Dual-energy X-ray Absorptiometry Testing Research Articles

Osteoporosis quality indicators using healthcare utilization data

SummaryHealthcare utilization data may be used to examine the quality of osteoporosis management by identifying dual-energy X-ray absorptiometry (DXA) testing (sensitivity = 98%, specificity = 93%) and osteoporosis pharmacotherapy (κ = 0.81) with minimal measurement error.IntroductionIn osteoporosis, key quality indicators among older women include risk assessment by DXA and/or pharmacotherapy within 6 months following fracture.MethodsThe purpose of this study was to examine healthcare utilization data for use as quality indicators of osteoporosis management. We linked data from 858 community-dwelling women aged over 65 years who completed a standardized telephone interview about osteoporosis management to their healthcare utilization (medical and pharmacy claims) data. Agreement between self-report of osteoporosis pharmacotherapy and pharmacy claims was examined using kappa statistics. We examined the sensitivity and specificity of medical claims to identify DXA testing as well as the sensitivity and specificity of medical and pharmacy claims to identify those with DXA-documented osteoporosis (T-score ≤ −2.5).ResultsParticipants were aged 75 (SD = 6) years on average; 96% were Caucasian. Agreement between self-report and claims-based osteoporosis pharmacotherapy was very good (κ = 0.81; 95% CI = 0.76, 0.86). The sensitivity of medical claims to identify DXA testing was 98% (95% CI = 95.9, 99.1), with estimated specificity of 93% (95% CI = 89.8, 95.4). We abstracted DXA results from test reports of 359 women, of whom 114 (32%) were identified with osteoporosis. Medical (osteoporosis diagnosis) and pharmacy (osteoporosis pharmacotherapy) claims within a year after DXA testing had a sensitivity of 80% (95% CI = 71.3, 86.8) and specificity of 72% (95% CI = 66.2, 77.8) to identify DXA-documented osteoporosis.ConclusionHealthcare utilization data may be used to examine the quality of osteoporosis management by identifying DXA testing and osteoporosis pharmacotherapy (care processes) with minimal measurement error. However, medical and pharmacy claims alone do not provide a good means for identifying women with underlying osteoporosis.

Independent clinical validation of a Canadian FRAX tool: Fracture prediction and model calibration

A FRAX model for Canada was constructed for prediction of osteoporotic and hip fracture risk using national hip fracture data with and without the use of femoral neck bone mineral density (BMD). Performance of this system was assessed independently in a large clinical cohort of 36,730 women and 2873 men from the Manitoba Bone Density Program database that tracks all clinical dual-energy X-ray absorptiometry (DXA) test results for the Province of Manitoba, Canada. Linkage with other provincial health databases allowed for the direct comparison of fracture risk estimates from the Canadian FRAX model with observed fracture rates to 10 years (549 individuals with incident hip fractures and 2543 with incident osteoporotic fractures). The 10-year Kaplan-Meier estimate for hip fractures in women was 2.7% [95% confidence interval (CI) 2.1-3.4%] with a predicted value of 2.8% for FRAX with BMD, and in men the observed risk was 3.5% (95% CI 0.8-6.2%) with predicted value of 2.9%. The 10-year estimate of osteoporotic fracture risk for all women was 12.0% (95% CI 10.8-13.4%) with a predicted value of 11.1% for FRAX with BMD, and in men, the observed risk was 10.7% (95% CI 6.6-14.9%) with a predicted value of 8.4%. Discrepancies were observed within some subgroups but generally were small. Fracture discrimination based on receiver operating characteristic curve analysis was comparable with published meta-analyses with area under the curve for osteoporotic fracture prediction of 0.694 (95% CI 0.684-0.705) for FRAX with BMD and for hip fractures 0.830 (95% CI 0.815-0.846), both of which were better than FRAX without BMD or BMD alone. Individual risk factors considered by FRAX made significant independent contributions to fracture prediction in one or more of the models. In conclusion, a Canadian FRAX tool calibrated on national hip fracture data generates fracture risk predictions that generally are consistent with observed fracture rates across a wide range of risk categories.

S1208 Papillary Thyroid Cancer and Inflammatory Bowel Disease: Is There an Association?

