Population-based Canadian hip fracture rates with international comparisons

Fracture Risk Assessment in the 2023 Osteoporosis Canada Guideline

Radiologists and other diagnostic imaging specialists play a pivotal role in the management of osteoporosis, a highly prevalent condition of reduced bone strength and increased fracture risk. Bone mineral density (BMD) measurement with dual-energy X-ray absorptiometry (DXA) is a critical component of identifying individuals at high risk for fracture. Strategies to prevent fractures are consolidated in the Osteoporosis Canada clinical practice guideline which was updated in 2023. In this guideline, treatment recommendations are based upon a consideration of fracture history, 10-year major osteoporotic fracture (MOF) risk, and BMD T-score in conjunction with age. The current review aims to familiarize radiologists and other diagnostic imaging specialists with the reporting requirements needed to support implementation of this guideline using the FRAX™ risk calculation tool. Fortunately, for specialists already familiar with the Canadian Association of Radiologists and Osteoporosis Canada (CAROC) tool, the transition to FRAX-based reporting is readily accommodated in a radiology workflow.

Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women

BACKGROUND

Although it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear.

METHODS

A total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck.

RESULTS

Compared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased.

CONCLUSION

These results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

Effects of Muscles on Bone Metabolism—with a Focus on Myokines

Skeletal muscles and bones, the largest tissues in the body of a non-obese person, comprise the musculoskeletal system, which allows mobility and protects internal organs. Although muscles and bones are closely related throughout life, observations during development and aging and in human and animal disuse models have revealed the synchronization of tissue mass such that muscle phenotype changes precede alterations in bone mineral density and strength. This review discussed that mechanical forces, which have been the traditional research focus, are not the only mechanism by which muscle-derived signals may affect bone metabolism and emphasized the significance of skeletal muscles as an endocrine organ that secretes bone-regulatory factors. Consequently, both mechanical and biochemical aspects should be considered to fully understand muscle–bone crosstalk. This review also suggested that specific myokines could be ideal therapeutic targets for osteoporosis to both increase bone formation and reduce bone resorption; moreover, these myokines could also be potential circulating biomarkers to predict musculoskeletal health.

Comparison of femoral neck geometric parameters between Chinese and Japanese females

OBJECTIVES

Femoral neck fracture is the most serious osteoporotic fractures that is responsible for high medical costs and high mortality. Femoral neck geometric parameters (FNGPs) are important parameters that reflect the geometrical characteristics of femoral neck, and are closely related to the strength of femoral neck and the risk of fragility fracture.There are differences in the incidence of femoral neck fractures among races. However, whether there is difference in FNGPs among races is unknown.Therefore, this study aims to compare the differences in FNGPs between Chinese and Japanese females.

METHODS

This study was a cross-sectional study, in which 3 859 healthy females aged 10-86 (45.7±17.1) years old were recruited from Changsha City of Hunan Province and surrounding areas. The weight and height were measured and recorded, and the body mass index (BMI) was calculated. A dual energy X-ray absorptiometry (DXA) bone densitometer was used to measure femoral neck projective bone area (BA) and bone mineral density (BMD). FNGPs were calculated using the BMD and BA, which included the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compression strength index (CSI). The data of FNGPs in Japanese females was collected from literature. These subjects were grouped by 10-year age. The mean and standard deviation of height, weight, BMI, femoral neck BMD, and FNGPs of each group were calculated. The model with the best goodness-of-fit was selected from various mathematical regression models to analyze the distribution trend and the best fitting curve of FNGPs with age. The differences in FNGPs between Chinese and Japanese females were analyzed by using age-corresponding mean fitting curve for paired t-test, and the relative change rates of FNGPs were compared.

RESULTS

The mean values of FNGPs were significantly different among different years old healthy females (all P<0.01). The mean values of OD, CSA, CT, SM, and CSMI in femoral neck were high at 30 to 39 years old, and then they were gradually decreased with age. The CSI reached its peak at 20-29 years old, and it was decreased gradually after 30 years old. ED and BR were at a low level before 40 years old, they were gradually increased after 40 years old, and reached the maximum average value at 80-86 years old. The variations in FNGPs with age were fitted with the best goodness-of-fit by applying the cubic regression model and the determination coefficients of regression equations (R2: 0.062-0.404) were significant (all P<0.01). The distribution trend of FNGPs with age varied with the indices, among which CSA, CT, SM, CSMI and CSI were increased with age before 35 years old, and then they were decreased with age; BR was at a low level in the early stage, and then it was increased with age after about 40 years. There were significant differences in the fitting curves of FNGPs related to age between Chinese and Japanese females (all P<0.01). The fitting curves of OD, ED, BR and SM in Chinese females were significantly higher than those in Japanese females (all P<0.01), while those of CSA and CT in Chinese females were significantly lower than those in Japanese females (all P<0.01). Before the age of 50, the curves of CSMI and CSI of Chinese females were significantly higher than those of Japanese females (all P<0.01), while after the age of 60 the situation was reversed (all P<0.01). Except for SM and CSI, there were significant differences in the rate of OD, CSA, CT, ED, BR and CSMI with age (all P<0.01). By the age of 80 years old, the rates of change in OD, ED, and BR with the age in Chinese females were increased by 0.91%,3.94%, and 47.5%, respectively, while those in Japanese females were increased by 8.57%, 15.8% and 85.3%, respectively；the rates of change of CSA, CT, and CSMI with the age in Chinese females were declined 28.0%, 29.6%, and 25.2%, respectively, while those in Japanese females were declined 29.9%, 36.2%, and 10.9%, respectively. There were significant difference in the rates of change in FNGPs with the age between Chinese and Japanese females (all P<0.01).

CONCLUSIONS

The study reveals the variation of FNGPs with age in Chinese, and confirms that there are racial differences in FNGPs between Chinese and Japanese females, which may be one of the important reasons for the difference in the incidence of femoral neck fracture between Chinese and Japanese females.

Higher latitude and lower solar radiation influence on hip fracture admissions in Chilean older population

Data linking solar radiation with fractures are lacking. We found that lower solar radiation was associated with higher hip fracture admission rates in men from Chile. This supports the idea that solar radiation, a surrogate of vitamin D, may be involved in the development of fractures in older population. INTRODUCTION : To explore the associations between solar radiation and latitude with hip fracture admission rates in people aged 65 years or older in Chile, the country with the greatest variation in solar radiation in the world.

METHODS

In this ecological study, we investigated the associations between regional solar radiation and latitude with hospitalizations due to hip fracture in population aged 65 years or older, by reviewing national records between 2013 and 2018. We also evaluated the role of sociodemographic factors such as poverty, education, indigenous ethnicity, and rurality rates.

RESULTS

Between 2013 and 2018, there were 44,328 admissions due to hip fracture in people aged 65 years or older; 77.5% were women and 65.1% were aged 80 years or older. The national admission rate was 389.3 per 100,000 inhabitants (95% CI: 382.4-396.2). The highest admission rate was registered in the Region IX (445.3 per 100,000, 95% CI: 398.3-492.4), which has the highest poverty rates, indigenous ethnicity rates, and rurality rates. We found a north-south increasing gradient of admission rates in men (β=1.5 [95% CI: 0 to 3], p=0.044) and a significant association between solar radiation and admission rates in men (β=-4.4 [95% CI: -8 to 0.8], p=0.02). Admission rates in men were also associated with sociodemographic variables such as poverty (β=2.4 [95% CI: 0 to 4.8], p=0.048) and rurality rates (β=1.2 [95% CI: 0.1 to 2.4], p=0.039).

CONCLUSION

Regional solar radiation and latitude were associated with hip fracture admission rates in men aged 65 years or older in Chile, with highest admission rates at higher latitudes and lower solar radiation.

Relationship between bone mineral density and fragility fracture risk: a case-control study in Changsha, China

Background

Fragility fracture is associated with bone mineral density (BMD), and most databases used in related researches are instrument-matched. Little is known about the relationship between BMD and fragility fracture risk of native Chinese, especially using local databases as reference databases.

Objective

To investigate relationship between BMD and risk of fragility fracture in native China.

Methods

3,324 cases, including 2,423 women (67.7 ± 8.9 years) and 901 men (68.4 ± 11.6 years) having radiological fragility fractures and 3,324 age- and gender-matched controls participated in the study. We measured BMD at posteroanterior spine and hip using dual-energy X-ray absorptiometry (DXA), calculated BMD measurement parameters based on our own BMD reference database.

Results

BMDs and mean T-scores were lower in case group (with clinical fragility) than in control group (without clinical fragility). In patients with fragility fractures, prevalence of lumbar osteoporosis, low bone mass, and normal BMD were 78.9 %, 19.3 %, and 1.8 %, respectively, in women, and 49.5, 44.8 %, and 5.7 %, respectively, in men. In hip, these prevalence rates were 67.2 %, 28.4 %, and 4.4 % in females, and 43.2 %, 45.9 %, and 10.9 % in males, respectively, showing differences between females and males. Multivariate Cox regression analysis showed that after adjusting age, height, weight, and body mass index, fracture hazard ratio (HR) increased by 2.7–2.8 times (95 % CI 2.5–3.1) and 3.6–4.1 times (95 %CI 3.0–5.1) for women and men respectively with decreasing BMD parameters. In both sexes, risk of fragility fracture increased approximately 1.6–1.7 times (95 % CI 1.5–1.8) for every 1 T-score reduction in BMD.

Conclusions

Risk of clinical fragility fracture increases with decreasing BMD measurement parameters and anthropometric indicators in native China, and fracture HR varies from gender and site.

