Risk of hip fracture derived from relative risks: an analysis applied to the population of Sweden

Opportunistic screening for osteoporosis and osteopenia from CT scans of the abdomen and pelvis using machine learning

OBJECTIVES

To use multivariable machine learning using the computed tomography (CT) attenuation of each of the bones in the lumbar spine, pelvis, and sacrum, to predict osteoporosis/osteopenia.

METHODS

This was a retrospective study of 394 patients aged 50 years or older with CT scans of the abdomen and pelvis and dual-energy x-ray absorptiometry (DXA) scans obtained within 6 months of each other. Volumetric segmentations were performed for each of the bones from L1-L4 vertebrae, pelvis, and sacrum to obtain the mean CT attenuation of each bone. The data was randomly split into training/validation (n = 274, 70%) and test (n = 120, 30%) datasets. The CT attenuation of the L1 vertebrae, univariate logistic regression, least absolute shrinkage and selection operator (LASSO), and support vector machines (SVM) with radial basis function (RBF) were used to predict osteoporosis/osteopenia. The performance of using the CT attenuation at L1 to the univariate logistic regression, LASSO, and SVM models were compared using DeLong's test in the test dataset.

RESULTS

All CT attenuation measurements were predictive of osteoporosis/osteopenia (p < 0.001 for all). The SVM model (accuracy = 0.892, AUC = 0.886) outperformed the models using the CT attenuation of threshold of 173.9 Hounsfield units (HU) at L1 (accuracy = 0.725, AUC = 0.739, p = 0.010), the univariate logistic regression model (accuracy = 0.767, AUC = 0.533, p < 0.001) and the LASSO model (accuracy = 0.817, AUC = 0.711, p = 0.007) to predict osteoporosis/osteopenia.

CONCLUSION

A SVM model using the CT attenuations of multiple bones within the lumbar spine and pelvis and clinical data has a better ability to predict osteoporosis/osteopenia than using the CT attenuation of L1 or a LASSO model.

KEY POINTS

• Multivariable SVM model using the CT attenuation of multiple bones and clinical/demographic data was more predictive than using the CT attenuation at L1 only.

The need to distinguish intervention thresholds and diagnostic thresholds in the management of osteoporosis

This position paper of the International Osteoporosis Foundation (IOF) and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) addresses the rationale for separate diagnostic and intervention thresholds in osteoporosis. We conclude that the current BMD-based diagnostic criteria for osteoporosis be retained whilst clarity is brought to bear on the distinction between diagnostic and intervention thresholds.

Can frailty in conjunction with FRAX identify additional women at risk of fracture - a longitudinal cohort study of community dwelling older women

BACKGROUND

Fracture risk assessment is still far from perfect within the geriatric population. The overall aim of this study is to better identify older women at risk for fractures, using a quantitative measure of frailty in conjunction with the web-based Fracture Risk Assessment Tool (FRAX®).

METHODS

This study was performed in the Osteoporosis Risk Assessment (OPRA) cohort of n = 1023, 75-year-old women followed for 10-years. A frailty index (FI) of 'deficits in health' was created, and FRAX 10-year probability for major osteoporotic and hip fractures was calculated and bone mineral density measured. Incident fractures were continuously registered for 10-years. Receiver Operating Characteristic (ROC) curves were used to compare FI, FRAX and the combination FI + FRAX as instruments for risk prediction. Discriminative ability was estimated by comparing Area Under the Curve (AUC). In addition, using guidelines from the Swedish Osteoporosis Foundation, a category of low risk women who would not have been recommended for pharmacological treatment (non-treatment group) was identified, categorized by frailty status and for relative risk analysis, hazard ratios (HR) and 95% confidence intervals were calculated using Cox proportional hazard regressions.

RESULTS

For hip fracture, FRAX and frailty performed almost equally (HIP AUC 10y: 0.566 vs. 0.567, p = 0.015 and p = 0.013). Next, FI was used in conjunction with FRAX; proving marginally better than either score alone (AUC 10y: 0.584, p = 0.002). Comparable results were observed for osteoporotic fracture. In the non-treatment group (564 women), being frail was associated with higher 10y hip fracture risk (HR 2.01 (1.13-3.57)), although failing to reach statistical significance for osteoporotic fracture (HR 1.40 (0.97-2.01). The utility of measuring frailty was also demonstrated when using T-score as an index of bone density to define fracture risk. Among n = 678 non-osteoporotic women, frailty added to the 10-year fracture risk (Hip; HR 2.22 (1.35-3.71); Osteoporotic fracture; HR 1.57 (1.15-2.14)).

CONCLUSIONS

While the addition of frailty to FRAX marginally improved fracture prediction, applying a frailty measurement to a group of 'low risk' women, identified a set of individuals with high actual hip fracture risk that would not be prioritized for pharmacological treatment. Further cost-benefit analysis studies are needed to formally test potential benefit.

Menopause Hormone Therapy in the Management of Postmenopausal Osteoporosis

ABSTRACT

This narrative review analyzes the customization of menopause hormone therapy (MHT) for osteoporosis prevention and treatment in the context of the patients' age and menopausal age. In short, MHT is indicated in most women suffering from menopause before the age of 45 years except for breast cancer survivors. These women should be treated with MHT until the age of 50 years. For women who have entered menopause at around the age of 50 years, risks associated with MHT are low, and MHT is a safe option, provided there is an indication for it. We suggest that pursuing MHT entails different risks than initiating it, after the age of 60 years. In both cases, advantages and risks should be evaluated. We suggest using risk calculators to assess the magnitude of these risks and choosing regimens that entail the lowest breast and thrombosis risks.

Western Osteoporosis Alliance Clinical Practice Series: Treat-to-Target for Osteoporosis

Patients often start treatment to reduce fracture risk because of a bone mineral density T-score consistent with osteoporosis (≤ -2.5). Others with a T-score above -2.5 may be treated when there is a history of fragility fracture or when a fracture risk algorithm categorizes them as having a high risk for fracture. It is common to initiate therapy with a generic oral bisphosphonate, unless contraindicated, and continue therapy if the patient is responding as assessed by stability or an increase in bone mineral density. However, some patients may respond well to an oral bisphosphonate, yet remain with an unacceptably high risk for fracture. Recognition of this occurrence has led to the development of an alternative strategy: treat-to-target. This involves identifying a biological marker (treatment target) that represents an acceptable fracture risk and then initiating treatment with an agent likely to reach this target. If the patient is on a path to reaching the target with initial therapy, treatment is continued. If it appears the target will not be reached with initial therapy, treatment is changed to an agent more likely to achieve the goal.

Cost-effectiveness of pharmacological fracture prevention for osteoporosis as prescribed in clinical practice in France, Germany, Italy, Spain, and the United Kingdom

This study estimated the cost-effectiveness of pharmacological fracture prevention as prescribed in the five largest European countries (EU5) using the IOF reference cost-effectiveness model. Pharmacological fracture prevention as prescribed in clinical practice was cost-saving (provided more QALYs at lower costs) compared to no treatment in each of the EU5.

PURPOSE

To estimate the real-world cost-effectiveness of pharmacological fracture prevention as prescribed in the five largest European countries by population size: France, Germany, Italy, Spain, and the United Kingdom (UK) (collectively EU5).

MATERIALS AND METHODS

We analyzed sales data on osteoporosis drugs in each of the EU5 to derive a hypothetical intervention that corresponds to the mix of osteoporosis medication prescribed in clinical practice. The costs for this treatment mix were obtained directly from the sales data, and the efficacy of the treatment mix was estimated by weighing the treatment-specific fracture risk reductions from a published meta-analysis. Subsequently, we estimated the cost-effectiveness using costs per quality adjusted life year (QALY) of the intervention compared to no treatment in each of the EU5 using the International Osteoporosis Foundation (IOF) reference cost-effectiveness model. The model population comprised postmenopausal women, mean age 72 years with established osteoporosis (T-score ≤ - 2.5) among whom 23.6% had a prevalent vertebral fracture. The model was populated with country-specific data from the literature.

RESULTS

Pharmacological fracture prevention as prescribed in clinical practice was cost-saving (provided more QALYs at lower costs) compared to no treatment in each country. The findings were robust in scenario analyses.

CONCLUSIONS

Pharmacological fracture prevention as prescribed in clinical practice is cost-saving in each of the EU5. Because of the under-diagnosis and under-treatment of post-menopausal osteoporosis, from a health economic perspective, further cost-savings may be reached by expanding treatment to those at increased risk of fracture currently not receiving any treatment.

Derivation and External Validation of a Scoring System for Predicting Fracture Risk After Ischemic Stroke in a Canadian Cohort

Importance

The risk for low-trauma fracture is increased by more than 30% after ischemic stroke, but existing fracture risk scores do not account for history of stroke as a high-risk condition.

Objective

To derive a risk score to predict the probability of fracture within 1 year after ischemic stroke and validate it in a separate cohort.