Aim: Low bone mineral density (BMD) is prevalent in the IBD population. Our aim was 1) to determine predictors for the work-up and treatment of low BMD and 2) to assess the prevalence of secondary causes of low BMD in the IBD population. Methods: 317 patients (pts) with a diagnosis of IBD and who underwent dual energy x-ray absorptiometry (DEXA) tests were identified from 1/1/1996-10/27/2006 at 7 US veterans' hospitals. Low BMD was defined as T score 1yr follow-up after DEXA. Testing rates for serum calcium, phosphate, 25OH vitamin D, and testosterone (in male pts only) were 88%, 89%, 42%, and 61%, respectively. Low calcium, phosphate, 25-OH vitamin D, and male testosterone levels were seen in 8%, 8%, 35%, and 29% of tested pts, respectively. Calcium/Vitamin D supplements (Ca/VitD) and bisphosphonates (BPs) were prescribed to 64% and 71% of pts, respectively (14% received neither). Ergocalciferol and male testosterone replacement was given in 53% and 44% of pts with low levels, respectively. Overall rates of testing for and treatment of causes of low BMD in our population are listed in the table. Logistic regression confirmed endocrine clinic as an independent predictor of 25-OH vitamin D and testosterone testing. Ca/VitD and BPs use did not differ significantly based on clinic. Conclusions: Vitamin D deficiency and male hypogonadism are relatively common contributors to secondary bone loss in IBD pts with T<-2 on DEXA. However, testing for these conditions is suboptimal. Education of GI providers regarding the testing for and treatment of these conditions is warranted, or endocrine referral should be considered. Ca/VitD and BPs are underutilized in the IBD population with low BMD.

S1206 Testing for and Treatment of Secondary Causes of Bone Loss in Inflammatory Bowel Disease (IBD) Patients With Abnormal Dexa Studies

Aim: Low bone mineral density (BMD) is prevalent in the IBD population. Our aim was 1) to determine predictors for the work-up and treatment of low BMD and 2) to assess the prevalence of secondary causes of low BMD in the IBD population. Methods: 317 patients (pts) with a diagnosis of IBD and who underwent dual energy x-ray absorptiometry (DEXA) tests were identified from 1/1/1996-10/27/2006 at 7 US veterans' hospitals. Low BMD was defined as T score 1yr follow-up after DEXA. Testing rates for serum calcium, phosphate, 25OH vitamin D, and testosterone (in male pts only) were 88%, 89%, 42%, and 61%, respectively. Low calcium, phosphate, 25-OH vitamin D, and male testosterone levels were seen in 8%, 8%, 35%, and 29% of tested pts, respectively. Calcium/Vitamin D supplements (Ca/VitD) and bisphosphonates (BPs) were prescribed to 64% and 71% of pts, respectively (14% received neither). Ergocalciferol and male testosterone replacement was given in 53% and 44% of pts with low levels, respectively. Overall rates of testing for and treatment of causes of low BMD in our population are listed in the table. Logistic regression confirmed endocrine clinic as an independent predictor of 25-OH vitamin D and testosterone testing. Ca/VitD and BPs use did not differ significantly based on clinic. Conclusions: Vitamin D deficiency and male hypogonadism are relatively common contributors to secondary bone loss in IBD pts with T<-2 on DEXA. However, testing for these conditions is suboptimal. Education of GI providers regarding the testing for and treatment of these conditions is warranted, or endocrine referral should be considered. Ca/VitD and BPs are underutilized in the IBD population with low BMD.

Simplified 10-Year Absolute Fracture Risk Assessment: A Comparison of Men and Women

A simplified (semiquantitative) approach developed by the Canadian Association of Radiologists and Osteoporosis Canada (denoted as CAROC) for absolute fracture risk assessment incorporates age, sex, prior fragility fracture, and systemic corticosteroid use, together with bone mineral density (BMD) to define absolute fracture risk. The CAROC system has been shown to predict fracture rates in women referred for clinical BMD testing, but it is uncertain how this system performs in routine clinical practice in men who are much less likely to undergo BMD testing with potential for referral biases. Thirty-six thousand seven hundred and thirty women and 2873 men aged 50 yr or older at the time of baseline BMD testing were identified in a database containing all clinical dual-energy X-ray absorptiometry test results for the Province of Manitoba, Canada. Population-based health service records from 1987 to 2008 were assessed for fracture codes and medication use. Fracture risk under the CAROC model was categorized as low (<10%), moderate (10–20%), or high (>20%). Ten-year fracture risk estimated by the Kaplan-Meier method showed the same gradient in observed fracture risk for men and women. Despite evidence of greater referral bias in men resulting in a higher rate of clinical risk factors, the performance of the prediction algorithm was not affected.

