Central DXA utilization shifts from office-based to hospital-based settings among medicare beneficiaries in the wake of reimbursement changes

Performance of FRAX in older adults with frailty: the Framingham Heart Study

We compared the performance of FRAX according to frailty status in 3554 individuals from the Framingham Study. During 10-year follow-up, 6.9% and 3.0% of participants with and without frailty experienced MOF. Discrimination profiles were lower in participants with frailty compared to those without, but they improved when FRAX included BMD.

INTRODUCTION

Frailty increases fracture risk. FRAX was developed to predict fractures but never validated in individuals with frailty. We aimed to compare the predictive performance of FRAX (v4.3) in individuals with and without frailty.

METHODS

We conducted a cohort study using the Framingham Heart Study. Frailty was defined by the Fried phenotype. Major osteoporotic fractures (MOF) were ascertained from medical records during 10-year follow-up. To evaluate discrimination and calibration of FRAX, we calculated the area-under-the-receiver-operating characteristics curves (AUC) using logistic regression models and observed-to-predicted fracture probabilities. Analyses were stratified by frailty status.

RESULTS

Frailty was present in 550/3554 (15.5%) of participants. Participants with frailty were older (81.1 vs. 67.6 years), female (68.6% vs. 55.1%), and had greater mean FRAX scores (MOF: 15.9% vs. 10.1%) than participants without frailty. During follow-up, 38 participants with frailty (6.9%) and 91 without (3.0%) had MOFs. The AUC for FRAX (without BMD) was lower in participants with frailty (0.584; 95% CI 0.504-0.663) compared to those without (0.695; 95% CI 0.649-0.741); p value = 0.02. Among participants with frailty, the AUC improved when FRAX included BMD (AUC 0.658, p value < 0.01). FRAX overestimated MOF risk, with larger overestimations in individuals without frailty. Performance of FRAX for hip fracture was similar.

CONCLUSION

FRAX may have been less able to identify frail individuals at risk for fracture, as compared with individuals without frailty, unless information on BMD is available. This suggests that BMD captures features important for fracture prediction in frail persons. Future fracture prediction models should be developed among persons with frailty.

Dual-energy X-ray Absorptiometry Trends Among US Medicare Beneficiaries: 2005-2019

INTRODUCTION

Bone density measured using dual-energy X-ray absorptiometry (DXA) volume, performance site and interpreters have changed in the US since 2005. The purpose of this report is to provide updated trends in DXA counts, rates, place of service and interpreter specialty for the Medicare fee-for-service population.

METHODS

The 100 % Medicare Physician/Supplier Procedure Summary Limited Data Set between 2005-2019 was used. DXA counts and annual rates per 10,000 Medicare beneficiaries were calculated. Annual distributions of scan performance location, provider type and interpreter specialty were described. Place of service trends (significance assigned at p < 0.05) of the mean annual share of DXA utilization were identified using linear regression.

RESULTS

Annual DXA use per 10,000 beneficiaries peaked in 2008 at 832, declined to 656 in 2015 then increased (p < 0.001) by 38 per year to 807 in 2019. From 2005 to 2019 DXA performance in office settings declined from 70.7 % to 47.2 %. Concurrently, outpatient hospital (OH) DXA increased from 28.6 % to 51.7 %. In 2005, 43.5 % of DXAs were interpreted by radiologists. This increased (p < 0.001) in the office and OH, averaging 0.3 and 2.0 percentage points per year respectively, reaching 73.5 % in 2019. Interpretation by most non-radiologist specialties declined (p < 0.001).

CONCLUSIONS

From 2005-2019, total DXA use among Medicare beneficiaries declined reaching a nadir in 2015 then returned to 2005 levels by 2019. Office DXA declined since 2005 with 51.7 % of all scans now occurring in an OH setting. The proportion of DXAs interpreted by radiologists increased over time, reaching 73.5 % in 2019.

Detection of osteoporotic-related bone changes and prediction of distal radius strength using Raman spectra from excised human cadaver finger bones

While osteoporosis is reliably diagnosed using dual energy X-ray absorptiometry (DXA), screening rates are alarmingly low, contributing to preventable fractures. Raman spectroscopy (RS) can detect biochemical changes that occur in bones transcutaneously and can arguably be more accessible than DXA as a fracture risk assessment. A reasonable approach to translate RS is to interrogate phalangeal bones of human hands, where the soft tissues covering the bone are less likely to hamper transcutaneous measurements. To that end, we set out to first determine whether Raman spectra obtained from phalangeal bones correlate with distal radius fracture strength, which can predict subsequent osteoporotic fractures at the spine and hip. We performed RS upon diaphyseal and epiphyseal regions of exposed proximal phalanges from 12 cadaver forearms classified as healthy (n = 3), osteopenic (n = 4), or osteoporotic (n = 5) based on wrist T-scores measured by DXA. We observed a significant decrease in phosphate to matrix ratio and a significant increase in carbonate substitution in the osteoporotic phalanges relative to healthy and osteopenic phalanges. Multivariate regression models produced wrist T-score estimates with significant correlation to the DXA-measured values (r = 0.79). Furthermore, by accounting for phalangeal RS parameters, body mass index, and age, a multivariate regression significantly predicted distal radius strength measured in a simulated-fall biomechanical test (r = 0.81). These findings demonstrate the feasibility of interrogating the phalanges using RS for bone quality assessment of distant clinical sites of fragility fractures, such as the wrist. Future work will address transcutaneous measurement challenges as another requirement for scale-up and translation.

Cost-effectiveness of opportunistic QCT-based osteoporosis screening for the prediction of incident vertebral fractures

Objectives

Opportunistic quantitative computed tomography (oQCT) derived from non-dedicated routine CT has demonstrated high accuracy in diagnosing osteoporosis and predicting incident vertebral fractures (VFs). We aimed to investigate the cost-effectiveness of oQCT screening compared to dual-energy X-ray absorptiometry (DXA) as the standard of care for osteoporosis screening.

Methods

Three screening strategies ("no osteoporosis screening", "oQCT screening", and "DXA screening") after routine CT were simulated in a state-transition model for hypothetical cohorts of 1,000 patients (women and men aged 65 years) over a follow-up period of 5 years (base case). The primary outcomes were the cumulative costs and the quality-adjusted life years (QALYs) estimated from a U.S. health care perspective for the year 2022. Cost-effectiveness was assessed based on a willingness-to-pay (WTP) threshold of $70,249 per QALY. The secondary outcome was the number of prevented VFs. Deterministic and probabilistic sensitivity analyses were conducted to test the models' robustness.

Results

Compared to DXA screening, oQCT screening increased QALYs in both sexes (additional 2.40 per 1,000 women and 1.44 per 1,000 men) and resulted in total costs of $3,199,016 and $950,359 vs. $3,262,934 and $933,077 for women and men, respectively. As a secondary outcome, oQCT screening prevented 2.6 and 2.0 additional VFs per 1,000 women and men, respectively. In the probabilistic sensitivity analysis, oQCT screening remained cost-effective in 88.3% (women) and 90.0% (men) of iterations.

Conclusion

oQCT screening is a cost-effective ancillary approach for osteoporosis screening and has the potential to prevent a substantial number of VFs if considered in daily clinical practice.

3D printed trabeculae conditionally reproduce the mechanical properties of the actual trabeculae - A preliminary study

Three-dimensional (3D) printing has been used to fabricate synthetic trabeculae models and to test mechanical behavior that cannot be recognized in the actual sample, but the extent to which 3D printed trabeculae replicate the mechanical behavior of the actual trabeculae remains to be quantified. The aim of this study was to evaluate the accuracy of 3D printed trabeculae in reproducing the mechanical properties of the corresponding actual trabeculae. Twelve human trabecular cubes (5 × 5 × 5 mm) were scanned by micro-CT to form the trabecular 3D model. Each trabecular 3D model was scaled ×2-, ×3-, ×4- and ×5-fold and then printed twice at a layer thickness of 60 μm using poly (lactic acid) (PLA). The actual trabecular cubes and the 3D-printed trabecular cubes were first compressed under a loading rate of 1 mm/min; another replicated stack of 3D-printed trabecular cubes was compressed under a strain rate of 0.2/min. The results showed that the stiffness of the printed cubes tended to increase, while the strength tended to converge when the magnification increased under the two loading conditions. The strain rate effect was found in the printed cubes. The correlation coefficient (R2) of the mechanical properties between the printed and actual trabeculae can reach up to 0.94, especially under ×3-, ×4- and ×5-fold magnification. In conclusion, 3D printing could be a potential tool to evaluate the mechanical behavior of actual trabecular tissue in vitro and may help in the future to predict the risk of fracture and even personalize the treatment evaluation for osteoporosis and other trabecular bone pathologies.