Design, Setting, and Participants

Prognostic study of a cohort from the Ontario Stroke Registry, a population-based sample of adults in Ontario, Canada, who were hospitalized with ischemic stroke from July 1, 2003, to March 31, 2012, with 1 year of follow-up. A population-based validation cohort consisted of a sample of 13 698 consecutive stroke admissions captured across 5 years: April 2002 to March 2003, April 2004 to March 2005, April 2008 to March 2009, April 2010 to March 2011, and April 2012 to March 2013.

Exposures

Predictor variables were selected based on biological plausibility and association with fracture risk. Age, sex, and modified Rankin score were abstracted from the medical records part of the Ontario Stroke Audit, and other characteristics were abstracted from administrative health data.

Main Outcomes and Measures

Incidence of low-trauma fracture within 1 year of discharge, based on administrative health data.

Results

The Fracture Risk after Ischemic Stroke (FRAC-Stroke) Score was derived in 20 435 patients hospitalized for ischemic stroke (mean [SD] age, 71.6 [14.0] years; 9564 [46.8%] women) from the Ontario Stroke Registry discharged from July 1, 2003, to March 31, 2012, using Fine-Gray competing risk regression. Low-trauma fracture occurred within 1 year of discharge in 741 of the 20 435 patients (3.6%) in the derivation cohort. Age, discharge modified Rankin score (mRS), and history of rheumatoid arthritis, osteoporosis, falls, and previous fracture were associated with the cumulative incidence of low trauma fracture in the derivation cohort. Model discrimination in the validation cohort (n = 13 698) was good (C statistic, 0.70). Discharge mRS was an important discriminator of risk (relative integrated discrimination improvement, 8.7%), with highest risk in patients with mRS 3 and 4 but lowest in bedbound patients (mRS 5). From the lowest to the highest FRAC-Stroke quintile, the cumulative incidence of 1-year low-trauma fracture increased from 1.3% to 9.0% in the validation cohort. Predicted and observed rates of fracture were similar in the external validation cohort. Analysis was conducted from July 2016 to January 2019.

Conclusions and Relevance

The FRAC-Stroke score allows the clinician to identify ischemic stroke survivors at higher risk of low-trauma fracture within 1 year of hospital discharge. This information might be used to select patients for interventions to prevent fractures.

A brief history of FRAX

This paper reviews the research programme that went into the development of FRAX® and its impact in the 10 years since its release in 2008.

INTRODUCTION

Osteoporosis is defined on the measurement of bone mineral density though the clinical consequence is fracture. The sensitivity of bone mineral density measurements for fracture prediction is low, leading to the development of FRAX to better calculate the likelihood of fracture and target anti-osteoporosis treatments.

METHODS

The method used in this paper is literature review.

RESULTS

FRAX, developed over an 8-year period, was launched in 2008. Since the launch of FRAX, models have been made available for 64 countries and in 31 languages covering more than 80% of the world population.

CONCLUSION

FRAX provides an advance in fracture risk assessment and a reference technology platform for future improvements in performance characteristics.

Relationship between the FRAX index and physical and cognitive functioning in older people

OBJECTIVE

To assess the relationship between the FRAX index and the Barthel index/MiniMental State Examination in older people.

PATIENTS AND METHODS

Observational descriptive study. Demographic data, comorbidity, dependency and cognitive state, and risk of osteoporotic fracture were collected.

RESULTS

A total of 375 patients were included (60% female) Patients with a low-risk FRAX for hip fractures had a higher Mini-mental (25, 95% CI = 24-27 vs. 22, 95% = 21 to 23, p = .0001), a higher Barthel index (88, 95% CI = 84-93 vs 72, 69 to 76, p = .0001) without differences in the Charlson index. Bivariate analysis showed an inverse association between FRAX and scales but logistic regression showed only female sex (OR 4.4, 95% CI = 2.6-7.6) and the non-dependent Barthel index (OR = 0.104, 95% CI = 0.014-0.792) remained significant and. Barthel index/Mini-mental constructed a significant model capable of predicting a risk of hip fracture of >3% measured by the FRAX index, with an area under the curve of 0.76 (95% CI = 0.7-0.81).

CONCLUSIONS

The FRAX index is related to other markers of geriatric assessment and the association between these variables can predict a risk of hip fracture of >3% measured by the FRAX index. Key messages Geriatric assessment indexes may be as important as the FRAX index, which is based on clinical risk factors, in predicting the fracture risk in older patient.

Effect of conjugated estrogens/bazedoxifene on postmenopausal bone loss: pooled analysis of two randomized trials

OBJECTIVE

Conjugated estrogens/bazedoxifene reduces vasomotor symptoms and prevents postmenopausal bone loss without stimulating the breast and endometrium. We analyzed changes in bone mineral density (BMD) and bone markers using pooled data from two phase-3 trials.

METHODS

Selective Estrogens, Menopause, and Response to Therapy (SMART)-1 and SMART-5 were randomized, double-blind, placebo- and active-controlled studies conducted in postmenopausal nonhysterectomized women. BMD and turnover marker data were pooled for women given conjugated estrogens (0.45 or 0.625 mg) plus bazedoxifene 20 mg or placebo over 12 months. Sensitivity analyses were conducted using baseline Fracture Risk Assessment Tool score, age, years since menopause, body mass index, race, and geographic region.

RESULTS

There were 1,172 women, mean age 54.9 years, mean 6.21 years since menopause, mean lumbar spine, and total hip T scores -1.05 and -0.58; 58.8% had a Fracture Risk Assessment Tool score less than 5% indicating low fracture risk. At 12 months, adjusted differences (vs placebo) in BMD change in the groups taking conjugated estrogens 0.45 or 0.625 mg plus bazedoxifene 20 mg were 2.3% and 2.4% for lumbar spine, 1.4% and 1.5% for total hip, and 1.1% and 1.5% for femoral neck (all P < 0.001 vs placebo). These increases were unrelated to baseline Fracture Risk Assessment Tool score, age, years since menopause, body mass index, or geographic region. Both doses reduced bone turnover markers (P < 0.001).

CONCLUSIONS

Conjugated estrogens/bazedoxifene significantly improved BMD and turnover in a large population of younger postmenopausal women at low fracture risk and is a promising therapy for preventing postmenopausal bone loss.

Use of pamidronate for osteoporosis treatment in public health care in Brazil

PURPOSE

The use of bisphosphonates for osteoporosis is effective in reducing the risk of fractures. However, oral formulations are sometimes not well tolerated or are contraindicated. Due to its availability in Brazilian public health system, pamidronate is frequently prescribed for osteoporosis, despite the lack of studies demonstrating its anti-fracture efficacy and the absence of FDA or EMEA approval for this purpose. The aim of this study was to evaluate the bone mineral density (BMD) response to pamidronate in a group of women with osteoporosis in a tertiary care hospital.

PATIENTS AND METHODS

The medical records of women with osteoporosis who received pamidronate for up to two years of treatment were reviewed. Patients were stratified at high or intermediate risk of fracture.

RESULTS

A total of 70 women were in treatment with pamidronate. Among them, 74% were at high risk of fracture. A significant gain in spine BMD after 24 months of treatment was observed (p=0.012). There was no difference between the groups of high and not high risk of fracture. At the femur, no significant increase in BMD was present, though, a strong negative correlation with high PTH levels (r=-0.61; p=0.003) was seen. In the multivariate analysis BMI at 12 months had impact in the response to the treatment.

CONCLUSION

The intravenous pamidronate in a group of postmenopausal women with predominant high risk of fracture promoted an isolated gain in the spine BMD, even though, clinical randomized trials are needed to confirm its anti-fracture efficacy.

A model-based cost-effectiveness analysis of osteoporosis screening and treatment strategy for postmenopausal Japanese women

Although an osteoporosis screening program has been implemented as a health promotion project in Japan, its cost-effectiveness has yet to be elucidated fully. We performed a cost-effectiveness analysis and found that osteoporosis screening and treatment would be cost-effective for Japanese women over 60 years.

INTRODUCTION

The purpose of this study was to estimate the cost-effectiveness of osteoporosis screening and drug therapy in the Japanese healthcare system for postmenopausal women with no history of fracture.

METHODS

A patient-level state transition model was developed to predict the outcomes of Japanese women with no previous fracture. Lifetime costs and quality-adjusted life years (QALYs) were estimated for women who receive osteoporosis screening and alendronate therapy for 5 years and those who do not receive the screening and treatments. The incremental cost-effectiveness ratio (ICER) of the screening option compared with the no screening option was estimated. Sensitivity analyses were performed to examine the influence of parameter uncertainty on the base case results.

RESULTS

The ICERs of osteoporosis screening and treatments for Japanese women aged 50-54, 55-59, 60-64, 65-69, 70-74, and 75-79 years were estimated to be $89,242, $64,010, $40,596, $27,697, $17,027, and $9771 per QALY gained, respectively. Deterministic sensitivity analyses showed that several parameters such as the disutility due to vertebral fracture had a significant influence on the base case results. Applying a willingness to pay of $50,000 per QALY gained, the probability that the screening option became cost-effectiveness estimated to 50.9, 56.3, 59.1, and 64.7 % for women aged 60-64, 65-69, 70-74, and 75-79 years, respectively. Scenario analyses showed that the ICER for women aged 55-59 years with at least one clinical risk factor was below $50,000 per QALY.

