Cost-effective osteoporosis treatment thresholds: the United States perspective

A perspective on male osteoporosis

Osteoporosis and fragility fracture become common with advancing age in men. The incidence of osteoporosis-related fracture is similar to myocardial infarction and exceeds that of lung and prostate carcinoma combined. These fractures cause substantial morbidity, and the mortality following hip fracture is greater in men than in women. A decline in sex steroids and glucocorticoid and alcohol use, among other factors, contribute to bone loss and fracture risk. Approaches to reduce fracture risk in men are very similar to that in women - recognising and addressing muscle weakness/falls risk and optimising nutrition, with emphasis on calcium and vitamin D and medications when appropriate. Despite the high prevalence, osteoporosis remains largely undiagnosed and undertreated. Hopefully, increased recognition of male osteoporosis by health-care providers and the men themselves, in combination with recent consensus recommendations for treatment based on fracture-risk estimation, will reduce the burden of fragility fracture in men.

The cost-effectiveness of strontium ranelate in the UK for the management of osteoporosis

The cost-effectiveness of strontium ranelate was compared to no treatment in UK women using the FRAX algorithm for fracture risk assessment. At a willingness-to-pay of pound 30,000 per quality-adjusted life-year (QALY), strontium ranelate was generally cost-effective in women with prior fracture at the threshold of osteoporosis from an age of 65 years.

INTRODUCTION

The objectives of the study were to estimate the cost-effectiveness of strontium ranelate in the UK for the treatment of osteoporosis and to establish intervention thresholds for treatment using the FRAX tool.

METHODS

The cost-effectiveness of strontium ranelate was compared to no treatment in postmenopausal women with clinical risk factors for fracture using a lifetime simulation model based on Markov cohort methodology that incorporated the features of FRAX.

RESULTS

At a threshold of pound 30,000 per QALY, strontium ranelate was generally cost-effective in women from an age of 65 years with prior fracture at the threshold of osteoporosis (i.e., a T-score of -2.5 SD) and in women with a prior fracture (and no information on bone mineral density) from the age of 65 years. At a threshold of pound 20,000, strontium ranelate became cost-effective at a 10-year fracture probability of 25.7% and at 16.9% with a threshold of pound 30,000 for a QALY.

CONCLUSIONS

Strontium ranelate is a cost-effective agent for the treatment of established osteoporosis in women over the age of 65 years. Cost-effective scenarios were also found for the prevention and treatment of fractures associated with osteoporosis, in younger women with additional clinical risk factors.

Evidence-based medicine, clinical practice guidelines, and common sense in the management of osteoporosis

OBJECTIVE

To evaluate the benefits and limitations of randomized controlled trials (RCTs), clinical practice guidelines (CPGs), and clinical judgment in the management of osteoporosis.

METHODS

A review was conducted of the English-language literature on the origins and applications of RCTs, CPGs, evidence-based medicine, and clinical judgment in the management of osteoporosis.

RESULTS

Evidence-based medicine is use of the currently available best evidence in making clinical decisions for individual patients. CPGs are recommendations for making clinical decisions based on research evidence, sometimes with consideration of expert opinion, health care policy, and costs of care. The highest levels of medical evidence are usually thought to be RCTs and meta-analyses of high-quality RCTs. Although it is desirable and appropriate for clinicians to consider research evidence from RCTs and recommendations presented in CPGs in making clinical decisions, other factors-such as patient preference, comorbidities, affordability, and availability of care-are important for the actual implementation of evidence-based medicine.

CONCLUSION

Decisions about who to treat, which drug to use, how best to monitor, and how long to treat require clinical skills in addition to knowledge of medical research. The necessity of integrating common sense and clinical judgment is highlighted by the fact that many patients treated for osteoporosis in clinical practice would not qualify for participation in the pivotal clinical trials that demonstrated efficacy and safety of the drugs used to treat them.

A comparison of prediction models for fractures in older women: is more better?

BACKGROUND

A Web-based risk assessment tool (FRAX) using clinical risk factors with and without femoral neck bone mineral density (BMD) has been incorporated into clinical guidelines regarding treatment to prevent fractures. However, it is uncertain whether prediction with FRAX models is superior to that based on parsimonious models.

METHODS

We conducted a prospective cohort study in 6252 women 65 years or older to compare the value of FRAX models that include BMD with that of parsimonious models based on age and BMD alone for prediction of fractures. We also compared FRAX models without BMD with simple models based on age and fracture history alone. Fractures (hip, major osteoporotic [hip, clinical vertebral, wrist, or humerus], and any clinical fracture) were ascertained during 10 years of follow-up. Area under the curve (AUC) statistics from receiver operating characteristic curve analysis were compared between FRAX models and simple models.

RESULTS

The AUC comparisons showed no differences between FRAX models with BMD and simple models with age and BMD alone in discriminating hip (AUC, 0.75 for the FRAX model and 0.76 for the simple model; P = .26), major osteoporotic (AUC, 0.68 for the FRAX model and 0.69 for the simple model; P = .51), and clinical fracture (AUC, 0.64 for the FRAX model and 0.63 for the simple model; P = .16). Similarly, performance of parsimonious models containing age and fracture history alone was nearly identical to that of FRAX models without BMD. The proportion of women in each quartile of predicted risk who actually experienced a fracture outcome did not differ between FRAX and simple models (P > or = .16).

CONCLUSION

Simple models based on age and BMD alone or age and fracture history alone predicted 10-year risk of hip, major osteoporotic, and clinical fracture as well as more complex FRAX models.