MRI Based Validation of Abdominal Adipose Tissue Measurements From DXA in Postmenopausal Women

INTRODUCTION

Visceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI.

METHODOLOGY

Participants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed.

RESULTS

Participants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500.

CONCLUSIONS

New software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.

Proposed diagnostic volumetric bone mineral density thresholds for osteoporosis and osteopenia at the cervicothoracic spine in correlation to the lumbar spine

OBJECTIVES

To determine the correlation between cervicothoracic and lumbar volumetric bone mineral density (vBMD) in an average cohort of adults and to identify specific diagnostic thresholds for the cervicothoracic spine on the individual subject level.

METHODS

In this HIPPA-compliant study, we retrospectively included 260 patients (59.7 ± 18.3 years, 105 women), who received a contrast-enhanced or non-contrast-enhanced CT scan. vBMD was extracted using an automated pipeline ( https://anduin.bonescreen.de ). The association of vBMD between each vertebra spanning C2-T12 and the averaged values at the lumbar spine (L1-L3) was analyzed before and after semiquantitative assessment of fracture status and degeneration, and respective vertebra-specific cut-off values for osteoporosis were calculated using linear regression.

RESULTS

In both women and men, trabecular vBMD decreased with age in the cervical, thoracic, and lumbar regions. vBMD values of cervicothoracic vertebrae showed strong correlations with lumbar vertebrae (L1-L3), with a median Pearson value of r = 0.87 (range: r_C2 = 0.76 to r_T12 = 0.96). The correlation coefficients were significantly lower (p < 0.0001) without excluding fractured and degenerated vertebrae, median r = 0.82 (range: r_C2 = 0.69 to r_T12 = 0.93). Respective cut-off values for osteoporosis peaked at C4 (209.2 mg/ml) and decreased to 83.8 mg/ml at T12.

CONCLUSION

Our data show a high correlation between clinically used mean L1-L3 values and vBMD values elsewhere in the spine, independent of age. The proposed cut-off values for the cervicothoracic spine therefore may allow the determination of low bone mass even in clinical cases where only parts of the spine are imaged.

KEY POINTS

vBMD of all cervicothoracic vertebrae showed strong correlation with lumbar vertebrae (L1-L3), with a median Pearson's correlation coefficient of r = 0.87 (range: r_C2 = 0.76 to r_T12 = 0.96). The correlation coefficients were significantly lower (p < 0.0001) without excluding fractured and moderate to severely degenerated vertebrae, median r = 0.82 (range: r_C2 = 0.69 to r_T12 = 0.93). We postulate that trabecular vBMD < 200 mg/ml for the cervical spine and < 100 mg/ml for the thoracic spine are strong indicators of osteoporosis, similar to < 80 mg/ml at the lumbar spine.

Opportunistic CT screening of osteoporosis on thoracic and lumbar spine: a meta-analysis

BACKGROUND

Osteoporotic fractures are a major contributor to late life morbidity and mortality, and impose a substantial societal cost, yet osteoporosis remains substantially underdiagnosed and undertreated. The purpose of this meta-analysis was to assess the pooled diagnostic sensitivity and specificity of computed tomography (CT) images for diagnosing osteoporosis in patients who meet WHO dual X-ray absorptiometry (DXA) osteoporosis criteria using specific Hounsfield unit (HU) values as a threshold.

METHODS

Systematic literature searches in PubMed, Embase, Web of Science and Google Scholar were performed from the earliest available date through 1 July 2018, restricted to publications in English. Participants in all studies underwent CT scans that included the lumbar and/or thoracic spine for different indications and HU measurements were used to identify osteoporosis. DXA scans served as the reference standard.

RESULTS

Ten eligible studies were identified. The mean area under the hierarchical summary receiver operating characteristic (ROC) curve for diagnosis osteoporosis was 0.84 (95% CI: 0.81, 0.87). The pooled diagnostic sensitivity and specificity of CT images to identify osteoporosis were 0.83 (95% CI: 0.73, 0.90) and 0.74 (95% CI: 0.69, 0.79). The positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio were 3.4 (95% CI: 2.7, 4.5), 0.21 (95% CI: 0.12, 0.36), and 16.4 (95% CI: 7.8, 34.3), respectively. The bias-adjusted sensitivity and specificity of CT were 0.73 and 0.71. Meta-regression demonstrated that country of study, DXA criteria and scanner manufacturer were significant factors associated with the sensitivity of CT in detecting osteoporosis while scanner manufacturer was the only factor associated with specificity of CT.

CONCLUSIONS

This meta-analysis showed reasonable pooled sensitivity and specificity for using threshold values measured on CT scans to identify osteoporosis opportunistically.

Assessment of Skeletal Strength: Bone Density Testing and Beyond

A bone fractures when a force applied to it exceeds its strength. Assessment of bone strength is an important component in determining the risk of fracture and guiding treatment decisions. Dual-energy X-ray absorptiometry is used to diagnosis osteoporosis, estimate fracture risk, and monitor changes in bone density. Fracture risk algorithms provide enhanced fracture risk predictability. Advanced technologies with computed tomography (CT) and MRI can measure parameters of bone microarchitecture. Mathematical modeling using CT data can evaluate the behavior of bone structures in response to external loading. Microindentation techniques directly measure the strength of outer bone cortex.

Bone density and strength from thoracic and lumbar CT scans both predict incident vertebral fractures independently of fracture location

In a population-based study, we found that computed tomography (CT)-based bone density and strength measures from the thoracic spine predicted new vertebral fracture as well as measures from the lumbar spine, suggesting that CT scans at either the thorax or abdominal regions are useful to assess vertebral fracture risk.

INTRODUCTION

Prior studies have shown that computed tomography (CT)-based lumbar bone density and strength measurements predict incident vertebral fracture. This study investigated whether CT-based bone density and strength measurements from the thoracic spine predict incident vertebral fracture and compared the performance of thoracic and lumbar bone measurements to predict incident vertebral fracture.

METHODS

This case-control study of community-based men and women (age 74.6 ± 6.6) included 135 cases with incident vertebral fracture at any level and 266 age- and sex-matched controls. We used baseline CT scans to measure integral and trabecular volumetric bone mineral density (vBMD) and vertebral strength (via finite element analysis, FEA) at the T8 and L2 levels. Association between these measurements and vertebral fracture was determined by using conditional logistic regression. Sensitivity and specificity for predicting incident vertebral fracture were determined for lumbar spine and thoracic bone measurements.

RESULTS

Bone measurements from T8 and L2 predicted incident vertebral fracture equally well, regardless of fracture location. Specifically, for predicting vertebral fracture at any level, the odds ratio (per 1-SD decrease) for the vBMD and strength measurements at L2 and T8 ranged from 2.0 to 2.7 (p < 0.0001) and 1.8 to 2.8 (p < 0.0001), respectively. Results were similar when predicting fracture only in the thoracic versus the thoracolumbar spine. Lumbar and thoracic spine bone measurements had similar sensitivity and specificity for predicting incident vertebral fracture.

CONCLUSION

These findings indicated that like those from the lumbar spine, CT-based bone density and strength measurements from the thoracic spine may be useful for identifying individuals at high risk for vertebral fracture.

Factors Associated With Bone Density Monitoring While on Antiosteoporosis Treatment in Routine Clinical Practice: A Registry-Based Cohort Study

The role for bone mineral density (BMD) monitoring while on antiosteoporosis therapy remains controversial. The current study used population-based registries to identify factors associated with BMD monitoring in women within 5 yr of receiving antiosteoporosis treatment vs treatment without monitoring in routine clinical practice. The analytical dataset consisted of women age 40 yr and older at baseline receiving antiosteoporosis therapy: 6877 with BMD monitoring (mean interval 3.2 yr) and 6747 without BMD monitoring. There was a significant negative secular trend in BMD monitoring during the study period (p < 0.001). Multivariable logistic regression demonstrated that parental hip fracture, glucocorticoid and aromatase inhibitor use, and lower baseline BMD were independently and positively associated with BMD monitoring. Individuals with increasing age, greater body mass index, smoking, rheumatoid arthritis, later calendar year, diabetes, rural residency, lower income, and greater comorbidity score were less likely to undergo monitoring. A shorter monitoring interval (<23 mo) was strongly associated with glucocorticoid and aromatase inhibitor use. In conclusion, our study identifies factors associated with BMD monitoring over 5 yr in patients receiving antiosteoporosis therapy.

