Racial/ethnic differences in hip and diaphyseal femur fractures

Revision of the 1994 World Health Organization T-score definition of osteoporosis for use in older East Asian women and men to reconcile it with their lifetime risk of fragility fracture

The 1994 WHO criterion of a T-score ≤ -2.5 for densitometric osteoporosis was chosen because it results in a prevalence commensurate with the observed lifetime risk of fragility fractures in Caucasian women aged ≥ 50 years. Due to the much lower risk of fragility fracture among East Asians, the application of the conventional WHO criterion to East Asians leads to an over inflated prevalence of osteoporosis, particularly for spine osteoporosis. According to statistical modeling and when a local BMD reference is used, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.7 for Hong Kong Chinese women. Using radiographic osteoporotic vertebral fracture as a surrogate clinical endpoint, we empirically demonstrated that a femoral neck T-score of -2.77 for Chinese women was equivalent to -2.60 for Italian women, a spine T-score of -3.75 for Chinese women was equivalent to -2.44 for Italian women, and for Chinese men a femoral neck T-score of -2.77 corresponded to spine T-score of -3.37. For older Chinese men, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.2. With the BMD reference published by IKi et al. applied, T-score of femoral neck, total hip, and spine of -2.75, -3.0, and -3.9 for Japanese women will be more in line with the WHO osteoporosis definition. The revised definition of osteoporosis cutpoint T-scores for East Asians will allow a more meaningful international comparison of disease burden.

Bone Density Screening Rates Among Medicare Beneficiaries: An Analysis with a focus on Asian Americans

PURPOSE

To report osteoporosis screening utilization rates among Asian American (AsA) populations in the USA.

METHODS

We retrospectively assessed the use of dual-energy X-ray absorptiometry (DXA) screening using the Medicare 5% Research Identifiable Files. Using Current Procedural Terminology (CPT) codes indicative of a DXA scan, we identified patients recommended for DXA screening according to the ACR-SPR-SSR Practice Parameters (females ≥ 65 years, males ≥ 70 years). Sociodemographic factors and their association with screening were evaluated using chi-square tests.

RESULTS

There were 80,439 eligible AsA beneficiaries, and 12,102 (15.1%) received osteoporosis screening. DXA rate for women was approximately four times greater than the rate for men (19.8% vs. 5.0%; p < 0.001). AsA beneficiaries in zip codes with higher mean household income (MHI) were more likely to have DXA than those in lower MHI areas (17.6% vs. 14.3%, p < 0.001). AsA beneficiaries aged < 80 were more likely to receive DXA (15.5%) than those aged ≥ 80 (14.1%, p < 0.001). There were 2,979,801 eligible non-AsA beneficiaries, and 496,957 (16.7%) received osteoporosis screening during the study period. Non-Hispanic white beneficiaries had the highest overall screening rate (17.5%), followed by North American Native (13.0%), Black (11.8%), and Hispanic (11.1%) beneficiaries. Comparing AsA to non-AsA populations, there were significantly lower DXA rates among AsA beneficiaries when controlling for years of Medicare eligibility, patient age, sex, location, and mean income (p < 0.001).

CONCLUSION

We found lower than expected DXA screening rates for AsA patients. A better understanding of the barriers and facilitators to AsA osteoporosis screening is needed to improve patient care.

Osteoporosis and Fracture Risk among Older US Asian Adults

PURPOSE OF REVIEW

This review summarizes the current knowledge regarding osteoporosis and fracture among older US Asian adults.

