Epidemiology of hip fracture and the development of FRAX in Ukraine

Reverse engineering the FRAX algorithm: Clinical insights and systematic analysis of fracture risk

The Fracture Risk Assessment Tool (FRAX) is a computational tool developed to predict the 10-year probability of hip fracture and major osteoporotic fracture based on inputs of patient characteristics, bone mineral density (BMD), and a set of seven clinical risk factors. While the FRAX tool is widely available and clinically validated, its underlying algorithm is not public. The relative contribution and necessity of each input parameter to the final FRAX score is unknown. We systematically collected hip fracture risk scores from the online FRAX calculator for osteopenic Caucasian women across 473,088 unique inputs. This dataset was used to dissect the FRAX algorithm and construct a reverse-engineered fracture risk model to assess the relative contribution of each input variable. Within the reverse-engineered model, age and T-Score were the strongest contributors to hip fracture risk, while BMI had marginal contribution. Of the clinical risk factors, parent history of fracture and ongoing glucocorticoid treatment had the largest additive effect on risk score. A generalized linear model largely recapitulated the FRAX tool with an R2 of 0.91. Observed effect sizes were then compared to a true patient population by creating a logistic regression model of the Study of Osteoporotic Fractures (SOF) cohort, which closely paralleled the effect sizes seen in the reverse-engineered fracture risk model. Analysis identified several clinically relevant observations of interest to FRAX users. The role of major osteoporotic fracture risk prediction in contributing to an indication of treatment need is very narrow, as the hip fracture risk prediction accounted for 98% of treatment indications for the SOF cohort. Removing any risk factor from the model substantially decreased its accuracy and confirmed that more parsimonious models are not ideal for fracture prediction. For women 65 years and older with a previous fracture, 98% of FRAX combinations exceeded the treatment threshold, regardless of T-score or other factors. For women age 70+ with a parent history of fracture, 99% of FRAX combinations exceed the treatment threshold. Based on these analyses, we re-affirm the efficacy of the FRAX as the best tool for fracture risk assessment and provide deep insight into the interplay between risk factors.

FRAX-based intervention thresholds for Pakistan

We compared, for women in Pakistan, the utility of intervention thresholds either at a T-score ≤  - 2.5 or based on a FRAX probability equivalent to women of average body mass index (BMI) with a prior fragility fracture. Whereas the FRAX-based intervention threshold identified women at high fracture probability, the T-score threshold was less sensitive, and the associated fracture risk decreased markedly with age.

PURPOSE

The fracture risk assessment algorithm FRAX® has been recently calibrated for Pakistan, but guidance is needed on how to apply fracture probabilities to clinical practice.

METHODS

The age-specific 10-year probabilities of a major osteoporotic fracture were calculated in women with average BMI to determine fracture probabilities at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of - 2.5. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without bone mineral density (BMD). The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing.

RESULTS

When a BMD T-score ≤  - 2.5 was used as an intervention threshold, FRAX probabilities in women aged 50 years were approximately two-fold higher than in women of the same age but with no risk factors and average BMD. The relative increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T-score of - 2.5 was actually protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture, rose with age from 2.1% at the age of 40 years to 17%, at the age of 90 years, and identified women at increased risk at all ages.

CONCLUSION

Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a 'fracture threshold' target women at high fracture risk.

FRAX-Based Intervention Thresholds for Osteoporosis Treatment in Ukraine

OBJECTIVES

Osteoporosis, in addition to its consequent fracture burden, is a common and costly condition. FRAX^® is a well-established, validated, web-based tool which calculates the 10-year probability of fragility fractures. A FRAX model for Ukraine has been available since 2016 but its output has not yet been translated into intervention thresholds for the treatment of osteoporosis in Ukraine; we aimed to address this unmet need in this analysis.

METHODS

In a referral population sample of 3790 Ukrainian women, 10-year probabilities of major osteoporotic fracture (MOF) and hip fracture separately were calculated using the Ukrainian FRAX model, with and without femoral neck bone mineral density (BMD). We used a similar approach to that first proposed by the UK National Osteoporosis Guideline Group, whereby treatment is indicated if the probability equals or exceeds that of a woman of the same age with a prior fracture.

RESULTS

The MOF intervention threshold in females (the age-specific 10-year fracture probability) increased with age from 5.5% at the age of 40 years to 11% at the age of 75 years where it plateaued and then decreased slightly at age 90 (10%). Lower and upper thresholds were also defined to determine the need for BMD, if not already measured; the approach targets BMD measurements to those at or near the intervention threshold. The proportion of the referral populations eligible for treatment, based on prior fracture or similar or greater probability, ranged from 44% to 69% depending on age. The prevalence of the previous fracture rose with age, as did the proportion eligible for treatment. In contrast, the requirement for BMD testing decreased with age.