CONCLUSIONS

In conclusion, dual energy X-ray absorptiometry (DXA) screening and alendronate therapy for osteoporosis would be cost-effective for postmenopausal Japanese women over 60 years. In terms of cost-effectiveness, the individual need for osteoporosis screening should be determined by age and clinical risk factors.

A clinical decision support system for the diagnosis, fracture risks and treatment of osteoporosis

Expanding medical knowledge increases the potential risk of medical errors in clinical practice. We present, OPAD, a clinical decision support system in the field of the medical care of osteoporosis. We utilize clinical information from international guidelines and experts in the field of osteoporosis. Physicians are provided with user interface to insert standard patient data, from which OPAD provides instant diagnostic comments, 10-year risk of fragility fracture, treatment options for the given case, and when to offer a follow-up DXA-evaluation. Thus, the medical decision making is standardized according to the best expert knowledge at any given time. OPAD was evaluated in a set of 308 randomly selected individuals. OPAD's ten-year fracture risk computation is nearly identical to FRAX (r = 0.988). In 58% of cases OPAD recommended DXA evaluation at the present time. Following a DXA measurement in all individuals, 71% of those that were recommended to have DXA at the present time received recommendation for further investigation or specific treatment by the OPAD. In only 5.9% of individuals in which DXA was not recommended, the result of the BMD measurement changed the recommendations given by OPAD.

Cost-utility of denosumab for the treatment of postmenopausal osteoporosis in Spain

BACKGROUND

The objective of this study was to estimate the cost-effectiveness of denosumab for fracture prevention compared with no treatment, generic bisphosphonates, and strontium ranelate in a cohort of osteoporotic postmenopausal women in Spain.

METHODS

A Markov model represented the possible health state transitions of Spanish postmenopausal women from initiation of fracture prevention treatment until age 100 years or death. The perspective was that of the Spanish National Health System. Fracture efficacy data for denosumab were taken from a randomized controlled trial. Fracture efficacy data for alendronate, ibandronate, risedronate, and strontium ranelate were taken from an independent meta-analysis. Data on the incidence of fractures in Spain were either taken from the published literature or derived from Swedish data after applying a correction factor based on the reported incidence from each country. Resource use in each health state was obtained from the literature, or where no data had been published, conservative assumptions were made. Utility values for the various fracture health states were taken from published sources. The primary endpoints of the model were life-years gained, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios for denosumab against the comparators.

RESULTS

Denosumab reduced the risk of fractures compared with either no treatment or the other active interventions, and produced the greatest gains in life-years and QALYs. With an annual acquisition cost of €417.34 for denosumab, the incremental cost-effectiveness ratios for denosumab versus no treatment, alendronate, risedronate, and ibandronate were estimated at €6,823, €16,294, €4,895, and €2,205 per QALY gained, respectively. Denosumab dominated strontium ranelate. Sensitivity analyses confirmed the robustness of these findings.

CONCLUSION

Our analyses show that denosumab is a cost-effective intervention for fracture prevention in osteoporotic postmenopausal women in Spain compared with alendronate and risedronate, and is a dominant treatment option compared with strontium ranelate.

Goal-directed treatment of osteoporosis in Europe

Despite the proven predictive ability of bone mineral density, Fracture Risk Assessment Tool (FRAX®), bone turnover markers, and fracture for osteoporotic fracture, their use as targets for treatment of osteoporosis is limited.

INTRODUCTION

Treat-to-target is a strategy applied in several fields of medicine and has recently become an area of interest in the management of osteoporosis. Its role in this setting remains controversial. This article was prepared following a European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) working group meeting convened under the auspices of the International Osteoporosis Foundation (IOF) to discuss the feasibility of applying such a strategy in osteoporosis in Europe.

METHODS

Potential targets range from the absence of an incident fracture to fixed levels of bone mineral density (BMD), a desired FRAX® score, a specified level of bone turnover markers or indeed changes in any one or a combination of these parameters.

RESULTS

Despite the proven predictive ability of all of these variables for fracture (particularly BMD and FRAX), their use as targets remains limited due to low sensitivity, the influence of confounders and current lack of evidence that targets can be consistently reached.

CONCLUSION

ESCEO considers that it is not currently feasible to apply a treat-to-target strategy in osteoporosis, though it did identify a need to continue to improve the targeting of treatment to those at higher risk (target-to-treat strategy) and a number of issues for the research agenda. These include international consensus on intervention thresholds and definition of treatment failure, further exploration of the relationship between fracture and BMD, and FRAX and treatment efficacy and investigation of the potential of short-term targets to improve adherence.

Cost-effectiveness analysis of hip fracture prevention with vitamin D supplementation: a Markov micro-simulation model applied to the French population over 65 years old without previous hip fracture

We performed a cost-effectiveness analysis of four vitamin D supplementation strategies for primary prevention of hip fracture among the elderly population and found that the most cost-effective strategy was screening for vitamin D insufficiency followed by adequate treatment to attain a minimum 25(OH) serum level.

INTRODUCTION

Vitamin D supplementation has a demonstrated ability to reduce the incidence of hip fractures. The efficiency of lifetime supplementation has not yet been assessed in the population over 65 years without previous hip fracture. The objective was to analyze the efficiency of various vitamin D supplementation strategies for that population.

METHODS

A Markov micro-simulation model was built with data extracted from published studies and from the French reimbursement schedule. Four vitamin D supplementation strategies were evaluated on our study population: (1) no treatment, (2) supplementation without any serum level check; (3) supplementation with a serum level check 3 months after initiation and subsequent treatment adaptation; (4) population screening for vitamin D insufficiency followed by treatment based on the vitamin D serum level.

RESULTS

"Treat, then check" and "screen and treat" were two cost-effective strategies and dominated "treat without check" with incremental cost-effectiveness ratios of €5,219/quality-adjusted life-years (QALY) and €9,104/QALY, respectively. The acceptability curves showed that over €6,000/QALY, the "screen and treat" strategy had the greatest probability of being cost-effective, and the "no treatment" strategy would never be cost-effective if society were willing to spend over €8,000/QALY. The sensitivity analysis showed that among all parameters varying within realistic ranges, the cost of vitamin D treatment had the greatest effect and yet remained below the WHO cost-effectiveness thresholds.

CONCLUSIONS

Population screening for vitamin D insufficiency followed by treatment based on the vitamin D serum level is the most cost-effective strategy for preventing hip fracture occurrence in the population over 65 years old.

Sensitivity of osteoporosis screening guidelines for eventual hip fracture in older male veterans

This study sought to determine whether guideline-recommended clinical criteria to select men for osteoporosis screening provide significantly better sensitivity than the osteoporotic screening tool (OST) among men who later went on to have a hip fracture, and whether the sensitivity differs by race. This retrospective observational study uses data from the Department of Veterans Affairs Austin Automation Center. We identified 825 male veterans with hip fractures from 2007 to 2009. Clinical risk factors used as screening selection criteria were abstracted from five accepted guidelines. Outpatient encounters were examined for each subject to determine whether they would have met screening selection criteria for each guideline in the 5 years before their hip fracture event. Sensitivities for each guideline were compared with the OST, using McNemar's exact test. Sensitivities of Veterans Affairs Health Service Research and Development Services (VA HSR&D) and National Osteoporosis Foundation (NOF) guidelines were 77% and 82%, respectively, and were significantly better than the OST sensitivity of 72% (P<0.05). Sensitivities of American College of Physicians (ACP; 68%), VA Secretary's Letters (45%) and Center for Medicare and Medicaid Services (13%) were significantly worse than the OST sensitivity (P<0.001). The sensitivities of the VA HSR&D, ACP and NOF were significantly higher in Whites compared with non-Whites (76% vs 65%, P<0.01; 70% vs 58%, P<0.01; and 84% vs 70%, P<0.001, respectively). Only VA HSR&D and NOF clinical screening criteria are more sensitive than OST in identifying veterans who subsequently experience hip fractures, and these sensitivities vary by race.

Impact of changes in mortality on FRAX-derived fracture probabilities

BACKGROUND

Accurate hip fracture incidence and mortality rates are two essential requirements for FRAX calculators.

PURPOSE

To investigate the effects of change in mortality on FRAX-derived fracture estimates.

METHODS

Lebanese FRAX calculator was updated in 2012 from version 3.00 utilizing WHO mortality data from year 1999, and hip fracture incidence rates from 2007, to version 3.05 utilizing mortality data from 2009, but with identical hip fracture data. FRAX-derived estimates from 679 patients were computed using both FRAX versions and compared. Numbers presented as median [25th-75th] percentiles.