Spinal microglia: A crucial player in pathological chronic pain

To describe the rationale and design of an NIH funded randomized controlled trial: the Patient Activation after DXA Result Notification (PAADRN) study. The aim of this trial is to evaluate the effect that a direct mailing of Dual-Energy X-ray Absorptiometry (DXA) results from bone density testing centers to patients will have on patients' knowledge, treatment and self-efficacy.We will enroll approximately 7500 patients presenting for DXA at three study sites, the University of Iowa, the University of Alabama at Birmingham, and Kaiser Permanente of Atlanta, Georgia. We will randomize providers (and their respective patients) to either the intervention arm or usual care. Patients randomized to the intervention group will receive a letter with their DXA results and an educational brochure, while those randomized to usual care will receive their DXA results according to standard practice. The seven discrete outcomes are changes from baseline to 12-weeks and/or 52-weeks post-DXA in: (1) guideline concordant pharmacologic and non-pharmacologic therapy; (2) knowledge of DXA results; (3) osteoporosis-specific knowledge; (4) general health-related quality of life; (5) satisfaction with bone-related health care, (6) patient activation; and, (7) osteoporosis-specific self-efficacy.This trial will offer evidence of the impact of a novel approach—direct-to-patient mailing of test results—to improve patient activation in their bone health care. The results will inform clinical practice for the communication of DXA and other test results.

Low serum folate and vitamin B-6 are associated with an altered cancellous bone structure in humans

BackgroundSeveral clinical trials have reported B vitamins to be associated with osteoporosis. ObjectiveOur objective was to investigate whether low serum B vitamins are associated with altered structural and biomechanical properties of human bone. DesignFemoral heads of 94 men and women who underwent hip arthroplasty were analyzed by using dual-energy X-ray absorptiometry (DXA), biomechanical testing (indentation method), and histomorphometry. In addition, blood was collected to measure serum concentrations of homocysteine, folate, vitamin B-6, vitamin B-12, the bone formation marker osteocalcin, and the bone resorption marker tartrate-resistant acid phosphatase (TRAP). Measurement outcomes were grouped according to subjects with high and low serum concentrations, respectively, of folate, vitamin B-6, and vitamin B-12 (n = 47 for each group). ResultsHistomorphometric analysis showed a significantly lower trabecular thickness and trabecular area in subjects with low serum folate concentrations than in those with high serum folate concentrations and a significantly lower trabecular number in subjects with low serum vitamin B-6 concentrations than in those with high serum vitamin B-6 concentrations. In contrast, we found a comparable trabecular structure in subjects with high and low serum vitamin B-12 concentrations. DXA and biomechanical testing did not show significant differences between subjects with high and low serum B vitamin concentrations. Osteocalcin was significantly lowered in subjects with a low serum B vitamin concentration, whereas there was no association between serum B vitamins and TRAP. ConclusionThe results of the present study indicate that low serum folate and vitamin B-6 concentrations, but not low serum vitamin B-12 concentrations, are associated with an altered morphology of human bone.

Treatment thresholds for osteoporosis in men on androgen deprivation therapy: T-score versus FRAX™