Preoperative nerve blocks for hip fracture patients: A pilot randomized trial

PURPOSE

To determine the: 1) impact of pre-operative femoral nerve block(PreopFNB) on: a) pain; b) opioid use; and c) early post-operative mobilization relative to usual care(CONTROL) and 2) feasibility of a definitive randomized clinical trial(RCT).

METHODS

This pilot RCT, performed in a Canadian tertiary center, compared PreopFNB to CONTROL in 73 participants aged ≥65 years, who a) were ambulatory pre-hip fracture, b) had Mini Mental Status Examination(MMSE) score ≥13 and c) provided consent(direct/proxy). Participants were randomized to PreopFNB or CONTROL using 2 PreopFNB:1 CONTROL(48 PreopFNB:25 CONTROL) allocation. Pain, opioid use and early post-operative mobilization were compared between groups. Inclusion of those with cognitive impairment and PFNB treatment fidelity were also assessed.

RESULTS

The PreopFNB group was slightly older than CONTROL(mean ±SD: 79.9 ± 8.9 versus 76.8 ± 9.0; p = 0.15) with more males(21[42%] versus 5[22%]; p = 0.04). The overall mean MMSE score was ≥24. Mean pain scores were not significantly different between groups at rest(p = 0.17), with activity(p = 0.21) or non-verbal assessment(p = 0.79). Opioid use(oral morphine equivalents) was non-significantly higher and more variable in CONTROL than PreopFNB pre-operatively(Median [25,75 quartiles] 13.1[0,398] versus 7.5[0,125]) and post-operatively(15.0[0,950] versus 10.0[0,260])(p = 0.28). On day 1 post-operative, 40(87%) PFNB and 17(71%) CONTROL participants mobilized(p = 0.10).

CONCLUSION

We found similar reported pain between groups. Although not significant, opioid use was higher and more variable in CONTROL and more PreopFNB patients mobilized day 1 post-operatively. Participants with cognitive impairment were not frequently enrolled. With modification, a definitive RCT is feasible and would inform pain management after hip fracture.

Fragility fracture identifies patients at imminent risk for subsequent fracture: real-world retrospective database study in Ontario, Canada

BACKGROUND

The secondary fracture prevention gap in the osteoporosis field has been previously described as a 'crisis'. Closing this gap is increasingly important in the context of accumulating evidence showing that an incident fragility fracture is associated with an increased risk of subsequent fracture within 1-2 years, known as imminent fracture risk. The objective of this study was to use health services data to characterize the time between index fragility fractures occurring at different osteoporotic sites and subsequent fractures.

METHODS

This retrospective observational study used de-identified health services data from the publicly funded healthcare system in Ontario, the largest province of Canada. Patients aged > 65 with an index fragility fracture occurring between 2011 and 2015 were identified from the ICES Data Repository using International Classification of Diseases (ICD)-10 codes. We examined median time to subsequent fragility fractures for osteoporotic fracture sites until the end of follow-up (2017). BMD assessment and use of osteoporosis therapies following index fracture were also characterized.

RESULTS

Among 115,776 patients with an index fragility fracture, 17.8% incurred a second fragility fracture. Median time between index and second fracture occurring at any site was 555 days (interquartile range: 236-955). For each index fracture site examined, median time from index to second fracture was < 2 years. The proportion of patients with BMD assessment was 10.3% ≤1 year prior to and 16.4% ≤1 year post index fracture. The proportion of patients receiving osteoporosis therapy was 29.8% ≤1 year prior, 34.6% ≤1 year post, and 25.9% > 3 years post index fracture.

CONCLUSIONS

This cohort of Canadian patients aged > 65 years who experienced a fragility fracture at any site are at imminent risk of experiencing subsequent fracture within the next 2 years and should be proactively assessed and treated.

A scorecard for osteoporosis in Canada and seven Canadian provinces

The scorecard evaluates the burden and management of osteoporosis in Canada and how care pathways differ across Canadian provinces. The results showed there are inequities in patients' access to diagnosis, treatment, and post-fracture care programs in Canada. Interventions are needed to close the osteoporosis treatment gap and minimize these inequities.

INTRODUCTION

The purpose of this study was to develop a visual scorecard that assesses the burden of osteoporosis and its management within Canada and seven Canadian provinces.

METHODS

We adapted the Scorecard for Osteoporosis in Europe (SCOPE) to score osteoporosis indicators for Canada and seven provinces (British Columbia, Alberta, Saskatchewan, Ontario, Quebec, New Brunswick, and Newfoundland). We obtained data from a comprehensive literature review and interviews with osteoporosis experts. We scored 20 elements across four domains: burden of disease, policy framework, service provision, and service uptake. Each element was scored as red, yellow, or green, indicating high, intermediate, or low risk, respectively. Elements with insufficient data were scored black.

RESULTS

Canada performed well on several elements of osteoporosis care, including high uptake of risk assessment algorithms and minimal wait times for hip fracture surgery. However, there were no established fracture registries, and reporting on individuals with high fracture risk who remain untreated was limited. Furthermore, osteoporosis was not an official health priority in most provinces. Government-backed action plans and other osteoporosis initiatives were primarily confined to Ontario and Alberta. Several provinces (Saskatchewan, New Brunswick, Newfoundland) did not have any registered fracture liaison service (FLS) programs. Access to diagnosis and treatment was also inconsistent and reimbursement policies did not align with clinical guidelines.

CONCLUSION

Government-backed action plans are needed to address provincial inequities in patients' access to diagnosis, treatment, and FLS programs in Canada. Further characterization of the treatment gap and the establishment of fracture registries are critical next steps in providing high-quality osteoporosis care.

3D Analysis of the Proximal Femur Compared to 2D Analysis for Hip Fracture Risk Prediction in a Clinical Population

Due to the adverse impacts of hip fractures on patients' lives, it is crucial to enhance the identification of people at high risk through accessible clinical techniques. Reconstructing the 3D geometry and BMD distribution of the proximal femur could be beneficial in enhancing hip fracture risk predictions; however, it is associated with a high computational burden. It is also not clear whether it provides a better performance than 2D model analysis. Therefore, the purpose of this study was to compare the 2D and 3D model reconstruction's ability to predict hip fracture risk in a clinical population of patients. The DXA scans and CT scans of 16 cadaveric femurs were used to create training sets for the 2D and 3D model reconstruction based on statistical shape and appearance modeling. Subsequently, these methods were used to predict the risk of sustaining a hip fracture in a clinical population of 150 subjects (50 fractured, and 100 non-fractured) that were monitored for five years in the Canadian Multicentre Osteoporosis Study. 3D model reconstruction was able to improve the identification of patients who sustained a hip fracture more accurately than the standard clinical practice (by 40%). Also, the predictions from the 2D statistical model didn't differ significantly from the 3D ones (p > 0.76). These results indicated that to enhance hip fracture risk prediction in clinical practice implementing 2D statistical modeling has comparable performance with lower associated computational load.

Advanced 2D image processing technique to predict hip fracture risk in an older population based on single DXA scans

A new technique to enhance hip fracture risk prediction in older adults was presented and assessed. The new method dramatically improved prediction at high specificity levels using only a standard clinical diagnostic scan. This has the potential to be implemented in clinical practice to enhance patient fragility diagnosis.

INTRODUCTION

Diagnosis of osteoporosis is based on the measurement of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) scans. However, studies have shown this to be insufficient to accurately predict hip fractures. Therefore, complementary methods are needed to enhance hip fracture risk prediction to identify vulnerable patients.

METHODS

Hip DXA scans were obtained for 192 subjects from the Canadian Multicenter Osteoporosis Study (CaMos), 50 of whom had experienced a hip fracture within 5 years of the scan. 2D statistical shape and appearance modeling was performed to account for the effect of the femur's geometry and BMD distribution on hip fracture risk. Statistical shape modeling (SSM), and statistical appearance modeling (SAM) were also used separately to predict the fracture risk based solely on the femur's geometry and BMD distribution, respectively. Combined with BMD, age, and body mass index (BMI), logistic regression was performed to estimate the fracture risk over the 5-year period.

RESULTS

Using the new technique, hip fractures were correctly predicted in 78% of cases compared with 36% when using the T-score. The accuracy of the prediction was not greatly reduced when using SSM and SAM (78% and 74% correct, respectively). Various geometric and BMD distribution traits were identified in the fractured and non-fractured groups.

CONCLUSION

2D SSAM can dramatically improve hip fracture prediction at high specificity levels and estimate the year of the impending fracture using standard clinical images. This has the potential to be implemented in clinical practice to estimate hip fracture risk.

Geographic variations in hip fracture incidence in a high-risk country stretching into the Arctic: a NOREPOS study

There are geographic variations in hip fracture incidence rates across Norway, with a lower incidence in the coastal areas of the southwest and in the Arctic north, contrary to what may be expected with regard to vitamin D exposure from sunlight. The regional differences have become smaller in recent years.

INTRODUCTION

To investigate geographic variation in hip fracture incidence within Norway and regional differences in time trends.

METHODS

All hip fractures treated in Norwegian hospitals 2002-2013 were included, and demographic information was obtained from Statistics Norway. Age-standardized incidence rates were calculated separately for 19 counties. Incidence rate ratios with 95% confidence intervals for county differences and time trends were estimated using Poisson regression.

