FRAX for fracture prediction shorter and longer than 10 years: the Manitoba BMD registry

Electronic Health Records (EHRs) Can Identify Patients at High Risk of Fracture but Require Substantial Race Adjustments to Currently Available Fracture Risk Calculators

BACKGROUND

Osteoporotic fracture prediction calculators are poorly utilized in primary care, leading to underdiagnosis and undertreatment of those at risk for fracture. The use of these calculators could be improved if predictions were automated using the electronic health record (EHR). However, this approach is not well validated in multi-ethnic populations, and it is not clear if the adjustments for race or ethnicity made by calculators are appropriate.

OBJECTIVE

To investigate EHR-generated fracture predictions in a multi-ethnic population.

DESIGN

Retrospective cohort study using data from the EHR.

SETTING

An urban, academic medical center in Philadelphia, PA.

PARTICIPANTS

12,758 White, 7,844 Black, and 3,587 Hispanic patients seeking routine care from 2010 to 2018 with mean 3.8 years follow-up.

INTERVENTIONS

None.

MEASUREMENTS

FRAX and QFracture, two of the most used fracture prediction tools, were studied. Risk for major osteoporotic fracture (MOF) and hip fracture were calculated using data from the EHR at baseline and compared to the number of fractures that occurred during follow-up.

RESULTS

MOF rates varied from 3.2 per 1000 patient-years in Black men to 7.6 in White women. FRAX and QFracture had similar discrimination for MOF prediction (area under the curve, AUC, 0.69 vs. 0.70, p=0.08) and for hip fracture prediction (AUC 0.77 vs 0.79, p=0.21) and were similar by race or ethnicity. FRAX had superior calibration than QFracture (calibration-in-the-large for FRAX 0.97 versus QFracture 2.02). The adjustment factors used in MOF prediction were generally accurate in Black women, but underestimated risk in Black men, Hispanic women, and Hispanic men.

LIMITATIONS

Single center design.

CONCLUSIONS

Fracture predictions using only EHR inputs can discriminate between high and low risk patients, even in Black and Hispanic patients, and could help primary care physicians identify patients who need screening or treatment. However, further refinements to the calculators may better adjust for race-ethnicity.

Adjusting FRAX Estimates of Fracture Probability Based on a Positive Vertebral Fracture Assessment

Importance

FRAX is the most widely used and validated fracture risk prediction tool worldwide. Vertebral fractures, which are an indicator of subsequent osteoporotic fractures, can be identified using dual-energy x-ray absorptiometry (DXA) vertebral fracture assessment (VFA).

Objective

To assess the calibration of FRAX and develop a simple method for improving FRAX-predicted fracture probability in the presence of VFA-identified fracture.

Design, Setting, and Participants

This prognostic study analyzed the DXA and VFA results of all individuals who underwent a VFA between March 31, 2010, and March 31, 2018, who were included in the Manitoba Bone Mineral Density Registry. These individuals were randomly assigned to either the development cohort or validation cohort. A modified algorithm-based qualitative approach was used by expert readers to code VFAs as positive (≥1 vertebral fractures detected) or negative (0 vertebral fracture detected). Statistical analysis was conducted from August 7, 2022, to May 22, 2023.

Exposures

FRAX scores for major osteoporotic fracture (MOF) and hip fracture were calculated with or without VFA results.

Main Outcomes and Measures

Incident fractures and death were ascertained using linked population-based health care provincial data. Cumulative incidence curves for MOF and hip fracture were constructed, including competing mortality, to predict the 10-year observed risk of fracture. The observed probability was compared with FRAX-predicted fracture probability with and without VFA results and recalibrated FRAX from derived multipliers.

Results

The full cohort of 11 766 individuals was randomly allocated to the development cohort (n = 7854; 7349 females [93.6%]; mean [SD] age, 75.7 [6.8] years) or the validation cohort (n = 3912; 3713 females [94.9%]; mean [SD] age, 75.5 [6.9] years). Over a mean (SD) observation time of 3.8 (2.3) years, with the longest observation at 7.5 years, FRAX was well calibrated in subgroups with negative VFA results. For individuals without a prior clinical fracture but with a positive VFA result, the 10-year FRAX-predicted MOF probability was 16.3% (95% CI, 15.7%-16.8%) without VFA information and 23.4% (95% CI, 22.7%-24.1%) with VFA information. The observed 10-year probabilities were 26.9% (95% CI, 26.0%-27.8%) and 11.2% (95% CI, 10.3%-12.1%), respectively, resulting in recalibration multipliers of 1.15 (95% CI, 0.87-1.43) for MOF and 1.31 (95% CI, 0.75-1.87) for hip fracture. For individuals with a prior clinical fracture and a positive VFA result, the 10-year FRAX-predicted probabilities were 25.0% (95% CI, 24.2%-25.7%) for MOF and 9.3% (95% CI, 8.7%-10.0%) for hip fracture. The observed 10-year probabilities were 38.1% (95% CI, 37.0%-39.1%) for MOF and 16.4% (95% CI, 15.4%-17.4%) for hip fracture, resulting in a recalibration multiplier of 1.53 (95% CI, 1.10-1.96) for MOF and 1.76 (95% CI, 1.17-2.35) for hip fracture. Good calibration (>0.90) was confirmed using the derived multipliers in the validation cohort.