Men treated by androgen deprivation therapy (ADT) for localized prostate cancer are at risk for fracture, but it is not known which men require pharmacologic treatment. We found that 33% of men on ADT had osteoporosis of spine, hip, or forearm by dual-energy X-ray absorptiometry (DXA), thus requiring treatment. Using the new fracture prediction algorithm (FRAX) tool with corrected femoral neck T-score identified only 17% requiring treatment, and, if calculated without femoral neck, 54% were identified to need treatment. Men treated with androgen deprivation therapy (ADT) for prostate carcinoma live long enough to fracture. A new fracture prediction method, FRAX, is based on femoral neck DXA plus risk factors. Thus, DXA or FRAX could determine which men should receive osteoporosis therapy. Of 115 men undergoing ADT referred for DXA testing, those with bone mineral density (BMD) in spine, hip, or forearm of >or=2.5 standard deviations below a normal male ethnicity-adjusted mean were considered treatment candidates. Using FRAX with and without femoral neck BMD, men were treatment candidates if the 10-year hip fracture risk was >or=3% or the major osteoporotic fracture risk was >or=20%. The men averaged 77 years old; 58% were African-American, and 14.8% were current smokers. Mean femoral neck T-score was -1.4. Using DXA, 38 (33%) men would need treatment. When FRAX was calculated including the femoral neck T-score, only 20 men met criteria for treatment. However, when FRAX was calculated without the T-score, 62 men met criteria for treatment. Overlap among the groups was surprisingly modest. DXA and FRAX identify different ADT men for treatment.

Direct-to-participant feedback and awareness of bone mineral density testing results in a population-based sample of mid-aged Canadians

This population-based study of mid-aged Canadians assessed awareness of diagnosis by bone mineral density (BMD) following dual-energy X-ray absorptiometry (DXA) testing and compared the effects of feedback only to the physician with direct-to-participant feedback. Poor recall of osteoporosis results was observed irrespective of the feedback destination, but direct-to-participant feedback improved recall of borderline or normal results. BMD testing provides information about fracture risk. This study assessed whether awareness of results, in a random population sample of mid-aged Canadians, differed if results were provided to physicians only or directly to participants. Prospective cohort study of 2,678 women and men aged 40-60 years from the Canadian Multicentre Osteoporosis Study. Participants completed hip and spine DXA and interviewer-administered questionnaires regarding demographics and osteoporosis risk factors. Lateral spine X-rays were conducted on those > or =50 years of age. All test results were reported to the participant, the family physician or both. Associations between BMD results, feedback destination and correct self-report results, 3 years later, were assessed using logistic regression while adjusting for potential confounders. Only 25% of men and 33% of women correctly reported their osteoporosis diagnoses. Direct-to-participant vs. physician-only reports did not improve recall of osteoporosis diagnosis but improved recall of borderline or normal BMD. Older (vs. younger) men and men with prevalent vertebral fractures demonstrated better recall of their osteoporosis diagnosis. Recall of low BMD results was poor, despite direct-to-participant feedback and even in the presence of other osteoporosis risk factors. Direct-to-participant feedback may improve awareness of borderline or normal BMD results.

Is the NHANES III Femoral Neck Database Discordant With the Total Hip and Trochanteric Region Databases?

The results of dual-energy X-ray absorptiometry (DXA) testing frequently leads to a significant clinical treatment decision, based on T-score or Z-score results. Using the nearly universally accepted World Health Organization (WHO) criteria, which in turn are based on the validity of the population database, a flawed database may lead to an incorrect and deleterious clinical categorization. We have observed that the Hologic National Health and Nutrition Examination Survey III (NHANES III) femoral neck scores are frequently disproportionately low compared with scores in the other major hip regions and that the discordance is statistically significant. Although the WHO now uses the femoral neck T-score (in postmenopausal women and men 50 yr or older), many clinicians still use the lowest (worst) T-score in any 1 of 3 major scan regions—femoral neck, total hip, or lumbar spine—suggesting that patient misclassification may occur, leading to the potential for unnecessary pharmacologic intervention.

The geographic availability and associated utilization of dual-energy X-ray absorptiometry (DXA) testing among older persons in the United States