Biomechanical Computed Tomography analysis (BCT) for clinical assessment of osteoporosis

The surgeon general of the USA defines osteoporosis as "a skeletal disorder characterized by compromised bone strength, predisposing to an increased risk of fracture." Measuring bone strength, Biomechanical Computed Tomography analysis (BCT), namely, finite element analysis of a patient's clinical-resolution computed tomography (CT) scan, is now available in the USA as a Medicare screening benefit for osteoporosis diagnostic testing. Helping to address under-diagnosis of osteoporosis, BCT can be applied "opportunistically" to most existing CT scans that include the spine or hip regions and were previously obtained for an unrelated medical indication. For the BCT test, no modifications are required to standard clinical CT imaging protocols. The analysis provides measurements of bone strength as well as a dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) T-score at the hip and a volumetric BMD of trabecular bone at the spine. Based on both the bone strength and BMD measurements, a physician can identify osteoporosis and assess fracture risk (high, increased, not increased), without needing confirmation by DXA. To help introduce BCT to clinicians and health care professionals, we describe in this review the currently available clinical implementation of the test (VirtuOst), its application for managing patients, and the underlying supporting evidence; we also discuss its main limitations and how its results can be interpreted clinically. Together, this body of evidence supports BCT as an accurate and convenient diagnostic test for osteoporosis in both sexes, particularly when used opportunistically for patients already with CT. Biomechanical Computed Tomography analysis (BCT) uses a patient's CT scan to measure both bone strength and bone mineral density at the hip or spine. Performing at least as well as DXA for both diagnosing osteoporosis and assessing fracture risk, BCT is particularly well-suited to "opportunistic" use for the patient without a recent DXA who is undergoing or has previously undergone CT testing (including hip or spine regions) for an unrelated medical condition.

DEXA sensitivity analysis in patients with adult spinal deformity

BACKGROUND

Adult spinal deformity (ASD) is a debilitating condition that commonly requires surgical intervention. However, ASD patients may also present with osteoporosis, predisposing them to surgical complications and failure of instrumentation. As a result, proper detection of low bone mineral density (BMD) is critical in order to ensure proper patient care. Typically dual-energy x-ray absorptiometry (DEXA) scans are performed on the hip and spine. Unfortunately, in ASD patients, the latter is often inaccurate PURPOSE: In this study, we consider the value of obtaining a forearm DEXA scan in addition to a hip scan in patients suffering from ASD and osteoporosis in order to accurately detect low BMD.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Patient data between 2016 and 2018 from a single academic medical center was utilized. Two hundred eighty-six patients met the initial search criteria.

OUTCOME MEASURES

No outcomes measures related to self-reporting, physiology, or functionality were evaluated in this study. Primary outcome measures analyzed included T-scores across various anatomic locations and diagnoses relating to low bone density (ie, osteopenia and osteoporosis).

METHODS

This retrospective study examines patients that underwent DEXA studies between 2016 and 2018 and were previously diagnosed with both osteoporosis and adult spinal deformity. For each patient, age, gender, body mass index, and smoking history were noted, as well as whether there was long-term prednisone use. T-scores from both the forearm and hip were recorded and analyzed. Diagnoses from hip DEXA scans were compared with those obtained from forearm scans to identify which region was more sensitive in detecting low BMD. From this data, the frequency of a missed diagnosis, due to reliance on hip or spine T-scores for detection of low BMD, was extrapolated. No external funding source was received in support of this study.

RESULTS

Two hundred eighty-six patients matched the initial search criteria. Only 68% had one T-score value. However, 24.8% of patients had data for both the hip and forearm, whereas 7.1% had data for the forearm, hip, and spine. Among the 85 patients with more than one anatomical site of study, the forearm was more sensitive than the hip in its ability to detect osteopenia or osteoporosis 41.2% of the time. A two-tailed t test showed no statistically significant difference between hip T-scores and forearm T-scores. However, for more than 17% of patients, the forearm allowed clinicians to detect osteoporosis or osteopenia in a setting where using only the hip data would have missed such a diagnosis.

CONCLUSIONS

Clinicians need to ensure they survey at least two locations when conducting DEXA studies before precluding a diagnosis of osteopenia or osteoporosis. All ASD patients being evaluated for low bone density should receive DEXA scans that survey at least the hip and the forearm. Misdiagnoses can be costly in the setting of ASD. They occur frequently when only a single hip scan is relied upon to assess BMD.

Cross-calibration, Least Significant Change and Quality Assurance in Multiple Dual-Energy X-ray Absorptiometry Scanner Environments: 2019 ISCD Official Position

In preparation for the International Society for Clinical Densitometry Position Development Conference (PDC) 2019 in Kuala Lumpur, Malaysia, a cross-calibration and precision task force was assembled and tasked to review the literature, summarize the findings, and generate positions to answer 4 related questions provided by the PDC Steering Committee, which expand upon the current ISCD official positions on these subjects. (1) How should a provider with multiple dual-energy X-ray absorptiometry (DXA) scanners of the same make and model calculate least significant change (LSC)? (2) How should a provider with multiple DXA systems with the same manufacturer but different models calculate LSC? (3) How should a provider with multiple DXA systems from different manufacturers and models calculate LSC? (4) Are there specific phantom procedures that one can use to provide trustworthy in vitro cross calibration for same models, different models, and different makes? Based on task force deliberations and the resulting systematic literature reviews, 3 new positions were developed to address these more complex scenarios not addressed by current official positions on single scanner cross calibration and LSC. These new positions provide appropriate guidance to large multiple DXA scanner providers wishing to offer patients flexibility and convenience, and clearly define good clinical practice requirements to that end.

Improved prediction of incident vertebral fractures using opportunistic QCT compared to DXA

OBJECTIVES

To compare opportunistic quantitative CT (QCT) with dual energy X-ray absorptiometry (DXA) in their ability to predict incident vertebral fractures.

METHODS

We included 84 patients aged 50 years and older, who had routine CT including the lumbar spine and DXA within a 12-month period (baseline) as well as follow-up imaging after at least 12 months or who sustained an incident vertebral fracture documented earlier. Patients with bone disorders aside from osteoporosis were excluded. Fracture status and trabecular bone mineral density (BMD) were retrospectively evaluated in baseline CT and fracture status was reassessed at follow-up. BMDQCT was assessed by opportunistic QCT with asynchronous calibration of multiple MDCT scanners.

RESULTS

Sixteen patients had incident vertebral fractures showing lower mean BMDQCT than patients without fracture (p = 0.001). For the risk of incident vertebral fractures, the hazard ratio increased per SD in BMDQCT (4.07; 95% CI, 1.98-8.38), as well as after adjusting for age, sex, and prevalent fractures (2.54; 95% CI, 1.09-5.90). For DXA, a statistically significant increase in relative hazard per SD decrease in T-score was only observed after age and sex adjustment (1.57; 95% CI, 1.04-2.38). The predictability of incident vertebral fractures was good by BMDQCT (AUC = 0.76; 95% CI, 0.64-0.89) and non-significant by T-scores. Asynchronously calibrated CT scanners showed good long-term stability (linear drift ranging from - 0.55 to - 2.29 HU per year).

CONCLUSIONS

Opportunistic screening of mainly neurosurgical and oncologic patients in CT performed for indications other than densitometry allows for better risk assessment of imminent vertebral fractures than dedicated DXA.

KEY POINTS

• Opportunistic QCT predicts osteoporotic vertebral fractures better than DXA reference standard in mainly neurosurgical and oncologic patients. • More than every second patient (56%) with an incident vertebral fracture was misdiagnosed not having osteoporosis according to DXA. • Standard ACR QCT-cutoff values for osteoporosis (< 80 mg/cm 3 ) and osteopenia (≤ 120 mg/cm 3 ) can also be applied scanner independently in calibrated opportunistic QCT.

Cost-Effectiveness of Osteoporosis Screening Using Biomechanical Computed Tomography for Patients With a Previous Abdominal CT

Osteoporosis screening rates by DXA are low (9.5% women, 1.7% men) in the US Medicare population aged 65 years and older. Addressing this care gap, we estimated the benefits of a validated osteoporosis diagnostic test suitable for patients age 65 years and older with an abdominal computed tomography (CT) scan taken for any indication but without a recent DXA. Our analysis assessed a hypothetical cohort of 1000 such patients in a given year, and followed them for 5 years. Separately for each sex, we used Markov modeling to compare two mutually exclusive scenarios: (i) utilizing the CT scans, perform one-time "biomechanical computed tomography" (BCT) analysis to identify high-risk patients on the basis of both femoral strength and hip BMD T-scores; (ii) ignore the CT scan, and rely instead on usual care, consisting of future annual DXA screening at typical Medicare rates. For patients with findings indicative of osteoporosis, 50% underwent 2 years of treatment with alendronate. We found that BCT provided greater clinical benefit at lower cost for both sexes than usual care. In our base case, compared to usual care, BCT prevented hip fractures over a 5-year window (3.1 per 1000 women; 1.9 per 1000 men) and increased quality-adjusted life years (2.95 per 1000 women; 1.48 per 1000 men). Efficacy and savings increased further for higher-risk patient pools, greater treatment adherence, and longer treatment duration. When the sensitivity and specificity of BCT were set to those for DXA, the prevented hip fractures versus usual care remained high (2.7 per 1000 women; 1.5 per 1000 men), indicating the importance of high screening rates on clinical efficacy. Therefore, for patients with a previously taken abdominal CT and without a recent DXA, osteoporosis screening using biomechanical computed tomography may be a cost-effective alternative to current usual care. © 2019 American Society for Bone and Mineral Research.