RESULTS

Age-standardized number of hip fractures per 10,000 person-years varied between counties from 69 to 84 in women and from 34 to 41 in men. The highest rates were observed in the southeastern capital city of Oslo, while rates were low in the four northernmost counties. There was an east-west gradient, with lower incidence in the coastal southwest compared with the southeast. Women showed a statistically significant decline during 2002-2013 in almost all counties (up to 31%). In men, only a few counties showed a decline. In both genders, hip fracture rates at age 80 in the combined five counties with the highest rates were significantly higher than in the combined five counties with the lowest rates across the period, although the trends converged over time.

CONCLUSIONS

In Norway, the hip fracture incidence was lower in the north compared with the south. In addition, we observed an east-west gradient with the highest incidence in the southeast and lower incidence in the coastal southwest. While there has been an overall declining trend in hip fracture incidence over time, regional differences are still apparent.

Detection and localisation of hip fractures on anteroposterior radiographs with artificial intelligence: proof of concept

AIM

To investigate the feasibility of applying a deep convolutional neural network (CNN) for detection/localisation of acute proximal femoral fractures (APFFs) on hip radiographs.

MATERIALS AND METHODS

This study had institutional review board approval. Radiographs of 307 patients with APFFs and 310 normal patients were identified. A split ratio of 3/1/1 was used to create training, validation, and test datasets. To test the validity of the proposed model, a 20-fold cross-validation was performed. The anonymised images from the test cohort were shown to two groups of radiologists: musculoskeletal radiologists and diagnostic radiology residents. Each reader was asked to assess if there was a fracture and localise it if one was detected. The area under the receiver operator characteristics curve (AUC), sensitivity, and specificity were calculated for the CNN and readers.

RESULTS

The mean AUC was 0.9944 with a standard deviation of 0.0036. Mean sensitivity and specificity for fracture detection was 97.1% (81.5/84) and 96.7% (118/122), respectively. There was good concordance with saliency maps for lesion identification, but sensitivity was lower for characterising location (subcapital/transcervical, 84.1%; basicervical/intertrochanteric, 77%; subtrochanteric, 20%). Musculoskeletal radiologists showed a sensitivity and specificity for fracture detection of 100% and 100% respectively, while residents showed 100% and 96.8%, respectively. For fracture localisation, the performance decreased slightly for human readers.

CONCLUSION

The proposed CNN algorithm showed high accuracy for detection of APFFs, but the performance was lower for fracture localisation. Overall performance of the CNN was lower than that of radiologists, especially in localizing fracture location.

Incidence, risk factors and economic burden of fall-related injuries in older Chinese people: a systematic review

OBJECTIVE

China's population is ageing and fall-related injury in older Chinese people is a growing public health concern. This review aims to synthesise existing evidence on the incidence, risk factors and economic burden of fall-related injury among older Chinese people to inform health service planning.

METHODS

A systematic search of literature on falls and injury among older people living in China was performed in six electronic databases including both English and Chinese databases. Results were combined using narrative synthesis due to the heterogeneity of included studies.

RESULTS

A total of 93 studies from Mainland China, Taiwan and Hong Kong were included in this review. Most of these studies were descriptive; 82 reported the incidence of fall-related injury among older Chinese people, 7 studies examined the risk factors for fall-related injury and 22 studies described the economic burden of fall-related injury. The incidence of fall-related injury reported among older Chinese people ranged from 0.6% to 19.5%. Risk factors significantly associated with fall-related injury among older Chinese included older age, female sex, walking aid use, living environments, chronic disease, medication usage, visual impairment and a fall direction other than forward. The cost of fall-related injury among older Chinese people ranged from US$16 to US$3812 per person per fall.

CONCLUSION

Falls-related injuries are a significant public health issue for older Chinese people. Further studies using prospective design to identify risk factors and the economic burden of fall-related injuries are needed.

Assessment of hip fracture risk by cross-sectional strain-energy derived from image-based beam model

BACKGROUND

Clinicians have been looking for a simple and effective biomechanical tool for the assessment of hip fracture risk. Dual-energy X-ray absorptiometry (DXA) is currently the primary bone imaging modality in clinic, and the engineering beam is the simplest model for a mechanical analysis. Therefore, we developed a DXA-based beam model for the above purpose.

METHODS

A beam model of the proximal femur was constructed from the subject's hip DXA image and denoted DXA-beam. Femur stiffness was calculated at cross-sections of interest using areal bone-mineral-density profile. Impact force induced in a sideways fall was applied as a critical loading. Fracture risk index at a cross-section was defined as the ratio of strain-energy induced by the impact force to the allowable strain-energy. A clinic cohort was used to study the discriminability of DXA-beam, which was measured by the area under the curve and odds ratio, both with 95% confidential interval.

FINDINGS

Fracture risk measured by DXA-beam model at the femoral neck [odds ratio 2.23, 95% confidence interval (1.83, 2.57)], inter-trochanter [2.49, (2.14, 3.25)] and sub-trochanter [2.82, (2.38, 3.51)] were strongly associated with hip fracture. The area under the curve by DXA-beam at the femoral neck [0.74, 95% confidence interval (0.70, 0.76)], inter-trochanter [0.77, (0.75, 0.82)] and sub-trochanter [0.76, (0.74, 0.81)] were higher than that by femoral neck bone mineral density [0.71, (0.65, 0.78)].

INTERPRETATION

The DXA-beam model is a simple and yet effective mechanical model. It had promising performance in discrimination of fracture cases from controls.

Medical Costs of Delayed Hip Fracture Surgery

BACKGROUND

Waiting for hip fracture surgery is associated with complications. The objective of this study was to determine whether waiting for hip fracture surgery is associated with health-care costs.

METHODS

We conducted a population-based, propensity-matched cohort study of patients treated between 2009 and 2014 in Ontario, Canada. The primary exposure was early hip fracture surgery, performed within 24 hours after arrival at the emergency department. The primary outcome was direct medical costs, estimated for each patient in 2013 Canadian dollars, from the payer perspective. The costs in the early and delayed groups were then compared using a difference-in-differences approach: the baseline cost in the year prior to the hip fracture that had been accrued by patients with early surgery was subtracted from the cost in the first year following the surgery (first difference), and the difference was then compared with the same difference among propensity-score-matched patients who had received delayed surgery (second difference). The secondary outcome was the postoperative length of stay (in days).

RESULTS

The study included 42,230 patients who received hip fracture surgery from a total of 522 different surgeons at 72 hospitals. The mean cost (and standard deviation) attributed to the hip fracture was $39,497 ± $46,645 per person. The matched patients who underwent surgery after 24 hours had direct 1-year medical costs that were an average of $2,638 higher (95% confidence interval [CI] = $1,595 to $3,680, p < 0.0001) and a postoperative length of stay that was an average of 0.610 day longer (95% CI = 0.1749 to 1.0331 days, p = 0.0058) compared with those who underwent surgery within 24 hours.

CONCLUSIONS

Waiting >24 hours for hip fracture surgery was associated with increased medical costs and length of stay. Costs incurred by waiting may provide a financial incentive to mitigate delays in hip fracture surgery.

LEVEL OF EVIDENCE

Economic Level III. Please see Instructions for Authors for a complete description of levels of evidence.

In which patients does lumbar spine trabecular bone score (TBS) have the largest effect?

BACKGROUND

Lumbar spine TBS, a texture index derived from lumbar spine dual-energy x-ray absorptiometry (DXA) images, enhances fracture prediction. No studies to date have studied a broad range of clinical variables to determine which patients might experience the greatest benefit from the use of TBS.

METHODS

Using the Manitoba BMD Registry, we identified 37,176 subjects with baseline DXA, FRAX®-based fracture probability, lumbar spine TBS, and minimum 5 years of observation. Subgroups considered were based on sex, age, body mass index (BMI), prior fracture, chronic obstructive lung disease (COPD), high alcohol use, rheumatoid arthritis (RA), high glucocorticoid use, osteoporotic femoral neck T-score, number of comorbidities, diabetes, secondary osteoporosis, and prior osteoporosis treatment. Non-traumatic major osteoporotic fractures (MOF, n = 3741) and hip fractures (HF, n = 1008) were identified using population-based health services data. We analyzed baseline TBS using analysis of covariance (ANCOVA). FRAX-adjusted hazard ratios (HR) per SD reduction in TBS were estimated and tested for interactions. Categorical net reclassification improvement (NRI) was estimated using fixed FRAX-based intervention cut-offs.

RESULTS

Adjusted baseline TBS was significantly lower (p ≤ 0.001) for women (-4.2%), osteoporotic hip T-score (-4.0%), COPD (-2.8%), diabetes (-2.6%), high alcohol use (-2.3%), prior fracture (-2.2%), glucocorticoid use (-1.5%), RA (-0.9%) and secondary osteoporosis (-0.8%), whereas recent osteoporosis therapy was associated with greater TBS (+1.5%). HRs per SD reduction in TBS for fracture prediction were larger for age < 65 vs 65+ (MOF p-interaction = 0.004, HF p-interaction < 0.001), without vs with prior fracture (MOF p-interaction = 0.003, HF p-interaction = 0.048), without vs with glucocorticoid use (HF p-interaction = 0.029), lower vs higher comorbidity score (HF p-interaction < 0.001), and without vs with osteoporosis treatment (MOF p-interaction = 0.005). NRI for using the TBS adjustment to FRAX in all subjects was 1.2% for MOF (p = 0.002) and 1.7% for HF (p = 0.016). NRI was greater in subjects age < 65 y (MOF:1.7%, HF:5.6%), no prior fracture (HF: 2.4%), non-osteoporotic T-score (HF: 3.0%), and high glucocorticoid use (MOF: 3.9%).