Conclusions and Relevance

Results of this prognostic study suggest that FRAX underestimated fracture risk in patients with VFA-identified fractures. Simple multipliers could recover FRAX calibration in individuals with VFA-identified fractures.

Screening for the primary prevention of fragility fractures among adults aged 40 years and older in primary care: systematic reviews of the effects and acceptability of screening and treatment, and the accuracy of risk prediction tools

BACKGROUND

To inform recommendations by the Canadian Task Force on Preventive Health Care, we reviewed evidence on the benefits, harms, and acceptability of screening and treatment, and on the accuracy of risk prediction tools for the primary prevention of fragility fractures among adults aged 40 years and older in primary care.

METHODS

For screening effectiveness, accuracy of risk prediction tools, and treatment benefits, our search methods involved integrating studies published up to 2016 from an existing systematic review. Then, to locate more recent studies and any evidence relating to acceptability and treatment harms, we searched online databases (2016 to April 4, 2022 [screening] or to June 1, 2021 [predictive accuracy]; 1995 to June 1, 2021, for acceptability; 2016 to March 2, 2020, for treatment benefits; 2015 to June 24, 2020, for treatment harms), trial registries and gray literature, and hand-searched reviews, guidelines, and the included studies. Two reviewers selected studies, extracted results, and appraised risk of bias, with disagreements resolved by consensus or a third reviewer. The overview of reviews on treatment harms relied on one reviewer, with verification of data by another reviewer to correct errors and omissions. When appropriate, study results were pooled using random effects meta-analysis; otherwise, findings were described narratively. Evidence certainty was rated according to the GRADE approach.

