Adjusting conventional FRAX estimates of fracture probability according to the number of prior fractures

An Update on the Fracture Risk Assessment Tool: What Have We Learned over 15+ years?

The Fracture Risk Assessment Tool (FRAX) was launched in 2008 and uses clinical variables to estimate 10-year fracture risk. FRAX has been incorporated into clinical treatment guidelines and is well validated in specific disease states like chronic kidney disease. However, there are risk factors which are not captured by FRAX such as diabetes and falls. The use of race-ethnicity as a factor in FRAX is a source of controversy. Though other risk calculators exist, FRAX is likely to remain the gold standard for fracture risk prediction. An update of FRAX using data from a larger cohort is in development.

Cost-effectiveness intervention thresholds for romosozumab and teriparatide in the treatment of osteoporosis in the UK

Sequential romosozumab-to-alendronate or sequential teriparatide-to-alendronate can be a cost-effective treatment option for postmenopausal women at very high risk of fracture.

PURPOSE

To estimate the 10-year probability of a major osteoporotic fracture (MOF) at which sequential treatment with romosozumab or teriparatide followed by alendronate, compared with alendronate alone, becomes cost-effective in a UK setting.

METHODS

A microsimulation model with a Markov structure was used to simulate fractures, costs, and quality-adjusted life years (QALYs), in women receiving sequential treatment with either romosozumab or teriparatide followed by alendronate, compared with alendronate alone. Patients aged 50 to 90 years with a recent MOF, hip or spine fracture were followed from the start of a 5-year treatment until the age of 100 years or death. The analysis had a healthcare perspective. Efficacy of romosozumab, teriparatide and alendronate was derived from phase III randomised controlled trials. Resource use and unit costs were derived from the literature. Cost-effectiveness intervention threshold (CEIT), defined as the 10-year probability of a major osteoporotic fracture at which treatment becomes cost-effective, was compared with clinically appropriate intervention thresholds for bone-forming treatment in women with very high fracture risk as recommended by the UK National Osteoporosis Guideline Group (NOGG).

RESULTS

The base case analysis showed that sequential romosozumab-to-alendronate treatment was cost-effective from a 10-year MOF probability of 18-35% and above depending on age and site of sentinel fracture at a willingness to pay (WTP) of £30,000. For teriparatide-to-alendronate, treatment was cost-effective at a 10-year MOF probability of 27-57%. The results were sensitive to pricing of the drugs but relatively insensitive to treatment duration, romosozumab persistence assumptions, and site of sentinel fracture. The CEITs for romosozumab-to-alendronate treatment were lower than the clinical thresholds from the age of 70 years meaning that treatment could be considered both cost-effective and aligned with the NOGG treatment guidelines. By contrast, for teriparatide-to-alendronate the CEITs were higher than the clinical thresholds irrespective of age. However, cost-effective scenarios were found in the presence of strong clinical risk factors in addition to a recent sentinel fracture.

CONCLUSION

The results of this study indicate that sequential romosozumab-to-alendronate or teriparatide-to-alendronate treatment can be a cost-effective treatment option for postmenopausal women at very high risk of fracture.

[Osteoporosis-Definition, risk assessment, diagnosis, prevention and treatment (update 2024) : Guidelines of the Austrian Society for Bone and Mineral Research]

BACKGROUND

Austria is among the countries with the highest incidence and prevalence of osteoporotic fractures worldwide. Guidelines for the prevention and management of osteoporosis were first published in 2010 under the auspices of the then Federation of Austrian Social Security Institutions and updated in 2017. The present comprehensively updated guidelines of the Austrian Society for Bone and Mineral Research are aimed at physicians of all specialties as well as decision makers and institutions in the Austrian healthcare system. The aim of these guidelines is to strengthen and improve the quality of medical care of patients with osteoporosis and osteoporotic fractures in Austria.

METHODS

These evidence-based recommendations were compiled taking randomized controlled trials, systematic reviews and meta-analyses as well as European and international reference guidelines published before 1 June 2023 into consideration. The grading of recommendations used ("conditional" and "strong") are based on the strength of the evidence. The evidence levels used mutual conversions of SIGN (1++ to 3) to NOGG criteria (Ia to IV).