CONCLUSION

TBS is sensitive to the effects of multiple risk factors for fracture. TBS-adjusted fracture risk assessment resulted in significant improvements for multiple subgroups.

Association Between Wait Time and 30-Day Mortality in Adults Undergoing Hip Fracture Surgery

IMPORTANCE

Although wait times for hip fracture surgery have been linked to mortality and are being used as quality-of-care indicators worldwide, controversy exists about the duration of the wait that leads to complications.

OBJECTIVE

To use population-based wait-time data to identify the optimal time window in which to conduct hip fracture surgery before the risk of complications increases.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, retrospective cohort study of adults undergoing hip fracture surgery between April 1, 2009, and March 31, 2014, at 72 hospitals in Ontario, Canada. Risk-adjusted restricted cubic splines modeled the probability of each complication according to wait time. The inflection point (in hours) when complications began to increase was used to define early and delayed surgery. To evaluate the robustness of this definition, outcomes among propensity-score matched early and delayed surgical patients were compared using percent absolute risk differences (RDs, with 95% CIs).

EXPOSURE

Time elapsed from hospital arrival to surgery (in hours).

MAIN OUTCOMES AND MEASURES

Mortality within 30 days. Secondary outcomes included a composite of mortality or other medical complications (myocardial infarction, deep vein thrombosis, pulmonary embolism, and pneumonia).

RESULTS

Among 42 230 patients with hip fracture (mean [SD] age, 80.1 years [10.7], 70.5% women) who met study entry criteria, overall mortality at 30 days was 7.0%. The risk of complications increased when wait times were greater than 24 hours, irrespective of the complication considered. Compared with 13 731 propensity-score matched patients who received surgery earlier, 13 731 patients who received surgery after 24 hours had a significantly higher risk of 30-day mortality (898 [6.5%] vs 790 [5.8%]; % absolute RD, 0.79; 95% CI, 0.23-1.35) and the composite outcome (1680 [12.2%]) vs 1383 [10.1%]; % absolute RD, 2.16; 95% CI, 1.43-2.89).

CONCLUSIONS AND RELEVANCE

Among adults undergoing hip fracture surgery, increased wait time was associated with a greater risk of 30-day mortality and other complications. A wait time of 24 hours may represent a threshold defining higher risk.

Fractures in Kidney Transplant Recipients: A Comparative Study Between England and New York State

OBJECTIVES

Fractures are associated with high morbidity and are a major concern for kidney transplant recipients. No comparative analysis has yet been conducted between countries in the contemporary era to inform future international prevention trials.

MATERIALS AND METHODS

Data were obtained from the Hospital Episode Statistics and the Statewide Planning and Research Cooperative databases on all adult kidney transplants performed in England and New York State from 2003 to 2013, respectively, and on posttransplant fracture-related hospitalization from 2003 to 2014.

RESULTS

Our analysis included 18 493 English and 11 602 New York State kidney transplant recipients. Overall, 637 English recipients (3.4%) and 398 New York State recipients (3.4%) sustained a fracture, giving an unadjusted event rate of 7.0 and 5.9 per 1000 years, respectively (P = .948). Of these, 147 English (0.8%) and 101 New York State recipients (0.9%) sustained a hip fracture, giving an unadjusted event rate of 1.6 and 1.5 per 1000 years, respectively (P = .480). There were no differences in the cumulative incidence of all fractures or hip fractures. One-year mortality rates after any fracture (9% and 11%) or after a hip fracture (15% and 17%) were not different between cohorts.

CONCLUSIONS

Contemporaneous English and New York State kidney transplant recipients have similar fracture rates and mortality rates postfracture.

Clinical Utility of Using Lumbar Spine Trabecular Bone Score to Adjust Fracture Probability: The Manitoba BMD Cohort

Decreased lumbar spine trabecular bone score (TBS), a dual-energy X-ray absorptiometry (DXA)-derived image texture measurement, is a risk factor for major osteoporotic fracture (MOF) and hip fracture (HF) independent of 10-year fracture probability estimated using FRAX. We determined how often applying the TBS adjustment to fracture probability altered treatment qualification. Using a population-based registry containing all clinical DXA results for Manitoba, Canada, we identified 34,316 women with baseline spine and hip DXA, FRAX-based fracture probability measurements (computed with femoral neck bone mineral density), lumbar spine TBS, and minimum 5 years of observation (mean 8.7 years). Population-based health services data were used to identify incident non-traumatic MOF and HF in 3503 and 945 women, respectively. Baseline MOF and HF probabilities were estimated using FRAX before and after applying the TBS adjustment. Risk recategorization was assessed using net reclassification improvement (NRI) for individual FRAX-based intervention criteria and three national clinical practice guidelines (CPGs) (US National Osteoporosis Foundation, Osteoporosis Canada, and UK National Osteoporosis Guideline Group). Overall, proportions of women reclassified with the TBS adjustment to FRAX were small (less than 5%) with more than 90% of the reclassification occurring close to the intervention threshold. For women close to an intervention cut-off reclassification, rates ranged from 9.0% to 17.9% and were <1% otherwise. There was a small but significant improvement in overall NRI for all individual FRAX-based intervention criteria (range 0.007 to 0.018) and all three national CPGs (range 0.008 to 0.011). NRI was larger in women below age 65 years (up to 0.056 for hip fracture). In summary, a small but significant improvement in MOF and HF risk assessment was found by using lumbar spine TBS to adjust FRAX probability. An improvement in risk reclassification was observed for CPGs from three different countries, with almost all of the benefit found in individuals close to an intervention threshold. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Worldwide Fracture Prediction

The substantial increase in the burden of non-communicable diseases in general and osteoporosis in particular, necessitates the establishment of efficient and targeted diagnosis and treatment strategies. This chapter reviews and compares different tools for osteoporosis screening and diagnosis; it also provides an overview of different treatment guidelines adopted by countries worldwide. While access to dual-energy X-ray absorptiometry to measure bone mineral density (BMD) is limited in most areas in the world, the introduction of risk calculators that combine risk factors, with or without BMD, have resulted in a paradigm shift in osteoporosis screening and management. To-date, forty eight risk assessment tools that allow risk stratification of patients are available, however only few are externally validated and tested in a population-based setting. These include Osteoporosis Self-Assessment Tool; Osteoporosis Risk Assessment Instrument; Simple Calculated Osteoporosis Risk Estimation; Canadian Association of Radiologists and Osteoporosis Canada calculator; Fracture Risk Assessment Calculator (FRAX); Garvan; and QFracture. These tools vary in the number of risk factors incorporated. We present a detailed analysis of the development, characteristics, validation, performance, advantages and limitations of these tools. The World Health Organization proposes a dual-energy X-ray absorptiometry-BMD T-score ≤ -2.5 as an operational diagnostic threshold for osteoporosis, and many countries have also adopted this cut-off as an intervention threshold in their treatment guidelines. With the introduction of the new fracture assessment calculators, many countries chose to include fracture risk as one of the major criteria to initiate osteoporosis treatment. Of the 52 national guidelines identified in 36 countries, 30 included FRAX derived risk in their intervention threshold and 22 were non-FRAX based.  No universal tool or guideline approach will address the needs of all countries worldwide.  Osteoporosis screening and management guidelines are best tailored according to the needs and resources of individual counties. While few countries have succeeded in generating valuable epidemiological data on osteoporotic fractures, to validate their risk calculators and base their guidelines, many have yet to find the resources to assess variations and secular trends in fractures, the performance of various calculators, and ultimately adopt the most convenient care pathway algorithms.

Gender differences in a reference database of age-related femoral neck geometric parameters for Chinese population and their association with femoral neck fractures

Femoral neck geometric parameters (FNGPs) are closely related to the strength of the femoral neck and the risk of fragility fractures. No reference database is available for FNGPs for Chinese population, and gender-related differences in FNGPs as well as their association with the risk of femoral neck fractures are unknown. This investigation aimed to set up reference databases for FNGPs, understand gender-related differences in FNGPs, and examine the association between FNGPs and the risk of osteoporotic fractures of the femoral neck. This study included 5268 females and 2156 males (aged 15-91years) from Chinese population. A total of 384 patients (282 females and 102 males) had sustained femoral neck fractures; 384 age- and sex-matched individuals without any fractures served as controls. Femoral neck DXA images were used to measure bone mineral density (BMD) and eight FNGPs. Our results showed that the age-related trends of FNGPs were fitted with the best goodness-of-fit by applying the cubic regression model. The trends shown by FNGPs were significantly different between male and female subjects, and the fitting curves were significantly higher in male subjects. After adjustments were made for age, height, weight, and body mass index, Cox regression analysis showed that changes in all FNGPs were related to increased hazard ratios (HRs) of femoral neck fractures. After further adjustment was made for BMD of the femoral neck, the HRs related to a cortical thickness (CT) decrease and buckling ratio (BR) increase in females went up by 3.35-folds (95% CI: 2.75-4.07) and 1.86-folds (95% CI: 1.33-2.60), respectively. In males, the HRs related to the decrease in CT and cross-sectional area (CSA) increased by 3.21-folds (95% CI: 2.32-4.45) and 1.88-folds (95% CI: 1.03-3.44), respectively. In conclusions, the reference databases of FNGPs established in this study will assist in the evaluation and prediction of femoral neck fracture risk in the clinic. The decrease in CT and increase in BR of the femoral neck were independent risk factors for osteoporotic fractures of the femoral neck in females from mainland China, while a decrease in CT and CSA were risk factors in male.