RESULTS

We included 4 randomized controlled trials (RCTs) and 1 controlled clinical trial (CCT) for the benefits and harms of screening, 1 RCT for comparative benefits and harms of different screening strategies, 32 validation cohort studies for the calibration of risk prediction tools (26 of these reporting on the Fracture Risk Assessment Tool without [i.e., clinical FRAX], or with the inclusion of bone mineral density (BMD) results [i.e., FRAX + BMD]), 27 RCTs for the benefits of treatment, 10 systematic reviews for the harms of treatment, and 12 studies for the acceptability of screening or initiating treatment. In females aged 65 years and older who are willing to independently complete a mailed fracture risk questionnaire (referred to as "selected population"), 2-step screening using a risk assessment tool with or without measurement of BMD probably (moderate certainty) reduces the risk of hip fractures (3 RCTs and 1 CCT, n = 43,736, absolute risk reduction [ARD] = 6.2 fewer in 1000, 95% CI 9.0-2.8 fewer, number needed to screen [NNS] = 161) and clinical fragility fractures (3 RCTs, n = 42,009, ARD = 5.9 fewer in 1000, 95% CI 10.9-0.8 fewer, NNS = 169). It probably does not reduce all-cause mortality (2 RCTs and 1 CCT, n = 26,511, ARD = no difference in 1000, 95% CI 7.1 fewer to 5.3 more) and may (low certainty) not affect health-related quality of life. Benefits for fracture outcomes were not replicated in an offer-to-screen population where the rate of response to mailed screening questionnaires was low. For females aged 68-80 years, population screening may not reduce the risk of hip fractures (1 RCT, n = 34,229, ARD = 0.3 fewer in 1000, 95% CI 4.2 fewer to 3.9 more) or clinical fragility fractures (1 RCT, n = 34,229, ARD = 1.0 fewer in 1000, 95% CI 8.0 fewer to 6.0 more) over 5 years of follow-up. The evidence for serious adverse events among all patients and for all outcomes among males and younger females (<65 years) is very uncertain. We defined overdiagnosis as the identification of high risk in individuals who, if not screened, would never have known that they were at risk and would never have experienced a fragility fracture. This was not directly reported in any of the trials. Estimates using data available in the trials suggest that among "selected" females offered screening, 12% of those meeting age-specific treatment thresholds based on clinical FRAX 10-year hip fracture risk, and 19% of those meeting thresholds based on clinical FRAX 10-year major osteoporotic fracture risk, may be overdiagnosed as being at high risk of fracture. Of those identified as being at high clinical FRAX 10-year hip fracture risk and who were referred for BMD assessment, 24% may be overdiagnosed. One RCT (n = 9268) provided evidence comparing 1-step to 2-step screening among postmenopausal females, but the evidence from this trial was very uncertain. For the calibration of risk prediction tools, evidence from three Canadian studies (n = 67,611) without serious risk of bias concerns indicates that clinical FRAX-Canada may be well calibrated for the 10-year prediction of hip fractures (observed-to-expected fracture ratio [O:E] = 1.13, 95% CI 0.74-1.72, I² = 89.2%), and is probably well calibrated for the 10-year prediction of clinical fragility fractures (O:E = 1.10, 95% CI 1.01-1.20, I² = 50.4%), both leading to some underestimation of the observed risk. Data from these same studies (n = 61,156) showed that FRAX-Canada with BMD may perform poorly to estimate 10-year hip fracture risk (O:E = 1.31, 95% CI 0.91-2.13, I² = 92.7%), but is probably well calibrated for the 10-year prediction of clinical fragility fractures, with some underestimation of the observed risk (O:E 1.16, 95% CI 1.12-1.20, I² = 0%). The Canadian Association of Radiologists and Osteoporosis Canada Risk Assessment (CAROC) tool may be well calibrated to predict a category of risk for 10-year clinical fractures (low, moderate, or high risk; 1 study, n = 34,060). The evidence for most other tools was limited, or in the case of FRAX tools calibrated for countries other than Canada, very uncertain due to serious risk of bias concerns and large inconsistency in findings across studies. Postmenopausal females in a primary prevention population defined as <50% prevalence of prior fragility fracture (median 16.9%, range 0 to 48% when reported in the trials) and at risk of fragility fracture, treatment with bisphosphonates as a class (median 2 years, range 1-6 years) probably reduces the risk of clinical fragility fractures (19 RCTs, n = 22,482, ARD = 11.1 fewer in 1000, 95% CI 15.0-6.6 fewer, [number needed to treat for an additional beneficial outcome] NNT = 90), and may reduce the risk of hip fractures (14 RCTs, n = 21,038, ARD = 2.9 fewer in 1000, 95% CI 4.6-0.9 fewer, NNT = 345) and clinical vertebral fractures (11 RCTs, n = 8921, ARD = 10.0 fewer in 1000, 95% CI 14.0-3.9 fewer, NNT = 100); it may not reduce all-cause mortality. There is low certainty evidence of little-to-no reduction in hip fractures with any individual bisphosphonate, but all provided evidence of decreased risk of clinical fragility fractures (moderate certainty for alendronate [NNT=68] and zoledronic acid [NNT=50], low certainty for risedronate [NNT=128]) among postmenopausal females. Evidence for an impact on risk of clinical vertebral fractures is very uncertain for alendronate and risedronate; zoledronic acid may reduce the risk of this outcome (4 RCTs, n = 2367, ARD = 18.7 fewer in 1000, 95% CI 25.6-6.6 fewer, NNT = 54) for postmenopausal females. Denosumab probably reduces the risk of clinical fragility fractures (6 RCTs, n = 9473, ARD = 9.1 fewer in 1000, 95% CI 12.1-5.6 fewer, NNT = 110) and clinical vertebral fractures (4 RCTs, n = 8639, ARD = 16.0 fewer in 1000, 95% CI 18.6-12.1 fewer, NNT=62), but may make little-to-no difference in the risk of hip fractures among postmenopausal females. Denosumab probably makes little-to-no difference in the risk of all-cause mortality or health-related quality of life among postmenopausal females. Evidence in males is limited to two trials (1 zoledronic acid, 1 denosumab); in this population, zoledronic acid may make little-to-no difference in the risk of hip or clinical fragility fractures, and evidence for all-cause mortality is very uncertain. The evidence for treatment with denosumab in males is very uncertain for all fracture outcomes (hip, clinical fragility, clinical vertebral) and all-cause mortality. There is moderate certainty evidence that treatment causes a small number of patients to experience a non-serious adverse event, notably non-serious gastrointestinal events (e.g., abdominal pain, reflux) with alendronate (50 RCTs, n = 22,549, ARD = 16.3 more in 1000, 95% CI 2.4-31.3 more, [number needed to treat for an additional harmful outcome] NNH = 61) but not with risedronate; influenza-like symptoms with zoledronic acid (5 RCTs, n = 10,695, ARD = 142.5 more in 1000, 95% CI 105.5-188.5 more, NNH = 7); and non-serious gastrointestinal adverse events (3 RCTs, n = 8454, ARD = 64.5 more in 1000, 95% CI 26.4-13.3 more, NNH = 16), dermatologic adverse events (3 RCTs, n = 8454, ARD = 15.6 more in 1000, 95% CI 7.6-27.0 more, NNH = 64), and infections (any severity; 4 RCTs, n = 8691, ARD = 1.8 more in 1000, 95% CI 0.1-4.0 more, NNH = 556) with denosumab. For serious adverse events overall and specific to stroke and myocardial infarction, treatment with bisphosphonates probably makes little-to-no difference; evidence for other specific serious harms was less certain or not available. There was low certainty evidence for an increased risk for the rare occurrence of atypical femoral fractures (0.06 to 0.08 more in 1000) and osteonecrosis of the jaw (0.22 more in 1000) with bisphosphonates (most evidence for alendronate). The evidence for these rare outcomes and for rebound fractures with denosumab was very uncertain. Younger (lower risk) females have high willingness to be screened. A minority of postmenopausal females at increased risk for fracture may accept treatment. Further, there is large heterogeneity in the level of risk at which patients may be accepting of initiating treatment, and treatment effects appear to be overestimated.