Factors Associated With Osteoporosis Care of Men Hospitalized for Hip Fracture: A Retrospective Cohort Study

Rates of postfracture DXA and pharmacotherapy appear to be declining despite their known benefits in fracture reduction. We sought to identify factors associated with osteoporosis care among male veterans aged 50 years and older after hip fracture and to evaluate trends in rates of care with an observational cohort design using US Department of Veterans Affairs’ (VA) inpatient, pharmacy, and outpatient encounters and Centers for Medicare and Medicaid Services outpatient pharmacy claims (2007 to 2014) from men aged 50 years and older treated for hip fracture (N = 7317). We used the Cox proportional hazards model with random effects for the admitting facility. A sensitivity analysis was performed for a subset of patients aged 65 to 99 dually enrolled in Medicare ( N = 5821). Overall, approximately 13% of patients had evidence of osteoporosis care within one year of fracture. In the adjusted model, rural residence was associated with lower likelihood of care, and several comorbidities were associated with higher likelihood of receiving care. In sensitivity analyses of patients dually enrolled in Medicare, rural residence remained associated with lower likelihood of osteoporosis care. Overall rates of care decreased over time, but rates of DXA in the VA remained stable. These findings highlight the ongoing problem of low rates of postfracture care among a population with the highest risk of future fracture and its associated morbidity and mortality. The rural disparity in care and differences in rates of care across healthcare delivery systems illustrates the importance of healthcare delivery systems in promoting pharmacotherapy and DXA after sentinel events. Because the VA removes a majority of cost barriers to care, this integrated healthcare system may outperform the private sector in access to care. However, declining rates of pharmacotherapy imply knowledge gaps that undermine quality care. © 2019 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of 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.

Intervals between bone mineral density testing with dual-energy X-ray absorptiometry scans in clinical practice

Intervals between dual-energy X-ray absorptiometry (DXA) scans were evaluated in a large cohort of typical clinical practice. Intensive DXA scanning (intervals < 23 months) decreased substantially, from 16.7% in 2006 to 6.7% in 2015.

INTRODUCTION

Serial dual-energy X-ray absorptiometry (DXA) measurements are suggested for patients at high risk of fractures. However, little is known about how often DXA testing occurs in clinical practice.

METHODS

We examined time intervals between DXA testing for monitoring purpose at two academic medical centers in the US between 2004 and 2017. The primary outcome was the presence of testing intervals < 23 months (termed "intensive DXA testing"). A generalized linear mixed model was used to evaluate the association between selected patient-level clinical factors and intensive DXA testing.

RESULTS

Forty-nine thousand four hundred ninety-four DXA tests from 20,200 patients were analyzed. The mean time interval between scans was 36 ± 21 months. Only 11.1% of the repeated DXA testing met the criterion for intensive testing. The percentage of intensive DXA testing dropped from 16.7% in 2006 to 6.7% in 2015 (p for trend < 0.001). After adjusting for age, gender, number of outpatient visits, and calendar year, correlates of intensive DXA testing included a baseline T-score < -2.5 at any anatomic site (OR, 4.8; 95%CI, 4.0-5.7), active use of drugs for osteoporosis (OR, 1.6; 95%CI, 1.3-1.9), and active use of glucocorticoids (OR, 1.3; 95%CI, 1.2-1.4).

CONCLUSIONS

The predictors of intensive DXA testing suggest that this practice is used preferentially in patients with multiple risk factors and to monitor the response to pharmacotherapy. However, intensive DXA testing has become less common in real-world clinical practice over the last decade. Further studies are required to better define the optimal use of bone mineral density testing in this vulnerable population.

The Sensitivity of Orthopaedic Surgeons to the Secondary Prevention of Fragility Fractures

BACKGROUND

Orthopaedic surgeons must play an important role in the secondary prevention of fragility fractures; however, some surgeons are more aware than others of their responsibility regarding fracture prevention. The purpose of the present study was to identify which factors can lead to a higher sensitivity for fracture prevention.

METHODS

A cross-sectional survey was distributed to orthopaedic surgeons via online invitation or at academic conferences in China from July through October 2015. A total of 452 surgeons responded. As the primary outcome measure, we created a sensitivity scoring system for fracture prevention based on the respondents' answers to 5 questions regarding behavior in the following areas: risk-factor evaluation, pharmacologic therapy, nonpharmacologic therapy, patient education, and follow-up. Multivariable linear regression and multivariable logistic regression analyses were used to identify factors related to surgeon sensitivity to fracture prevention.

RESULTS

Very few surgeons reported having received adequate training regarding fracture prevention or reading guidelines or other fracture prevention literature (22% and 30%, respectively). Most respondents initiated pharmacologic or nonpharmacologic therapy (82% and 75%, respectively) for the treatment of confirmed osteoporosis among patients with fragility fractures, but only half performed a risk-factor evaluation, patient education, or timely patient follow-up (51%, 52%, and 48%, respectively). In the multivariable linear regression model, the orthopaedic surgeon's age (β = 0.09, p = 0.003), self-rated knowledge level regarding osteoporosis or related issues (β = 0.16, p < 0.001), self-perceived effectiveness in using preventive measures for patients with a fragility fracture (β = 0.62, p < 0.001), and use of clinical pathways for fragility fractures in his or her workplace (β = 1.24, p < 0.001) were independently associated with sensitivity scores for fracture prevention. Similar results were obtained from a multivariable logistic regression model.

CONCLUSIONS

In China, the sensitivity of orthopaedic surgeons to the secondary prevention of fragility fractures is relatively low. Implementation of a comprehensive prevention approach and targeted continuing medical education are required to encourage surgeons to take greater responsibility for screening, treating, educating, and following their patients with fragility fractures.

Fracture Prediction by Computed Tomography and Finite Element Analysis: Current and Future Perspectives

PURPOSE OF REVIEW

This review critiques the ability of CT-based methods to predict incident hip and vertebral fractures.

RECENT FINDINGS

CT-based techniques with concurrent calibration all show strong associations with incident hip and vertebral fracture, predicting hip and vertebral fractures as well as, and sometimes better than, dual-energy X-ray absorptiometry areal biomass density (DXA aBMD). There is growing evidence for use of routine CT scans for bone health assessment. CT-based techniques provide a robust approach for osteoporosis diagnosis and fracture prediction. It remains to be seen if further technical advances will improve fracture prediction compared to DXA aBMD. Future work should include more standardization in CT analyses, establishment of treatment intervention thresholds, and more studies to determine whether routine CT scans can be efficiently used to expand the number of individuals who undergo evaluation for fracture risk.

Osteoporosis and Hip Fracture Risk From Routine Computed Tomography Scans: The Fracture, Osteoporosis, and CT Utilization Study (FOCUS)

Methods now exist for analyzing previously taken clinical computed tomography (CT) scans to measure a dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) at the hip and a finite element analysis-derived femoral strength. We assessed the efficacy of this "biomechanical CT" (BCT) approach for identifying patients at high risk of incident hip fracture in a large clinical setting. Using a case-cohort design sampled from 111,694 women and men aged 65 or older who had a prior hip CT scan, a DXA within 3 years of the CT, and no prior hip fracture, we compared those with subsequent hip fracture (n = 1959) with randomly selected sex-stratified controls (n = 1979) and analyzed their CT scans blinded to all other data. We found that the age-, race-, and body mass index (BMI)-adjusted hazard ratio (HR; per standard deviation) for femoral strength was significant before (women: HR = 2.8, 95% confidence interval [CI] 2.2-3.5; men: 2.8, 2.1-3.7) and after adjusting also for the (lowest) hip BMD T-score by BCT (women: 2.1, 1.4-3.2; men: 2.7, 1.6-4.6). The hazard ratio for the hip BMD T-score was similar between BCT and DXA for both sexes (women: 2.1, 1.8-2.5 BCT versus 2.1, 1.7-2.5 DXA; men: 2.8, 2.1-3.8 BCT versus 2.5, 2.0-3.2 DXA) and was higher than for the (lowest) spine/hip BMD T-score by DXA (women: 1.6, 1.4-1.9; men: 2.1, 1.6-2.7). Compared with the latter as a clinical-practice reference and using both femoral strength and the hip BMD T-score from BCT, sensitivity for predicting hip fracture was higher for BCT (women: 0.66 versus 0.59; men: 0.56 versus 0.48), with comparable respective specificity (women: 0.66 versus 0.67; men: 0.76 versus 0.78). We conclude that BCT analysis of previously acquired routine abdominal or pelvic CT scans is at least as effective as DXA testing for identifying patients at high risk of hip fracture. © 2018 American Society for Bone and Mineral Research.