CONCLUSIONS

The present study describes the development and application of FRAX-based assessment guidelines in Ukraine. The thresholds can be used in the presence or absence of access to BMD and optimize the use of BMD where access is restricted.

3D analysis of bone mineral density in a cohort: age- and sex-related differences

Women have lower areal BMD (g/cm²) than men; however, the women have smaller-size bones. Our study showed that women ≤ 59 years have a hip volumetric BMD by DXA 3D similar to that of men of the same age. This makes us think about the importance of taking into account bone size at the time of analyzing the sex-related differences in bone mass.

PURPOSE

Women have lower areal BMD (g/cm²) than men; however, these studies do not take into account that women have smaller-size bones. Recently, three-dimensional (3D) modeling methods were proposed to analyze volumetric BMD (vBMD). We want to determine the values of vBMD at the hip by DXA-based 3D modeling in a cohort of people in order to know the age- and sex-related differences.

METHODS

A total of 2647 people of both sexes (65% women) were recruited from a large cohort (Camargo cohort, Santander, Spain). 3D-SHAPER® software (version 2.8, Galgo Medical, Barcelona, Spain) was used to derive 3D analysis from the hip DXA scans at baseline RESULTS: The differences were less pronounced for vBMD (cortical sBMD 9.3%, trabecular vBMD 6.4%, integral vBMD 2.2%) compared to aBMD (FN aBMD 11.4% and TH aBMD 13.3%). After stratifying by age (≤ 59 years, 60-69 years, 70-79 years, and ≥ 80 years), we observed in ≤ 59 years that aBMD was lower in women compared to men, at FN (0.758 [0.114] g/cm² vs. 0.833 [0.117] g/cm²; p = 1.4 × 10^-20) and TH (0.878 [0.117] g/cm² vs. 0.990 [0.119] g/cm²; p = 4.1 × 10^-40). Nevertheless, no statistically significant difference was observed for integral vBMD (331 [58] mg/cm³ in women and 326 [51] mg/cm³ in men; p = 0.19) and trabecular vBMD (190 [41] mg/cm³ in women and 195 [39] mg/cm³ in men; p = 0.20).

CONCLUSION

Our results make us think about the importance of taking into account bone size at the time of analyzing the sex-related differences in bone mass.

FRAX-based fracture probabilities in South Africa

The hip fracture rates in South Africa were used to create ethnic-specific FRAX® models to facilitate fracture risk assessment.

INTRODUCTION

The aim of this study was to develop FRAX models to compute the 10-year probability of hip fracture and major osteoporotic fracture and assess their potential clinical application.

METHODS

Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for the White, Black African, Coloured and Indian population of South Africa. Age-specific 10-year probabilities of a major osteoporotic fracture were calculated in women to determine fracture probabilities at a femoral neck T score of -2.5 SD, or those equivalent to a woman with a prior fragility fracture. Fracture probabilities were compared with those from selected countries.

RESULTS

Probabilities were consistently higher in Indian than in Coloured men and women, in turn, higher than in Black South Africans. For White South Africans, probabilities were lower than in Indians at young ages up to the age of about 80 years. When a BMD T score of -2.5 SD was used as an intervention threshold, FRAX probabilities in women age 50 years were approximately 2-fold higher than in women of the same age but with an average BMD and no risk factors. The increment in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T score of -2.5 SD was no longer a risk factor. Probabilities equivalent to women with a previous fracture rose with age and identified women at increased risk at all ages.

CONCLUSIONS

These FRAX models should enhance accuracy of determining fracture probability amongst the South African population and help guide decisions about treatment.

A novel risk assessment tool for bovine respiratory disease in preweaned dairy calves