CONCLUSION

An offer of 2-step screening with risk assessment and BMD measurement to selected postmenopausal females with low prevalence of prior fracture probably results in a small reduction in the risk of clinical fragility fracture and hip fracture compared to no screening. These findings were most applicable to the use of clinical FRAX for risk assessment and were not replicated in the offer-to-screen population where the rate of response to mailed screening questionnaires was low. Limited direct evidence on harms of screening were available; using study data to provide estimates, there may be a moderate degree of overdiagnosis of high risk for fracture to consider. The evidence for younger females and males is very limited. The benefits of screening and treatment need to be weighed against the potential for harm; patient views on the acceptability of treatment are highly variable.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42019123767.

The effect of fracture recency on observed 5-year fracture probability: A study based on the FRISBEE cohort

Introduction

Prediction models, especially the FRAX®, are largely used to estimate the fracture risk at ten years, but the current algorithm does not take into account the time elapsed after a fracture. Kanis et al. recently proposed correction factors allowing to adjust the FRAX® score for fracture recency. The objective of this work was to analyze the effect of fracture recency in the FRISBEE cohort.

Methods

We identified in the FRISBEE cohort subjects who sustained a validated fracture during the first 5 years following an incident MOF. We calculated their estimated 5-year risk of fracture using FRAX® uncorrected, adjusted for recency and further adjusted for the MOF/hip ratios calibration factors previously derived for the Belgian FRAX®. We compared the fracture risk estimated by FRAX® before and after these corrections to the observed incidence of validated fractures in our cohort.

Results

In our ongoing cohort, 376 subjects had a first non-traumatic incident validated MOF after inclusion; 81 had a secondary fracture during the 5 years follow-up period after this index fracture. The FRAX® score significantly under-evaluated the observed incidence of fractures in our cohort by 54.7 % (fracture rate of 9.7 %; 95 % CI, 6.8-12.9 %) if uncorrected (p < 0.001) and by 32.6 % after correction for recency (14.5 %; 95 % CI, 11.1-18.2 %) (p = 0.01). The calibration for MOF/hip ratios improved the prediction (17.5 %; 95 % CI: 13.7-21.4 %) (p = 0.2). After correcting for recency and for calibration, the predicted value was over-evaluated by 22 % (fracture rate of 26.1 %; 95 % CI, 21.6-30.5 %) but this over-evaluation was not significant (p = 0.1).

Conclusion

Our data indicate that the correction of the FRAX® score for fracture recency improves fracture prediction. However, correction for calibration and recency tends to overestimate fracture risk in this population of elderly women.

Establishment of a preliminary FRAX®-based intervention threshold for rheumatoid arthritis–associated fragility fracture: a 3-year longitudinal, observational, cohort study

Background:

To establish a FRAX®-based prediction model for rheumatoid arthritis (RA)-associated fragility fracture.

Methods:

This study is a longitudinal, real-world, registry cohort study. Patients with RA were registered to start in September 2014. The baseline demographics, bone mineral density (BMD), and risk factors of osteoporosis or fragility fracture were recorded. Subsequent fragility fractures during the 3-year observation period were also recorded. We developed a fixed intervention threshold (FITD) to identify fractures by choosing an optimal cut-off point on the receiver operating characteristic (ROC) curve and FRAX®. Several models for intervention thresholds (IT), including fixed intervention threshold (Taiwan) (FITT), age-specific individual intervention threshold (IIT), and hybrid intervention threshold (HIT), were compared to evaluate which IT model will have better discriminative power.

Results:

As of December 2020, a total of 493 RA participants have completed the 3-year observation study. The mean age of the participants was 59.3 ± 8.7, and 116 (23.5%) new fragility fractures were observed during the study period. In terms of pairwise comparisons of area under the curve ( n, 95% confidence interval) in the ROC curve, the FITD (0.669, 0.610–0.727, p < 0.001) with a value of 22% in major osteoporotic fracture and FITT (0.640, 0.582–0.699, p < 0.001) is significantly better than reference, but not for IIT (0.543, 0.485–0.601, p = 0.165) and HIT (0.543, 0.485–0.601, p = 0.165).

Conclusion:

An optimal FIT is established for intervention decisions in RA-associated fragility fractures. This model can offer an easy and simple guide to aid RA caregivers to provide interventions to prevent fragility fractures in patients with RA.