Bone mineral density measurements in vertebral specimens and phantoms using dual-layer spectral computed tomography

To assess whether phantomless calcium-hydroxyapatite (HA) specific bone mineral density (BMD) measurements with dual-layer spectral computed tomography are accurate in phantoms and vertebral specimens. Ex-vivo human vertebrae (n = 13) and a phantom containing different known HA concentrations were placed in a semi-anthropomorphic abdomen phantom with different extension rings simulating different degrees of obesity. Phantomless dual-layer spectral CT was performed at different tube current settings (500, 250, 125 and 50 mAs). HA-specific BMD was derived from spectral-based virtual monoenergetic images at 50 keV and 200 keV. Values were compared to the HA concentrations of the phantoms and conventional qCT measurements using a reference phantom, respectively. Above 125 mAs, errors for phantom measurements ranged between -1.3% to 4.8%, based on spectral information. In vertebral specimens, high correlations were found between BMD values assessed with spectral CT and conventional qCT (r ranging between 0.96 and 0.99; p < 0.001 for all) with different extension rings, and a high agreement was found in Bland Altman plots. Different degrees of obesity did not have a significant influence on measurements (P > 0.05 for all). These results suggest a high validity of HA-specific BMD measurements based on dual-layer spectral CT examinations in setups simulating different degrees of obesity without the need for a reference phantom, thus demonstrating their feasibility in clinical routine.

Opportunistic Use of CT Imaging for Osteoporosis Screening and Bone Density Assessment: A Qualitative Systematic Review

BACKGROUND

The purpose of this study was to determine the clinical opportunities for the use of computed tomography (CT) imaging for inferring bone quality and to critically analyze the correlation between dual x-ray absorptiometry (DXA) and diagnostic CT as reported in the literature.

METHODS

A systematic review of the MEDLINE database was performed in February 2016 using the PubMed interface. The inclusion criteria were English language, studies performed using living human subjects, studies pertaining to orthopaedics, use of conventional diagnostic CT scans, studies that measured cancellous bone, and studies that reported Hounsfield unit (HU) measurements directly rather than a computed bone mineral density.

RESULTS

Thirty-seven studies that reported on a total of 9,109 patients were included. Of these, 10 studies correlated HU measurements of trabecular bone with DXA-based bone assessment. Reported correlation coefficients ranged between 0.399 and 0.891, and 5 of the studies reported appropriate threshold HU levels for diagnosing osteoporosis or osteopenia.

CONCLUSIONS

Direct HU measurement from diagnostic CT scans has the potential to be used opportunistically for osteoporosis screening, but in its current state it is not ready for clinical implementation. There is a lack of exchangeability among different machines that limits its broad applicability. Future research efforts should focus on identifying thresholds at specific anatomic regions in high-risk patients in order to have the greatest impact on patients. However, using diagnostic CT to infer region-specific osteoporosis could be extraordinarily valuable to orthopaedic surgeons and primary care physicians, and merits further research.

Prevention of Adolescent Depression in Primary Care: Barriers and Relational Work Solutions

BACKGROUND AND PURPOSE

Depression affects millions of adolescents in the United States each year. This population may benefit from targeted preventive interventions. We sought to understand the internal factors that affect the ability of healthcare organizations to implement an intervention that involves mental health screening and depression prevention treatment of at-risk adolescents in primary care settings.

METHODS

From November 2011 to July 2016 we conducted a study of the implementation of a multisite (N=30) phase 3 randomized clinical trial of an Internet-based depression prevention intervention program (CATCH-IT). We describe the prevalence of internal barriers on the screening and enrollment process by reporting REACH (the proportion of target audience exposed to the intervention).

RESULTS

A total of 369 adolescents were randomized into the intervention or control program. Mean REACH values for the study clinics were 0.216 for screening and 0.181 for enrollment to CATCH-IT. Mean REACH enrollment lost due to internal barriers was 0.233. This translated to 4,691 adolescents lost at screening and 2,443 adolescents lost at enrollment due to internal barriers.

CONCLUSION

We propose a model of the implementation process that emphasizes the importance of positive relational work that assists in overcoming internal barriers to REACH. We also provide implications for policy and practice.

Trends in osteoporosis and low bone mass in older US adults, 2005-2006 through 2013-2014

This study examined trends in osteoporosis and low bone mass in older US adults between 2005 and 2014 using bone mineral density (BMD) data from the National Health and Nutrition Examination Survey (NHANES). Osteoporosis and low bone mass appear to have increased at the femur neck but not at the lumbar spine during this period.

INTRODUCTION

Recent preliminary data from Medicare suggest that the decline in hip fracture incidence among older US adults may have plateaued in 2013-2014, but comparable data on BMD trends for this time period are currently lacking. This study examined trends in the prevalence of osteoporosis and low bone mass since 2005 using BMD data from NHANES. The present study also updated prevalence estimates to 2013-2014 and included estimates for non-Hispanic Asians.

METHODS

Femur neck and lumbar spine BMD by DXA were available for 7954 adults aged 50 years and older from four NHANES survey cycles between 2005-2006 and 2013-2014.

RESULTS

Significant trends (quadratic or linear) were observed for the femur neck (mean T-score and osteoporosis in both sexes; low bone mass in women) but not for the lumbar spine. The trend in femur neck status was somewhat U-shaped, with prevalences being most consistently significantly higher (by 1.1-6.6 percentage points) in 2013-2014 than 2007-2008. Adjusting for changes in body mass index, smoking, milk intake, and physician's diagnosis of osteoporosis between surveys did not change femur neck trends. In 2013-2014, the percent of older adults with osteoporosis was 6% at the femur neck, 8% at the lumbar spine, and 11% at either site.

CONCLUSIONS

There was some evidence of a decline in femur neck BMD between 2005-2006 and 2013-2014, but not in lumbar spine BMD. Changes in the risk factors that could be examined did not explain the femur neck BMD trends.

Osteoporosis-Related Health Services Utilization Following First Hip Fracture Among a Cohort of Privately-Insured Women in the United States, 2008-2014: An Observational Study

Timely identification and treatment of osteoporosis following hip fracture is recommended to mitigate future fracture risk, yet prior work has demonstrated a disconnect between evidence-based recommendations and real-world implementation. We sought to describe contemporary patterns of osteoporosis screening and initiation of pharmacotherapy following hip fracture based on medical and pharmacy claims in the OptumLabs™ Data Warehouse. From a national sample, we identified 8349 women aged 50+ years enrolled in private commercial or Medicare Advantage plans with no prior history of osteoporosis diagnosis, osteoporosis pharmacotherapy, or hip fracture who experienced a hip fracture between 2008 and 2013. Just 17.1% and 23.1% of these women had evidence of osteoporosis assessment and/or treatment within 6 or 12 months of their fractures, respectively. Women aged 80+ years were one-third less likely to utilize recommended services within 6 months, compared to those aged 50 to 79 years (13.8% versus 20.8%; p < 0.001). Utilization of bone mass measurement increased significantly among women aged 65+ years over the study period (p < 0.001) while declining among those aged 50 to 64 years (p = 0.2). In contrast, rates of osteoporosis pharmacotherapy remained steady among women aged 50 to 64 years (p = 0.8) yet declined among women aged 65 to 79 years and aged 80+ years (p = 0.07 and p = 0.004, respectively). Accounting for differences in all measured characteristics, receipt of primary care was the strongest and most consistent predictor of osteoporosis assessment or treatment following fracture. © 2017 American Society for Bone and Mineral Research.

A Little Effort Can Withstand the Hardship: Fielding an Internet-Based Intervention to Prevent Depression among Urban Racial/Ethnic Minority Adolescents in a Primary Care Setting

BACKGROUND

This study explored the implementation of Chicago Urban Resiliency Building (CURB), a randomized clinical trial designed as an Internet-based primary care depression prevention intervention for urban African American and Latino adolescents.

METHODS

We utilized a mixed methods analysis to explore four aims. First, we estimated the percent of at-risk adolescents that were successfully screened. Second, we examined clinic site factors and performance. Third, primary care providers (n = 10) and clinic staff (n = 18) were surveyed to assess their knowledge and attitudes about the intervention. Fourth, clinic staff (nursing and medical assistant) interviews were analyzed using thematic analysis to gather perspectives of the implementation process.

RESULTS

We found that the estimated percent of at-risk adolescents who were successfully screened in each clinic varied widely between clinics with a mean of 14.48%. Daily clinic communication was suggestive of greater successful screening. Feasibility of screening was high for both primary care providers and clinic staff. Clinic staff exit interviews indicated the presence of community barriers that inhibited successful implementation of the intervention.