RESULTS

The 10-year FRAX-derived probability of major osteoporotic fracture and hip fracture increased substantially. Changes were most pronounced in high risk sub-groups. The relative increase in probability of major osteoporotic fracture in individuals with a baseline risk of 10-20% was 79% [19%-127%], and in individuals with a baseline risk >20% it was 125% (N=3). The numbers for relative increase in hip fracture probability were 98% [33%-135%], and 129%, respectively. Similarly, individuals older than 70 years had a 125% [89%-150%] relative increase in probability of major osteoporotic fracture and a 122% [95%-145%] relative increase in hip fracture probability. Using the FRAX-based Lebanese guidelines, FRAX 3.05 led to an additional increase in treatment qualification of 3.8 patients per 100 patients, or a relative increase of 24%.

CONCLUSIONS

Updates in mortality values increased FRAX-derived estimates, most substantially in older patients, and those at high risk for fracture. The update results in altering individuals' treatment decisions and modifying country wide osteoporosis management. Our results are relevant to the development and update of FRAX models for countries worldwide, and more importantly those with increasing longevity and possible increase in fracture rates.

Osteoporosis in healthy South Indian males and the influence of life style factors and vitamin d status on bone mineral density

Objective. To study the prevalence of osteoporosis and vitamin D deficiency in healthy men and to explore the influence of various life style factors on bone mineral density (BMD) and also to look at number of subjects warranting treatment. Methods. Ambulatory south Indian men aged above 50 were recruited by cluster random sampling. The physical activity, risk factors in the FRAX tool, BMD, vitamin D, and PTH were assessed. The number of people needing treatment was calculated, which included subjects with osteoporosis and osteopenia with 10-year probability of major osteoporotic fracture >20 percent and hip fracture >3 percent in FRAX India. Results. A total of 252 men with a mean age of 58 years were studied. The prevalence of osteoporosis and osteopenia at any one site was 20% (50/252) and 58%, respectively. Vitamin D deficiency (<20 ng/dL) was seen in 53%. On multiple logistic regression, BMI (OR 0.3; P value = 0.04) and physical activity (OR 0.4; P value < 0.001) had protective effect on BMD. Twenty-five percent warranted treatment. Conclusions. A significantly large proportion of south Indian men had osteoporosis and vitamin D deficiency. Further interventional studies are needed to look at reduction in end points like fractures in these subjects.

CER1 gene variations associated with bone mineral density, bone markers, and early menopause in postmenopausal women

Background

Osteoporosis has a multifactorial pathogenesis characterized by a combination of low bone mass and increased fragility. In our study, we focused on the effects of polymorphisms in CER1 and DKK1 genes, recently reported as important susceptibility genes for osteoporosis, on bone mineral density (BMD) and bone markers in osteoporotic women. Our objective was to evaluate the effect of CER1 and DKK1 variations in 607 postmenopausal women. The entire DKK1 gene sequence and five selected CER1 SNPs were amplified and resequenced to assess whether there is a correlation between these genes and BMD, early menopause, and bone turnover markers in osteoporotic patients.

Results

Osteoporotic women seem to suffer menopause 2 years earlier than the control group. The entire DKK1 gene sequence analysis revealed six variations. There was no correlation between the six DKK1 variations and osteoporosis, in contrast to the five common CER1 variations that were significantly associated with BMD. Additionally, osteoporotic patients with rs3747532 and rs7022304 CER1 variations had significantly higher serum levels of parathyroid hormone and calcitonin and lower serum levels of osteocalcin and IGF-1.

Conclusions

No significant association between the studied DKK1 variations and osteoporosis was found, while CER1 variations seem to play a significant role in the determination of osteoporosis and a potential predictive role, combined with bone markers, in postmenopausal osteoporotic women.

Fracture risk prediction: importance of age, BMD and spine fracture status

Our purpose was to identify factors for a parsimonious fracture risk assessment model considering morphometric spine fracture status, femoral neck bone mineral density (BMD) and the World Health Organization (WHO) clinical risk factors. Using data from 2761 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, longitudinal cohort study of randomly selected community-dwelling men and women aged ⩾50 years, we previously reported that a logistic regression model considering age, BMD and spine fracture status provided as much predictive information as a model considering these factors plus the remaining WHO clinical risk factors. The current analysis assesses morphometric vertebral fracture and/or nonvertebral fragility fracture at 5 years using data from an additional 1964 CaMos subjects who have now completed 5 years of follow-up (total N=4725). Vertebral fractures were identified from lateral spine radiographs assessed using quantititative morphometry at baseline and end point. Nonvertebral fragility fractures were determined by questionnaire and confirmed using radiographs or medical records; fragility fracture was defined as occurring with minimal or no trauma. In this analysis, a model including age, BMD and spine fracture status provided a gradient of risk per s.d. (GR/s.d.) of 1.88 and captured most of the predictive information of a model including morphometric spine fracture status, BMD and all WHO clinical risk factors (GR/s.d. 1.92). For comparison, this model provided more information than a model considering BMD and the WHO clinical risk factors (GR/s.d. 1.74). These findings confirm the value of age, BMD and spine fracture status for predicting fracture risk.

The Elders Risk Assessment Index, an electronic administrative database-derived frailty index, can identify risk of hip fracture in a cohort of community-dwelling adults

OBJECTIVE

To determine whether an Elders Risk Assessment (ERA) index can predict incident hip fractures without the need for physician-patient encounter or bone mineral density testing.

PATIENTS AND METHODS

A retrospective cohort study was conducted in a community-based cohort of 12,650 patients aged 60 years and older. An ERA score was computed for each subject at index time (January 1, 2005). Incidents of hip fracture from January 1, 2005, through December 31, 2006, were obtained from electronic medical records. We divided the cohort into 5 groups, with the lowest ERA scores forming group A (<15%); 15% to 49%, group B; 50% to 74%, group C; 75% to 89%, group D; and the top 11%, group E. With group A as a reference group, we used logistic regression to compute odds ratios of sustaining hip fracture during a 2-year period (January 1, 2005, through December 31, 2006) for groups B, C, D, and E. Sensitivity and specificity of each possible ERA score were calculated, and a receiver operating characteristic curve was created.

RESULTS

Two hundred sixty-five patients (2.1%) sustained at least 1 hip fracture from January 1, 2005, through December 31, 2006. Odds ratios (95% confidence intervals) for groups B, C, D, and E were 1.6 (0.7-3.4), 4.5 (2.2-9.4), 6.9 (3.3-14.3), and 18.4 (8.9-37.9), respectively. The area under the receiver operating characteristic curve was 74.5%.

CONCLUSION

An electronic medical record-based, easily derived ERA index might be useful in hip fracture risk stratification.

Modeling seasonal variation of hip fracture in Montreal, Canada

The investigation of the association of the climate variables with hip fracture incidences is important in social health issues. This study examined and modeled the seasonal variation of monthly population based hip fracture rate (HFr) time series. The seasonal ARIMA time series modeling approach is used to model monthly HFr incidences time series of female and male patients of the ages 40-74 and 75+ of Montreal, Québec province, Canada, in the period of 1993-2004. The correlation coefficients between meteorological variables such as temperature, snow depth, rainfall depth and day length and HFr are significant. The nonparametric Mann-Kendall test for trend assessment and the nonparametric Levene's test and Wilcoxon's test for checking the difference of HFr before and after change point are also used. The seasonality in HFr indicated sharp difference between winter and summer time. The trend assessment showed decreasing trends in HFr of female and male groups. The nonparametric test also indicated a significant change of the mean HFr. A seasonal ARIMA model was applied for HFr time series without trend and a time trend ARIMA model (TT-ARIMA) was developed and fitted to HFr time series with a significant trend. The multi criteria evaluation showed the adequacy of SARIMA and TT-ARIMA models for modeling seasonal hip fracture time series with and without significant trend. In the time series analysis of HFr of the Montreal region, the effects of the seasonal variation of climate variables on hip fracture are clear. The Seasonal ARIMA model is useful for modeling HFr time series without trend. However, for time series with significant trend, the TT-ARIMA model should be applied for modeling HFr time series.

Cost-effectiveness of denosumab in the treatment of postmenopausal osteoporosis in Canada

OBJECTIVE

Denosumab is a novel biologic agent approved in Canada for treatment of post-menopausal osteoporosis (PMO) in women at high risk for fracture or who have failed or are intolerant to other osteoporosis therapies. This study estimated cost-effectiveness of denosumab vs usual care from the perspective of the Ontario public payer.