Due to the increased morbidity and mortality of bovine respiratory disease (BRD) in dairy calves, as well as an increasing urgency for the judicious use of antimicrobials in farm animals, a comprehensive risk assessment tool for BRD in preweaned dairy calves has been designed based on a longitudinal and a cross-sectional study. As a multifactorial disease complex in which immune function stressors increase susceptibility to respiratory pathology, risk management programs for environmental and husbandry practices may be an effective approach for BRD control. Practices of known or suspected effect on BRD in preweaned calves have been explored in 2 large studies correlating management factors to BRD prevalence (BRD 100 study) and incidence (BRD 10K study) and forming the scores presented here. Priority was given to results from multivariable over univariable model estimates. However, when used, univariable model estimates were adjusted for confounders or stratified by effect modifiers if necessary. Regression coefficients were translated into scores, which are presented in a field-ready tool consisting of (1) a risk assessment questionnaire, which identifies the herd-specific risk factors and the risk scores associated with each; (2) the California BRD scoring system to estimate the BRD prevalence at the time of risk assessment for future comparison with the prevalence after interventions; and (3) the BRD control and prevention herd management plan, which can be used to plan and track the interventions identified. Scores for 100 dairies across California were used to benchmark a dairy's risk on a spectrum. With the help of the risk assessment tool, dairy producers, calf managers, and veterinarians may be able to adjust management factors that affect BRD risk on a farm and objectively monitor BRD prevalence before and after management interventions. As a result, the BRD risk assessment tool described here is the first comprehensive effort for herd-specific BRD control and prevention.

Bone Mineral Density and Risk of Osteoporotic Fractures in Women with Parkinson's Disease

Osteoporosis and Parkinson's disease (PD) are two important age-related diseases, which have an influence on pain, physical activity, disability, and mortality. The aim of this research was to study the parameters of bone mineral density (BMD), frequency, and 10-year probability of osteoporotic fractures (OFs) in females with Parkinson's disease (PD). We have examined 113 postmenopausal women aged 50-74 years old which were divided into 2 groups (I, control group (CG), n = 53 and II, subjects with PD, n = 60). Bone mineral density of lumbar spine, femoral neck, distal radius, and total body were measured, and quantity and localization of vertebral deformities were performed by the vertebral fracture assessment (VFA). Ten-year probability of OFs was assessed by Ukrainian version of FRAX®. It was established that BMD of lumbar spine, femoral neck, distal radius, and total body in PD women was reliably lower compared to CG. The frequency of OFs in PD subjects was higher compared to CG (51.7 and 11.3%, respectively) with prevalence of vertebral fractures (VFs) in women with PD (52.6% among all fractures). 47.4% of the females had combined VFs: 74.2% of VFs were in thoracic part of the spine and 73.7% were wedge ones. Ten-year probability of major OFs and hip fracture were higher in PD women compared to CG with and without BMD measurements. Inclusion of PD in the FRAX calculation increased the requirement of antiosteoporotic treatment from 5 to 28% (without additional examination) and increased the need of additional BMD measurement from 50 to 68%. Anterior/posterior vertebral height ratios (Th₈-Th₁₁) measured by VFA in PD females without confirmed vertebral deformities were lower compared to indices of CG. In conclusion, women with PD have lower BMD indices, higher rate of osteoporosis, and risk of future low-energy fractures that should be taken into account in the assessment of their osteoporosis risk and clinical management.

Epidemiology of osteoporotic fracture in Kazakhstan and development of a country specific FRAX model

Retrospective and prospective population-based survey in a region of the Republic of Kazakhstan determined the incidence of fractures at the hip, proximal humerus and distal forearm. The hip fracture rates were used to create a FRAX® model to enhance fracture risk assessment in Kazakhstan.

OBJECTIVE

This paper describes the epidemiology of osteoporotic fractures in the Republic of Kazakhstan that was used to develop a country specific FRAX® tool for fracture prediction.

METHODS

We carried out a retrospective population-based survey in Taldykorgan in the Republic of Kazakhstan representing approximately 1% of the country's population. Hip, forearm and humerus fractures were identified retrospectively in 2015 and 2016 from hospital registers and the trauma centre. Hip fractures were prospectively identified in 2017 from the same sources and additionally from primary care data. Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for Kazakhstan. Fracture probabilities were compared with those from neighbouring countries having FRAX models.

RESULTS

The difference in hip fracture incidence between the retrospective and prospective survey indicated that approximately 25% of hip fracture cases did not come to hospital attention. The incidence of hip fracture applied nationally suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2015 was 11,690 and is predicted to increase by 140% to 28,000 in 2050. Hip fracture incidence was a good predictor of forearm and humeral fractures in men but not in women.

CONCLUSION

The FRAX model should enhance accuracy of determining fracture probability among the Kazakh population and help guide decisions about treatment.

Epidemiology of osteoporotic fracture in Moldova and development of a country-specific FRAX model

Retrospective population-based survey in 2 regions of the Republic of Moldova determined the incidence of fractures at the hip, proximal humerus and distal forearm. The estimated number of such fractures nationwide for 2015 was 11,271 and is predicted to increase to 15,863 in 2050. The hip fracture rates were used to create a FRAX model to help guide decisions about treatment.