CONCLUSION

This study shares the challenges and successes for depression screening and implementing Internet-based mental health interventions for urban racial/ethnic minority adolescents in primary care settings.

Trends and Disparities in Osteoporosis Screening Among Women in the United States, 2008-2014

BACKGROUND

The United States Preventive Services Task Force recommends universal osteoporosis screening among women ages 65+ and targeted screening of younger women, but historically, adherence to these evidence-based recommendations has been suboptimal.

METHODS

To describe contemporary patterns of osteoporosis screening, we conducted a retrospective analysis using the OptumLabs^™ Data Warehouse, a database of de-identified administrative claims, which includes medical and eligibility information for over 100 million Medicare Advantage and commercial enrollees. Study participants included 1,638,454 women ages 50+ with no prior history of osteoporosis diagnosis, osteoporosis drug use, or hip fracture. Osteoporosis screening during the most recent 2-year period of continuous enrollment was assessed via medical claims. Patient sociodemographics, comorbidities, and utilization of other services were also determined using health insurance files.

RESULTS

Overall screening rates were low: 21.1%, 26.5%, and 12.8% among women ages 50-64, 65-79, and 80+ years, respectively. Secular trends differed significantly by age (P <.001). Between 2008 and 2014, utilization among women ages 50-64 years declined 31.4%, changed little among women 65-79, and increased 37.7% among women 80+ years. Even after accounting for socioeconomic status, health status, and health care utilization patterns, non-Hispanic black women were least likely to be screened, whereas non-Hispanic Asian and Hispanic women were most likely to undergo screening. Marked socioeconomic gradients in screening probabilities narrowed substantially over time, decreasing by 44.5%, 71.9%, and 59.7% among women ages 50-64, 65-79 and 80+ years, respectively.

CONCLUSIONS

Despite significant changes in utilization of osteoporosis screening among women ages 50-64 and 80+, in line with national recommendations, tremendous deficiencies among women 65+ remain.

Vertebral bone attenuation on low-dose chest CT: quantitative volumetric analysis for bone fragility assessment

This study evaluated the use of low-dose chest computed tomography (LDCT) for detecting bone fragility. LDCT-measured vertebral bone attenuation by volumetric methods showed good correlation with bone mineral density (BMD) measured by dual-energy x-ray absorptiometry (DXA, and good diagnostic performance for identifying osteoporosis and compression fractures. The results of this study suggest the feasibility of obtaining comprehensive information on bone health in subjects undergoing LDCT.

INTRODUCTION

Osteoporosis is a prevalent but underdiagnosed disease that increases fracture risk. This study evaluated the utility of vertebral attenuation derived from low-dose chest computed tomography (LDCT) compared to dual-energy x-ray absorptiometry (DXA) for detecting bone fragility.

METHODS

A total of 232 subjects (78 men and 154 women) aged above 50 years who underwent both LDCT and DXA within 30 days were evaluated. LDCT-measured bone attenuation in Hounsfield units (HU) of four vertebrae (T4, T7, T10, and L1) was evaluated using volumetric methods for correlation with DXA-measured bone mineral density (BMD) and for the diagnosis of compression fractures, osteoporosis, and low BMD (osteoporosis or osteopenia) in men and women, with DXA measurements as the reference standard.

RESULTS

The average attenuation of the four vertebrae showed strong correlation with DXA-measured BMD of the lumbar spine (r = 0.726, p < 0.05). In receiver-operating characteristic (ROC) analyses, the area under the curve (AUC) across LDCT-measured thresholds of the average attenuation to distinguish compression fractures was 0.827, and a threshold of 129.5 HU yielded 90.9 % sensitivity and 64.4 % specificity. Similarly, average attenuation showed high AUCs and good diagnostic performance for detecting osteoporosis and low BMD in both men and women. Among 44 subjects with compression fractures, the average bone attenuation showed strong negative correlation with both the worst fracture grade (r = -0.525, p < 0.05) and cumulative fracture grade score (r = -0.633, p < 0.05).

CONCLUSION

LDCT-measured bone attenuation by volumetric methods showed good correlation with BMD measured by DXA and good diagnostic performance for identifying bone fragility.

Predictors of bone mineral density testing among older women on Medicare

Although dual-energy X-ray absorptiometry (DXA) is recommended for all women ≥65 and is covered by Medicare, 40 % of women on Medicare report never having had a DXA. In a longitudinal cohort of 3492 women followed for two decades, we identified several risk factors that should be targeted to improve DXA testing rates.

INTRODUCTION

DXA is used to measure bone mineral density, screen for osteoporosis, and assess fracture risk. DXA is recommended for all women ≥65 years old. Although Medicare covers DXA every 24 months for women, about 40 % report never having had a DXA test, and little is known from prospective cohort studies about which subgroups of women have low use rates and should be targeted for interventions. Our objective was to identify predictors of DXA use in a nationally representative cohort of women on Medicare.

METHODS

We used baseline and biennial follow-up survey data (1993-2012) for 3492 women ≥70 years old from the nationally representative closed cohort known as the Survey on Assets and Health Dynamics among the Oldest Old (AHEAD). The survey data for these women were then linked to their Medicare claims (1991-2012), yielding 17,345 person years of observation. DXA tests were identified from the Medicare claims, and Cox proportional hazard regression models were used with both fixed and time-dependent predictors from the survey interviews including demographic characteristics, socioeconomic factors, health status, health habits, and the living environment.

RESULTS

DXA use was positively associated with being Hispanic American, better cognition, higher income, having arthritis, using other preventative services, and living in Florida or other southern states. DXA use was negatively associated with age, being African-American, being overweight or obese, having mobility limitations, and smoking.

CONCLUSIONS

Interventions to increase DXA use should target the characteristics that were observed here to be negatively associated with such screening.

Dual Energy X-Ray Absorptiometry Compared with Anthropometry in Relation to Cardio-Metabolic Risk Factors in a Young Adult Population: Is the 'Gold Standard' Tarnished?

Background and Aims

Assessment of adiposity using dual energy x-ray absorptiometry (DXA) has been considered more advantageous in comparison to anthropometry for predicting cardio-metabolic risk in the older population, by virtue of its ability to distinguish total and regional fat. Nonetheless, there is increasing uncertainty regarding the relative superiority of DXA and little comparative data exist in young adults. This study aimed to identify which measure of adiposity determined by either DXA or anthropometry is optimal within a range of cardio-metabolic risk factors in young adults.

Methods and Results

1138 adults aged 20 years were assessed by DXA and standard anthropometry from the Western Australian Pregnancy Cohort (Raine) Study. Cross-sectional linear regression analyses were performed. Waist to height ratio was superior to any DXA measure with HDL-C. BMI was the superior model in relation to blood pressure than any DXA measure. Midriff fat mass (DXA) and waist circumference were comparable in relation to glucose. For all the other cardio-metabolic variables, anthropometric and DXA measures were comparable. DXA midriff fat mass compared with BMI or waist hip ratio was the superior measure for triglycerides, insulin and HOMA-IR.

Conclusion

Although midriff fat mass (measured by DXA) was the superior measure with insulin sensitivity and triglycerides, the anthropometric measures were better or equal with various DXA measures for majority of the cardio-metabolic risk factors. Our findings suggest, clinical anthropometry is generally as useful as DXA in the evaluation of the individual cardio-metabolic risk factors in young adults.

Bone Density Screening and Re-screening in Postmenopausal Women and Older Men

Clinical practice guidelines universally recommend bone mineral density (BMD) screening to identify osteoporosis in women aged 65 years and older. Risk assessment is recommended to guide BMD screening in postmenopausal women under age 65. Insufficient data are available to inform standard ages to start and stop BMD screening in postmenopausal women. Based on longitudinal studies of incident osteoporosis and fracture in postmenopausal women, an initial BMD test should be ordered for all women aged 65, and the frequency of re-screening should be based on age and BMD T score (more frequent testing for older age and lower T score). Although clinical practice guidelines recommend BMD screening according to risk factors for fracture in postmenopausal women under age 65, no standard approach to risk assessment exists. Minimal evidence is available to guide osteoporosis screening in men, but some experts recommend initiation of BMD screening in men at age 70.

Cost-effectiveness of fracture prevention in rural women with limited access to dual-energy X-ray absorptiometry

A reduced reimbursement for office-based dual-energy X-ray absorptiometry (DXA) is likely to exacerbate the burden of fractures in rural areas. Our cost-effective analysis suggests that, in areas where access to DXA is limited, treatment for women at high clinical risk for fractures could both improve health and save money.

INTRODUCTION

To evaluate the cost-effectiveness of various fracture prevention strategies for rural women with limited access to dual-energy X-ray absorptiometry (DXA).