The potential impact of new National Osteoporosis Foundation guidance on treatment patterns

This analysis of National Health and Nutrition Examination Survey III data describes the prevalence of risk factors for osteoporosis and the proportions of men and postmenopausal women age 50 years and older who are candidates for treatment to lower fracture risk, according to the new FRAX-based National Osteoporosis Foundation Clinician's Guide.

INTRODUCTION

Little information is available on prevalence of osteoporosis risk factors or proportions of US men and women who are potential candidates for treatment.

METHODS

The prevalence of risk factors used in the new National Osteoporosis Foundation (NOF) FRAX-based Guide to the Prevention and Treatment of Osteoporosis was estimated using data from the third National Health and Nutrition Examination Survey (NHANES III). Risk factors not measured in NHANES III were simulated using World Health Organization cohorts. The proportion of US men and postmenopausal women age 50+ years who are treatment candidates by the new NOF Guide were calculated; for non-Hispanic white (NHW) women, the proportion eligible by the new NOF Guide was compared with that based on an earlier NOF Guide.

RESULTS

Twenty percent of men and 37% of women were potential candidates for treatment to prevent fractures by the new NOF Guide. Among NHW women, 53% were potential candidates by the previous NOF Guide compared with 41% by the new guide.

CONCLUSIONS

One fifth of men and 37% of postmenopausal women are eligible for osteoporosis treatment consideration by the new NOF Guide. However, fewer NHW women are eligible by the new guide than by the previous NOF Guide.

Update in male osteoporosis

CONTEXT

Osteoporosis in men is becoming an increasingly important public health problem. One in five men over the age of 50 yr will suffer an osteoporotic fracture during their lifetime, and men who sustain fractures have an increased mortality risk.

EVIDENCE ACQUISITION

Evidence was obtained by PubMed search and author's knowledge of the field.

EVIDENCE SYNTHESIS

Studies using computed quantitative tomography and high-resolution peripheral computed quantitative tomography have provided new insights into the bone structural changes with aging in men, including the somewhat surprising demonstration of significant, ongoing trabecular bone loss starting in young adult life. In addition, there are now data demonstrating that serum estradiol levels are important predictors of fracture risk in men and that there is a threshold estradiol level below which not only bone loss but also fracture risk increases markedly. Criteria for diagnosing and managing osteoporosis in men are also evolving, including the application of the fracture risk assessment tool to derive 10-yr fracture risks in men. Three bisphosphonates (alendronate, risedronate, and zolendronic acid) and teriparatide are currently U.S. Food and Drug Administration approved for the treatment of osteoporosis in men, with a number of new compounds, including a monoclonal antibody against receptor activator of nuclear factor-kappaB ligand, selective estrogen receptor modulators, and selective androgen receptor modulators in varying stages of development.

CONCLUSIONS

Despite significant advances, there remain a number of key unresolved issues regarding the pathogenesis and management of male osteoporosis, not the least of which is increasing public awareness of this important cause of morbidity and mortality in men.

Application of the National Osteoporosis Foundation Guidelines to postmenopausal women and men: the Framingham Osteoporosis Study

We applied the 2008 National Osteoporosis Foundation (NOF) Guidelines to Framingham Osteoporosis Study participants and found nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

INTRODUCTION

Little is known about the public health impact of the NOF Guidelines. Therefore, we determined the proportion of US Caucasians recommended for treatment of osteoporosis according to NOF Guidelines (2003 and 2008).

METHODS

One thousand nine hundred and forty-six postmenopausal women and 1,681 men aged > or =50 years from the Framingham Study with information on bone mineral density (1987-2001) were included. Information on clinical predictors was used to estimate the 10-year probability of hip and major osteoporotic fracture by FRAX (version 3.0).

RESULTS

Overall proportion of women meeting treatment criterion was less when the 2008 NOF Guidelines were applied (41.1%) compared with 2003 Guidelines (47.8%). The proportion of women aged <65 years meeting treatment criterion was much less when applying 2008 Guidelines (23.1% in 2003, 8.3% in 2008), whereas the proportion of women aged >75 years increased slightly (78.3% in 2003, 86.0% in 2008). Seventeen percent of men aged > or =50 years met treatment criterion (2.5% aged 50-64 years, 49.8% aged >75 years).

CONCLUSIONS

Nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment according to 2008 NOF Guidelines. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

A blinded randomized controlled trial of motivational interviewing to improve adherence with osteoporosis medications: design of the OPTIMA trial

We have designed an innovative randomized controlled trial for improving adherence with osteoporosis medications. Recruitment and randomization have been successful. Also, the counseling intervention has been well accepted by subjects randomized to this treatment arm.

INTRODUCTION

While many effective treatments exist for osteoporosis, most people do not adhere to such treatments long term. No proven interventions exist to improve osteoporosis medication adherence. We report here on the design and initial enrollment in an innovative randomized controlled trial aimed at improving adherence to osteoporosis treatments.

METHODS

The trial represents a collaboration between academic researchers and a state-run pharmacy benefits program for low-income older adults. Beneficiaries beginning treatment with a medication for osteoporosis are targeted for recruitment. We randomize consenting individuals to receive 12 months of mailed education (control arm) or an intervention consisting of one-on-one telephone-based counseling and the mailed education. Motivational interviewing forms the basis for the counseling program which is delivered by seven trained and supervised health counselors over ten telephone calls. The counseling sessions include scripted dialog and open-ended questions about medication adherence and its barriers, as well as structured questions. The primary end point of the trial is medication adherence measured over the 12-month intervention period. Secondary end points include fractures, nursing home admissions, health care resource utilization, and mortality.