Independent External Validation of FRAX and Garvan Fracture Risk Calculators: A Sub-Study of the FRISBEE Cohort

Probabilistic models including clinical risk factors with or without bone mineral density (BMD) have been developed to estimate the 5‐ or 10‐year absolute fracture risk. We investigated the performance of the FRAX and Garvan tools in a well‐characterized population‐based cohort of 3560 postmenopausal, volunteer women, aged 60 to 85 years at baseline, included in the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) cohort, during 5 years of follow‐up. Baseline data were used to calculate the estimated 10‐year risk of hip and major osteoporotic fractures (MOFs) for each participant using FRAX (Belgium). We computed the 5‐year risk according to the Garvan model with BMD. For calibration, the predicted risk of fracture was compared with fracture incidence across a large range of estimated fracture risks. The accuracy of the calculators to predict fractures was assessed using the area under the receiver operating characteristic curves (AUC). The FRAX tool was well calibrated for hip fractures (slope 1.09, p < 0.001; intercept −0.001, p = 0.46), but it consistently underestimated the incidence of major osteoporotic fractures (MOFs) (slope 2.12, p < 0.001; intercept −0.02, p = 0.06). The Garvan tool was well calibrated for “any Garvan” fractures (slope 1.05, p < 0.001; intercept 0.01, p = 0.37) but largely overestimated the observed hip fracture rate (slope 0.32, p < 0.001; intercept 0.006, p = 0.05). The predictive value for hip fractures was better for FRAX (AUC: 0.841, 95% confidence interval [CI] 0.795–0.887) than for Garvan (AUC: 0.769, 95% CI 0.702–0.836, p = 0.01). The Garvan AUC for “any Garvan” fractures was 0.721 (95% CI 0.693–0.749) and FRAX AUC for MOFs was 0.708 (95% CI 0.675–0.741). In conclusion, in our Belgian cohort, FRAX estimated quite well hip fractures but underestimated MOFs, while Garvan overestimated hip fracture risk but showed a good estimation of “any Garvan” fractures. Both models had a good discriminatory value for hip fractures but only a moderate discriminatory ability for MOFs or “any Garvan” fractures. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Preventing hip fractures with multidisciplinary teams: a Canadian perspective

Fragility fractures (FFs) are low-energy trauma fractures that occur at or below standing height. Among FFs, hip fractures are associated with the greatest morbidity, mortality and cost to Canadian health care systems. This review highlights the current state of medical care for hip fractures in Canada, with specific focus on the role of the multidisciplinary team. Gaps in care exist, as FFs represent a unique challenge requiring both acute and chronic management. Furthermore, there is a lack of ownership of FFs by a medical specialty. These gaps can be addressed through the use of multidisciplinary teams, which have been shown to be efficacious and cost-effective. This model of care also addresses numerous patient-identified barriers to treatment, including inadequate patient counselling. However, there is still room for improvement in both the identification of patients at risk for hip fracture and patient adherence to therapy.

The use of 2-, 5-, and 10-year probabilities to characterize fracture risk after a recent sentinel fracture

The increase in fracture risk associated with a recent fragility fracture is more appropriately captured using a 10-year fracture probability than 2- or 5-year probabilities.

INTRODUCTION

The recency of prior fractures affects subsequent fracture risk. The aim of this study was to quantify the effect of a recent sentinel fracture, by site, on the 2-, 5-, and 10-year probability of fracture.

METHODS

The study used data from the Reykjavik Study fracture register that documented prospectively all fractures at all skeletal sites in a large sample of the population of Iceland. Fracture probabilities were determined after a sentinel fracture (humeral, clinical vertebral, forearm and hip fracture) occurring within the previous 2 years and probabilities for a prior osteoporotic fracture irrespective of recency. The probability ratios were used to adjust fracture probabilities over a 2-, 5-, and 10-year time horizon.

RESULTS

As expected, probabilities decreased with decreasing time horizon. Probability ratios varied according to age and the site of sentinel fracture. Probability ratios to adjust for a prior fracture within the previous 2 years were higher the shorter the time horizon, but the absolute increases in fracture probabilities were much reduced. Thus, fracture probabilities were substantially lower with time horizons less than 10 years.

CONCLUSION

The 10-year probability of fractures is the appropriate metric to capture the impact of the recency of sentinel fractures. The probability ratios provide adjustments to conventional FRAX estimates of fracture probability for recent sentinel fractures, adjustments which can readily inform clinical decision-making.

Testing a theoretical model of imminent fracture risk in elderly women: an observational cohort analysis of the Canadian Multicentre Osteoporosis Study

We examined the underlying relationship between fracture risk factors and their imminent risk. Results suggested that having past year fracture, worse past year general health, worse past year physical functioning, and lower past year BMD T-score directly predicted higher imminent fracture risk. Past year falls indirectly predicted imminent risk through physical functioning and general health.

INTRODUCTION

This study aimed to examine direct and indirect effects of several factors on imminent (1 year) fracture risk.

METHODS

Data from women age 65 and older from population-based Canadian Multicentre Osteoporosis Study were used. Predictors were identified from study years 5 and 10, and imminent fracture data (1-year fracture) came from years 6 and 11 (year 5 predicts year 6, year 10 predicts year 11). A structural equation model (SEM) was used to test the theoretical construct. General health and physical functioning were measured as latent variables using items from the 36-Item Short Form Health Survey (SF-36) and bone mineral density (BMD) T-score was a latent variable based on observed site-specific BMD data (spine L1-L4, femoral neck, total hip). Observed variables were fractures and falls. Model fit was evaluated using root mean square error of approximation (RMSEA), Tucker Lewis index (TLI), and comparative fit index (CFI).