The impact of a standardized order set for the management of non-hip fragility fractures in a Fracture Liaison Service

We analysed the impact of a standardized order set empowering staff nurses to independently manage a Fracture Liaison Service over a 9-month period. Nurses identified between 30 and 70 % of non-hip fragility fractures to the unit in charge of management over time. The latter managed 58 % of referred patients.

INTRODUCTION

The main goal of this study was to evaluate the impact of a standardized order set empowering nurses to independently manage a fracture liaison service (FLS).

METHODS

Since November 2014, an order set allowed nurses of a Montreal hospital, Quebec, Canada to entirely manage an FLS on their own. Nurses followed an 6-h training program on-site. Emergency department (ED) and orthopaedic outpatient clinic (OC) nurses identified non-hip fragility fractures. Medical day treatment unit (MDTU) nurses were in charge of the management (investigation and treatment initiation). The list of patients, 50 years and older, with a fracture were retrieved for the period of November 2014 to July 2015. Performance was assessed with the rate of identification over time and the rate of management of non-hip fragility fractures.

RESULTS

Over the 9-month period, 346 patients of ≥50 years old were seen for a fracture, of which 190 met fragility criteria (excluding hip fractures). A sinusoid pattern of rates of identification between 30-70 % was observed over time. An average proportion of 58.1 % of fracture patients were managed by MDTU nurses.

CONCLUSIONS

A standardized order set legally allowing nurses to manage an FLS led to identification rates varying from 30-70 % and a management rate close to 60 % for referred patients over a 9-month period, which largely exceeds that of standard care. Identification was mostly compromised by difficulty integrating the order set into routine practice. Enforcement of the hospital policy on fragility fractures could help yield efficiency of identification of osteoporosis-related fractures by the staff.

Fracture Incidence in Adult Kidney Transplant Recipients

BACKGROUND

It remains uncertain whether kidney transplant recipients are a high-risk group for fracture.

METHODS

We conducted a cohort study using Ontario, Canada health care databases to estimate the 3-, 5- and 10-year cumulative incidence of nonvertebral fracture (proximal humerus, forearm, hip) in adult kidney transplant recipients between 1994 and 2009, stratifying by sex and age (<50 versus ≥50 years) at transplant. We also assessed the 3-year cumulative incidence of all fracture locations (excluding skull, toes, and fingers) and falls, 10-year cumulative incidence of hip fracture alone, and nonvertebral fracture incidence in recipients compared to nontransplant reference groups matched on age, sex, and cohort entry year. We studied 4821 recipients (median age, 50 years).

RESULTS

Among the age and sex strata, female recipients aged 50 years or older had the highest 3-year cumulative incidence of nonvertebral fracture (3.1%; 95% confidence interval [95% CI], 2.1-4.4%). Recipients had a higher 3-year cumulative incidence of nonvertebral fracture (1.6%; 95% CI, 1.3-2.0%) compared to the general population with no previous nonvertebral fracture (0.5%; 95% CI, 0.4-0.6%; P < 0.0001) and nondialysis chronic kidney disease (1.1%; 95% CI, 0.9-1.2%; P = 0.03), but a lower fracture incidence than the general population with a previous nonvertebral fracture (2.3%; 95% CI, 1.9-2.8%; P = 0.007). The 10-year cumulative incidence of hip fracture in all recipients was 1.7% (≥3% defined as high risk in clinical guidelines).

CONCLUSIONS

Kidney transplant recipients may have a lower fracture risk than previously suggested in the literature. Results inform our understanding of fracture incidence after kidney transplantation and how it compares to nontransplant populations.

Ten-year incident osteoporosis-related fractures in the population-based Canadian Multicentre Osteoporosis Study - comparing site and age-specific risks in women and men

BACKGROUND

Population-based incident fracture data aid fracture prevention and therapy decisions. Our purpose was to describe 10-year site-specific cumulative fracture incidence by sex, age at baseline, and degree of trauma with/without consideration of competing mortality in the Canadian Multicentre Osteoporosis Study adult cohort.

METHODS

Incident fractures and mortality were identified by annual postal questionnaires to the participant or proxy respondent. Date, site and circumstance of fracture were gathered from structured interviews and medical records. Fracture analyses were stratified by sex and age at baseline and used both Kaplan-Meier and competing mortality methods.

RESULTS

The baseline (1995-97) cohort included 6314 women and 2789 men (aged 25-84 years; mean±SD 62±12 and 59±14, respectively), with 4322 (68%) women and 1732 (62%) men followed to year-10. At least one incident fracture occurred for 930 women (14%) and 247 men (9%). Competing mortality exceeded fracture risk for men aged 65+years at baseline. Age was a strong predictor of incident fractures especially fragility fractures, with higher age gradients for women vs. men. Major osteoporotic fracture (MOF) (hip, clinical spine, forearm, humerus) accounted for 41-74% of fracture risk by sex/age strata; in women all MOF sites showed age-related increases but in men only hip was clearly age-related. The most common fractures were the forearm for women and the ribs for men. Hip fracture incidence was the highest for the 75-84 year baseline age-group with no significant difference between women 7.0% (95% CI 5.3, 8.9) and men 7.0% (95% CI 4.4, 10.3).

INTERPRETATION

There are sex differences in the predominant sites and age-gradients of fracture. In older men, competing mortality exceeds cumulative fracture risk.

Sex- and age-specific associations between income and incident major osteoporotic fractures in Canadian men and women: a population-based analysis

We investigated sex- and age-specific associations between income and fractures at the hip, humerus, spine, and forearm in adults aged ≥50 years. Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women.

INTRODUCTION

Associations between income and hip fractures are contested, even less is known about other fracture sites. We investigated sex- and age-specific associations between income and major osteoporotic fractures (MOF) at the hip, humerus, spine, and forearm.

METHODS

Incident fractures were identified from administrative health data for adults aged ≥50 years in Manitoba, Canada, 2000-2007. Mean neighborhood (postal code area) annual household incomes were extracted from 2006 census files and categorized into quintiles. We calculated age-adjusted and age-specific sex-stratified fracture incidence across income quintiles. We estimated relative risks (RR) and 95% CI for income quintile 1 (Q1, lowest income) vs. income quintile 5 (Q5) and tested the linear trend across quintiles.

RESULTS

We identified 15,094 incident fractures (4736 hip, 3012 humerus, 1979 spine, and 5367 forearm) in 2718 men and 6786 women. For males, the RR of fracture for the lowest vs. highest income quintile was 1.63 (95% CI 1.42-1.87) and the negative trend was statistically significant (p < 0.0001); individual skeletal sites showed similar associations. For females, the RR of fracture for the lowest vs. highest income quintile was 1.14 (95% CI 1.01-1.28), with a statistically significant negative trend (p = 0.0291); however, the only skeletal site associated with income in women was the forearm (Q1 vs. Q5 RR 1.09, 95% CI 1.01-1.28).

CONCLUSIONS

Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women. For men, these effect sizes seem large enough to warrant public health concern.

Major osteoporotic to hip fracture ratios in canadian men and women with Swedish comparisons: a population-based analysis

Fracture Risk Assessment (FRAX) tools are calibrated from country-specific fracture epidemiology. Although hip fracture data are usually available, data on non-hip fractures for most countries are often lacking. In such cases, rates are often estimated by assuming similar non-hip to hip fracture ratios from historical (1987 to 1996) Swedish data. Evidence that countries share similar fracture ratios is limited. Using data from Manitoba, Canada (2000 to 2007, population 1.2 million), we identified 21,850 incident major osteoporotic fractures (MOF) in men and women aged >50 years. Population-based age- and sex-specific ratios of clinical vertebral, forearm, and humerus fractures to hip fractures were calculated, along with odds ratios (ORs) and 95% confidence intervals (CIs). All ratios showed decreasing trends with increasing age for both men and women. Men and women showed similar vertebral/hip fracture ratios (all p > 0.1, with ORs 0.86 to 1.25). Forearm/hip and humerus/hip fracture ratios were significantly lower among men than women (forearm/hip ratio: p < 0.01 for all age groups, with ORs 0.29 to 0.53; humerus/hip ratio: p < 0.05 for all age groups [except 80 to 84 years] with ORs 0.46 to 0.86). Ratios for any MOF/hip fracture were also significantly lower among men than women in all but two subgroups (p < 0.05 for all age groups [except 80 to 84 and 90+ years] with ORs 0.48 to 0.87). Swedish vertebral/hip fracture ratios were similar to the Canadian fracture ratios (within 7%) but significantly lower for other sites (men and women: 46% and 35% lower for forearm/hip ratios, 19% and 15% lower for humerus/hip ratios, and 19% and 23% lower for any MOF/hip ratios). These differences have implications for updating and calibrating FRAX tools, fracture risk estimation, and intervention rates. Moreover, wherever possible, it is important that countries try to collect accurate non-hip fracture data.

FRAX provides robust fracture prediction regardless of socioeconomic status

We investigated the fracture risk assessment tool (FRAX) Canada calibration and discrimination according to income quintile in 51,327 Canadian women, with and without a competing mortality framework. Our data show that, under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of socioeconomic status (SES).

INTRODUCTION

FRAX® predicts 10-year fracture risk. Social factors may independently affect fracture risk. We investigated FRAX calibration and discrimination according to SES.