METHODS

A Markov model was developed using data from the published literature and the Manitoba Bone Density Program. The participants were a simulated cohort of rural women aged 65 years with travel distance between 10 and 24 mi to the nearest DXA site. The evaluated strategies were (1) watchful waiting, (2) bone mineral density (BMD)-based strategy (i.e., DXA screening followed by pharmacotherapy based on BMD), and (3) clinical risk factor (CRF)-based strategy (i.e., pharmacotherapy for women at high risk for fractures by the World Health Organization Fracture Risk Assessment Tool [FRAX]). The outcome was an incremental cost-effectiveness ratio (ICER) measured by cost per quality-adjusted life-year (QALY) gained. The analysis was preformed from a societal perspective over a lifetime horizon.

RESULTS

In the base-case analysis, the BMD-based strategy had an ICER of $6000 per QALY gained. For those with travel distance between 25 and 39 mi, the BMD-based strategy would have an ICER of $140,800 per QALY gained. For those with travel distance greater than 40 mi, the CRF-based strategy would be more effective and less costly than other strategies.

CONCLUSIONS

In areas where DXA is readily available, DXA screening followed by pharmacotherapy guided by BMD would be preferred. In areas with more limited access to DXA, pharmacotherapy for women at high clinical risk for fractures based on FRAX could both improve health and save money from the societal perspective.

Comprehensive Assessment of Osteoporosis and Bone Fragility with CT Colonography

PURPOSE

To evaluate the ability of additional analysis of computed tomographic (CT) colonography images to provide a comprehensive osteoporosis assessment.

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act-compliant study was approved by our institutional review board with a waiver of informed consent. Diagnosis of osteoporosis and assessment of fracture risk were compared between biomechanical CT analysis and dual-energy x-ray absorptiometry (DXA) in 136 women (age range, 43-92 years), each of whom underwent CT colonography and DXA within a 6-month period (between January 2008 and April 2010). Blinded to the DXA data, biomechanical CT analysis was retrospectively applied to CT images by using phantomless calibration and finite element analysis to measure bone mineral density and bone strength at the hip and spine. Regression, Bland-Altman, and reclassification analyses and paired t tests were used to compare results.

RESULTS

For bone mineral density T scores at the femoral neck, biomechanical CT analysis was highly correlated (R(2) = 0.84) with DXA, did not differ from DXA (P = .15, paired t test), and was able to identify osteoporosis (as defined by DXA), with 100% sensitivity in eight of eight patients (95% confidence interval [CI]: 67.6%, 100%) and 98.4% specificity in 126 of 128 patients (95% CI: 94.5%, 99.6%). Considering both the hip and spine, the classification of patients at high risk for fracture by biomechanical CT analysis--those with osteoporosis or "fragile bone strength"--agreed well against classifications for clinical osteoporosis by DXA (T score ≤-2.5 at the hip or spine), with 82.8% sensitivity in 24 of 29 patients (95% CI: 65.4%, 92.4%) and 85.7% specificity in 66 of 77 patients (95% CI: 76.2%, 91.8%).

CONCLUSION

Retrospective biomechanical CT analysis of CT colonography for colorectal cancer screening provides a comprehensive osteoporosis assessment without requiring changes in imaging protocols.

DXA Utilization Between 2006 and 2012 in Commercially Insured Younger Postmenopausal Women

Reimbursement for dual-energy X-ray absorptiometry (DXA) scans in the outpatient setting has declined significantly since 2006. Research through 2011 has suggested reimbursement reductions for DXA scans have corresponded with an overall decreased utilization of DXA. This study updates utilization estimates for DXAs through 2012 in patients with commercial insurance and compares DXA rates before and after reimbursement changes. We evaluated DXA utilization for women aged 50-64 yr from Marketscan Commercial Claims and Encounter database between January 2006 and December 2012 based on CPT codes. We estimated utilization rates per 1000 person years (PY). We also used segmented regression analysis of monthly rates to evaluate the change in utilization rates after a proposed reimbursement reduction in July 2009. In women aged 50-64 yr, 451,656 DXAs were performed in 2006, a rate of 144 DXAs per 1000 PY. This rate increased to 149 DXAs per 1000 PY in 2009 before decreasing to 110 DXAs per 1000 PY or 667,982 scans in 2012. DXA utilization increased by 2.24 per 1000 PY until July 2009 then declined by 12.98 DXAs per 1000 persons, resulting in 37.5 DXAs per PY fewer performed in 2012 compared with 2006. Since July 2009 a significant decline in DXA utilization occurred in a younger postmenopausal commercially insured population. This decline corresponds with a time period of reductions in Medicare DXA reimbursement.

Overuse of short-interval bone densitometry: assessing rates of low-value care

We evaluated the prevalence and geographic variation of short-interval (repeated in under 2 years) dual-energy X-ray absorptiometry tests (DXAs) among Medicare beneficiaries. Short-interval DXA use varied across regions (coefficient of variation = 0.64), and unlike other DXAs, rates decreased with payment cuts.

INTRODUCTION

The American College of Rheumatology, through the Choosing Wisely initiative, identified measuring bone density more often than every 2 years as care "physicians and patients should question." We measured the prevalence and described the geographic variation of short-interval (repeated in under 2 years) DXAs among Medicare beneficiaries and estimated the cost of this testing and its responsiveness to payment change.

METHODS

Using 100 % Medicare claims data, 2006-2011, we identified DXAs and short-interval DXAs for female Medicare beneficiaries over age 66. We determined the population rate of DXAs and short-interval DXAs, as well as Medicare spending on short-interval DXAs, nationally and by hospital referral region (HRR).

RESULTS

DXA use was stable 2008-2011 (12.4 to 11.5 DXAs per 100 women). DXA use varied across HRRs: in 2011, overall DXA use ranged from 6.3 to 23.0 per 100 women (coefficient of variation = 0.18), and short-interval DXAs ranged from 0.3 to 8.0 per 100 women (coefficient of variation = 0.64). Short-interval DXA use fluctuated substantially with payment changes; other DXAs did not. Short-interval DXAs, which represented 10.1 % of all DXAs, cost Medicare approximately US$16 million in 2011.

CONCLUSIONS

One out of ten DXAs was administered in a time frame shorter than recommended and at a substantial cost to Medicare. DXA use varied across regions. Short-interval DXA use was responsive to reimbursement changes, suggesting carefully designed policy and payment reform may reduce this care identified by rheumatologists as low value.

Fracture risk assessment after BMD examination: whose job is it, anyway?

Fracture risk assessments on bone mineral density reports guide family physicians' treatment decisions but are subject to inaccuracy. Qualitative analysis of interviews with 22 family physicians illustrates their pervasive questioning of reported assessment accuracy and independent assumption of responsibility for assessment. Assumption of responsibility is common despite duplicating specialists' work.

INTRODUCTION

Fracture risk is the basis for recommendations of treatment for osteoporosis, but assessments on bone mineral density (BMD) reports are subject to known inaccuracies. This creates a complex situation for referring physicians, who must rely on assessments to inform treatment decisions. This study was designed to broadly understand physicians' current experiences with and preferences for BMD reporting; the present analysis focuses on their interpretation and use of the fracture risk assessments on reports, specifically

METHODS

A qualitative, thematic analysis of one-on-one interviews with 22 family physicians in Ontario, Canada was performed.

RESULTS

The first major theme identified in interview data reflects questioning by family physicians of reported fracture risk assessments' accuracy. Several major subthemes related to this included questioning of: 1) accuracy in raw bone mineral density measures (e.g., g/cm(2)); 2) accurate inclusion of modifying risk factors; and 3) the fracture risk assessment methodology employed. A second major theme identified was family physicians' independent assumption of responsibility for risk assessment and its interpretation. Many participants reported that they computed risk assessments in their practice to ensure accuracy, even when provided with assessments on reports.

CONCLUSIONS

Results indicate family physicians question accuracy of risk assessments on BMD reports and often assume responsibility both for revising and relating assessments to treatment recommendations. This assumption of responsibility is common despite the fact that it may duplicate the efforts of reading physicians. Better capture of risk information on BMD referrals, quality control standards for images and standardization of risk reporting may help attenuate some inefficiency.

Utility of heel dual-energy X-ray absorptiometry in diagnosing osteoporosis

Although peripheral dual-energy X-ray absorptiometry measurements have been found to predict fractures in population studies of white subjects, little is known about their utility in other races and in patients with greater risk of fracture. In a cross-sectional study of 874 women referred for bone mineral density (BMD) testing, we examined the utility of heel BMD in African-American (AA) compared with Caucasian (CA) women and in women using glucocorticoids. The ability of heel T-score to predict central osteoporosis was similar in AA and CA women (odds ratio [OR] per 1 unit decrease in T-score of 2.79 [95% confidence interval {CI} 2.16-3.60] and 3.15 [95% CI 2.53-3.92], respectively). The association between heel T-score and prevalent vertebral fractures was also similar in the 2 groups (OR 1.46 [95% CI 1.15-1.85] in AA and 1.42 [95% CI 1.16-1.74] in CA). In women using glucocorticoids heel T-score was better than central T-score in predicting vertebral fractures (OR 1.38 [95% CI 1.03-1.85] and 1.22 [95% CI 0.86-1.73], respectively). We conclude that in a multiracial referral population heel BMD predicts central osteoporosis and prevalent vertebral fractures equally well in AA as in CA women and may be better than central BMD in assessing fragility in glucocorticoid users.

