Treatment thresholds for osteoporosis and reimbursability criteria: perspectives associated with fracture risk-assessment tools

A systematic review on the performance of fracture risk assessment tools: FRAX, DeFRA, FRA-HS

PURPOSE

Preventing fragility fractures by treating osteoporosis may reduce disability and mortality worldwide. Algorithms combining clinical risk factors with bone mineral density have been developed to better estimate fracture risk and possible treatment thresholds. This systematic review supported panel members of the Italian Fragility Fracture Guidelines in recommending the use of best-performant tool. The clinical performance of the three most used fracture risk assessment tools (DeFRA, FRAX, and FRA-HS) was assessed in at-risk patients.

METHODS

PubMed, Embase, and Cochrane Library were searched till December 2020 for studies investigating risk assessment tools for predicting major osteoporotic or hip fractures in patients with osteoporosis or fragility fractures. Sensitivity (Sn), specificity (Sp), and areas under the curve (AUCs) were evaluated for all tools at different thresholds. Quality assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies-2; certainty of evidence (CoE) was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Forty-three articles were considered (40, 1, and 2 for FRAX, FRA-HS, and DeFRA, respectively), with the CoE ranging from very low to high quality. A reduction of Sn and increase of Sp for major osteoporotic fractures were observed among women and the entire population with cut-off augmentation. No significant differences were found on comparing FRAX to DeFRA in women (AUC 59-88% vs. 74%) and diabetics (AUC 73% vs. 89%). FRAX demonstrated non-significantly better discriminatory power than FRA-HS among men.

CONCLUSION

The task force formulated appropriate recommendations on the use of any fracture risk assessment tools in patients with or at risk of fragility fractures, since no statistically significant differences emerged across different prediction tools.

Patients with osteoporosis: children of a lesser god

Osteoporosis is a common non-communicable disease with enormous societal costs. Antiosteoporosis medications have been proven efficacious in reducing the refracture rate and mortality; moreover, we have now convincing evidence about the cost-effectiveness of antiosteoporotic medications. However, albeit preventable and treatable, osteoporosis has been somehow neglected by health authorities. Drugs approval has been unnecessarily lengthy, especially when compared with other non-communicable diseases. Herein, we discuss the issue of procrastinating drug approval in osteoporosis and future implications.

Postmenopausal osteoporosis: risk evaluation and treatment options

Postmenopausal osteoporosis is a chronic progressive condition characterized by reduced bone mass and impaired bone quality, leading to an increased risk of fragility fractures. Osteoporotic fractures reduce quality of life and are associated with high morbidity, mortality and economic burden. Primary and secondary prevention interventions are always recommended starting from the premenopausal age, in women after menopause, however, it is essential to develop a long-term intervention strategy that allows to identify patients at high risk of fracture and the choice of therapy based on the estimated risk. This narrative review described the tools for layering the management approach in relation to low, high and very high fracture risk. Several medications are now available for the treatment of osteoporosis and the prevention of fractures; the knowledge of the efficacy, safety and additional benefits profile of the individual preparations allows an appropriate choice between the different drugs available and the possibility of adapting the prescription to the lifetime fracture risk spectrum. From the literature it emerges that menopausal hormone therapy (MHT), TSEC combination and SERMs can be drugs of choice to counteract postmenopausal bone loss in younger women or at low risk of fracture, while bisphosphonates and denosumab are appropriate for women with high risk or at an older age. Therapy with denosumab and anabolic agents such as teriparatide and romosozumab is particularly indicated for subjects with very high risk of fracture.

Risk of fragility fractures in obesity and diabetes: a retrospective analysis on a nation-wide cohort

This study aims to investigate the role of obesity and diabetes on bone health in a nation-wide cohort of women with high risk of fracture.

INTRODUCTION

The role of obesity and diabetes on fracture risk is yet poorly understood. Body mass index (BMI) and bone mineral density (BMD) are strongly correlated; however, patients with elevated BMI are not protected against fractures, configuring the obesity paradox. A similar controversial association has been also found in diabetic patients. Herein, we present a retrospective analysis on 59,950 women.

METHODS

Using a new web-based fracture risk-assessment tool, we have collected demographic (including BMI), densitometric, and clinical data (including history of vertebral or hip and non-vertebral, non-hip fractures, presence of comorbidities). We performed a propensity score generation with 1:1 matching for patients in the obese (BMI ≥ 30) and non-obese (BMI < 30) groups, in the diabetics and non-diabetics. Propensity score estimates were estimated using a logistic regression model derived from the clinical variables: age, lumbar spine T-score, and femoral neck T-score.