RESULTS

The analysis included 3298 women. Model fit tests showed that the SEM fit the data well; χ²(172) = 1122.10 < .001, RMSEA = .03, TLI = .99, CFI = .99. Results suggested that having past year fracture, worse past year general health, worse past year physical functioning, and lower past year BMD T-score directly predicted higher risk of fracture in the subsequent year (p < .001). Past year falls had a statistically significant but indirect effect on imminent fracture risk through physical functioning and general health (p < .001).

CONCLUSIONS

We found several direct and indirect pathways that predicted imminent fracture risk in elderly women. Future studies should extend this work by developing risk scoring methods and defining imminent risk thresholds.

New Developments in Fracture Risk Assessment for Current Osteoporosis Reports

PURPOSE OF REVIEW

Identifying individuals at high fracture risk can be used to target those likely to derive the greatest benefit from treatment. This narrative review examines recent developments in using specific risk factors used to assess fracture risk, with a focus on publications in the last 3 years.

RECENT FINDINGS

There is expanding evidence for the recognition of individual clinical risk factors and clinical use of composite scores in the general population. Unfortunately, enthusiasm is dampened by three pragmatic randomized trials that raise questions about the effectiveness of widespread population screening using clinical fracture prediction tools given suboptimal participation and adherence. There have been refinements in risk assessment in special populations: men, patients with diabetes, and secondary causes of osteoporosis. New evidence supports the value of vertebral fracture assessment (VFA), high resolution peripheral quantitative CT (HR-pQCT), opportunistic screening using CT, skeletal strength assessment with finite element analysis (FEA), and trabecular bone score (TBS). The last 3 years have seen important developments in the area of fracture risk assessment, both in the research setting and translation to clinical practice. The next challenge will be incorporating these advances into routine work flows that can improve the identification of high risk individuals at the population level and meaningfully impact the ongoing crisis in osteoporosis management.

Comparison of Fracture Prediction Tools in Individuals Without and With Early Chronic Kidney Disease: A Population-Based Analysis of CARTaGENE

Whether fracture prediction tools developed for the management of osteoporosis can be used in chronic kidney disease (CKD) is poorly known. We aimed to compare the performance of fracture prediction tools in non-CKD and CKD. We analyzed CARTaGENE, a population-based survey of 40-year-old to 69-year-old individuals recruited between 2009 and 2010. Renal function was assessed using baseline creatinine and categorized according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines (non-CKD, stage 2, stage 3). Individuals without creatinine measurements or with advanced CKD (stage 4 or 5; prevalence <0.25%) were excluded. Predicted 5-year fracture probabilities (using Fracture Risk Assessment Tool [FRAX], QFracture, and Garvan) were computed at baseline. Fracture incidence (major fracture [MOF] or any fracture) was evaluated in administrative databases from recruitment to March 2016. Discrimination (hazard ratios [HRs] per standard deviation [SD] increase in Cox models; c-statistics) and calibration (standardized incidence ratios [SIRs] before and after recalibration) were assessed in each CKD strata. We included 19,393 individuals (9522 non-CKD; 9114 stage 2; 757 stage 3). A total of 830 patients had any fracture during follow-up, including 352 MOF. FRAX (HR = 1.89 [1.63-2.20] non-CKD; 1.64 [1.41-1.91] stage 2; 1.76 [1.10-2.82] stage 3) and QFracture (HR = 1.90 [1.62-2.22] non-CKD; 1.57 [1.35-1.82] stage 2; 1.86 [1.19-2.91] stage 3) discriminated MOF similarly in non-CKD and CKD. In contrast, the discrimination of Garvan for any fracture tended to be lower in CKD stage 3 compared to non-CKD and CKD stage 2 (HR = 1.36 [1.22-1.52] non-CKD; 1.34 [1.20-1.50] stage 2; 1.11 [0.79-1.55] stage 3). Before recalibration, FRAX globally overestimated fracture risk while QFracture and Garvan globally underestimated fracture risk. After recalibration, FRAX and QFracture were adequately calibrated for MOF in all CKD strata whereas Garvan tended to underestimate any fracture risk in CKD stage 3 (SIR = 1.31 [0.95-1.81]). In conclusion, the discrimination and calibration of FRAX and QFracture is similar in non-CKD and CKD. Garvan may have a lower discrimination in CKD stage 3 and underestimate fracture risk in these patients. © 2020 American Society for Bone and Mineral Research.