METHODS

A previously published PMO Markov cohort model was adapted for Canada to estimate cost-effectiveness of denosumab. The primary analysis included women with demographic characteristics similar to those from the pivotal phase III denosumab PMO trial (FREEDOM; age 72 years, femoral neck BMD T-score -2.16 SD, vertebral fracture prevalence 23.6%). Three additional scenario sub-groups were examined including women: (1) at high fracture risk, defined in FREEDOM as having at least two of three risk factors (age 70+; T-score ≤ -3.0 SD at lumbar spine, total hip, or femoral neck; prevalent vertebral fracture); (2) age 75+; and (3) intolerant or contraindicated to oral bisphosphonates (BPs). Analyses were conducted over a lifetime horizon comparing denosumab to usual care ('no therapy', alendronate, risedronate, or raloxifene [sub-group 3 only]). The analysis considered treatment-specific persistence and post-discontinuation residual efficacy, as well as treatment-specific adverse events. Both deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

The multi-therapy comparisons resulted in incremental cost-effectiveness ratios for denosumab vs alendronate of $60,266 (2010 CDN$) (primary analysis) and $27,287 per quality-adjusted life year gained for scenario sub-group 1. Denosumab dominated all therapies in the remaining scenarios.

LIMITATIONS

Key limitations include a lack of long-term, real-world, Canadian data on persistence with denosumab as well as an absence of head-to-head clinical data, leaving one to rely on meta-analyses based on trials comparing treatment to placebo.

CONCLUSIONS

Denosumab may be cost-effective compared to oral PMO treatments for women at high risk of fractures and those who are intolerant and/or contraindicated to oral BPs.

Cost-effectiveness of Denosumab for the treatment of postmenopausal osteoporosis

Denosumab is an injectable drug that reduces the risk of fractures. The objective was to estimate the cost-effectiveness of denosumab in a Swedish setting, also accounting for poor adherence to treatment. Denosumab is cost-effective, particularly for patients at high risk of fracture and low adherence to oral treatments.

INTRODUCTION

Denosumab is a novel biologic agent developed for the treatment of osteoporosis and osteoporotic fractures that has been shown to reduce the risk of fractures in a phase III trial. The objective of this study was to estimate the cost-effectiveness of denosumab from a societal perspective compared with generic alendronate, branded risedronate, strontium ranelate, and no treatment in a Swedish setting.

METHODS

A Markov cohort model was used to estimate the cost-effectiveness of denosumab given for up to 5 years to a typical Swedish patient population (women aged 71 years, T-score ≤ -2.5 SD and a prevalence of morphometric vertebral fractures of 34%). The model included treatment persistence and residual effect after discontinuation assumed to be equal to the time on treatment. Persistence with the comparator treatments and with denosumab was derived from prescription data and a persistence study, respectively.

RESULTS

The base-case incremental cost-effectiveness ratios were estimated at €27,000, €12,000, €5,000, and €14,000, for denosumab compared with generic alendronate, risedronate, strontium ranelate, and no treatment, respectively. Sub-optimal persistence had the greatest impact in the comparison with generic alendronate, where the difference in drug cost was large.

CONCLUSION

Improving persistence with osteoporosis treatment impacts positively on cost-effectiveness with a larger number of fractures avoided in the population targeted for treatment. Denosumab is a cost-effective alternative to oral osteoporosis treatments, particularly for patients at high risk of fracture and low expected adherence to oral treatments.

Cost-effectiveness of bazedoxifene incorporating the FRAX® algorithm in a European perspective

The cost-effectiveness of bazedoxifene was compared to placebo in France, Germany, Italy, Spain, Sweden and the UK from a healthcare perspective using FRAX® for both fracture risks and for treatment efficacy. Cost/QALY differences were explained to a large extent by differences in fracture risk.

INTRODUCTION

In cost-effectiveness modelling of osteoporosis treatments, the fracture risk has traditionally been calculated with risk adjustments based on age, bone mineral density and prior fracture. However, knowledge of additional clinical risk factors contributes to fracture risk assessment as demonstrated by the FRAX® tool. Bazedoxifene, a new selective estrogen receptor modulator for the treatment and prevention of osteoporosis, has been shown in a phase III clinical trial to reduce the risk of osteoporotic fractures in women. In an analysis using FRAX®, the efficacy of bazedoxifene was greater in patients with higher fracture risk.

METHODS

The aim of this study was to evaluate the cost-effectiveness of bazedoxifene compared to placebo in France, Germany, Italy, Spain, Sweden and the UK from a healthcare perspective using FRAX®. A Markov cohort model was adapted to incorporate the FRAX® risk factors. FRAX® produces relative risks for hip fractures and major osteoporotic fractures. Patients were given a 5-year intervention, reducing the risk of fractures in a risk-dependent manner. The effect of treatment on fractures was assumed to decline linearly over 5 years after the intervention.

RESULTS

There are large cost/quality-adjusted life year variations between countries in the European setting studied. The base case values ranged from cost saving (Sweden) to EUR 105,450 (Spain) in 70-year-old women with a T-score of -2.5 SD and a prior fracture.

CONCLUSION

Bazedoxifene can be a cost-effective treatment for postmenopausal osteoporosis. The variability between countries was explained to a large extent by differences in fracture risk, and the estimated cost-effectiveness was highly dependent on the population's FRAX®-estimated probability of major osteoporotic fracture.

A FRAX® model for the assessment of fracture probability in Belgium

A country-specific FRAX® model was developed from the epidemiology of fracture and death in Belgium. Fracture probabilities were identified that corresponded to currently accepted reimbursement thresholds.

INTRODUCTION

The objective of this study was to evaluate a Belgian version of the WHO fracture risk assessment (FRAX®) tool to compute 10-year probabilities of osteoporotic fracture in men and women. A particular aim was to determine fracture probabilities that corresponded to the reimbursement policy for the management of osteoporosis in Belgium and the clinical scenarios that gave equivalent fracture probabilities.

METHODS

Fracture probabilities were computed from published data on the fracture and death hazards in Belgium. Probabilities took account of age, sex, the presence of clinical risk factors and femoral neck bone mineral density (BMD). Fracture probabilities were determined that were equivalent to intervention (reimbursement) thresholds currently used in Belgium.

RESULTS

Fracture probability increased with age, lower BMI, decreasing BMD T-score and all clinical risk factors used alone or combined. The 10-year probabilities of a major osteoporosis-related fracture that corresponded to current reimbursement guidelines ranged from approximately 7.5% at the age of 50 years to 26% at the age of 80 years where a prior fragility fracture was used as an intervention threshold. For women at the threshold of osteoporosis (femoral neck T-score = -2.5 SD), the respective probabilities ranged from 7.4% to 15%. Several combinations of risk-factor profiles were identified that gave similar or higher fracture probabilities than those currently accepted for reimbursement in Belgium.

CONCLUSIONS

The FRAX® tool has been used to identify possible thresholds for therapeutic intervention in Belgium, based on equivalence of risk with current guidelines. The FRAX® model supports a shift from the current DXA-based intervention strategy, towards a strategy based on fracture probability of a major osteoporotic fracture that in turn may improve identification of patients at increased fracture risk. The approach will need to be supported by health economic analyses.

Meta-analysis: excess mortality after hip fracture among older women and men

BACKGROUND

Although an increased risk for death after hip fracture is well established, whether this excess mortality persists over time is unclear.

PURPOSE

To determine the magnitude and duration of excess mortality after hip fracture in older men and women.

DATA SOURCES

Electronic search of MEDLINE and EMBASE for English and non-English articles from 1957 to May 2009 and manual search of article references.

STUDY SELECTION

Prospective cohort studies were selected by 2 independent reviewers. The studies had to assess mortality in women (22 cohorts) or men (17 cohorts) aged 50 years or older with hip fracture, carry out a life-table analysis, and display the survival curves of the hip fracture group and age- and sex-matched control groups.

DATA EXTRACTION

Survival curve data and items relevant to study validity and generalizability were independently extracted by 2 reviewers.

DATA SYNTHESIS

Time-to-event meta-analyses showed that the relative hazard for all-cause mortality in the first 3 months after hip fracture was 5.75 (95% CI, 4.94 to 6.67) in women and 7.95 (CI, 6.13 to 10.30) in men. Relative hazards decreased substantially over time but did not return to rates seen in age- and sex-matched control groups. Through use of life-table methods, investigators estimated that white women having a hip fracture at age 80 years have excess annual mortality compared with white women of the same age without a fracture of 8%, 11%, 18%, and 22% at 1, 2, 5, and 10 years after injury, respectively. Men with a hip fracture at age 80 years have excess annual mortality of 18%, 22%, 26%, and 20% at 1, 2, 5, and 10 years after injury, respectively.

LIMITATIONS

Cohort studies varied, sometimes markedly, in size, duration of observation, selection of control populations, ascertainment of death, and adjustment for comorbid conditions. Only published data that displayed findings with survival curves were examined. Publication bias was possible.

CONCLUSION

Older adults have a 5- to 8-fold increased risk for all-cause mortality during the first 3 months after hip fracture. Excess annual mortality persists over time for both women and men, but at any given age, excess annual mortality after hip fracture is higher in men than in women.

PRIMARY FUNDING SOURCE

Fund for Scientific Research and Willy Gepts Foundation, Universitair Ziekenhuis Brussel.

Hip and fragility fracture prediction by 4-item clinical risk score and mobile heel BMD: a women cohort study

Background

One in four Swedish women suffers a hip fracture yielding high morbidity and mortality. We wanted to revalidate a 4-item clinical risk score and evaluate a portable heel bone mineral density (BMD) technique regarding hip and fragility fracture risk among elderly women.

