switch treatment when a lack of response was confirmed, or at any time point, dependent on clinical practice. In each 6-month cycle, we assessed risk of subsequent hip, vertebral and non-hip/non-vertebral fracture, remaining without subsequent fracture, or death. Fracture risk was derived from FRAX® and imminent fracture risk algorithms, and was updated for each patient in the event of subsequent fracture. Hypothetical examples were used for illustrative purposes. Treatment with a bone-forming agent immediately after fragility fracture was compared with treatment given 2 years after fracture. In an illustrative 75-year old woman with an initial vertebral fracture, the 10-year cumulative risk of a subsequent fracture was 11% lower for immediate treatment versus treatment after 2 years, fracture-related costs were 6% lower, QALY gain was 0.0172 and total costs were £1,758 higher. Similar values were derived with a lifetime perspective. This new economic modelling framework allows an estimation of the consequences of recurring fragility fractures over time and of the utility of flexible treatment sequencing. Our model will enable future evaluation of the cost effectiveness of individual treatment strategies.