|Cost effectiveness of the German screen-and-treat strategy for postmenopausal osteoporosis
|Mueller D, Weyler E, Gandjour A
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
The objective was to determine the cost-effectiveness of a screening and treatment strategy, for postmenopausal osteoporosis, versus no intervention. The authors concluded that alendronate treatment with screening appeared to be cost-effective. Overall the methodology was good, and the methods and results were adequately reported. Given the scope of the analysis, the authors’ conclusions appear to be appropriate.
Type of economic evaluation
The objective was to determine the cost-effectiveness of a screening and treatment strategy for postmenopausal osteoporosis compared with no intervention, in the general population of German women aged between 50 and 90 years.
The intervention was screening and treatment for postmenopausal osteoporosis, using a strategy developed by the German osteology organisation; DVO (Dachverband Osteologie). In this strategy, women diagnosed with osteoporosis received alendronate, risedronate, or teriparatide.
Germany/out-patient secondary care.
A decision analytic Markov model with a one-year cycle length was used to simulate the costs and effects. A lifetime horizon was used and the authors reported that the perspective was that of the German statutory health insurer.
A literature search, for the effectiveness estimates, identified meta-analyses and randomised controlled trials (RCTs), published between January 2005 and June 2006. For other model parameters, such as mortality, absolute fracture risk and incidence, and diagnostic sensitivity and specificity, the data were derived from a number of sources including routinely available statistics, published studies, and reports. The main measure of effectiveness was the proportion of fractures with each treatment, which was derived from published RCTs and meta-analyses.
Monetary benefit and utility valuations:
The health-related quality of life data were derived from the published literature. For the model state of no fracture, the quality of life data were estimated using a time trade-off questionnaire in the general population. For the health states of fractures, the quality of life data were derived using the European Quality of life (EQ-5D) questionnaire and expert opinion.
Measure of benefit:
Quality-adjusted life-years (QALYs) were the measure of benefit.
The direct costs to the health care insurer were used and these included: screening and diagnosis, which included the costs of false positives and follow-up; anti-osteoporotic drugs; treatment of fractures; and general health care costs resulting from additional years of life. Co-payments made by patients were not included. The costs of screening, diagnosis, and medication were derived from estimates in German guidelines, price lists for out-patient treatment, and a public database of medication costs. In-patient costs were derived using weighted average diagnosis-related group data. Out-patient treatment costs were calculated using data from a large random sample survey. The price year was 2006 and all prices were in Euros (EUR). As costs could be incurred over the lifetime of the patient, all future costs were discounted at an annual rate of 3%.
Analysis of uncertainty:
A series of one-way sensitivity analyses was undertaken on all the model inputs by varying them within the limits of the uncertainty ranges obtained from the literature. In addition, the authors undertook a probabilistic sensitivity analysis by fitting the model parameters with probability distributions. A Monte Carlo simulation, with 1,000 iterations, was performed and the results were reported as a cost-effectiveness acceptability curve. This provides the probability of a given intervention being cost-effective at a willingness-to-pay for each QALY gained.
The QALYs gained with no intervention ranged from 2.796 for women aged 80 to 90 years to 12.055 for women aged 50 to 60 years. With screening and alendronate, they ranged from 3.153 for women aged 80 to 90 years to 12.216 for women aged 50 to 60 years. With screening and risedronate they ranged from 3.084 for women aged 80 to 90 years to 12.198 for women aged 50 to 60 years. With screening and teriparatide they ranged from 2.961 for women aged 80 to 90 years to 12.137 for women aged 50 to 60 years.
The lifetime costs per patient with no intervention ranged from EUR 47,379 for women aged 80 to 90 years to EUR 74,227 for women aged 60 to 70 years. With screening and alendronate they ranged from EUR 48,212 for women aged 80 to 90 years to EUR 78,621 for women aged 60 to 70 years. With screening and risedronate they ranged from EUR 48,289 for women aged 80 to 90 years to EUR 78,542 for women aged 60 to 70 years. With screening and teriparatide they ranged from EUR 52,081 for women aged 80 to 90 years to EUR 90,622 for women aged 60 to 70 years.