Using national Medicare data from 1999-2006, we evaluated the relationship between travel distance and receipt of dual-energy X-ray absorptiometry (DXA). After adjusting for potentially confounding factors, travel distance was strongly associated with DXA testing. Rural residents were most strongly dependent on the availability of DXAs performed in physician offices. Medicare reimbursement for DXAs performed in non-facility settings (e.g., physician offices) decreased in 2007. With declining reimbursement, some DXA providers may cease providing this service, which would increase travel distance for some people. The impact of travel distance on access to DXA is unclear. Using national Medicare data, we identified claims for DXA to evaluate trends in the number and locations of DXAs performed. Travel distance was the distance from beneficiaries' residence and the nearest DXA provider. Binomial regression evaluated the relationship between travel distance and receipt of DXA. In 2006, 2.9 million DXAs were performed, a 103% increase since 1999. In 2005-2006, 8.0% of persons were tested at non-facility sites versus 4.2% at facility sites. The remainder (88%) had no DXA. Persons traveling 5-9, 10-24, 25-39, and 40-54, and > or = 55 miles were less likely to receive DXA (adjusted risk ratios = 0.92, 0.79, 0.43, 0.32, and 0.26, respectively, < 5 miles referent). Rural residents were more dependent than urban residents on the availability of DXA from non-facility providers. Approximately two-thirds of DXAs in 2005-2006 were performed in non-facility settings (e.g., physician offices). Rural residents would have preferentially reduced access to DXA if there were fewer non-facility sites.

Predictors of bone density testing in patients with rheumatoid arthritis

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

Regional Variation in the Denial of Reimbursement for Bone Mineral Density Testing Among US Medicare Beneficiaries

Although the Bone Mass Measurement Act outlines the indications for central dual-energy X-ray absorptiometry (DXA) testing for US Medicare beneficiaries, the specifics regarding the appropriate ICD-9 codes to use for covered indications have not been specified by Medicare and are sometimes ambiguous. We describe the extent to which DXA reimbursement was denied by gender and age of beneficiary, ICD-9 code submitted, time since previous DXA, whether the scan was performed in the physician's office and local Medicare carrier. Using Medicare administrative claims data from 1999 to 2005, we studied a 5% national sample of beneficiaries age ≥65 yr with part A + B coverage who were not health maintenance organization enrollees. We identified central DXA claims and evaluated the relationship between the factors listed above and reimbursement for central DXA (CPT code 76075). Multivariable logistic regression was used to evaluate the independent relationship between DXA reimbursement, ICD-9 diagnosis code, and Medicare carrier. For persons who had no DXA in 1999 or 2000 and who had 1 in 2001 or 2002, the proportion of DXA claims denied was 5.3% for women and 9.1% for men. For repeat DXAs performed within 23 mo, the proportion denied was approximately 19% and did not differ by sex. Reimbursement varied by more than 6-fold according to the ICD-9 diagnosis code submitted. For repeat DXAs performed at <23 mo, the proportion of claims denied ranged from 2% to 43%, depending on Medicare carrier. Denial of Medicare reimbursement for DXA varies significantly by sex, time since previous DXA, ICD-9 diagnosis code submitted, place of service (office vs facility), and local Medicare carrier. Greater guidance and transparency in coding policies are needed to ensure that DXA as a covered service is reimbursed for Medicare beneficiaries with the appropriate indications.

Concordance of a Self Assessment Tool and Measurement of Bone Mineral Density in Identifying the Risk of Osteoporosis in Elderly Taiwanese Women

Objective Osteoporosis is the most common generalized bone disease related to aging. The Osteoporosis Self-Assessment Tool for Asians (OSTA) risk index was developed to screen postmenopausal Asian women to identify women who should be evaluated with bone densitometry. In Taiwan, there is no report of the validity of the OSTA with dual energy X-ray absorptiometry (DXA) as a reference. In this study, we assessed the validity of the OSTA risk index and discuss its applications, using DXA of the lumbar spine as the gold standard. Patients and Methods Healthy subjects, aged 30–85 years, who were receiving a health check-up at a teaching hospital in eastern Taiwan were invited to participate in this study. All subjects gave their consent to analyze their data. A self-administered questionnaire was used to assess their demographic characteristics, and reproductive and medical histories. Bone mineral density of the posterior-anterior lumbar spine was measured by DXA, and a diagnosis of osteoporosis was made according to World Health Organization criteria. The sensitivity and specificity and their 95% confidence intervals (CIs) were calculated for the dichotomized OSTA risk index. Results This cohort consisted of 498 postmenopausal Taiwanese women, with a mean age of 60.3 ± 7.6 years and a mean weight of 57.9 ± 8.9 kg. Spinal DXA revealed that 35.9% were osteoporotic (with a T-score of £ −2.5). The OSTA risk index at the standard cut-off point of £ −1 had a sensitivity of 57.0% (95% CI: 52.7, 61.3) and a specificity of 69.3% (95% CI: 65.3, 73.4). Among women aged 60–70 years, the sensitivity, specificity, and accuracy of the OSTA risk index were 77.1% (95% CI: 63.7, 76.9), 49.2% (95% CI: 42.0, 56.4), and 64.9% (95% CI: 60.7, 69.8), respectively. Conclusion The OSTA risk index is a convenient but not a very sensitive tool to help target high-risk women aged 60–70 years for DXA testing. Clinical risk factors and the OSTA risk index should be combined to assess women aged £ 60 years. Further study of the validity of the OSTA risk index among elderly women with a larger sample size in different populations should be conducted with spinal and femur neck DXA testing as references.