Commentary: the five Ws of a Fracture Liaison Service: why, who, what, where, and how? In osteoporosis, we reap what we sow

Establishing a Fracture Liaison Service (FLS) to identify and treat patients with a recent fragility fracture has been shown to be effective, save money, useful to document high quality of care, and makes good clinical sense. A FLS starts with an osteoporosis champion and encompasses identification of patients with a recent fracture, diagnostic workup, treatment, and follow-up. A FLS is most effective when it is able to function in multiple settings: the hospital, emergency department, and outpatient clinic. Implementation may be somewhat easier in a closed healthcare system but can be feasible even in an open system. There are many barriers to implementation which can be addressed. The future of FLS care lies in a collaborative systems-based approach with appropriate stakeholder engagement, leading to seamless integration of osteoporosis care.

Repeat bone mineral density screening and prediction of hip and major osteoporotic fracture

IMPORTANCE

Screening for osteoporosis with bone mineral density (BMD) is recommended for older adults. It is unclear whether repeating a BMD screening test improves fracture risk assessment.

OBJECTIVES

To determine whether changes in BMD after 4 years provide additional information on fracture risk beyond baseline BMD and to quantify the change in fracture risk classification after a second BMD measure.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study involving 310 men and 492 women from the Framingham Osteoporosis Study with 2 measures of femoral neck BMD taken from 1987 through 1999.

MAIN OUTCOMES AND MEASURES

Risk of hip or major osteoporotic fracture through 2009 or 12 years following the second BMD measure.

RESULTS

Mean age was 74.8 years. The mean (SD) BMD change was -0.6% per year (1.8%). Throughout a median follow-up of 9.6 years, 76 participants experienced an incident hip fracture and 113 participants experienced a major osteoporotic fracture. Annual percent BMD change per SD decrease was associated with risk of hip fracture (hazard ratio [HR], 1.43 [95% CI, 1.16 to 1.78]) and major osteoporotic fracture (HR, 1.21 [95% CI, 1.01 to 1.45]) after adjusting for baseline BMD. At 10 years' follow-up, 1 SD decrease in annual percent BMD change compared with the mean BMD change was associated with 3.9 excess hip fractures per 100 persons. In receiver operating characteristic (ROC) curve analyses, the addition of BMD change to a model with baseline BMD did not meaningfully improve performance. The area under the curve (AUC) was 0.71 (95% CI, 0.65 to 0.78) for the baseline BMD model compared with 0.68 (95% CI, 0.62 to 0.75) for the BMD percent change model. Moreover, the addition of BMD change to a model with baseline BMD did not meaningfully improve performance (AUC, 0.72 [95% CI, 0.66 to 0.79]). Using the net reclassification index, a second BMD measure increased the proportion of participants reclassified as high risk of hip fracture by 3.9% (95% CI, -2.2% to 9.9%), whereas it decreased the proportion classified as low risk by -2.2% (95% CI, -4.5% to 0.1%).

CONCLUSIONS AND RELEVANCE

In untreated men and women of mean age 75 years, a second BMD measure after 4 years did not meaningfully improve the prediction of hip or major osteoporotic fracture. Repeating a BMD measure within 4 years to improve fracture risk stratification may not be necessary in adults this age untreated for osteoporosis.

Clinical assessment of the 1/3 radius using a new desktop ultrasonic bone densitometer

The objectives of this study were to evaluate the capability of a novel ultrasound device to clinically estimate bone mineral density (BMD) at the 1/3 radius. The device rests on a desktop and is portable, and permits real-time evaluation of the radial BMD. The device measures two net time delay (NTD) parameters, NTD(DW) and NTD(CW). NTD(DW) is defined as the difference between the transit time of an ultrasound pulse to travel through soft-tissue, cortex and medullary cavity, and the transit time through soft tissue only of equal overall distance. NTD(CW) is defined as the difference between the transit time of an ultrasound pulse to travel through soft-tissue and cortex only, and the transit time through soft tissue only again of equal overall distance. The square root of the product of these two parameters is a measure of the radial BMD at the 1/3 location as measured by dual-energy X-ray absorptiometry (DXA). A clinical IRB-approved study measured ultrasonically 60 adults at the 1/3 radius. BMD was also measured at the same anatomic site and time using DXA. A linear regression using NTD produced a linear correlation coefficient of 0.93 (p < 0.001). These results are consistent with previously reported simulation and in vitro studies. In conclusion, although X-ray methods are effective in bone mass assessment, osteoporosis remains one of the largest undiagnosed and under-diagnosed diseases in the world today. The research described here should enable significant expansion of diagnosis and monitoring of osteoporosis through a desktop device that ultrasonically assesses bone mass at the 1/3 radius.

Choosing wisely: the American College of Rheumatology's Top 5 list of things physicians and patients should question

OBJECTIVE

We sought to develop a list of 5 tests, treatments, or services commonly used in rheumatology practice whose necessity or value should be questioned and discussed by physicians and patients.

METHODS

We used a multistage process combining consensus methodology and literature reviews to arrive at the American College of Rheumatology's (ACR) Top 5 list. Rheumatologists from diverse practice settings generated items using the Delphi method. Items with high content agreement and perceived high prevalence advanced to a survey of ACR members, who comprise >90% of the US rheumatology workforce. To increase the response rate, a nested random sample of 390 rheumatologists received more intensive survey followup. The samples were combined and weighting procedures were applied to ensure generalizability. Items with high ratings underwent literature review. Final items were then selected and formulated by the task force.

RESULTS

One hundred five unique items were proposed and narrowed down to 22 items during the Delphi rounds. A total of 1,052 rheumatologists (17% of those contacted) participated in the member-wide survey, whereas 33% of those in the nested random sample participated; respondent characteristics were similar in both samples. Based on survey results and available scientific evidence, 5 items (relating to antinuclear antibodies, Lyme disease, magnetic resonance imaging, bone absorptiometry, and biologic therapy for rheumatoid arthritis) were selected for inclusion.

CONCLUSION

The ACR Top 5 list is intended to promote discussions between physicians and patients about health care practices in rheumatology whose use should be questioned and to assist rheumatologists in providing high-value care.

The effect modification of supplemental insurance on the relationship between race and bone mineral density screening in female Medicare beneficiaries

To determine the effect modification of supplemental insurance on the relationship between race and bone mineral density (BMD) in female Medicare beneficiaries. Retrospectively analyzing hospital administrative claim and clinical data of female Medicare beneficiaries (n = 1,398), we performed multivariate logistic regressions of BMD testing including data from all study participants and the subsets of health insurance. Significantly fewer Black than White female Medicare beneficiaries received the BMD testing in the overall sample (odds ratio, OR = 0.63; p = 0.02) and those without supplementary health insurance (n = 709; OR = 0.38; p = 0.004). By contrast, the magnitude of this racial disparity in the BMD testing was diminished among those with supplementary private health insurance (n = 689). We found a significant racial disparity in BMD testing for Black and White female Medicare beneficiaries. This disparity became more pronounced among those without supplementary private health insurance.

Effect of reimbursement reductions on bone mineral density testing for female Medicare beneficiaries

BACKGROUND

We examined whether the recent reimbursement reductions on the bone mineral density (BMD) test affected BMD testing in female Medicare beneficiaries with or without supplemental private health insurance.

METHODS

Retrospectively analyzing hospital administrative and clinical data on female Medicare beneficiaries (n=1320), we reviewed whether participants received BMD testing before (January 2004-December 2006) or after (January 2007-December 2009) reimbursement reductions for BMD testing. After adjusting for demographics and clinical characteristics, we performed Cox proportional hazard regression analyses of the BMD test including data from all study participants; we then performed separate regression analyses using data with or without supplemental private health insurance.

RESULTS

In those without supplemental private health insurance (n=421), less frequent BMD testing occurred after reimbursement reductions for BMD testing (hazard ratio [HR] 0.67, 95% confidence intervals [CI] 0.34-0.98; p=0.03). By contrast, in the overall participants (n=1320) and those with supplemental private health insurance (n=899), the number of BMD tests did not change significantly after reimbursement reductions for BMD testing.

CONCLUSIONS

We found a significant association between reimbursement reductions and decrease in BMD tests in female Medicare beneficiaries without supplemental private health insurance.