RESULTS

We found an association between diabetes and fractures of any kind (OR 1.3, 95% CI 1.1-1.4 and 1.3, 95% CI 1.2-1.5 for vertebral or hip fractures and non-vertebral, non-hip fractures, respectively). Obesity, on the other hand, was significantly associated only with non-vertebral, non-hip fractures (OR 1.3, 95% CI 1.1-1.6). To estimate the individual effect of obesity and diabetes on bone health, we ran sensitivity analyses which included obese non-diabetic patients and non-obese diabetic patients, respectively.

CONCLUSIONS

Non-obese diabetics had the highest risk of vertebral or hip fracture, whereas obese non-diabetics predominantly had non-vertebral, non-hip fracture's risk. These results should raise awareness in clinical practice when evaluating diabetic and/or obese patients.

The obesity paradox and osteoporosis

Overweight and obesity according to the definition of the WHO are considered as an abnormal or excessive fat accumulation that may impair health. Studies comparing fracture incidence in obese and non-obese individuals have demonstrated that obesity, defined on the basis of body mass index (BMI), is associated with increased risk of fracture at some sites but seems to be protective at others. The results of the studies are influenced by the distribution of BMI in the population studied; for example, in cohorts with a low prevalence of obesity, a predilection for certain fracture sites in obese individuals becomes difficult to detect, whereas, in populations with a high prevalence of obesity, previously unreported associations may emerge. Furthermore, obesity can bring with itself many complications (Type 2 diabetes mellitus, vitamin D deficiency, and motor disability) which, in the long run, can have a definite influence in terms of overall risk and quality of life, as well. This is a narrative review focusing on the relationship between bone metabolism and overweight/obesity and dealing with the fundamental dilemma of a disease (obesity) apparently associated with improved values of bone mineral density, part of a complicated relationship which revolves around obesity called "the obesity paradox".

Decreasing trend of hip fractures incidence in Italy between 2007 and 2014: epidemiological changes due to population aging

We analyzed hospitalization for hip fractures in elderly Italian people from 2007 to 2014. The number of fractures increased by 5.50% (women + 3.36; men + 12.9%) only due to people aged ≥ 85 years old. Incidence rates per 10,000 inhabitants decreased in all the age groups (65-74, 75-84, and also ≥ 85).

PURPOSE

To assess the burden of hip fractures in elderly Italian population moving from our previous researches documented a reduced incidence of hip fractures in Italian women aged 65-74 years old.

METHODS

We analyzed national hospitalization records from 2007 to 2014 to compute age- and sex-specific rates at national and regional level.

RESULTS

Seven hundred forty-one thousand six hundred thirty-three a total of 741,633 hospitalizations were observed in people ≥ 65 (women 568,203; men 173,430), with an overall increase of 5.50% over the 8-year period (females + 3.36; males + 12.9%). About 43.75% of total hip fractures were suffered by patients aged ≥ 85 years old. Women aged ≥ 85 accounted for 34.49% (n = 255,763) of total fractures. The incidence rate per 10,000 inhabitants in people aged 65-74 decreased from 28.65 to 25.31 in women (- 13.02%) and from 13.41 to 11.65 in men (- 13.12%). Incidence per 10,000 in people 75-84 decreased from 121.6 to 105.2 in women (- 13.49%) and from 55.8 to 47.5 in men (- 14.87%). Also, in people aged ≥ 85, the incidence per 10,000 declined from 300.99 to 268.72 in women (- 10.72%) and from 174.59 to 171.17 in men (- 1.96%). Standardized rates (SR) per 10,000 in the overall population aged 65 years old and over decreased between 2007 and 2014 from 22.9 to 20.1 and from 7.0 to 6.3 in women and men, respectively. Decreasing trends were documented in all Italian regions between 65 and 79 years old, with further reduction up to 84 years old in 16 regions out of 20. Region Lazio showed a decreasing trend also in people aged > 85 years old.

CONCLUSION

While the number of hospitalizations for hip fractures in Italy is still increasing due to the fractures occurring in people ≥ 85 years old, incidence rates are decreasing in all the age groups, including the oldest one, possibly because the number of subjects aged ≥ 85 is growing faster than the number of fractures.