An evaluation of osteoporosis screening tools for the osteoporotic fractures in men (MrOS) study

No large-scale evaluations of osteoporosis screening tools have been done in men. OST and MOST were examined among 4658 US Caucasian and 1914 Hong Kong Chinese men. Both tools have high negative predictive values, accurately screening out men with low risk, and saving a third of DXA tests. Prior investigations have studied the performance of osteoporosis screening tools in women, but no large-scale evaluations have been done in men. This study examines the performance of the Osteoporosis Self-assessment Tool (OST), the Male Osteoporosis Screening Tool (MOST), quantitative ultrasound index (QUI), and body weight as screening tools. Osteoporosis was defined by a dual-energy X-ray absorptiometry (DXA) measured bone mineral density (BMD) T-score < or =-2.5. Four thousand six hundred and fifty-eight US Caucasian and 1914 Hong Kong Chinese men, aged > or =65 years and community-dwelling, were included in the analysis. Receiver operating characteristic (ROC) analysis was used to compare the area under the ROC curve (AUC) between different screening tools. MOST had a significantly larger AUC (> or =0.8) than OST, QUI, and body weight in detecting osteoporosis. Using the second tertile as cutoff, OST and MOST yielded sensitivities of around 90% and negative predictive values (NPVs) of >97%, accurately screening out Caucasian and Chinese men with low risk of osteoporosis. OST and MOST can effectively rule out osteoporosis for both Caucasian and Chinese men, and compared to referring men 65 years and older for BMD DXA testing, they save a third of DXA resources.

The utility of clinical decision tools for diagnosing osteoporosis in postmenopausal women with rheumatoid arthritis

BackgroundPatients with rheumatoid arthritis have a higher risk of low bone mineral density than normal age matched populations. There is limited evidence to support cost effectiveness of population screening in rheumatoid arthritis and case finding strategies have been proposed as a means to increase cost effectiveness of diagnostic screening for osteoporosis. This study aimed to assess the performance attributes of generic and rheumatoid arthritis specific clinical decision tools for diagnosing osteoporosis in a postmenopausal population with rheumatoid arthritis who attend ambulatory specialist rheumatology clinics.MethodsA cross-sectional study of 127 ambulatory post-menopausal women with rheumatoid arthritis was performed. Patients currently receiving or who had previously received bone active therapy were excluded. Eligible women underwent clinical assessment and dual-energy-xray absorptiometry (DXA) bone mineral density assessment.Clinical decision tools, including those specific for rheumatoid arthritis, were compared to seven generic post-menopausal tools to predict osteoporosis (defined as T score < -2.5). Sensitivity, specificity, positive predictive and negative predictive values and area under the curve were assessed. The diagnostic attributes of the clinical decision tools were compared by examination of the area under the receiver-operator-curve.ResultsOne hundred and twenty seven women participated. The median age was 62 (IQR 56–71) years. Median disease duration was 108 (60–168) months. Seventy two (57%) women had no record of a previous DXA examination. Eighty (63%) women had T scores at femoral neck or lumbar spine less than -1. The area under the ROC curve for clinical decision tool prediction of T score <-2.5 varied between 0.63 and 0.76. The rheumatoid arthritis specific decision tools did not perform better than generic tools, however, the National Osteoporosis Foundation score could potentially reduce the number of unnecessary DXA tests by approximately 45% in this population.ConclusionThere was limited utility of clinical decision tools for predicting osteoporosis in this patient population. Fracture prediction tools that include risk factors independent of BMD are needed.