METHODS

Women aged ≥50 years with baseline femoral neck bone mineral density (BMD) were identified from the Manitoba Bone Density Program, Canada (n = 51,327), 1996-2011. Mean household income, extracted from 2006 census files, was categorized into quintiles. Ten-year fracture probabilities were calculated using FRAX Canada. Incident non-traumatic fractures were studied in relation to income quintile in adjusted Cox proportional hazards models. We compared observed versus predicted fractures with and without a competing mortality framework.

RESULTS

During mean 6.2 ± 3.7 years of follow up, there were 6,392 deaths, 3,723 women with ≥1 major osteoporotic fracture (MOF), and 1,027 with hip fractures. Lower income was associated with higher risk for death, MOF, and hip fracture in adjusted models (all p < 0.005). More women in income quintile 1 (lowest) versus quintile 5 experienced death (19 vs. 8%), MOF (10 vs. 6%), or hip fracture (3.0 vs. 1.3 %) (all p ≤ 0.001). Adjustment for competing mortality mitigated the effect of SES on FRAX calibration, and good calibration was observed. FRAX provided good fracture discrimination for MOF and hip fracture within each income quintile (all p < 0.001). Area under the curve was slightly lower for income quintiles 1 versus 5 for FRAX with BMD to predict MOF (0.68, 95% CI 0.66-0.70 vs. 0.71, 95% CI 0.69-0.74) and hip fracture (0.79, 95% CI 0.76-0.81 vs. 0.87, 95% CI 0.84-0.89).

CONCLUSION

Increased fracture risk in individuals of lower income is offset by increased mortality. Under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of SES.

Temporal trends in the incidence of osteoporotic fractures

Osteoporotic fractures are associated with excess mortality and decreased functional capacity and quality of life. Age-standardized incidence rates of fragility fractures, particularly of the hip and forearm, have been noted to be decreasing in the last decade across many countries with the notable exception of Asia. The causes for the observed changes in fracture risk have not been fully identified but are likely the result of multiple factors, including birth cohort and period effects, increasing obesity, and greater use of anti-osteoporosis medications. Changing rates of fragility fractures would be expected to have an important impact on the burden of osteoporosis.

Direct comparison of eight national FRAX® tools for fracture prediction and treatment qualification in Canadian women

SUMMARY

We compared the calibration of FRAX tools from Canada, the US (white), UK, Sweden, France, Australia, New Zealand, and China when used to assess fracture risk in 36,730 Canadian women. Our data underscores the importance of applying country-specific FRAX tools that are based upon high-quality national fracture epidemiology.

PURPOSE

A FRAX® model for Canada was constructed for prediction of hip fracture and major osteoporotic fracture (MOF) using national hip fracture and mortality data. We examined the calibration of this model in Canadian women and compared it with seven other FRAX tools.

METHODS

In women aged ≥50 years with baseline bone mineral density (BMD) measures identified from the Manitoba Bone Density Program, Canada (n = 36,730), 10-year fracture probabilities were calculated with and without BMD using selected country-specific FRAX tools. FRAX risk estimates were compared with observed fractures ≤10 years (506 hip, 2,380 MOF). Ten-year fracture risk was compared with predicted probabilities, and proportions exceeding specific treatment thresholds contrasted.

RESULTS

For hip fracture prediction, good calibration was observed for FRAX Canada and most other country-specific FRAX tools, excepting Sweden (risk overestimated) and China (risk underestimated). For MOF prediction, greater between-country differences were seen; FRAX Sweden and FRAX China showed the largest over- and underestimation in this Canadian population. Relative to treatment qualification based upon FRAX Canada, treatment of high-hip fracture probability (≥3%) was greater by FRAX Sweden (ratio 1.41 without and 1.55 with BMD), and markedly less by FRAX China (ratio 0.09 without and 0.11 with BMD). Greater between-country differences were observed for treatment of high MOF (≥20%); FRAX Sweden again greatly increased (ratio 1.76 without and 1.83 with BMD), and FRAX China severely reduced treatment qualification (ratio 0.00 without and 0.01 with BMD).

CONCLUSIONS

The use of country-specific FRAX tools, accurately calibrated to the target population, is essential. Relatively small calibration differences can have large effects on high-risk categorization and treatment qualification.

Incidence of hip fractures in Greece during a 30-year period: 1977-2007

The incidence of hip fractures doubled in Greece from 1977 to 2007 among people aged 50 and over. A mild decrease was observed after 2002, although the future trend cannot be safely anticipated at the moment. Half of all hip fractures in 2007 were derived from the age group of 80 and over.

INTRODUCTION

The purpose of this study was to determine the incidence of hip fractures during a 30-year period in Greece among people aged 50 and over and to document possible alterations in secular trends.

METHODS

We studied hip fractures during 2007 and compared them with those of previous years starting from 1977 with an in-between 5-year interval (1977, 1982, 1987, 1992, 1997, 2002). Age- and sex-specific incidence was calculated, and secular trends were recorded. The relative risk of hip fracture in every age group was estimated according to the corresponding incidence of 1977.

RESULTS

The adjusted incidence of hip fractures increased approximately 100 % throughout the study; it progressively increased from 1977 to 2002 and exhibited a mild significant decrease thereafter. The relative risk of hip fractures among subjects aged 60-69 in 2007 has declined compared with 1977 [0.85, 95 % confidence intervals (CI) 0.79-0.92, p < 0.0005]. Among people aged 70-79, an increased relative fracture risk (1.53, 95 % CI 1.45-1.61, p < 0.0005) was estimated in 2007 compared with 1977. People ≥80 years old were responsible for half of the hip fractures in 2007 but only for the 22.5 % of fractures in 1977. The relative fracture risk in people aged ≥80 was 2.81 times higher (95 % CI 2.64-2.98, p < 0.0005) in 2007 than in 1977.

CONCLUSIONS

The incidence of hip fractures doubled during the last 30 years among people aged ≥50 years, although a mild decrease was observed in almost all age groups after 2002. The most affected group is 80 and over.

Precision study of DXA-based patient-specific finite element modeling for assessing hip fracture risk

Finite element (FE) modeling based on a patient's hip dual energy X-ray absorptiometry (DXA) image is a promising tool for more accurately assessing hip fracture risk, as it is able to comprehensively consider effects from all the mechanical parameters affecting hip fracture. However, a number of factors influence the precision (also known as repeatability or reproducibility) of a DXA-based FE procedure, for example, subject positioning in DXA scanning. As a procedure is required to have adequately high precision in clinical application, we investigated the effects of the involved factors on the precision of a DXA-based patient-specific FE procedure developed by the authors, to provide insight into how the precision of the procedure can be improved so that it can meet the clinical standards. Fracture risk indices corresponding to initial and repeat DXA scans acquired in 30 typical clinical subjects were computed and compared to assess short term repeatability of the procedure. It was found that inconsistent positioning followed by manual segmentation of the projected femur contour induced significant variability in the predicted fracture risk indices. This research suggests that, to apply the DXA-based FE procedure in clinical assessment, it will be necessary to pay more strict attention to subject positioning in DXA scanning.

Survey of Current Practices: Peripheral Nerve Block Utilization by ED Physicians for Treatment of Pain in the Hip Fracture Patient Population

Background

In 2010–11 approximately 968 hip fracture patients presented to emergency departments in the Greater Toronto Local Health Integration Network (GTA-LHIN). Optimal pain management is a frequently overlooked aspect of hip fracture patient care, which may contribute to patient outcomes.

Although recommendations have been published, there is currently not a standardized approach to the analgesic management of pain in the hip fracture patient. Nerve blocks, including the fascia iliaca compartment block (FICB), are more effective than traditional opioid analgesics in reducing pain after hip fracture. Research suggests that analgesia via nerve blockade is best initiated early, upon arrival to the emergency department.

Emergency physicians are trained in ultrasound, and do utilize regional anaesthesia; however, the frequency of block utilization and techniques used for block insertion are unknown. We sought to undertake the first survey of Emergency Department (ED) staff and resident physicians across the GTA-LHIN, looking at the current ED practice of nerve block analgesia in hip fracture patients.

Purpose

The primary aim was to determine the prevalence and range of techniques utilized. The secondary aims were to determine the extent of training in nerve block insertion techniques, to gauge opinion on the most important objectives for future training courses, and to seek an understanding of the barriers to establishing a standardized approach for nerve block utilization in hip fracture patients.

Conclusions

This data will be used to develop a multidisciplinary training program specifically for use by ED physicians. ED physicians and anesthesiologists will collaborate to standardize nerve block insertion techniques and develop an optimal analgesic management plan of hip fracture patients at Sunnybrook Hospital.

Direct health-care costs attributed to hip fractures among seniors: a matched cohort study

SUMMARY

Using a matched cohort design, we estimated the mean direct attributable cost in the first year after hip fracture in Ontario to be $36,929 among women and $39,479 among men. These estimates translate into an annual $282 million in direct attributable health-care costs in Ontario and $1.1 billion in Canada.

INTRODUCTION

Osteoporosis is a major public health concern that results in substantial fracture-related morbidity and mortality. It is well established that hip fractures are the most devastating consequence of osteoporosis, yet the health-care costs attributed to hip fractures in Canada have not been thoroughly evaluated.

METHODS

We determined the 1- and 2-year direct attributable costs and cost drivers associated with hip fractures among seniors in comparison to a matched non-hip fracture cohort using health-care administrative data from Ontario (2004-2008). Entry into long-term care and deaths attributable to hip fracture were also determined.