The costs and benefits were combined in an incremental cost-utility ratio (ICUR), which is the additional cost per QALY gained, compared with no screening.
For women aged 50 to 60 years, the ICUR was EUR 3,849 for screening and alendronate, EUR 4,570 for screening and risedronate, and EUR 50,036 for screening and teriparatide.
For those aged 60 to 70 years, it was EUR 16,589 for screening and alendronate, EUR 20,485 for screening and risedronate, and EUR 124,165 for screening and teriparatide.
For those aged 70 to 80 years, it was EUR 6,600 for screening and alendronate, EUR 7,827 for screening and risedronate, and EUR 62,687 for screening and teriparatide.
For those aged 80 to 90 years, it was EUR 2,337 for screening and alendronate, EUR 3,159 for screening and risedronate, and EUR 28,550 for screening and teriparatide.
The results of the sensitivity analysis showed that screening and alendronate was superior in all age groups, followed by screening and risedronate. At a willingness to pay of EUR 10,000 per QALY gained, both these interventions had a probability of being cost-effective of over 65% in women aged 50 to 60 years and approximately 90% in women aged over 80 years. For women aged 70 to 80 years, the probability of cost-effectiveness was over 50% for alendronate and over 15% for risedronate.
The authors concluded that alendronate treatment with screening appeared to be cost-effective compared with other generally accepted medical interventions.
The interventions were reported clearly and in detail.
The effectiveness data were derived from a literature review identifying randomised controlled trials (RCTs) and meta-analyses. The results of RCTs and meta-analyses are considered to be the gold standard, and the internal validity of this data is likely to be high. The authors reported some of the details of their review, such as the inclusion criteria, and they provided more details in supplementary material.
The perspective was clearly reported and all the relevant cost categories were included. As the authors pointed out, some costs were not included such as those of medications other than for osteoporosis, such as analgesics, muscle relaxants and antibacterials. The treatment costs for vertebral fractures in the years following the fracture, and fracture costs at skeletal sites other than the hip, vertebra or forearm were not included. The authors concluded that these omissions may have led to an underestimate of the potential cost savings from the prevention of fractures. The sources of unit costs and resource use data were appropriately reported. The price year, time horizon, discount rate, and currency were all reported.
Analysis and results:
The model used to synthesise the evidence was adequately reported, with diagrams. The impact of uncertainty was thoroughly investigated in a series of one-way and probabilistic sensitivity analyses. Probabilistic sensitivity analysis is considered to be the gold standard in the UK, as it assesses the overall uncertainty in all the model parameters. The authors reported the main limitations of their analysis.
Overall the methodology was good, and the methods and results were adequately reported. Given the scope of the analysis, the authors’ conclusions appear to be appropriate.
Mueller D, Weyler E, Gandjour A. Cost effectiveness of the German screen-and-treat strategy for postmenopausal osteoporosis. PharmacoEconomics 2008; 26(6): 513-536
Other publications of related interest
Liu H, Michaud K, Nayak S, et al. The cost-effectiveness of therapy with teriparatide and alendronate in women with severe osteoporosis. Archives of Internal Medicine 2006; 166: 1209-1217.
Kanis JA, Johnell O, Oden A, et al. Intervention thresholds for osteoporosis in men and women: a study based on data from Sweden. Osteoporosis International 2005; 16: 6-14.
Chrischilles E, Shireman T, Wallace R. Costs and health effects of osteoporotic fractures. Bone 1994; 15(4): 377-386.
Subject indexing assigned by NLM
Absorptiometry, Photon /economics; Aged; Aged, 80 and over; Bone Density Conservation Agents /economics /therapeutic use; Cost-Benefit Analysis; Drug Costs; Female; Germany; Health Care Costs /statistics & Humans; Insurance, Health /economics; Markov Chains; Middle Aged; Models, Statistical; Osteoporosis, Postmenopausal /diagnosis /drug therapy /economics; Practice Guidelines as Topic; numerical data /trends
Date bibliographic record published
Date abstract record published