Diagnosis of renal osteodystrophy

Chronic Kidney Disease (CKD) is commonly associated with alterations in bone and mineral metabolism (renal osteodystrophy). To date, bone biopsy remains the gold standard for the diagnosis and classification of the various types of renal osteodystrophy, namely: osteitis fibrosa, mixed uremic osteodystrophy, osteomalacia, aplastic and adynamic bone disease. However, due to its invasive nature and the fact that it is quite expensive, there has been a clamor for a search for other tests. Traditionally, the level of parathyroid hormone (PTH) has been considered a surrogate of bone turnover. At this time, the search continues for a specific and sensitive biochemical marker for monitoring bone turnover in CKD., e.g., alkaline phosphatase, osteocalcin, collagen degradation products, etc. In this chapter, we also present the common radiographic findings that are commonly seen in patients with renal osteodystrophy. Other radiographic techniques such as, dual energy x-ray absorptiometry (DEXA) and deferoxamine challenge test (DFO) are also briefly discussed.

Access to Osteoporosis Treatment is Critically Linked to Access to Dual-Energy X-ray Absorptiometry Testing

To determine if inequities in access to osteoporosis investigation [dual-energy x-ray absorptiometry (DXA) testing] and treatment (bisphosphonate, calcitonin, and/or raloxifene) exist among older women in a region with universal health care coverage. Community-dwelling women aged 65-89 years residing within 2 regions of Ontario, Canada were randomly sampled. Data were collected by standardized telephone interview. Potential correlates of DXA testing (verified by physician records), and current treatment were grouped by type as: "predisposing characteristics," "enabling resources," or "need factors" based on hypothesized relationships formulated before data collection. Variables associated with each outcome independent of "need factors" identified inequities in the system. Of the 871 participants (72% response rate), 55% had been tested by DXA and 20% were receiving treatment. Using multiple variable logistic regression to adjust for need factors, significant inequities in access to DXA testing existed by age, health beliefs, education, income, use of preventive health services, region, and provider sex. DXA testing mediated access to treatment; 34% of those having had a DXA were treated compared with 2% of those who did not. Among women with osteoporosis, correctly reporting that their DXA test indicated osteoporosis and higher perceived benefits of taking pharmacological agents for osteoporosis were associated with treatment. Significant inequities in access to fracture prevention exist in a region with universal health care coverage. Improved access to DXA and better communication to patients of both their DXA results and the benefits of treatment has the potential to reduce the burden of osteoporosis.

Single-Site vs Multisite Bone Density Measurement for Fracture Prediction

Bone density measurement with dual-energy x-ray absorptiometry is widely used for fracture risk assessment. Discordance between measurement sites is common, but it is unclear how this affects fracture prediction. We performed a historical cohort study among 16 505 women 50 years or older at the time of baseline dual-energy x-ray absorptiometry of the spine and hip (mean +/- SD observation period, 3.2 +/- 1.5 years). The study population was drawn from a database that contains all clinical dual-energy x-ray absorptiometry test results for the province of Manitoba, Canada. Each subject's longitudinal health service record was assessed for the presence of fracture codes after bone density testing. The likelihood ratio test was used to assess the improvement in fracture prediction from Cox proportional hazards models using bone density covariates from a single site or from combined sites. Age-adjusted hazard ratios (HRs) per standard deviation for osteoporotic fracture ranged from 1.61 (95% confidence interval [CI], 1.39-1.87) for the lumbar spine to 1.85 (95% CI, 1.70-2.01) for the total hip, with intermediate values for the femur neck (HR, 1.76 [95% CI, 1.62-1.92]) and trochanter (HR, 1.77 [95% CI, 1.63-1.92]). For fracture prediction, use of the minimum bone density measurement was no better than use of a hip measurement alone. When the total hip measurement was included in a fracture prediction model for the overall population, none of the other measurements added substantial information. The spine was the most useful site for the prediction of spine fractures alone. Proximal femur bone density measurements consistently outperformed lumbar spine measurements for global fracture prediction. In this cohort, the total hip was the best site for overall fracture assessment.

A High School Soccer Player with Energy Deficiency

A High School Soccer Player with Energy Deficiency