RESULTS

During the first 7 months of recruitment, we have screened 3,638 potentially eligible subjects. After an initial mailing, 1,115 (30.6%) opted out of telephone recruitment and 1,019 (28.0%) could not be successfully contacted. Of the remaining, 879 (24.2%) consented to participate and were randomized. Women comprise over 90% of all groups; mean ages range from 77 to 80 years old, and the majority in all groups was white. The distribution of osteoporosis medications was comparable across groups and the median number of different prescription drugs used in the prior year was eight to ten.

CONCLUSIONS

We have developed a novel intervention for improving osteoporosis medication adherence. The intervention is currently being tested in a large-scale randomized controlled trial. If successful, the intervention may represent a useful model for improving adherence to other chronic treatments.

Updated fracture incidence rates for the US version of FRAX

On the basis of updated fracture and mortality data, we recommend that the base population values used in the US version of FRAX be revised. The impact of suggested changes is likely to be a lowering of 10-year fracture probabilities.

INTRODUCTION

Evaluation of results produced by the US version of FRAX indicates that this tool overestimates the likelihood of major osteoporotic fracture. In an attempt to correct this, we updated underlying fracture and mortality rates for the model.

METHODS

We used US hospital discharge data from 2006 to calculate annual age- and sex-specific hip fracture rates and age-specific ratios to estimate clinical vertebral fracture rates. To estimate the incidence of any one of four major osteoporotic fractures, we first summed these newly derived hip and vertebral fracture estimates with Olmsted County, MN, wrist and upper humerus fracture rates, and then applied 10-20% discounts for overlap.

RESULTS

Compared with rates used in the current FRAX tool, 2006 hip fracture rates are about 16% lower, with greatest reductions observed among those below age 65 years; major osteoporotic fracture rates are about one quarter lower, with similar reductions across all ages.

CONCLUSIONS

We recommend revising the US-FRAX by updating current base population values for hip fracture and major osteoporotic fracture. The impact of these revisions on FRAX is likely to be lowering of 10-year fracture probabilities, but more precise estimates of the impact of these changes will be available after these new rates are incorporated into the FRAX tool.

The effects of a FRAX revision for the USA

A revision (version 3.0) of the fracture risk assessment tool (FRAX) is developed based on an update of epidemiological information for the USA. With the revised tool, there were strong correlations (r > 0.99) between versions 2.0 and 3.0 for FRAX estimates of fracture probability, but the revised models gave lower probability estimates.

INTRODUCTION

The aim of this study was to determine the effects of a revision of the epidemiological data used to compute fracture probabilities in the USA with FRAX.

METHODS

Models were constructed to compute fracture probabilities based on updated fracture incidence and mortality rates in the USA. The models comprised the ten-year probability of hip fracture and the ten-year probability of a major osteoporotic fracture, both including femoral neck bone mineral density (BMD). For each model, fracture and death hazards were computed as continuous functions. The effect of the revised rates on fracture probability was examined by piecewise linear regression using multiple combinations of clinical risk factors and BMD.

RESULTS

At all ages, there was a strong correlation (r > 0.99) between version 2.0 and revised FRAX estimates of fracture probability. For a major osteoporotic fracture, the revised model gave lower median probabilities by 13% to 24% in men, depending on age, and by 19% to 24% in women. For hip fracture probability, the revised model gave lower median fracture probabilities by 40% and 27% at the ages of 50 and 60 years in men and by 43% and 30%, respectively, in women. At the ages of 70 years and older the revised model gave similar hip fracture probabilities as version 2.0 in both men and women.

CONCLUSION

The revised FRAX model for the USA (version 3.0) does not alter the ranking of fracture probabilities but provides lower probability estimates than version 2.0, particularly, in younger women and men.

Physician follow-up care for osteoporosis after fragility fractures

Osteoporosis affects > 10 million Americans each year. The disease is characterized by low bone mass and decreased bone strength, and patients often sustain fragility fractures. Previous research highlights low rates of identification and treatment of the disease after a fragility fracture, yet patients are still overlooked. This study identified patients who did not receive proper osteoporosis care after a fragility fracture in Southeastern Pennsylvania. In a telephone interview, we asked patients who had sustained a fragility fracture in 2008 and were treated at one orthopedic practice about information on events before and after their fractures. We concluded that a patient's bone health had suboptimal care if, after the fracture, the patient had no doctor interview, did not receive bone mineral density testing, and did not begin or change medications. Of the 224 patients who participated in our study, we determined that 149 (67%) patients received insufficient osteoporosis care. One hundred fourteen (63%) women and 35 (80%) men received inadequate osteoporosis care. The high incidence of unsatisfactory care, particularly in men, indicates that osteoporosis care continues to be a problem. We believe that one contributing factor is physician accountability for care. Our study indicates that no specific specialist takes responsibility for follow-up care, possibly signifying the lack of an adequate system for identifying and treating the disease. The opportunity to address this issue should be a high priority for both primary care physicians and orthopedic surgeons.

Can fall risk be incorporated into fracture risk assessment algorithms: a pilot study of responsiveness to clodronate

SUMMARY

Fall risk does not significantly impact on the efficacy of the bisphosphonate clodronate in reducing the incidence of fracture.

INTRODUCTION

The debate about the efficacy of skeletal therapies on fracture risk in women at increased risk of falling continues. We determined whether fall risk impeded the efficacy of clodronate to reduce osteoporotic fracture incidence.

METHODS

This is a post hoc analysis of a 3-year placebo-controlled study of bisphosphonate clodronate involving 5,212 women aged 75 years or more. At entry, self-reported multiple falls in the previous month and ability to rise from a chair were documented. Their interaction with treatment efficacy was examined using Poisson regression.

