Purpose:
Osteoporosis and its consequence of fracture represent a public health problem in Vietnam. Approximately 30% of postmenopausal women are having osteoporosis. Antiresorptive therapies such as alendronate and zoledronate are first-line treatments of osteoporosis in Vietnam. Recently, the health insurance has limited the number of hospitals reimburse these drugs but the cost-effectiveness has never been studied in the country. This study was undertaken to evaluate the cost-effectiveness of alendronate and zoledronate in postmenopausal women to provide evidence for future decision making.
Method:
A Markov decision model was utilized, using health system perspective to follow a cohort of Vietnamese women aged 50 years and older who were participants of the Vietnam Osteoporosis Study. Oral alendronate 70 mg/week and zoledronate 5 mg/year were compared with no treatment. The entire cohort started in the ‘osteoporosis’ state, and then transitioned to other health states including ‘hip fracture’, ‘vertebral fracture’, ‘post-hip fracture’, and ‘post-vertebral fracture’ until death or age 100. The incremental cost-effectiveness ratio (ICER) was calculated as incremental costs divided by incremental QALYs for each age group. A threshold of 3 GDP per capita was applied. Unit costs were derived from Vietnam Ministry of Health database, all costs were adjusted to 2015 US dollars ($) and includes only direct cost. Costs and effectiveness were discounted at 3% per year. One-way and probabilistic sensitivity analyses were used to incorporate the impact of parameters uncertainty.
Result:
For all age group, zoledronate presented the highest cost and QALY, followed by alendronate. Zoledronate presented the most cost-effective treatment in all groups at a willingness-to-pay threshold of 3 GDP per capita. At age 65, both alendronate and zoledronate had the lowest ICER of 1597$/QALY and 1812$/QALY, respectively. In one-way sensitivity analysis, the cost of post-fracture and treatment adherence has the highest impact on the cost-effectiveness of therapies. In probability sensitivity analysis, zoledronate had the probability of being the most cost-effective from 68%-98% at the age group from 50 to 80. The results were robust.
Conclusion:
Zoledronate acid presented the most cost-effective therapy at a willingness-to-pay threshold of 3 GDP per capita in all age group.
Authors: Van Pham Nu Hanh, Binh Nguyen Thanh, Phuc Le Hong, Tung Dang Pham, Lan Ho Pham Truc, Son Pham Luong, Tuan Nguyen Van
Source: Van H. N. Pham, Binh T. Nguyen, Phuc H. Le, Tung D. Pham, Lan T. Ho-Pham, Tuan V. Nguyen, Cost-effectiveness of alendronate and zoledronate for osteoporosis treament: an analysis in Vietnamese women, 39th Annual North American Meeting, Pittsburgh, United state, October 22 - October 25, 2017