Deterioration of Cortical and Trabecular Microstructure Identifies Women With Osteopenia or Normal Bone Mineral Density at Imminent and Long-Term Risk for Fragility Fracture: A Prospective Study

More than 70% of women sustaining fractures have osteopenia or "normal" bone mineral density (BMD). These women remain undetected using the BMD threshold of -2.5 SD for osteoporosis. As microstructural deterioration increases bone fragility disproportionate to the bone loss producing osteopenia/normal BMD, we hypothesized that the structural fragility score (SFS) of ≥70 units, a measure capturing severe cortical and trabecular deterioration, will identify these women. Distal radial images were acquired using high-resolution peripheral quantitative tomography in postmenopausal French women, mean age 67 years (range 42-96 years); 1539 women were followed for 4 years (QUALYOR) and 561 women followed for 8 years (OFELY). Women with osteopenia or normal BMD accounted for ~80% of fractures. Women ≥70 years, 29.2% of the cohort, accounted for 39.2% to 61.5% of fractures depending on follow-up duration. Women having fractures had a higher SFS, lower BMD, and a higher fracture risk assessment score (FRAX) than women remaining fracture-free. In each BMD category (osteoporosis, osteopenia, normal BMD), fracture incidence was two to three times higher in women with SFS ≥70 than <70. In multivariable analyses, associations with fractures remained for BMD and SFS, not FRAX. BMD was no longer, or weakly, associated with fractures after accounting for SFS, whereas SFS remained associated with fracture after accounting for BMD. SFS detected two-to threefold more women having fractures than BMD or FRAX. SFS in women with osteopenia/normal BMD conferred an odds ratio for fracture of 2.69 to 5.19 for women of any age and 4.98 to 12.2 for women ≥70 years. Receiver-operator curve (ROC) analyses showed a significant area under the curve (AUC) for SFS, but not BMD or FRAX for the women ≥70 years of age. Targeting women aged ≥70 years with osteopenia indicated that treating 25% using SFS to allocate treatment conferred a cost-effectiveness ratio < USD $21,000/QALY saved. Quantifying microstructural deterioration complements BMD by identifying women without osteoporosis at imminent and longer-term fracture risk. © 2019 American Society for Bone and Mineral Research.

FRAX prognostic and intervention thresholds in the management of major bone fractures in hemodialysis patients: A two-year prospective multicenter cohort study

PURPOSE

The usefulness of FRAX in predicting major bone fractures in patients with end-stage kidney disease on maintenance hemodialysis treatment has been confirmed in previous studies. For meaningful clinical use, the prognostic and intervention FRAX thresholds need to be established.

METHODS

The primary aim of our study was to calculate the optimal cut-off point of FRAX for the best prediction of an increased bone fracture risk in dialysis patients and additionally, to propose its intervention threshold, indicating the need for antifracture pharmacological treatment. The study included 718 hemodialysis patients, who were followed up for two years. Thirty low-energy major bone fractures were diagnosed during the study period. We used the Polish version of FRAX (without the DXA examination) and some particular variables of the FRAX calculator. The optimal cut-off point for prediction of an increased major bone fracture risk was based on the analysis of the sensitivity and specificity curves of FRAX.

RESULTS

The analysis revealed FRAX >5% (sensitivity of 70.0%, specificity of 69.8%) as the prognostic threshold for major bone fractures. Its sensitivity for bone fracture prediction was significantly higher, but specificity lower than those of FRAX ≥10%, used in general Polish population. The reason for this can be an underestimation of bone fracture risk with FRAX in dialysis patients.

CONCLUSIONS

We conclude that the FRAX prognostic threshold for identification of an increased risk of major bone fractures in hemodialysis patients is >5%. We propose to use this specific value of FRAX as an intervention threshold for pharmacological antifracture treatment in hemodialysis patients.

Performance of FRAX in Women with Breast Cancer Initiating Aromatase Inhibitor Therapy: A Registry-Based Cohort Study

FRAX was developed to predict 10-year probability of major osteoporotic fracture (MOF) and hip fracture in the general population. Aromatase inhibitors (AI) used in breast cancer induce loss in bone mineral density (BMD) and are reported to increase fracture risk. AI exposure is not a direct input to FRAX but is captured under "secondary osteoporosis". To inform use of FRAX in women treated with AI, we used a population-based registry for the Province of Manitoba, Canada, to identify women aged ≥40 years initiating AI for breast cancer with at least 12 months' AI exposure (n = 1775), women with breast cancer not receiving AI (n = 1016), and women from the general population (n = 34,205). Among AI users, fracture probability estimated without BMD (AI use coded as secondary osteoporosis) significantly overestimated risk (10-year observed/predicted ratio 0.56, 95% confidence interval [CI] 0.45-0.68; 10-year hip fracture observed/predicted ratio 0.33, 95% CI 0.18-0.49). However, when BMD was included in the fracture probability, there was no significant difference between observed and predicted fracture risk. In Cox proportional hazards models, FRAX stratified risk of MOF, hip, and any fracture equally well in all subgroups (p-interaction >0.1). When adjusted for FRAX score without BMD, with AI use coded as secondary osteoporosis, AI users were at significantly lower risk for MOF (hazard ratio [HR] = 0.78, 95% CI 0.64-0.95), hip fracture (HR = 0.46, 95% CI 0.29-0.73) and any fracture (HR = 0.75, 95% CI 0.63-0.89). AI use was no longer significantly associated with fractures when AI use was not entered as secondary osteoporosis in FRAX without BMD or when BMD was included in the FRAX calculation. In conclusion, FRAX scores stratify fracture risk equally well in women receiving AI therapy as in non-users, but including secondary osteoporosis as a risk factor for AI users overestimates fracture risk. Our results call this practice into question. © 2019 American Society for Bone and Mineral Research.