RESULTS

Oral doses of clodronate at 800 mg daily reduced osteoporotic fracture incidence by 24% (hazard ration (HR) 0.76, 95% confidence interval 0.63-0.93). The efficacy was similar in women with recent multiple falls compared to those without (HR 0.61 vs. 0.77, p value for interaction >0.30) or impaired ability in rising compared to those with no impairment (HR 0.79 vs. 0.74, respectively; p value > 0.30).

CONCLUSION

Fall risk does not significantly impact on the anti-fracture efficacy of clodronate. If confirmed with other agents, fall risk may be incorporated into risk assessment tools designed to target skeletal therapies.

Lasofoxifene for the prevention and treatment of postmenopausal osteoporosis

Lasofoxifene is a selective estrogen receptor modulator (estrogen agonist/antagonist) that has completed phase III trials to evaluate safety and efficacy for the prevention and treatment of osteoporosis and for the treatment of vaginal atrophy in postmenopausal women. In postmenopausal women with low or normal bone mineral density (BMD), lasofoxifene increased BMD at the lumbar spine and hip and reduced bone turnover markers compared with placebo. In women with postmenopausal osteoporosis, lasofoxifene increased BMD, reduced bone turnover markers, reduced the risk of vertebral and nonvertebral fractures, and decreased the risk of estrogen receptor-positive breast cancer. In postmenopausal women with low bone mass, lasofoxifene improved the signs and symptoms of vulvovaginal atrophy. Clinical trials show that lasofoxifene is generally well tolerated with mild to moderate adverse events that commonly resolve even with drug continuation. Lasofoxifene has been associated with an increase in the incidence of venous thromboembolic events, hot flushes, muscle spasm, and vaginal bleeding. It is approved for the treatment of postmenopausal women at increased risk for fracture in some countries and is in the regulatory review process in others.

[Economic concepts for measuring the costs of illness of osteoporosis: an international comparison]

Worldwide osteoporosis is underestimated and despite availability of effective and cost effective treatments, these are often not implemented. Apart from a demographically driven increase in disease cases, failure to implement or tardy implementation of preventive measures as well as poor treatment compliance leads to a deterioration of the health economic outcomes. This in turn causes considerable costs to the health care system and to society, through ineffective intake of medication, diminished quality of life and inability to work as well as substantial costs of rehabilitation of patients. Health economic analyses and methods are increasingly used by decision makers to set priorities and evaluate alternative treatment measures about their cost-effectiveness. In order to be able to capture the costs of illness incurred by osteoporosis, different diseases specific models and methods have been developed, such as the reference model of the IOF, an osteoporosis-specific Markov model or internationally comparable intervention thresholds. Health economists estimate that osteoporosis-related costs will double by 2050 in both Europe and the individual countries. For Europe this means an increase from 40 billion Euro in 2000 to almost 80 billion Euro in 2050. In Austria, an aggregation of the different costs of osteoporosis is not possible, due to a lack of comparability and availability of data. The international ICUROS study and the Austrian Osteoporosis Report 2007 are the first steps towards counteracting this situation.

FRAX®: a fracture risk-assessment tool

There is a need to identify patients with osteopenia who are at high risk of sustaining fractures and who would benefit from treatment, since many patients with osteopenia do not sustain fractures. In 2008, the WHO unveiled the fracture risk-assessment tool (FRAX®), which calculates the 10-year probability of a patient sustaining a fracture. It is available on the internet free of charge, and represents a major step forward since it takes into account a number of risk factors and allows clinicians to focus on those patients at high risk of sustaining fractures, in whom the benefits of treating a silent disease outweigh the potential adverse effects and cost. In the USA, the National Osteoporosis Foundation has suggested a fracture threshold to recommend treatment. In this article, the various risk factors included in the FRAX tool are briefly reviewed, and the advantages, potential limitations and possible future developments are discussed.

Trends in hip fracture epidemiology in Australia: possible impact of bisphosphonates and hormone replacement therapy

The purposes of this study were to analyse trends in hip fracture (HF) epidemiology over a 13-year period (1994-2007) in the Australian Capital Territory (ACT), to assess the potential impact of concurrent changes in hormone replacement therapy (HRT) and bisphosphonate use and to present a new prediction of HFs in Australia up to 2021. Annual sex- and age-specific incidence rates (per 100,000 population) were determined and standardized using the Australian 2006 population. The projected number of HFs was estimated by two models applying age- and sex-specific HF rates averaged for 2002-2006 (model 1) or continuously changing as observed in this period (model 2, Poisson regression) to the projected population. In 2006 compared to 2001, the population > or = 60 years in the ACT increased by 19.7%. Over the last 5 years the average annual incidence HF rate compared to the previous 3-year period decreased in females > or = 60 years of age by 28.3%. Between 2001 and 2006 the number of prescriptions for HRT dispensed in the ACT declined by 54.6, while the number of prescriptions for bisphosphonate increased by 245%, accompanied by a decline in standardized incidence of HF rates of 36.4%, mainly in women (42.1%). This represents an annual cost for bisphosphonates per one prevented HF, of $A45,250 or $A576 person/year. Compared to 2006 the total number of HFs in Australia according to model 1 will increase in 2011 by 20.1% and in 2021 by 58.8%, but according to model 2 will decrease by 15.5% in 2011 and 27.5% in 2021. Our data suggest that the previously predicted rising trend in HFs in elderly women reversed, but did not so for men. This was coincident with a significant fall in HRT use and increased prescribing of bisphosphonates, which is cost-effective. However caution should be used in attributing causation as this is an ecological study. If trends in HF observed in 2002-2006 continue, the absolute number of HFs in Australia in 2011-2021 will stabilise or decline (which is more likely), despite the rapid ageing of the population.

