Health economics of osteoporosis

Abstract: Health economics is concerned about how the scarce resources should most efficiently be allocated to maximise the health outcomes. Health economic evaluation is a method for assessing costs and benefits of alternative treatment strategies for allocating resources to assist decisions aiming at improving efficiency. Osteoporosis is a systemic skeletal disease characterised by low bone mass and micro architectural deterioration of bone tissue leading to increased bone fragility and thus an increased risk of fractures. Fractures are a burden to society, with respect to mortality, costs as well as quality of life. There are several treatments available for the prevention and treatment of osteoporosis. The general purpose of this thesis was to develop important aspects of the health economics of osteoporosis. More specifically, the aspects addressed were fracture related costs and quality of life for use in economic evaluation, economic modelling of osteoporosis therapies and health economics as a tool in treatment guidelines and patient selection (intervention thresholds). Data concerning costs and quality of life related to osteoporotic fractures in Sweden was collected in a prospective study that followed hip, vertebral and wrist fracture patients 18 months after fracture. The results for the first year after fracture indicate that hip fracture is associated with the highest costs whereas vertebral fracture leads to the largest loss in quality of life of the three types of fracture. Using computer simulation models the cost-effectiveness was assessed for two drugs: raloxifene and strontium ranelate. The cost-effectiveness of raloxifene compared to no treatment was estimated on Swedish women who were similar in characteristics to the women included in the Multiple Outcomes of Raloxifene study. The study was based on Swedish women who were similar in characteristics to the patients in the Spinal Osteoporosis Therapeutic Intervention study (SOTI) and Treatment Of Peripheral Osteoporosis Study (TROPOS). Compared to no treatment, both drugs were indicated to be cost-effective treatments. Intervention thresholds for osteoporosis can be defined as the ten-year risk of hip fracture at which intervention becomes cost-effective. Based on a Markov cohort model intervention thresholds were estimated for seven countries. The ten-year risk of hip fracture at which treatment becomes cost-effective varied between countries mainly due to differences in the willingness to pay (WTP) for a QALY gained, fracture related costs and intervention costs. Economic evaluation has become an important tool for evaluating the value for money of new medical technologies. However, much of the quality of an economic evaluation relies on the quality of the data used in the analysis. Using a new framework for collecting data on fracture related costs and quality of life this thesis has provided new information on costs and quality of life for fractures in Sweden, which will improve future economic evaluations of osteoporosis therapies. Moreover, this demonstrates that economic evaluation can be a tool for improving the selection of patients in clinical practice who are suitable for treatment, based on a cost-effectiveness criterion.