Methods

In a population-based prospective cohort study we used clinical risk factors from a baseline questionnaire and heel BMD to predict a two-year hip and fragility fracture outcome for women, in a fracture preventive program. Calcaneal heel BMD was measured by portable dual X-ray laser absorptiometry (DXL) and compared to hip BMD, measured with stationary dual X-ray absorptiometry (DXA) technique.

Results

Seven women suffered hip fracture and 14 women fragility fracture/s (at hip, radius, humerus and pelvis) among 285 women; 60% having heel BMD ≤ -2.5 SD. The 4-item FRAMO (Fracture and Mortality) Index combined the clinical risk factors age ≥80 years, weight <60 kg, prior fragility fracture, and impaired rise-up ability. Women having 2-4 risk factors showed odds ratio (OR) for hip fracture of 5.9 and fragility fracture of 4.4. High risk group hip fracture risk was 2.8% annually compared to 0.5% for the low risk majority (69%). Heel BMD showed hip fracture OR of 3.1 and fragility fracture OR of 2.6 per SD decrease. For 30 DXA assessed participants mean hip BMD at -2.5 SD level corresponded to a lower BMD at the heel. Five of seven hip fractures occurred within a small risk group of 32 women, identified by high FRAMO Index + prior fragility fracture + heel T-score ≤-3.5 SD.

Conclusions

In a follow-up study we identified high risk groups for hip and fragility fracture with our plain 4-item risk model. Increased fracture risk was also related to decreasing heel BMD in calcaneal bone, measured with a mobile DXL technique. A combination of high FRAMO Index, prior fragility fracture, and very low BMD restricted the high risk group to 11%, among whom most hip fractures occurred (71%). These practical screening methods could eventually reduce hip fracture incidence by concentrating preventive resources to high fracture risk women.

HIV and bone mineral density

PURPOSE OF REVIEW

This review details the clinical aspects and pathogenesis of low bone mineral density (BMD) in HIV, discusses broad management issues and outlines areas in which our understanding of this condition is incomplete.

RECENT FINDINGS

Low BMD is prevalent in HIV-infected patients, with traditional risk factors, HIV infection and exposure to antiretroviral therapy all contributing. The role of specific antiretrovirals in the development of low BMD remains controversial, but most changes arise at either antiretroviral therapy initiation or switch.

SUMMARY

Further research is needed to clarify mechanisms underlying low BMD in HIV, whether low BMD will translate to increased fractures and to determine the correct therapeutic approach to low BMD in HIV, particularly in younger HIV-infected patients.

Meta-analysis: excess mortality after hip fracture among older women and men

BACKGROUND

Although an increased risk for death after hip fracture is well established, whether this excess mortality persists over time is unclear.

PURPOSE

To determine the magnitude and duration of excess mortality after hip fracture in older men and women.

DATA SOURCES

Electronic search of MEDLINE and EMBASE for English and non-English articles from 1957 to May 2009 and manual search of article references.

STUDY SELECTION

Prospective cohort studies were selected by 2 independent reviewers. The studies had to assess mortality in women (22 cohorts) or men (17 cohorts) aged 50 years or older with hip fracture, carry out a life-table analysis, and display the survival curves of the hip fracture group and age- and sex-matched control groups.

DATA EXTRACTION

Survival curve data and items relevant to study validity and generalizability were independently extracted by 2 reviewers.

DATA SYNTHESIS

Time-to-event meta-analyses showed that the relative hazard for all-cause mortality in the first 3 months after hip fracture was 5.75 (95% CI, 4.94 to 6.67) in women and 7.95 (CI, 6.13 to 10.30) in men. Relative hazards decreased substantially over time but did not return to rates seen in age- and sex-matched control groups. Through use of life-table methods, investigators estimated that white women having a hip fracture at age 80 years have excess annual mortality compared with white women of the same age without a fracture of 8%, 11%, 18%, and 22% at 1, 2, 5, and 10 years after injury, respectively. Men with a hip fracture at age 80 years have excess annual mortality of 18%, 22%, 26%, and 20% at 1, 2, 5, and 10 years after injury, respectively.

LIMITATIONS

Cohort studies varied, sometimes markedly, in size, duration of observation, selection of control populations, ascertainment of death, and adjustment for comorbid conditions. Only published data that displayed findings with survival curves were examined. Publication bias was possible.

CONCLUSION

Older adults have a 5- to 8-fold increased risk for all-cause mortality during the first 3 months after hip fracture. Excess annual mortality persists over time for both women and men, but at any given age, excess annual mortality after hip fracture is higher in men than in women.

PRIMARY FUNDING SOURCE

Fund for Scientific Research and Willy Gepts Foundation, Universitair Ziekenhuis Brussel.

BMD, clinical risk factors and their combination for hip fracture prevention

SUMMARY

This study examined the effects of the use of clinical risk factors (CRFs) alone, BMD alone or the combination using the FRAX tool for the detection of women at risk of hip fracture. BMD tests alone selected women at higher risk and a greater number of hip fracture cases were identified compared to the use of CRFs alone. The combined use of CRFs and BMD identified fewer women above a threshold risk than the use of BMD alone, but with a higher hip fracture risk and thus had the more favourable positive predictive value (PPV) and number needed to treat (NNT).

INTRODUCTION

Algorithms have recently become available for the calculation of hip fracture probability from CRFs with and without information on femoral neck BMD. The aim of this study was to examine the effects of the use of CRFs alone, BMD alone or their combination using the FRAX tool for the detection of women at risk of hip fracture.

METHODS

Data from 10 prospective population based cohorts, in which BMD and CRFs were documented, were used to compute the 10-year probabilities of hip fracture calibrated to the fracture and death hazards of the UK. The effects of the use of BMD tests were examined in simulations where BMD tests were used alone, CRFs alone or their combined use. The base case examined the effects in women at the age of 65 years. The principal outcome measures were the number of women identified above an intervention threshold, the number of hip fracture cases that would be identified, the positive predicted value and the NNT to prevent a hip fracture during a hypothetical treatment with an effectiveness of 35% targeted to those above the threshold fracture risk. We also examined BMD values in women selected for treatment. Sensitivity analysis examined the effect of age and limited use of BMD resources.

RESULTS

BMD tests alone selected women at higher risk of hip fracture than the use of CRFs alone (6.1% versus 5.3%). BMD tests alone also identified a greater number of hip fracture cases (219/1,000) compared to the use of CRFs alone (140/1,000). The combined use of CRFs and BMD identified fewer women above a threshold risk than the use of BMD alone (168/1,000 versus 219/1,000, respectively), but with a higher hip fracture risk (PPV, 8.6% versus 6.1%), and consequently a lower number needed to treat (NNT) (33 versus 47). In sensitivity analyses, the PPV and NNT were always better for the combination than either BMD or CRFs alone across all ages studied (50-70 years).

CONCLUSIONS

The use of FRAX in combination with BMD increases the performance characteristics of fracture risk assessment.

Incorporating adherence into health economic modelling of osteoporosis

Osteoporosis medications are seldom taken according to the recommendations of health-care providers. A theoretical model was constructed to investigate the variables of drug adherence that affect the cost-effectiveness of drugs, using osteoporosis treatment as a model. Important variables were the magnitude of drug effect, drug price, and fracture-related costs.

INTRODUCTION

Adherence to anti-fracture medication is far from optimal and poses a challenge in osteoporosis management. The objectives of this study were to develop a model that could address adherence and identify the important drivers of cost-effectiveness.

METHODS

An individual state transition model was constructed to compare two theoretical medications, one of which conferred optimal adherence and was 50% more costly. Adherence was divided into persistence and compliance. Partial compliance was assumed to be associated with a 20% loss of anti-fracture effect. Non-persistent patients had an offset time as long as their time on medication, to a maximum of 5 years.

RESULTS

The potentially important drivers of cost-effectiveness include reduced drug effectiveness due to poor compliance, offset time, fracture risk, anti-fracture drug effect, and drug price. Optimal adherence was associated with fewer osteoporotic fractures, and the impact was more evident among those with prior fractures. However, the health benefits of adherence were often partially offset by increased intervention costs associated with the improved drug-taking behaviour.

CONCLUSIONS

High adherence is likely to be associated with added value for health-care systems, but should be used with care as a central health economic argument.

Use of anthropometric indicators in screening for undiagnosed vertebral fractures: a cross-sectional analysis of the Fukui Osteoporosis Cohort (FOC) study

Background

Vertebral fractures are the most common type of osteoporotic fracture. Although often asymptomatic, each vertebral fracture increases the risk of additional fractures. Development of a safe and simple screening method is necessary to identify individuals with asymptomatic vertebral fractures.