Population-based fracture risk assessment and osteoporosis treatment disparities by race and gender

BACKGROUND

Undertreatment of osteoporosis has been recognized as a common problem in selected patient subgroups. However, primary prevention has been hampered by limited risk assessment tools that can be applied to large populations.

OBJECTIVES

Using clinical risk factors with a new tool from the World Health Organization (FRAX) and recommendations from the National Osteoporosis Foundation (NOF), we evaluated fracture risk and osteoporosis treatment in a US cohort.

PARTICIPANTS

African Americans and Caucasians recruited from 2003-7 across the US as part of a longitudinal study.

DESIGN

Cross-sectional.

MEASURES

The number of persons receiving prescription osteoporosis medications was assessed by race, sex, and fracture risk. Multivariable logistic regression evaluated the association between receipt of osteoporosis medications and fracture risk after controlling for potential confounders.

RESULTS

Among 24,783 participants, estimated fracture risk was highest for Caucasian women. After multivariable adjustment for fracture-related risk factors, the likelihood of receipt of osteoporosis medications among African Americans was lower than among Caucasians [odds ratio (OR) = 0.44, 95% confidence interval (CI) 0.37, 0.53] and for men compared to women (OR = 0.08, 95% CI 0.06-0.10). Even for the highest risk group, Caucasian women with 10-year hip fracture risk > or = 3% (n = 3,025, 39.7%), only 26% were receiving treatment.

CONCLUSIONS

A substantial gap exists between 2008 NOF treatment guidelines based on fracture risk and the receipt of prescription osteoporosis medications. This gap was particularly notable for African Americans and men. FRAX is likely to be useful to assess risk at a population level and identify high-risk persons in need of additional evaluation.

Clinical assessment of fracture risk and novel therapeutic strategies to combat osteoporosis

OBJECTIVE

To review the latest tools in the clinical assessment of fracture risk and to review new and emerging options for osteoporosis therapy.

DESIGN

Retrospective analysis of published studies regarding the diagnosis and treatment of osteoporosis.

RESULT(S)

Large-scale epidemiologic data were recently assembled by the World Health Organization to produce a Web-based clinical assessment tool, FRAX, which uses clinical and historical data to provide prompt assessment and quantitation of fracture risk. The FRAX models were developed from studying population-based cohorts in Europe, North America, Asia, and Australia. The FRAX algorithms indicate the 10-year probability of hip fracture and the 10-year probability of a major osteoporotic fracture (at the clinical spine, forearm, hip, or shoulder) on which to base treatment decisions. Recent progress in the study of bone metabolism including anabolic pathways that enhance bone maintenance, is anticipated to improve the ways in which skeletal health can be maintained and osteoporosis can be treated.

CONCLUSION(S)

Using FRAX, fracture risk in now easily assessed in the clinical setting. New and emerging treatment strategies for bone maintenance are reviewed. Improved assessment of fracture risk, combined with tailored therapies for at-risk patients, will increase the number of patients who receive appropriate bone-sparing therapies.

Evaluating the Claim of Enhanced Persistence: The Case of Osteoporosis and Implications for Payers

Cost-effectiveness analysis (CEA) has been widely used in evaluating treatments for osteoporosis. To study the claim of enhanced persistence, this research determined the effects of persistence (the proportion of individuals who remain on treatment) and efficacy on incremental cost-effectiveness ratios (ICERs) for bisphosphonate treatment relative to no bisphosphonate treatment in the United States. For 2 age groups, 55 to 59 and 75 to 79, the authors relied on published fracture rates and applied them to 1000 postmenopausal osteoporotic patients with bone mineral density (BMD) T score ≤−2.5 during 3 years of treatment. After developing an algebraic ICER, with effectiveness measured by either quality-adjusted life years (QALYs) gained or number of fractures averted, they determined the effects of persistence and efficacy and then calibrated the model to variable estimates from the literature. For the younger (older) cohort, the cost per fracture averted was $66,606 ($18,256), consistent with a validated Markov simulation model. The effect of a 1 percentage point change in vertebral efficacy was 24 (5) times the effect of a 1 percentage point change in persistence for the younger cohort when QALYs (fractures) were involved. Nonvertebral efficacy had approximately 27 (9) times the effect of persistence. For the older cohort, the ratios were 15 (4.5) and 33 (10) for vertebral and nonvertebral fractures, respectively. In evaluating the claim of enhanced persistence, formulary decision makers need to exercise caution to ensure that efficacy is not compromised. Two drugs would have to be virtually identical in efficacy for better persistence to improve cost-effectiveness.

Bazedoxifene reduces vertebral and clinical fractures in postmenopausal women at high risk assessed with FRAX

INTRODUCTION

Bazedoxifene has been shown to significantly decrease the risk of vertebral fractures in postmenopausal women. No significant effect was noted on the risk of clinical fractures, but fracture risk reduction was reported in a post hoc subgroup analysis in a high risk group categorised on the basis of BMD and prior fracture.

AIMS

The aim of this study was to re-evaluate the efficacy of bazedoxifene on fracture outcomes avoiding subgroup analysis by examining the efficacy of intervention as a function of fracture risk.

METHODS

The phase III study was a double-blind, randomised, placebo- and raloxifene-controlled randomised 3-year multinational study that enrolled 7492 osteoporotic women aged 55 years or more (mean age=66 years). For the present analysis, women taking raloxifene were excluded (n=1849), and we compared the effects of two doses of bazedoxifene (20 and 40 mg daily combined) with placebo on the risk of all clinical fractures as well as the risk of morphometric vertebral fracture. The risk of a major osteoporotic fracture was assessed using region specific FRAX algorithms, and the relationship between pre hoc 10-year fracture probabilities and efficacy examined by Poisson regression.