RESULTS

The guidelines include all aspects associated with osteoporosis and osteoporotic fractures, such as secondary causes, prevention, diagnosis, estimation of the 10-year fracture risk using FRAX®, determination of Austria-specific FRAX®-based intervention thresholds, drug-based and non-drug-based treatment options and treatment monitoring. Recommendations for the office-based setting and decision makers and institutions in the Austrian healthcare system consider structured care models and options for osteoporosis-specific screening.

CONCLUSION

The guidelines present comprehensive, evidence-based information and instructions for the treatment of osteoporosis. It is expected that the quality of medical care for patients with this clinical picture will be substantially improved at all levels of the Austrian healthcare system.

Update on fracture risk assessment in osteoporosis

PURPOSE OF REVIEW

The assessment of fracture risk is playing an ever-increasing role in osteoporosis clinical management and informing international guidelines for osteoporosis. FRAX, a fracture risk calculator that provides individualized 10-year probabilities of hip and major osteoporotic fracture, has been widely used since 2008. In this review, we recap the development and limitations of intervention thresholds and the role of absolute fracture risk.

RECENT FINDINGS

There is an increasing awareness of disparities and inequities in the setting of intervention thresholds in osteoporosis. The limitations of the simple use of prior fracture or the DXA-derived BMD T -score threshold are increasingly being discussed; one solution is to use fracture risk or probabilities in the setting of such thresholds. This approach also permits more objective assessment of high and very high fracture risk to enable physicians to make choices not just about the need to treat but what agents to use in individual patients.

SUMMARY

Like all clinical tools, FRAX has limitations that need to be considered, but the use of fracture risk in deciding who to treat, when to treat and what agent to use is a mechanism to target treatment equitably to those at an increased risk of fracture.

An overview of the use of the fracture risk assessment tool (FRAX) in osteoporosis

FRAX®, a simple-to-use fracture risk calculator, was first released in 2008 and since then has been used increasingly worldwide. By calculating the 10-year probabilities of a major osteoporotic fracture and hip fracture, it assists clinicians when deciding whether further investigation, for example a bone mineral density measurement (BMD), and/or treatment is needed to prevent future fractures. In this review, we explore the literature around osteoporosis and how FRAX has changed its management. We present the characteristics of this tool and describe the use of thresholds (diagnostic and therapeutic). We also present arguments as to why screening with FRAX should be considered. FRAX has several limitations which are described in this review. This review coincides with the release of a version, FRAXplus, which addresses some of these limitations.

Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Romosozumab efficacy and safety in European patients enrolled in the FRAME trial

In this post hoc analysis, we assessed romosozumab efficacy and safety in European patients enrolled in FRAME. Romosozumab treatment through 12 months, followed by denosumab for a further 24 months, resulted in early and sustained risk reduction for major fracture categories, associated with large gains in bone mineral density.

INTRODUCTION

In the multinational FRAME phase 3 trial of romosozumab in postmenopausal women with osteoporosis, marked differences between clinical and non-vertebral fracture outcomes were observed among patients from Central and Southern America versus rest of world. This post hoc analysis assessed romosozumab efficacy and safety in European patients enrolled in the FRAME trial and extension study.

METHODS

In FRAME (NCT01575834), patients were randomised 1:1 to romosozumab 210 mg or placebo monthly (QM) for 12 months, followed by open-label denosumab 60 mg Q6M to month 36, including a 12-month extension study. We report incidence of major fracture outcomes, bone mineral density (BMD) change from baseline and safety for European patients enrolled in FRAME.

RESULTS

In FRAME, 3013/7180 (41.96%) patients were European; 1494 received romosozumab and 1519 received placebo. Through 12 months, romosozumab reduced fracture risk versus placebo for non-vertebral fracture (1.4% versus 3.0%; p = 0.004), clinical fracture (1.4% versus 3.6%; p < 0.001), new vertebral fracture (0.4% versus 2.1%; p < 0.001) and major osteoporotic fracture (0.9% versus 2.8%; p < 0.001), with results sustained through 36 months following transition to denosumab. Hip fractures were numerically reduced with romosozumab at month 12 (0.2% versus 0.6%; p = 0.092). Romosozumab increased BMD versus placebo at month 12; all patients in the romosozumab and placebo groups experienced further increases by month 36 after transition to denosumab. Adverse events were balanced between groups.

CONCLUSIONS

Among European patients in FRAME, romosozumab resulted in early and sustained risk reduction for all major fracture categories, associated with large BMD gains that continued after transition to denosumab.