Methods

Lateral imaging of the spine by single energy X-ray absorptiometry and vertebral morphometry were conducted in 116 Japanese women (mean age: 69.9 ± 9.3 yr). Vertebral deformities were diagnosed by the McCloskey-Kanis criteria and were used as a proxy for vertebral fractures. We evaluated whether anthropometric parameters including arm span-height difference (AHD), wall-occiput distance (WOD), and rib-pelvis distance (RPD) were related to vertebral deformities. Positive findings were defined for AHD as ≥ 4.0 cm, for WOD as ≥ 5 mm, and for RPD as ≤ two fingerbreadths. Receiver operating characteristics curves analysis was performed, and cut-off values were determined to give maximum difference between sensitivity and false-positive rate. Expected probabilities for vertebral deformities were calculated using logistic regression analysis.

Results

The mean AHD for those participants with and without vertebral deformities were 7.0 ± 4.1 cm and 4.2 ± 4.2 cm (p < 0.01), respectively. Sensitivity and specificity for use of AHD-positive, WOD-positive and RPD-positive values in predicting vertebral deformities were 0.85 (95% CI: 0.69, 1.01) and 0.52 (95% CI: 0.42, 0.62); 0.70 (95% CI: 0.50, 0.90) and 0.67 (95% CI: 0.57, 0.76); and 0.67 (95% CI: 0.47, 0.87) and 0.59 (95% CI: 0.50, 0.69), respectively. The sensitivity, specificity, and likelihood ratio for a positive result (LR) for use of combined AHD-positive and WOD-positive values were 0.65 (95% CI: 0.44, 0.86), 0.81 (95% CI: 0.73, 0.89), and 3.47 (95% CI: 3.01, 3.99), respectively. The expected probability of vertebral deformities (P) was obtained by the equation; P = 1-(exp [-1.327-0.040 × body weight +1.332 × WOD-positive + 1.623 × AHD-positive])^-1. The sensitivity, specificity and LR for use of a 0.306 cut-off value for probability of vertebral fractures were 0.65 (95% CI: 0.44, 0.86), 0.87 (95% CI: 0.80, 0.93), and 4.82 (95% CI: 4.00, 5.77), respectively.

Conclusion

Both WOD and AHD effectively predicted vertebral deformities. This screening method could be used in a strategy to prevent additional vertebral fractures, even when X-ray technology is not available.

The cost-effectiveness of the treatment of high risk women with osteoporosis, hypertension and hyperlipidaemia in Sweden

This paper assessed the cost-effectiveness of the treatment of high risk women with osteoporosis, hypertension and hyperlipidaemia in Sweden, using one model and a societal perspective. Cost-effective scenarios were found in all these chronic disorders. These findings are of relevance for decisions on the efficient allocation of health care resources.

INTRODUCTION

There is a need to assess the cost-effectiveness (CE) of treatment of osteoporosis from a societal perspective and to relate this to the CE of interventions in other disease areas. This is of relevance for decisions on the efficient allocation of health care resources within and between disease areas. The purpose of the paper was to estimate the CE of the treatment and prevention of osteoporosis and to put that into the perspective of treating hypertension and hyperlipidaemia. The CE was assessed for different high risk female populations aged 50-80 years.

METHODS

The estimation of CE was based on a model populated with data for Sweden.

RESULTS

Compared to no intervention, a 5-year treatment of osteoporosis, hypertension, and hyperlipidaemia, is cost effective for most of the assessed high risk female populations. The cost per gained quality adjusted life year (QALY) for the treatment of a 70-year-old woman never exceeded SEK 330,000 (US$ 44,000), which is generally judged as an acceptable cost for a gained QALY.

CONCLUSIONS

The study demonstrates that it is possible to produce reliable estimates of the CE of treatments in different disease areas within the context of a single model.

FRAX and the assessment of fracture probability in men and women from the UK

A fracture risk assessment tool (FRAX) is developed based on the use of clinical risk factors with or without bone mineral density tests applied to the UK.

INTRODUCTION

The aim of this study was to apply an assessment tool for the prediction of fracture in men and women with the use of clinical risk factors (CRFs) for fracture with and without the use of femoral neck bone mineral density (BMD). The clinical risk factors, identified from previous meta-analyses, comprised body mass index (BMI, as a continuous variable), a prior history of fracture, a parental history of hip fracture, use of oral glucocorticoids, rheumatoid arthritis and other secondary causes of osteoporosis, current smoking, and alcohol intake 3 or more units daily.

METHODS

Four models were constructed to compute fracture probabilities based on the epidemiology of fracture in the UK. The models comprised the ten-year probability of hip fracture, with and without femoral neck BMD, and the ten-year probability of a major osteoporotic fracture, with and without BMD. For each model fracture and death hazards were computed as continuous functions.

RESULTS

Each clinical risk factor contributed to fracture probability. In the absence of BMD, hip fracture probability in women with a fixed BMI (25 kg/m(2)) ranged from 0.2% at the age of 50 years for women without CRF's to 22% at the age of 80 years with a parental history of hip fracture (approximately 100-fold range). In men, the probabilities were lower, as was the range (0.1 to 11% in the examples above). For a major osteoporotic fracture the probabilities ranged from 3.5% to 31% in women, and from 2.8% to 15% in men in the example above. The presence of one or more risk factors increased probabilities in an incremental manner. The differences in probabilities between men and women were comparable at any given T-score and age, except in the elderly where probabilities were higher in women than in men due to the higher mortality of the latter.

CONCLUSION

The models provide a framework which enhances the assessment of fracture risk in both men and women by the integration of clinical risk factors alone and/or in combination with BMD.

Cost effectiveness of hormone therapy in women at high risks of fracture in Sweden, the US and the UK--results based on the Women's Health Initiative randomised controlled trial

OBJECTIVE

The purpose of the study was to assess the cost effectiveness of hormone therapy (HT) for postmenopausal women without menopausal symptoms at an increased risk of fracture in Sweden, the UK and the US.

METHODS

Using a state-transition model, the cost effectiveness of 50 year old women was assessed based on a societal perspective and the medical evidence found in the Women Health Initiative (WHI) trials. The model had a lifetime horizon divided into cycle lengths of 1 year and comprised the following disease states: hip fracture, vertebral fracture, wrist fracture, breast cancer, colorectal cancer, coronary heart disease, stroke and venous thromboembolic events. An intervention was modelled by its impact on the disease risks during and after the cessation of treatment. The model required data on clinical effects, risks, mortality rates, quality of life weights and costs valid for Sweden, the UK and the US. The main outcome of the model was cost per QALY gained of HT compared to no treatment.

RESULTS

The results indicated that HT compared to no treatment was cost-effective for most sub-groups of hysterectomised women, whereas for women with an intact uterus without a previous fracture, HT was commonly dominated by no treatment. Fracture risks were the single most important determinant of the cost effectiveness results.

CONCLUSIONS

HT is cost-effective in women with a hysterectomy irrespective of prior fracture status. In women with an intact uterus, opposed HT was cost-effective in those with a prior vertebral fracture, but cost-ineffective in women without a prior vertebral fracture. Even though HT is found cost-effective for a selection of osteoporotic women, it is unlikely to be considered for first-line therapy for osteoporosis because bisphosphonates have shown a similar reduction in fracture risks but without an increased risk of adverse events.

T-plus Z-score in the assessment of relative fracture risk

THE OBJECTIVE OF THE STUDY: We aimed to prove that the relative risk of fractures (RR) is higher in women whose T- and Z-score values come under the category of increased risk than in the women whose T-score only falls within the category of increased risk.

PATIENTS AND METHODS

We analysed 498 (n=498) densitometric findings from the area of proximal femur: neck (ROI1), Ward's area (ROI2), great trochanter (ROI3) (DXA-dual energy X-ray absorptiometry, Osteocore II, France) from a population of Bratislava women of an average age of 59.71 years <58.63; 60.80>. Measured values of T- and Z-score were categorized as follows: 1--increased fracture risk (T-score<-2.5 SD/T=1, Z-score<or=-1.0 SD/Z=1), 0-without increased fracture risk (T-score>-2.5 SD/T=0, Z-score>-1.0 SD/Z=0).

RESULTS

RR for development of fracture was higher for all measurement sites (ROI(1)-29.87; ROI(2)-15.3; ROI(3)-5.5) for women having T-score<-2.5 SD and simultaneously Z-score<or=-1.0 SD than for the women having T-score<-2.5 SD and simultaneously Z-score>-1.0 SD. When the women were divided according to age into two groups, it was found that the RR of fracture for women<65 years having a T-score<-2.5 SD and also a Z-score<or=-1.0 SD is very high (RR=infinity), elderly women (>or=65 years) had a RR for ROI(1)-32.61, for ROI(2)-7.72, and for ROI(3)-6.9. The probability (P) of the presence of women with T-score values<-2.5 SD and Z-score<or=-1.0 SD in the group under 65 years for ROI1 was 12.5%; for ROI2 34.4%; for ROI3 20.5%, and the probability for women>or=65 years was for ROI1 75%; ROI2 98% and for ROI3 100%.