RESULTS

Overall, bazedoxifene was associated with a significant 39% decrease in incident morphometric vertebral fractures (hazard ratio HR=0.61; 95% CI=0.43-0.86; p=0.005) and a non-statistically significant 16% decrease in all clinical fractures (hazard ratio HR=0.84; 95% CI=0.67-1.06; p=0.14) compared to placebo. Hazard ratios for the effect of bazedoxifene on all clinical fractures decreased with increasing fracture probability. In patients with 10-year fracture probabilities at or above 16%, bazedoxifene was associated with a significant decrease in the risk of all clinical fractures. The 16% probability threshold corresponded to the 80th percentile of the study population. Hazard ratios for the effect of bazedoxifene on morphometric vertebral fractures also decreased with increasing fracture probability. In patients with 10-year fracture probabilities above 6.9% (corresponding to the 41st percentile), bazedoxifene was associated with a significant decrease in the risk of morphometric vertebral fractures. At equivalent fracture probability percentiles, the treatment effect of bazedoxifene was greater on vertebral fracture risk than on the risk of all clinical fractures. For example, at the 90th percentile of FRAX probability, bazedoxifene was associated with a relative risk reduction of 33% (95% CI=7-51%) for all clinical fractures and 51% reduction (95% CI=21-69%) for morphometric vertebral fractures. The findings were robust to several sensitivity analyses.

CONCLUSION

Bazedoxifene (20 and 40 mg doses combined) significantly decreased the risk of all clinical fractures and morphometric vertebral fractures in women at or above a FRAX based fracture probability threshold. These results, consistent with the previous subgroup analysis, suggest that bazedoxifene should be targeted preferentially to women at high fracture risk.

Secreted frizzled related protein 1 is a target to improve fracture healing

Genetic studies have identified a high bone mass of phenotype in both human and mouse when canonical Wnt signaling is increased. Secreted frizzled related protein 1 (sFRP1) is one of several Wnt antagonists and among the loss-of-function mouse models in which 32-week-old mice exhibit a high bone mass phenotype. Here we show that impact fracture healing is enhanced in this mouse model of increased Wnt signaling at a physiologic level in young (8 weeks) sFRP1(-/-) mice which do not yet exhibit significant increases in BMD. In vivo deletion of sFRP1 function improves fracture repair by promoting early bone union without adverse effects on the quality of bone tissue reflected by increased mechanical strength. We observe a dramatic reduction of the cartilage callous, increased intramembranous bone formation with bone bridging by 14 days, and early bone remodeling during the 28-day fracture repair process in the sFRP1(-/-) mice. Our molecular analyses of gene markers indicate that the effect of sFRP1 loss-of-function during fracture repair is to accelerate bone healing after formation of the initial hematoma by directing mesenchymal stem cells into the osteoblast lineage via the canonical pathway. Further evidence to support this conclusion is the observation of maximal sFRP1 levels in the cartilaginous callus of a WT mouse. Hence sFRP1(-/-) mouse progenitor cells are shifted directly into the osteoblast lineage. Thus, developing an antagonist to specifically inhibit sFRP1 represents a safe target for stimulating fracture repair and bone formation in metabolic bone disorders, osteoporosis and aging.

FRAX and its applications to clinical practice

The introduction of the WHO FRAX algorithms has facilitated the assessment of fracture risk on the basis of fracture probability. FRAX integrates the influence of several well validated risk factors for fracture with or without the use of BMD. Its use in fracture risk prediction poses challenges for patient assessment, the development of practice guidelines, the evaluation of drug efficacy and reimbursement, as well as for health economics which are the topics outlined in this review.

Screening for osteoporosis in the adult U.S. population: ACPM position statement on preventive practice

CONTEXT

Osteoporosis is a common and costly disease that is associated with high morbidity and mortality. There is a lack of direct evidence supporting the benefits of bone mineral density (BMD) screening on osteoporosis outcomes. However, there is indirect evidence to support screening for osteoporosis given the availability of medications with good antifracture efficacy. This paper addresses the position of the American College of Preventive Medicine (ACPM) on osteoporosis screening.

EVIDENCE ACQUISITION

The medical literature was reviewed for studies examining the benefits and harms of osteoporosis screening. An overview is also provided of available modalities for osteoporosis screening, risk-assessment tools, cost effectiveness, benefits and harms of screening, rationale for the study, and recommendations from leading health organizations and ACPM. A review was done of English language articles published prior to September 2008 that were retrieved via search on PubMed, from references from pertinent review or landmark articles, and from websites of leading health organizations.

EVIDENCE SYNTHESIS

There were no randomized controlled trials (RCTs) of osteoporosis screening on fracture outcomes. However, there was one observational study that demonstrated reduced fracture incidence among recipients of BMD testing. Dual energy x-ray absorptiometry is currently one of the most widely accepted and utilized methods for assessing BMD. Other potential tests for detecting osteoporosis include quantitative ultrasound, quantitative computer tomography, and biochemical markers of bone turnover. Testing via BMD is a cost-effective method for detecting osteoporosis in both men and women. Osteoporosis risk-assessment tools such as the WHO fracture-risk algorithm are useful supplements to BMD assessments as they provide estimates of absolute fracture risks. They can also be used with or without BMD testing to assist healthcare providers and patients in making decisions regarding osteoporosis treatments.

CONCLUSIONS

All adult patients aged >or=50 years should be evaluated for risk factors for osteoporosis. Screening with BMD testing for osteoporosis is recommended in women aged >or=65 years and in men aged >or=70 years. Younger postmenopausal women and men aged 50-69 years should undergo screening if they have at least one major or two minor risk factors for osteoporosis. It is also recommended that clinicians consider using an osteoporosis risk-assessment tool to evaluate absolute fracture risk to determine appropriate osteoporosis therapies.