RESULTS

We successfully matched 22,418 female (mean age = 83.3 years) and 7,611 male (mean age = 81.3 years) hip fracture patients. The mean attributable cost in the first year after fracture was $36,929 (95 % CI $36,380-37,466) among women and $39,479 (95 % CI $38,311-$40,677) among men. These estimates translate into an annual $282 million in direct attributable health-care costs in Ontario and $1.1 billion in Canada. Primary cost drivers were acute and post-acute institutional care. Approximately 24 % of women and 19 % of men living in the community at the time of fracture entered a long-term care facility, and 22 % of women and 33 % of men died within the first year following hip fracture. Attributable costs remained elevated into the second year ($9,017 among women, $10,347 among men) for patients who survived the first year.

CONCLUSIONS

We identified significant health-care costs, entry into long-term care, and mortality attributed to hip fractures. Results may inform health economic analyses and policy decision-making in Canada.

Partnership for fragility bone fracture care provision and prevention program (P4Bones): study protocol for a secondary fracture prevention pragmatic controlled trial

Background

Fractures associated with bone fragility in older adults signal the potential for secondary fracture. Fragility fractures often precipitate further decline in health and loss of mobility, with high associated costs for patients, families, society and the healthcare system. Promptly initiating a coordinated, comprehensive pharmacological bone health and falls prevention program post-fracture may improve osteoporosis treatment compliance; and reduce rates of falls and secondary fractures, and associated morbidity, mortality and costs.

Methods/design

This pragmatic, controlled trial at 11 hospital sites in eight regions in Quebec, Canada, will recruit community-dwelling patients over age 50 who have sustained a fragility fracture to an intervention coordinated program or to standard care, according to the site. Site study coordinators will identify and recruit 1,596 participants for each study arm. Coordinators at intervention sites will facilitate continuity of care for bone health, and arrange fall prevention programs including physical exercise. The intervention teams include medical bone specialists, primary care physicians, pharmacists, nurses, rehabilitation clinicians, and community program organizers.

The primary outcome of this study is the incidence of secondary fragility fractures within an 18-month follow-up period. Secondary outcomes include initiation and compliance with bone health medication; time to first fall and number of clinically significant falls; fall-related hospitalization and mortality; physical activity; quality of life; fragility fracture-related costs; admission to a long term care facility; participants’ perceptions of care integration, expectations and satisfaction with the program; and participants’ compliance with the fall prevention program. Finally, professionals at intervention sites will participate in focus groups to identify barriers and facilitating factors for the integrated fragility fracture prevention program.

This integrated program will facilitate knowledge translation and dissemination via the following: involvement of various collaborators during the development and set-up of the integrated program; distribution of pamphlets about osteoporosis and fall prevention strategies to primary care physicians in the intervention group and patients in the control group; participation in evaluation activities; and eventual dissemination of study results.

Study/trial registration

Clinical Trial.Gov NCT01745068

Study ID number

CIHR grant # 267395

Bias towards dementia: are hip fracture trials excluding too many patients? A systematic review

Patients with hip fractures are older and often present many co-morbidities, including dementia. These patients cannot answer quality of life questionnaires and are generally excluded from trials. We hypothesized that a significant number of patients are being excluded from these studies and this may impact outcomes. This was a two part study; the first analyzing databases of two ongoing large-scale multi-centred hip fracture trials and the second being a systematic review. The FAITH and HEALTH studies were analyzed for exclusion incidence directly related to dementia. The second part consisted of a systematic search of all relevant studies within the last 20 years. In the FAITH study, a total of 1690 subjects were excluded, 375 (22.2%) of which were due to dementia or cognitive impairment. In the HEALTH study, 575 were excluded with dementia/cognitive impairment representing 207 patients (36%). Following the systematic review, 251 articles were identified 17 of which were retained. The overall prevalence of dementia was 27.9% (range 2-51%). Only two studies compared demented and non-demented groups. In these studies significant increases in both mortality and complications were found. In summary, when investigating hip fractures, choosing appropriate objective endpoints is essential to ensure results are also applicable to patients with dementia.

Denosumab: mechanism of action and clinical outcomes

AIMS

To describe the mechanisms of action of denosumab, a novel antiresorptive agent, contrasting it with other antiresorptive and anabolic osteoporosis treatments.

METHODS

Published papers related to the mechanism of action of approved osteoporosis treatments were sought through MEDLINE searches.

FINDINGS

Osteoporotic fractures carry a substantial burden of morbidity and mortality, but pharmacotherapy can prevent such fractures in high-risk individuals. Antiresorptive drugs (e.g. bisphosphonates, oestrogen, denosumab) reduce bone turnover by distinct mechanisms. Denosumab, a recently approved therapy, is a fully human monoclonal antibody that binds the cytokine RANKL (receptor activator of NFκB ligand), an essential factor initiating bone turnover. RANKL inhibition blocks osteoclast maturation, function and survival, thus reducing bone resorption. In contrast, bisphosphonates bind bone mineral, where they are absorbed by mature osteoclasts, inducing osteoclast apoptosis and suppressing resorption. These differences in mechanism influence both the onset and reversibility of treatment.

DISCUSSION

Effective pharmacotherapy is necessary for patients at high risk of fracture. Among the treatment options for postmenopausal osteoporosis, there are significant differences in mechanism and dosing. Denosumab acts by a novel mechanism and is administered twice yearly by subcutaneous injection. Identified by Osteoporosis Canada Clinical Practice Guidelines as a first-line agent for treatment of postmenopausal osteoporosis, denosumab represents an important addition to our treatment options.

Geographic differences in fractures among women

Osteoporotic fracture is associated with considerable morbidity and mortality in women throughout the world. However, significant variation in hip fracture rates among women from different nations has been observed and is likely to represent a combination of real and apparent differences due to ascertainment bias. Higher rates are observed in Caucasian women, with lowest rates observed in black women and intermediate rates among Asian women. These differences are likely to represent a combination of genetic and environmental differences; for example, among European women, the highest fracture rates are observed in Scandinavian women where vitamin D insufficiency is common. In all groups, an increase in absolute fracture numbers is anticipated due to demographic changes.

The burden of illness of osteoporosis in Canada

To update the 1993 burden of illness of osteoporosis in Canada, administrative and community data were used to calculate the 2010 costs of osteoporosis at $2.3 billion in Canada or 1.3% of Canada's healthcare expenditures. Prevention of fractures in high-risk individuals is key to decrease the financial burden of osteoporosis.

INTRODUCTION

Since the 1996 publication of the burden of osteoporosis in 1993 in Canada, the population has aged and the management of osteoporosis has changed. The study purpose was to estimate the current burden of illness due to osteoporosis in Canadians aged 50 and over.

METHODS

Analyses were conducted using five national administrative databases from the Canadian Institute for Health Information for the fiscal-year ending March 31 2008 (FY 2007/2008). Gaps in national data were supplemented by provincial and community data extrapolated to national levels. Osteoporosis-related fractures were identified using a combination of most responsible diagnosis at discharge and intervention codes. Fractures associated with severe trauma codes were excluded. Costs, expressed in 2010 dollars, were calculated for osteoporosis-related hospitalizations, emergency care, same day surgeries, rehabilitation, continuing care, homecare, long-term care, prescription drugs, physician visits, and productivity losses. Sensitivity analyses were conducted to measure the impact on the results of key assumptions.

RESULTS

Osteoporosis-related fractures were responsible for 57,413 acute care admissions and 832,594 hospitalized days in FY 2007/2008. Acute care costs were estimated at $1.2 billion. When outpatient care, prescription drugs, and indirect costs were added, the overall yearly cost of osteoporosis was over $2.3 billion for the base case analysis and as much as $3.9 billion if a proportion of Canadians were assumed to be living in long-term care facilities due to osteoporosis.

CONCLUSIONS

Osteoporosis is a chronic disease that affects a large segment of the adult population and results in a substantial economic burden to the Canadian society.

The burden of illness of osteoporosis in Canadian men

There is a dearth of information about the burden of osteoporosis in Canadian men. To fill this gap, we conducted a burden of illness study aimed at estimating the economic burden attributable to osteoporosis in Canadian men aged 50 years and older. Five national data sources were used to estimate health care resource utilization and costs (in 2010 Canadian dollars) associated with osteoporosis in men. Any information gap was supplemented by using data from provincial and community sources. Direct medical costs included costs associated with hospitalizations, same day surgeries, emergency room visits, rehabilitation, chronic care, long-term care, home care, physician visits, and prescribed medications. The value of lost productivity from patients and informal caregivers was also determined to provide a societal perspective. Sensitivity analyses were conducted to evaluate the impact of key assumptions on the results. In fiscal year 2007/2008, the total economic burden of treating and rehabilitating male osteoporotic fractures was estimated at $570 million per year, where direct medical costs accounted for 86%. Acute care utilization was responsible for 70% of all direct costs. About 51% of all hospitalizations were for hip fractures and hip fractures alone accounted for 54% of the acute care spending. If a proportion of Canadian men were assumed to live in long-term care facilities due to osteoporosis, the overall annual cost of osteoporosis would increase from $570 million to $910 million. Male osteoporosis has a substantial economic burden on the Canadian society.

Osteoporosis-related fracture case definitions for population-based administrative data

Background

Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a) compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b) test for differences in incidence estimates from multiple administrative data case definitions.

Methods

Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos). Generalized linear models were used to test for differences in incidence estimates.

Results

For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions.

Conclusions

The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.