How Good is Our Best Guess? Clinical Application of the WHO FRAX Tool in Osteoporotic Fracture Risk Determination and Treatment Decisions

Historically, treatment decisions for osteoporosis were based on bone mineral density. However, many fractures occur in patients with T-scores outside the osteoporotic range, emphasizing the importance of multi-factorial risk assessments. The World Health Organization Fracture Risk Assessment Tool (FRAX) predicts 10-year risk of osteoporotic fracture. We hypothesized that physicians' clinical estimates of osteoporotic fracture risk would differ significantly from that calculated by FRAX. Thus, treatment decisions would differ depending whether or not physicians used FRAX. A survey consisting of five clinical scenarios was administered to 76 endocrinologists, family physicians, internists, and internal medicine residents. They were asked to estimate the osteoporotic fracture risk and decide whether they would offer preventative treatment. Their estimates were compared to the risk predicted by FRAX and national treatment threshold guidelines. The primary outcome was the difference between the participant's estimate and the FRAX-based estimate of the 10-year risk of osteoporotic fracture for each scenario. In each scenario, physicians statistically significantly over-estimated fracture risk compared to that predicted by FRAX. Estimates for hip fracture risk were 2-4 times higher than FRAX estimates. The major osteoporotic fracture risk at which participants would offer treatment varied with physician group, with endocrinologists, family physicians, and residents requiring a 10-20 % 10-year risk, while internal medicine physician thresholds ranged from 2 to 20 %. Physicians greatly over-estimated the risk of hip fracture based on clinical information. FRAX is necessary to accurately quantify risk, but because physicians varied in the level of risk required before they would offer treatment, uniform approaches to risk estimation may still not result in uniform clinical treatment decisions.

Italian association of clinical endocrinologists (AME) position statement: drug therapy of osteoporosis

Treatment of osteoporosis is aimed to prevent fragility fractures and to stabilize or increase bone mineral density. Several drugs with different efficacy and safety profiles are available. The long-term therapeutic strategy should be planned, and the initial treatment should be selected according to the individual site-specific fracture risk and the need to give the maximal protection when the fracture risk is highest (i.e. in the late life). The present consensus focused on the strategies for the treatment of postmenopausal osteoporosis taking into consideration all the drugs available for this purpose. A short revision of the literature about treatment of secondary osteoporosis due both to androgen deprivation therapy for prostate cancer and to aromatase inhibitors for breast cancer was also performed. Also premenopausal females and males with osteoporosis are frequently seen in endocrine settings. Finally particular attention was paid to the tailoring of treatment as well as to its duration.

The use of bisphosphonates in women: when to use and when to stop

INTRODUCTION

Bisphosphonates (BPs) are the most commonly used drugs in osteoporosis.

AREAS COVERED

This review focuses on the criteria for identifying patients who should be treated with BPs and also the rational for the duration of treatment.

EXPERT OPINION

BPs remain the mainstay for the treatment of osteoporosis. For their low cost, the treatment threshold is related exclusively to the ratio between expected benefits and the risk of side effects. This is the case of patients with prior fragility fracture or with low bone density and the presence of other relevant risk factors. The treatment should continue for 3 - 5 years or until fracture risk is no longer high. Afterward a treatment holiday should be considered on the light of the increasing risk of side effects but its duration is still controversial. The duration of this treatment holiday depends on the drug used. Discontinuation of risedronate and ibandronate is associated with the quick loss of the acquired benefits and with these two BPs discontinuation should not exceed 6 months. Alendronate and zoledronate are characterized by a persistent effect after discontinuing treatment and this would allow a more prolonged drug holiday.

Assessment of Fracture Risk in A Population of Postmenopausal Italian Women: A Comparison of Two Different Tools

The main objective of this study was to compare in the assessment of risk of fractures in postmenopausal women two algorithms for 10-year fracture risk evaluation, the WHO-endorsed FRAX(®) and the Italian FRAX-derived version (DeFRA), which considers BMD of different bone sites and allows the inclusion of other data. In a secondary analysis, we compared the performance of the tools in discriminating subjects who sustained previous major fractures from those who did not. The 10-year fracture risk score was evaluated in a sample of 989 climacteric women using FRAX and DeFRA tools. Bone mineral density was also included in the calculation of these algorithms. Comparing how the subjects were assigned to different risk classes by the two tools, we found that DeFRA attributed higher risk categories than FRAX, among women in the subgroups between 50 and 59 and, mostly, 60-69 years of age. ROC curve analysis showed that DeFRA had the same discriminative ability to identify previous major osteoporotic fractures compared to FRAX (AUC = 0.74 for both). If confirmed by prospective studies, our findings would suggest that DeFRA might be ascribed as at least equivalent to FRAX or perhaps slightly most appropriate in the categorization of the fracture risk, particularly in women aged 60-69 years, a period in which bone densitometry analysis is highly recommended.