2008 Santa Fe Bone Symposium: update on osteoporosis

The Ninth Annual Santa Fe Bone Symposium was held on August 1-2, 2008, in Santa Fe, New Mexico, USA. The symposium faculty presented the current best evidence on selected topics of clinical relevance in the fields of osteoporosis, metabolic bone disease, and assessment of skeletal health. The educational venues were in the form of didactic presentations, panel discussions, challenging cases, and numerous interactive discussions. Knowledge of basic science and clinical trials was applied to real-world patient scenarios that were discussed by faculty experts and clinician participants. Topics included an update on the rationale and development of new agents for the treatment of osteoporosis, the use of bone turnover markers in clinical practice, hospital-based pathways for the management of hip fracture patients, injectable bisphosphonates for the treatment of osteoporosis, combination therapy with anabolic and antiresorptive agents, and assessment of skeletal health with devices other than central dual-energy X-ray absorptiometry. This is a collection of scientific essays based on presentations and discussions at the 2008 Santa Fe Bone Symposium.

Variance in 10-year fracture risk calculated with and without T-scores in select subgroups of normal and osteoporotic patients

The World Health Organization fracture risk assessment tool (FRAX) uses clinical risk factors to predict the patient's 10-yr probability of sustaining a hip or other major osteoporosis-related fracture. Inclusion of the femoral neck T-score is optional in the calculation. We evaluated the impact of including the T-score in the calculation of fracture risk and resultant treatment recommendation. We retrospectively reviewed charts of 180 white women scanned on a Hologic dual-energy X-ray absorptiometry (DXA). FRAX scores were calculated with T-scores (FRAX+) and without T-scores (FRAX-). We compared the National Osteoporosis Foundation (NOF) treatment recommendations (>or=20% risk of a major osteoporotic fracture or >or=3% risk of hip fracture for osteopenic patients) between FRAX+ and FRAX- scores. Agreement between FRAX+ and FRAX- was 89.4%. Disagreement occurred in 2 distinct subgroups of patients (10.6% of cases), that is, FRAX+ scores exceeded the NOF recommended treatment thresholds and FRAX- scores did not, or vice versa. One subgroup comprised older patients with normal T-scores for whom FRAX- scores exceeded the treatment threshold. The second subgroup comprised younger patients with high body mass index (BMI) and low T-scores for whom FRAX- scores did not exceed the treatment threshold. FRAX scores generated without T-scores may lead to treatment recommendations for patients who have normal bone mineral density and no treatment recommendations for patients who have osteoporosis. T-scores should be used for optimal application of FRAX.

New guidelines for the prevention and treatment of osteoporosis

The World Health Organization Fracture Risk Assessment Tool (FRAX) and the National Osteoporosis Foundation's (NOF) Clinician's Guide to Prevention and Treatment of Osteoporosis are helpful clinical tools in the management of osteoporosis. Appropriate use of these tools requires a clear understanding of their limitations as well as their benefits. Good clinical judgment should be the ultimate determinant of treatment decisions. We anticipate that further refinements to FRAX and subsequent updates of the NOF guide will improve their clinical utility.

Osteoporosis risk perceptions among patients who have sustained a fragility fracture

OBJECTIVE

To explore the perceptions of patients who have sustained a fragility fracture regarding their future fracture risk and the beliefs underlying their perceptions.

METHODS

Patients with fragility fracture participated in a telephone interview. Quantitative and qualitative methods were used to characterize patient characteristics and perspectives of future fracture risk. Content analysis of qualitative statements was independently performed by three investigators to identify common themes and contrasting statements, and the findings were discussed to ensure consensus.

RESULTS

Consistent themes were identified among participant responses irrespective of whether they responded "yes", "no" or "unsure" when asked whether they were at increased fracture risk: (1) patients' perception of risk was influenced by whether or not they believed they had osteoporosis, which may be altered by interaction with health care providers; (2) patients' had their own perceptions of their bone health; (3) patients' attributed their risk to their own actions or "carefulness"; and (4) patients' had specific beliefs about their fracture and determinants of fracture risk.

CONCLUSION

Patients who experience fragility fractures develop perceptions about future fracture risk that are influenced by interactions with health care providers, as well as beliefs about their fracture and beliefs that they can modify their risk.

PRACTICE IMPLICATIONS

Health care providers should discuss strategies for fracture prevention with all patients after fragility fracture to ensure that patients understand that participation in preventative behaviours can modify their risk.

Effectiveness of bisphosphonate therapy in a community setting

BACKGROUND

Osteoporosis is a major cause of morbidity and mortality. Clinical trials have shown the effectiveness of bisphosphonates, the most commonly prescribed treatments, in reducing fracture risk. The population-based effectiveness of bisphosphonates in clinical practice is uncertain.

METHODS

This retrospective cohort study used a matched design that compared time to clinical fracture in at-risk community women who initiated a bisphosphonate medication between 7/1/1996 and 6/30/2006 to those who did not. The study was conducted in an HMO in Oregon and Washington. Clinical electronic databases provided data. Eligible members were newly treated women aged > or = 55 years with either a BMD T-score of < or = -2.0 or a prior qualifying clinical fracture. They did not have contraindications for bisphosphonate therapy or a diagnosis associated with secondary osteoporosis (n=1829). They were matched to a similar comparison group (n=1829; total N=3658). The primary outcome was the first new incident fracture validated through chart review (closed clinical fracture of any bone except face, skull, finger, or toe or pathological fracture secondary to malignancy) during follow-up. An intention-to-treat analysis used Cox proportional hazards models to estimate the hazard ratio of fracture for treated relative to comparison patients, adjusting for differences in potential confounders.

