Purpose: To estimate the change in net health benefits of medication to prevent osteoporotic fracture if patients perceive a small disutility from having to take medication.
Methods: Fifty percent of those treated to prevent osteoporotic fracture stop the medication prematurely within one year. A significant subset of patients dislike taking medication even if they have no side effects due to a sense of being dependent on them, altered personal identity, and/or fear of harm from taking them. A substantial number of osteoporosis patients need to be treated to prevent one fracture. We hypothesized that even a small decrement in quality of life from taking medication would significantly alter the cost-effectiveness of fracture prevention therapy. We used a previously validated Markov microsimulation model using the patient perspective to assess the lifetime net health benefits and costs per QALY gained for five years of bisphosphonate therapy compared to no therapy for two 65 year old Caucasian women with a femoral neck T-score of -2.5; one with no history of fracture, and another with a history of a prior fracture. For the base case analyses, we assumed willingness to pay per QALY gained of $50,000, discount rates of 3%, yearly out of pocket drug cost of $60, that patients out of pocket costs for fracture care would be 10% of total costs, and previously published rates, costs, and disutility estimates for hip, clinical vertebral, morphometric vertebral, wrist, and other fractures. We ran several models varying the assumed disutility from taking medication from zero to 0.04 QALY. We repeated these model runs assuming a) discount rates of 15%, and b) disutility estimates for fractures one half that of the base case.
Results: With no disutility from taking medication, treatment was dominant over no treatment. Net health benefits are diminished with increasing disutility from taking medication (figure), and become zero with disutilities ranging from 0.008 QALY (no prior fracture, discount rates 15%) to 0.036 (prior fracture, discount rates 3%). 
Conclusion: Perceived disutility from taking medication even in the absence of actual medication adverse events could substantially alter the cost-effectiveness of fracture prevention medication. More research is needed to characterize the implicit utility function patients employ when deciding whether or not to take fracture prevention medication.