Purpose: According to the current Norwegian guidelines based on cost-effectiveness, only women at high risk of fracture (i.e. previous fracture and a t-score less than -1.6 or t-score ≤ -2.5 without fracture) should receive the first-line alendronate. The purpose of this study was to guide revision of osteoporosis guidelines to account for price reductions because alendronate went generic.
Method: We developed a Markov cohort model with hip fracture, vertebral fracture and wrist fracture and four sequelae states (mild, moderate and severe hip and vertebral fracture sequela). We analysed women aged 55, 65 and 75 with t-score of -1.5, -2.0 and -2.5without fracture and with t-score -2 with fracture. We modelled five years of treatment with vitamin D and calcium alone versus vitamin D and calcium plus 70 mg alendronate weekly. The cohorts were followed until death or 100 years of age. Unit prices were based on Norwegian tariffs and resource consumption on published literature and expert opinions. Quality of life population norms and multipliers were gathered from published literature. Efficacy data were based on meta-analyses of published RCTs.
Result: In 65 old women with a t-score of –2.0 and no previous fracture, the expected discounted life costs of fracture treatment is $491,180 without treatment and $486,273 with alendronate, while the expected discounted QALYs are 10.1103 and 10.1115, representing a cost saving of $ 4,304,037per QALY. Assuming a willingness to pay per QALY of $77,000, alendronate is cost effective for all groups aged 65 or older with a probability of 70% or higher. For women aged 55, alendronate was cost effective for a t-score of -2 and a previous fracture with a probability of 77%.
Conclusion: With current price levels alendronate treatment for five years is likely to be cost-effective in all women 65 years and older with t-scores of less than -1.5.
Candidate for the Lee B. Lusted Student Prize Competition