RESULTS

Treated and comparison patients were similar in mean age (72.0 years) and history of fracture (about 45%). The treated group had more women with T-scores of < or = -2.5 (67.3% vs. 54.7%) and a lower mean weight (146.6 lb vs. 151.8 lb). Only about 45% of treated patients had a bisphosphonate medication possession ratio (MPR) of > or = 0.80. During follow-up, 198 (10.8%) of patients in the treated group had incident fractures, vs. 179 (9.8%) of patients in the comparison group. After adjustments, patients in the treated group were 0.91 (95% CI 0.74-1.13) as likely to have an incident fracture as the comparison patients (p=0.388). The treatment effect remained non-significant after accounting for MPR.

CONCLUSIONS

In this analysis of a community cohort of post-menopausal women at risk, the fracture risk of patients who received bisphosphonates did not differ significantly from those who did not. An enhanced understanding of this lack of treatment effect is urgently needed.

Denosumab for the Treatment of Postmenopausal Osteoporosis

Denosumab is an investigational fully human monoclonal antibody to RANKL, a cytokine member of the tumor necrosis factor family that is the principal mediator of osteoclastic bone resorption. RANKL stimulates the differentiation, activity and survival of osteoclasts, and is implicated in the pathogenesis of postmenopausal osteoporosis and other skeletal disorders associated with high rates of bone remodeling. By inhibiting the action of RANKL, denosumab reduces the differentiation, activation and survival of osteoclasts and slows the rate of bone resorption. Postmenopausal women with low bone mineral density treated with denosumab have an increase in bone mineral density and a reduction of bone turnover markers that is rapid, sustained and reversible. In postmenopausal women with osteoporosis, denosumab reduces the risk of vertebral, hip and nonvertebral fractures. Denosumab is well tolerated with a favorable safety profile.

Predictors of bone density testing in patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) are at increased risk of low bone density and fractures. This study identifies predictors of initiation of dual energy X-ray absorptiometry (DXA) testing in RA. We identified RA patients from the CORRONA registry with >or=1 year follow-up without reported DXA at study entry. The primary outcome was report of DXA in the first year of follow-up (DXA initiation). Variables associated with DXA initiation were considered for the multivariate model. Stepwise logistic regression identified independent predictors. Of the 2,717 RA patients without DXA documented at enrollment, 297 (11%) reported DXA initiation. Independent predictors of DXA initiation included age, female sex, history of fracture, steroid use, and physician's assessment of RA activity. In conclusion, DXA initiation in RA patients in the CORRONA cohort is low despite increased risk of osteoporosis. Predictors of DXA initiation include fracture, common risk factors for osteoporosis, and RA-associated factors.

Health economics of osteoporosis

Rather than reviewing the many studies of cost effectiveness in osteoporosis, this paper reviews the principles of cost-effectiveness analysis and the gaps in our knowledge that are required to improve such analyses in osteoporosis. These include more information on the cost of fractures and their consequences on health states, particularly on an international basis. New developments include the incorporation of adherence into models, the use of the FRAX tool to assess cost-effectiveness in individuals with any combination of risk factors for fracture, and the setting of intervention thresholds based on cost-effectiveness.

Case finding for the management of osteoporosis with FRAX--assessment and intervention thresholds for the UK

Assessment and intervention thresholds are developed and proposed in men aged over 50 years and postmenopausal women for the UK based on fracture probability from the WHO fracture risk assessment tool (FRAX).

INTRODUCTION

The FRAX tool has recently become available to compute the 10-year probability of fractures in men and women from clinical risk factors (CRFs) with or without the measurement of femoral neck bone mineral density (BMD). The aim of this study was to develop a case-finding strategy for men and women from the UK at high risk of osteoporotic fracture by delineating the fracture probabilities at which BMD testing or intervention should be recommended.

METHODS

Fracture probabilities were computed using the FRAX tool calibrated to the epidemiology of fracture and death in the UK. The relationship between cost effectiveness and fracture probability used the source data from a prior publication that examined the cost effectiveness of generic alendronate in the UK. An intervention threshold was set by age in men and women, based on the fracture probability equivalent to that of women with a history of a prior osteoporosis related fracture. In addition, assessment thresholds for the use of BMD testing were explored. Assessment thresholds for the measurement of BMD followed current practice guidelines where individuals were considered to be eligible for assessment in the presence of one or more CRF. An upper assessment threshold (i.e. a fracture probability above which patients could be treated without recourse to BMD) was based on optimisation of the positive predictive value of the assessment tool. The consequences of assessment and intervention thresholds on the requirement for BMD test and interventions were assessed using the distribution of clinical risk factors and femoral neck BMD for women in the source cohorts used for the development of the FRAX models

RESULTS

Treatment was cost effective at all ages when the 10-year probability of a major fracture exceeded 7%. The intervention threshold at the age of 50 years corresponded to a 10-year probability of a major osteoporotic fracture of 7.5%. This rose progressively with age to 30% at the age of 80 years, so that intervention was cost effective at all ages. Assessment thresholds for testing with BMD (6-9% at the age of 50 years) also rose with age (18-36% at the age of 80 years). The use of these thresholds in a case-finding strategy would identify 6-20% of women as eligible for BMD testing and 23-46% as eligible for treatment, depending on age. The same threshold can be used in men.

CONCLUSION

The study provides a method of developing management algorithms for osteoporosis from the estimation of fracture probabilities, rather than those based on BMD alone or BMD with single or multiple CRFs.