CONCLUSIONS

The study's contribution lies in the finding that the relative fracture risk of the proximal femur in women increases if the T-score is <-2.5 SD and, simultaneously, the Z-score<or=-1.0 SD, this risk is especially high for women under the age of 65. In assessing the individual fracture risk in female patients we recommend to add also Z-score values in the measured area to T-score values and to other anamnestic and biochemical risk factors.

The cost-effectiveness of alendronate in the management of osteoporosis

The National Institute for Health and Clinical Excellence (NICE) in the UK has recently issued health economic appraisals for the primary and secondary prevention of osteoporotic fracture that are more restrictive than previous guidelines for the management of osteoporosis despite a marked reduction of the cost of intervention. The aim of the present study was to examine the cost-effectiveness of the bisphosphonate, alendronate for the prevention and treatment of fractures associated with osteoporosis. A second aim was to investigate reasons for any disparities in cost-effectiveness between our findings and the NICE appraisals. We compared the effects of alendronate 70 mg weekly by mouth for 5 years with no treatment in postmenopausal women with clinical risk factors for fracture and computed the incremental cost-effectiveness ratio (ICER) using a lifetime simulation model based on Markov cohort methodology. A sensitivity analysis examined other common interventions. Using a threshold of pound sterling 30,000 and pound sterling 20,000 per quality of life-year (QALY) gained to determine cost-effectiveness, alendronate was cost-effective for the primary prevention of fracture in women with osteoporosis irrespective of age as was treatment of women with a prior fragility fracture irrespective of BMD. Cost-effective scenarios were also found in women with strong risk factors for fracture with a bone mineral density value above the threshold for osteoporosis. The results were robust over reasonable assumptions in sensitivity analysis. We conclude that alendronate is a cost-effective agent for the prevention and treatment of fractures associated with osteoporosis. These findings, suitable for informing practice guidance, contrast with recent appraisals from NICE.

Advances in the medical management of osteoporosis

Osteoporosis is a skeletal disorder characterised by compromised bone strength predisposing to increased risk of fracture, which is rapidly reaching epidemic proportions as the population ages. Many patients presenting with a fracture caused by a fall from standing height or less are not on any kind of therapy and many patients who sustain these fragility fractures are not started on therapy by their orthopaedic surgeon. In 2004, the United States Surgeon General released a report on osteoporosis recommending that physicians adopt a pyramidal approach to therapy. The base of the pyramid includes calcium, vitamin D, physical therapy and fall prevention. The second level calls for management or elimination of secondary causes of osteoporosis. The third level consists of treatment with either anti-resorptive or anabolic medications. The orthopaedic surgeon is in an ideal position to diagnose fragility fractures and suggest treatment in the hope of preventing future fractures. Anti-resorptive and anabolic therapies currently available are discussed.

Cost-effectiveness of alendronate in the treatment of postmenopausal women in 9 European countries--an economic evaluation based on the fracture intervention trial

Treatment with alendronate (Fosamax) has been shown to significantly reduce the risk of fragility fractures. Cost-effectiveness of treatment was assessed in nine European countries in a Markov model and was generally found to be cost effective in women with a previous spine fracture.

INTRODUCTION

Treatment with alendronate (Fosamax) reduces the risk of osteoporotic fractures at the spine, hip and wrist in women with and without prevalent vertebral fracture. Cost-effectiveness estimates in one country may not be applicable elsewhere due to differences in fracture risks, costs and drug prices. The aim of this study was to assess the cost-effectiveness of treating postmenopausal women with alendronate in nine European countries, comprising Belgium, Denmark, France, Germany, Italy, Norway, Spain, Sweden, and the UK.

METHODS

A Markov model was populated with data for the nine European populations. Effect of treatment was taken from the Fracture Intervention Trial, which recruited women with low BMD alone or with a prior vertebral fracture.

RESULTS

The cost per QALY gained of treating postmenopausal women with prior vertebral fractures ranged in the base case from "cost saving" in the Scandinavian countries to <euro>15,000 in Italy. Corresponding estimates for women without prior vertebral fractures ranged from "cost saving" to <euro>40,000.

CONCLUSIONS

In relation to thresholds generally used, the analysis suggests that alendronate is very cost effective in the treatment of women with previous vertebral fracture, and in women without previous vertebral fracture, cost-effectiveness depends on the country setting, discount rates, and chosen monetary thresholds.

Ten-year risk of osteoporotic fractures in postmenopausal Chinese women according to clinical risk factors and BMD T-scores: a prospective study

Independent risk factors for osteoporotic fracture were identified for a Southern Chinese postmenopausal population. Clinical risk factor assessment with or without BMD measurement was shown to be an effective predictor of 10-yr risk of osteoporotic fracture and provides a more accessible tool for patient evaluation.

INTRODUCTION

Asian-specific data on risk factors for osteoporosis remain sparse. However, risk factor assessment, in addition to BMD measurement, is increasingly recognized as a reliable predictor of absolute osteoporotic fracture risk. The purpose of this prospective study was to determine the specific independent risk factors for osteoporotic fracture and to predict the 10-yr risk of osteoporotic fracture in the postmenopausal Southern Chinese population.

MATERIALS AND METHODS

A total of 1435 community-dwelling, postmenopausal, treatment-naive women were recruited. Baseline demographic characteristics and clinical risk factors were obtained, and BMD at the spine and hip was measured. Subjects were followed for outcomes of incident low trauma fracture. Ten-year risk of osteoporotic fracture was predicted from the risk factor assessment and BMD measurement by Cox proportional hazards models.

RESULTS

The mean age of subjects was 63.4 +/- 8.3 yr. After 5.0 +/- 2.3 yr (range, 1.0-11.0 yr) of follow-up, 80 nontraumatic new fractures were reported during follow-up. Eight independent clinical risk factors identified at baseline were found to be significant predictors of osteoporotic fracture, with the most important being use of walking aids (RR, 4.2; 95% CI, 2.7-6.7; p < 0.001) and a history of fall (RR, 4.0; 95% CI, 2.5-6.2; p < 0.001). Other predictive factors included being homebound, calcium intake < 400 mg/d, age > 65 yr, history of fracture, and BMI < 19 kg/cm(2). Subjects with three to eight clinical risk factors had a predicted 10-year risk of osteoporotic fracture of 25%, which increased to 30% if they also had total hip BMD T-score <or= -2.5.

CONCLUSIONS

Clinical risk factor assessment, with or without BMD measurement, is a reliable predictor of 10-year risk of osteoporotic fracture and may be particularly useful in regions or primary care clinics without access to bone densitometry equipment.

Absolute fracture risk

Clinical evaluation of patients with low bone mass attempts to determine which patients should be offered one of the effective therapies for fracture prevention. Current guidelines are primarily based on bone density. Risk factors are used, but their contribution to fracture risk is not easily assessed. The combination of bone density and risk factors can be used to assess absolute fracture risk, the risk of fracture over a period of time expressed as a percent. This model will allow identification of patients who would benefit most from treatment.

Changes to osteoporosis prevalence according to method of risk assessment

The impact of clinical risk factor-based absolute risk methods on the prevalence of high risk for osteoporotic fracture is unknown. We applied absolute risk methods to 6646 subjects and found that the prevalence of elderly women deemed to be at high risk increased substantially, whereas the overall prevalence was highly dependent on the threshold used to designate high risk.

INTRODUCTION

Many groups have advocated using absolute risk methods that incorporate clinical risk factors to target patients for osteoporosis therapy. We examined how the application of such absolute risk classification systems influences the prevalence of those considered to be at high risk for osteoporotic fracture and compared these systems to one based solely on BMD.

MATERIALS AND METHODS

Using 6646 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, randomly selected, population-based cohort, we assessed three different systems for determining prevalence of high risk for osteoporotic fracture: a BMD-based system; a simplified risk factor system incorporating age, sex, BMD, and two clinical risk factors; and a comprehensive system, incorporating age, sex, BMD, and seven clinical risk factors. The 10-year absolute risks of incident fragility fracture were compared across systems using three different high-risk thresholds.

RESULTS

The prevalence of a T score < or = -2.5 was 18.8% (95% CI: 17.7-19.9%) in women and 3.9% (95% CI: 3.0-4.7%) in men. Using a 15% 10-year risk of fracture threshold, the prevalence of women at high risk increased to 46.9% (95% CI: 45.4-48.4) and 42.5% (95% CI: 41.1-43.9) when the comprehensive and simplified risk factor classification systems were used, respectively. Using a 25% 10-year absolute risk threshold, the prevalence of high risk was similar to that of the BMD-based system, whereas the 20% threshold gave intermediate rates. All thresholds analyzed resulted in an increased prevalence of older women at high risk for fracture, whereas only the 15% 10-year risk of fracture threshold resulted in an increase in the prevalence of men at high risk.

CONCLUSIONS

The application of risk factor-based systems results in an increased prevalence of older women at high risk. The prevalence of individuals at high risk may increase with changes to the methods used to determine those who are eligible for therapy. These data have important implications for the pattern of care and costs of treating osteoporotic fractures.