OBJECTIVE

This paper describes the epidemiology of osteoporotic fractures in Republic of Moldova that was used to develop the country-specific fracture prediction FRAX® tool.

METHODS

We carried out a retrospective population-based survey in 2 regions of the Republic of Moldova (Anenii Noi district and Orhei district) representing approximately 6% of the country's population. We identified hip, forearm and humerus fractures in 2011 and 2012 from hospital registers and primary care sources. Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for Moldova. Fracture probabilities were compared with those from neighbouring countries having FRAX models.

RESULTS

The incidence of hip fracture applied nationally suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2015 was 3911 and is predicted to increase by 60% to 6492 in 2050. Hip fracture incidence was a good predictor of forearm and humeral fractures. FRAX-based probabilities were higher in Moldova than neighbouring countries (Ukraine and Romania).

CONCLUSION

The FRAX model should enhance accuracy of determining fracture probability among the Moldavan population and help guide decisions about treatment.

Epidemiology of hip fracture and the development of a FRAX model for Uzbekistan

A prospective population-based survey in a region of the Republic of Uzbekistan determined the incidence of fractures at the hip. The hip fracture rates were used to create a FRAX® model to facilitate fracture risk assessment in Uzbekistan.

OBJECTIVE

This paper describes the epidemiology of hip fracture in the Republic of Uzbekistan that was used to develop a country-specific FRAX® tool for fracture prediction.

METHODS

During a 1-year (2016/17) prospective population-based survey in the Pap district of the Republic of Uzbekistan, hip fractures were prospectively identified from hospital registers, trauma centres and primary care and community sources. Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for Uzbekistan. Fracture probabilities were compared with those from neighbouring Kazakhstan and Kyrgystan.

RESULTS

Approximately 41% of hip fracture cases did not come to medical attention, and two thirds of patients overall were not admitted to hospital. The incidence of hip fracture applied nationally suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2015 was 16,764 and is predicted to increase more than three-fold to 60,272 in 2050. FRAX-based probabilities were higher in Uzbekistan than Kazakhstan or Kyrgystan.

CONCLUSION

The FRAX model should enhance accuracy of determining fracture probability among the Uzbek population and help guide decisions about treatment.

Epidemiology of hip fractures in Bulgaria: development of a country-specific FRAX model

A retrospective population-based survey was undertaken in a region of Bulgaria to determine the incidence of hip fracture. The estimated number of hip fractures nationwide for 2015 was 9322 and is predicted to increase to 11,398 in 2050. The hip fracture rates were used to create a FRAX model.

OBJECTIVE

To describe the epidemiology of hip fractures in Bulgaria, which was then used to develop the country-specific fracture prediction FRAX® tool.

METHODS

We carried out a retrospective population-based survey in Stara Zagora, Bulgaria, representing approximately 4.6% of the country's population. We identified hip fractures occurring in 2015, 2016 and 2017 from hospital registers and primary care sources held by the regional health insurance agency. Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for Bulgaria. Fracture probabilities were compared with those from neighbouring countries having FRAX models.

RESULTS

The incidence of hip fracture applied nationally suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2015 was 9322 and is predicted to increase to 11,398 in 2050. FRAX-based probabilities were higher in Bulgaria than those in Serbia or Romania, lower than those in Turkey and similar to those in Greece.

CONCLUSION

The FRAX model should enhance accuracy of determining fracture probability among the Bulgarian population and help guide decisions about treatment.

A brief history of FRAX

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

INTRODUCTION

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

METHODS

The method used in this paper is literature review.

RESULTS

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

CONCLUSION

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

Epidemiology of Hip Fractures in Two Regions of Ukraine

Worldwide, the number of hip fractures, the most important osteoporotic complication in the elderly, continues to increase in line with the ageing of the population. In some countries, however, including the Ukraine, data on the incidence of hip fracture are limited. This article describes the first analysis to characterize the incidence of hip fracture in the Ukrainian population from the age of 40 years. It is based on data from two regional studies, namely, the Vinnitsa city study and the STOP study, which were performed during 1997-2002 and 2011-2012 years, respectively. Hip fracture incidence rates were demonstrated to increase with increasing age. The rates were higher among younger men than women, however, with a female preponderance from the age of 65 years upwards. The incidence of hip fractures in Ukraine is 255.5 per 100,000 for women aged 50 years and older and 197.8 per 100,000 for men of the corresponding age. Overall, the incidence of hip fracture was comparable with data from neighboring countries, such as Poland and Romania. Hip fractures constitute a serious healthcare problem in Ukraine, and changes in healthcare are required to improve the management and long-term care of osteoporosis and its complications.