Healthcare Policy Changes in Osteoporosis Can Improve Outcomes and Reduce Costs in the United States

In the United States, osteoporosis affects over 10 million adults, has high societal costs ($22 billion in 2008), and is currently being underdiagnosed and undertreated. Given an aging population, this burden is expected to rise. We projected the fracture burden in US women by modeling the expected demographic shift as well as potential policy changes. With the anticipated population aging and growth, annual fractures are projected to increase from 1.9 million to 3.2 million (68%), from 2018 to 2040, with related costs rising from $57 billion to over $95 billion. Policy‐driven expansion of case finding and treatment of at‐risk women could lower this burden, preventing 6.1 million fractures over the next 22 years while reducing payer costs by $29 billion and societal costs by $55 billion. Increasing use of osteoporosis‐related interventions can reduce fractures and result in substantial cost‐savings, a rare and fortunate combination given the current landscape in healthcare policy. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Risk of imminent fracture following a previous fracture in a Swedish database study

This study examined the imminent risk of a future fracture within 1 and 2 years following a first fracture in women aged 50 years and older and assessed independent factors associated with risk of subsequent fractures. The study highlights the need to intervene rapidly after a fracture to prevent further fractures.

INTRODUCTION

This study aims to determine the imminent risk of subsequent fractures within 1 and 2 years following a first fracture and to assess independent factors associated with subsequent fractures.

METHODS

Retrospective, observational cohort study of women aged ≥ 50 years with a fragility fracture was identified from Swedish national registers. Clinical/demographic characteristics at the time of index fracture and cumulative fracture incidences up to 12 and 24 months following index fracture were calculated. Risk factors for subsequent fracture were identified using multivariate regression analysis.

RESULTS

Two hundred forty-two thousand one hundred eight women (mean [SD] age 74 [12.5] years) were included. The cumulative subsequent fracture incidence at 12 months was 7.1% (95% confidence interval [CI], 6.9-7.2) and at 24 months was 12.0% (95% CI, 11.8-12.1). The rate of subsequent fractures was highest in the first month (~ 15 fractures per 1000 patient-years) and remained steady between 4 and 24 months (~ 5 fractures/1000 patient-years). Higher age was an independent risk factor for imminent subsequent fractures (at 24 months, sub-distribution hazard ratio [HR], 3.07; p < 0.001 for women 80-89 years [reference 50-59 years]). Index vertebral fracture was a strong independent risk factor for subsequent fracture (sub-distribution HR, 2.72 versus hip fracture; p < 0.001 over 12 months; HR, 2.23; p < 0.001 over 24 months).

CONCLUSIONS

Our findings highlight the need to intervene rapidly after any fragility fracture in postmenopausal women. The occurrence of a fragility fracture provides healthcare systems with a unique opportunity to intervene to reduce the increased risk of subsequent fractures.

Validation of a one year fracture prediction tool for absolute hip fracture risk in long term care residents

BACKGROUND

Frail older adults living in long term care (LTC) homes have a high fracture risk, which can result in reduced quality of life, pain and death. The Fracture Risk Scale (FRS) was designed for fracture risk assessment in LTC, to optimize targeting of services in those at highest risk. This study aims to examine the construct validity and discriminative properties of the FRS in three Canadian provinces at 1-year follow up.

METHODS

LTC residents were included if they were: 1) Adults admitted to LTC homes in Ontario (ON), British Columbia (BC) and Manitoba (MB) Canada; and 2) Received a Resident Assessment Instrument Minimum Data Set Version 2.0. After admission to LTC, one-year hip fracture risk was evaluated for all the included residents using the FRS (an eight-level risk scale, level 8 represents the highest fracture risk). Multiple logistic regressions were used to determine the differences in incident hip or all clinical fractures across the provinces and FRS risk levels. We examined the differences in incident hip or all clinical fracture for each FRS level across the three provinces (adjusted for age, BMI, gender, fallers and previous fractures). We used the C-statistic to assess the discriminative properties of the FRS for each province.

RESULTS

Descriptive statistics on the LTC populations in ON (n = 29,848), BC (n = 3129), and MB (n = 2293) are: mean (SD) age 82 (10), 83 (10), and 84 (9), gender (female %) 66, 64, and 70% respectively. The incident hip fractures and all clinical fractures for FRS risk level were similar among the three provinces and ranged from 0.5 to 19.2% and 1 to 19.2% respectively. The overall discriminative properties of the FRS were similar between ON (C-statistic = 0.673), BC (C-statistic = 0.644) and MB (C-statistic = 0.649) samples.

CONCLUSION

FRS is a valid tool for identifying LTC residents at different risk levels for hip or all clinical fractures in three provinces. Having a fracture risk assessment tool that is tailored to the LTC context and embedded within the routine clinical assessment may have significant implications for policy, service delivery and care planning, and may improve care for LTC residents across Canada.