Hip fracture incidence from 1981 to 2009 in the Czech Republic as a basis of the country-specific FRAX model

The aim of this study was to calculate rates of hospitalization for hip fracture and the incidence of hip fractures in the Czech Republic over a period of 29 years. A second aim was to use the most recent data to populate a FRAX(®) model for the assessment of fracture probability in individual patients. Data on hospitalizations for hip fracture (1981-2009) and number of women and men with hip fractures (2000-2009) were obtained, and incidences were computed for the entire population ≥50 years of age. Incidence of hospitalization for hip fracture in the Czech population aged ≥50 years increased progressively by calendar year. Age-standardized incidence of hip fractures increased to 2004 but leveled off thereafter and decreased after 2005. Data for hip fracture risk in 2008 and 2009 and the death hazard were used to populate a Czech-specific FRAX model for the computation of 10-year fracture probability. The customized FRAX model, using the verified epidemiological data, will be used to identify patients at increased fracture risk.

Secular decreases in fracture rates 1986-2006 for Manitoba, Canada: a population-based analysis

SUMMARY

We examined trends in fracture rates over 20 years in the Province of Manitoba, Canada. Hip fractures, major low-trauma fractures, and high-trauma fractures declined significantly from 1986 to 2006.

INTRODUCTION

Secular decreases in hip fracture rates have been reported in some countries. Whether this phenomenon applies to other fracture sites is not well described.

METHODS

We used 20 years of data from the Population Health Research Data Repository for the Province of Manitoba, Canada. Age-adjusted fracture rates were calculated for men and women age 50 years and older 1986-2006 according to fracture site and mechanism (presence/absence of external injury codes). Generalized linear models with generalized estimating equations were used to derive adjusted annual rates and test for linear change in men and women.

RESULTS

Major low-trauma fractures (hip, forearm, spine, and humerus) showed a significant annual linear decline in women (-1.2% [95% CI, -0.7% to -1.8%]) and in men (-0.4% [95% CI, -0.7% to -0.2%]). Hip fracture showed a significant annual decline for both sexes, while forearm and humerus fractures showed a significant decline only in women. The only fracture category that did not show a significant annual decline in either sex was the spine. The observed annual reduction in high-trauma fractures was even larger and did not show a sex difference (-1.8% [95% CI, -2.8% to -0.7%]).

CONCLUSION

We observed a decrease in both low-trauma and high-trauma fracture rates over the study period. This decline was apparent in years prior to widespread osteoporosis testing or availability of modern pharmacotherapy.

Construction and validation of a simplified fracture risk assessment tool for Canadian women and men: results from the CaMos and Manitoba cohorts

A procedure for creating a simplified version of fracture risk assessment tool (FRAX®) is described. Calibration, fracture prediction, and concordance were compared with the full FRAX tool using two large, complementary Canadian datasets.

INTRODUCTION

The Canadian Association of Radiologists and Osteoporosis Canada (CAROC) system for fracture risk assessment is based upon sex, age, bone mineral density (BMD), prior fragility fracture, and glucocorticoid use. CAROC does not require computer or web access, and categorizes 10-year major osteoporotic fracture risk as low (<10%), moderate (10-20%), or high (>20%).

METHODS

Basal CAROC fracture risk tables (by age, sex, and femoral neck BMD) were constructed from Canadian FRAX probabilities for major osteoporotic fractures (adjusted for prevalent clinical risk factors). We assessed categorization and fracture prediction with the updated CAROC system in the CaMos and Manitoba BMD cohorts.

RESULTS

The new CAROC system demonstrated high concordance with the Canadian FRAX tool for risk category in both the CaMos and Manitoba cohorts (89% and 88%). Ten-year fracture outcomes in CaMos and Manitoba BMD cohorts showed good discrimination and calibration for both CAROC (6.1-6.5% in low-risk, 13.5-14.6% in moderate-risk, and 22.3-29.1% in high-risk individuals) and FRAX (6.1-6.6% in low-risk, 14.4-16.1% in moderate-risk, and 23.4-31.0% in high-risk individuals). Reclassification from the CAROC risk category to a different risk category under FRAX occurred in <5% for low-risk, 20-24% for moderate-risk, and 27-30% for high-risk individuals. Reclassified individuals had 10-year fracture outcomes that were still within or close to the original nominal-risk range..

CONCLUSION

The new CAROC system is well calibrated to the Canadian population and shows a high degree of concordance with the Canadian FRAX tool. The CAROC system provides s a simple alternative when it is not feasible to use the full Canadian FRAX tool.

Fracture prediction and calibration of a Canadian FRAX® tool: a population-based report from CaMos

A new Canadian WHO fracture risk assessment (FRAX®) tool to predict 10-year fracture probability was compared with observed 10-year fracture outcomes in a large Canadian population-based study (CaMos). The Canadian FRAX tool showed good calibration and discrimination for both hip and major osteoporotic fractures.

INTRODUCTION

The purpose of this study was to validate a new Canadian WHO fracture risk assessment (FRAX®) tool in a prospective, population-based cohort, the Canadian Multicentre Osteoporosis Study (CaMos).

METHODS

A FRAX tool calibrated to the Canadian population was developed by the WHO Collaborating Centre for Metabolic Bone Diseases using national hip fracture and mortality data. Ten-year FRAX probabilities with and without bone mineral density (BMD) were derived for CaMos women (N = 4,778) and men (N = 1,919) and compared with observed fracture outcomes to 10 years (Kaplan-Meier method). Cox proportional hazard models were used to investigate the contribution of individual FRAX variables.

RESULTS

Mean overall 10-year FRAX probability with BMD for major osteoporotic fractures was not significantly different from the observed value in men [predicted 5.4% vs. observed 6.4% (95%CI 5.2-7.5%)] and only slightly lower in women [predicted 10.8% vs. observed 12.0% (95%CI 11.0-12.9%)]. FRAX was well calibrated for hip fracture assessment in women [predicted 2.7% vs. observed 2.7% (95%CI 2.2-3.2%)] but underestimated risk in men [predicted 1.3% vs. observed 2.4% (95%CI 1.7-3.1%)]. FRAX with BMD showed better fracture discrimination than FRAX without BMD or BMD alone. Age, body mass index, prior fragility fracture and femoral neck BMD were significant independent predictors of major osteoporotic fractures; sex, age, prior fragility fracture and femoral neck BMD were significant independent predictors of hip fractures.

CONCLUSION

The Canadian FRAX tool provides predictions consistent with observed fracture rates in Canadian women and men, thereby providing a valuable tool for Canadian clinicians assessing patients at risk of fracture.

Construction of a FRAX® model for the assessment of fracture probability in Canada and implications for treatment

We describe the creation of a FRAX® model for the assessment of fracture probability in Canadian men and women, calibrated from national hip fracture and mortality data. This FRAX tool was used to examine possible thresholds for therapeutic intervention in Canada in two large complementary cohorts of women and men.

OBJECTIVE

To evaluate a Canadian World Health Organization (WHO) fracture risk assessment (FRAX®) tool for computing 10-year probabilities of osteoporotic fracture.

METHODS

Fracture probabilities were computed from national hip fracture data (2005) and death hazards (2004) for Canada. Probabilities took account of age, sex, clinical risk factors (CRFs), and femoral neck bone mineral density (BMD). Treatment implications were studied in two large cohorts of individuals age 50 years and older: the population-based Canadian Multicentre Osteoporosis Study (4,778 women and 1,919 men) and the clinically referred Manitoba BMD Cohort (36,730 women and 2,873 men).

RESULTS

Fracture probabilities increased with age, decreasing femoral neck T-score, and number of CRFs. Among women, 10.1-11.3% would be designated high risk based upon 10-year major osteoporotic fracture probability exceeding 20%. A much larger proportion would be designated high risk based upon 10-year hip fracture probability exceeding 3% (25.7-28.0%) or osteoporotic BMD (27.1-30.9%), and relatively few from prior hip or clinical spine fracture (1.6-4.2%). One or more criteria for intervention were met by 29.2-34.0% of women excluding hip fracture probability (35.3-41.0% including hip fracture probability). Lower intervention rates were seen among CaMos (Canadian Multicentre Osteoporosis Study) men (6.8-12.9%), but in clinically referred men from the Manitoba BMD Cohort, one or more criteria for high risk were seen for 26.4% excluding hip fracture probability (42.4% including hip fracture probability).

CONCLUSIONS

The FRAX tool can be used to identify intervention thresholds in Canada. The FRAX model supports a shift from a dual X-ray absorptiometry (DXA)-based intervention strategy, towards a strategy based on fracture probability for a major osteoporotic fracture.

Epidemiology of hip fracture: Worldwide geographic variation

Osteoporosis is a major health problem, especially in elderly populations, and is associated with fragility fractures at the hip, spine, and wrist. Hip fracture contributes to both morbidity and mortality in the elderly. The demographics of world populations are set to change, with more elderly living in developing countries, and it has been estimated that by 2050 half of hip fractures will occur in Asia. This review conducted using the PubMed database describes the incidence of hip fracture in different regions of the world and discusses the possible causes of this wide geographic variation. The analysis of data from different studies show a wide geographic variation across the world, with higher hip fracture incidence reported from industrialized countries as compared to developing countries. The highest hip fracture rates are seen in North Europe and the US and lowest in Latin America and Africa. Asian countries such as Kuwait, Iran, China, and Hong Kong show intermediate hip fracture rates. There is also a north-south gradient seen in European studies, and more fractures are seen in the north of the US than in the south. The factors responsible of this variation are population demographics (with more elderly living in countries with higher incidence rates) and the influence of ethnicity, latitude, and environmental factors. The understanding of this changing geographic variation will help policy makers to develop strategies to reduce the burden of hip fractures in developing countries such as India, which will face the brunt of this problem over the coming decades.