RECENT FINDINGS

Asian adults have lower (areal) bone density than non-Hispanic White adults and thus are more likely to be diagnosed and treated for osteoporosis, despite their lower risk of hip fracture. The latter may relate to favorable characteristics in hip geometry, volumetric bone density, and bone microarchitecture; lower risk of falls; and other clinical factors. The fracture risk calculator FRAX accounts for the lower risk of hip fracture among US Asian adults. However, data on major osteoporotic fracture risk remain limited. Fracture rates also vary by Asian subgroup, which may have implications for fracture risk assessment. Furthermore, among women receiving bisphosphonate drugs, Asian race is a risk factor for atypical femur fracture, an uncommon complication associated with treatment duration. Recent clinical trial efficacy data pertaining to lower bisphosphonate doses and longer dosing intervals may be relevant for Asian adults. More research is needed to inform osteoporosis care of US Asian adults, including risk-benefit considerations and the optimal duration of bisphosphonate treatment. Greater evidence-based guidance for primary fracture prevention among US Asian adults will ensure health equity in the prevention of osteoporotic fractures.

Is the traction table necessary to treat femoral fractures with intramedullary nailing? A meta-analysis

BACKGROUND

The traction table is generally used in femoral intramedullary nailing surgery. Recently, some published studies have shown that the same or better treatment effects can be gotten without a traction table. It remains no consensus on this issue.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was applied in this study. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for eligible studies. The random-effect model was used to calculate the standardized mean difference (SMD) and risk ratios with 95% CIs. Trial sequential analysis (TSA) was performed to verify the results.

RESULTS

The pooled estimates of seven studies, including 266 cases each in the manual traction group and traction table group, indicated that manual traction could shorten operative time [SMD, - 0.77; 95% CI (- 0.98, - 0.55); P < 0.00001] and preoperative set-up time [SMD, - 2.37; 95% CI (- 3.90, - 0.84); P = 0.002], but it would not reduce intraoperative blood loss volume and fluoroscopy time. No statistical difference was found in their fracture healing time, postoperative Harris scores, and malunion rate. The use of a Traction repositor could reduce the set-up time [SMD, - 2.48; 95% CI (- 4.91, - 0.05); P < 0.00001].

CONCLUSIONS

Compared with manual traction, the traction table in femoral intramedullary nailing surgery lengthened operative time and preoperative set-up time. At the same time, it did not show significant advantages in reducing blood loss volume and fluoroscopy time, or improving prognosis. In clinical practice, the optimal surgical plan must be made on a case-by-case basis to avoid unnecessary traction table use.

Progression of atypical femur stress fracture after discontinuation of bisphosphonate therapy

Atypical femur fracture (AFF) is an uncommon complication of long-term bisphosphonate use, but the risk declines substantially after treatment cessation. We report a case of a 70-year-old woman with osteopenia treated with alendronate for 9 years who presented with right mid-thigh pain and radiographic findings of focal lateral cortical thickening in the right mid-femur and lateral cortex irregularity in the proximal-mid left femur. Alendronate was discontinued, but she remained on estrogen for menopausal symptoms. Four years later, a horizontal linear translucent defect was seen in the right mid-femur area of cortical hypertrophy, consistent with an incomplete AFF. The patient underwent prophylactic intramedullary rodding of the right femur and estrogen was discontinued. Three years later (7 years after initial presentation), the cortical irregularities in the left femur were more prominent and three small horizontal linear translucent defects were now evident, consistent with early incomplete atypical fracture development. The patient also suffered a wrist fracture. She was treated with teriparatide for 1.5 years with resolution of the translucent defects in the left but not the right femur, although abnormal thickening of the lateral cortex persisted in both femurs. Our case demonstrates incomplete atypical femur fracture progression in a patient with long-term bisphosphonate exposure, even after treatment cessation. These findings highlight the importance of follow-up for patients who develop diaphyseal femur stress fractures and the potential for early healing with anabolic therapy. This case also demonstrates the challenge in managing older patients with incomplete AFF at risk for progression to complete AFF and osteoporotic fracture.

Racial and Ethnic Disparities in Bone Health and Outcomes in the United States

Osteoporosis is a bone disease classified by deterioration of bone microarchitecture and decreased bone strength, thereby increasing subsequent risk of fracture. In the United States, approximately 54 million adults aged 50 years and older have osteoporosis or are at risk due to low bone mass. Osteoporosis has long been viewed as a chronic health condition affecting primarily non-Hispanic white (NHW) women; however, emerging evidence indicates racial and ethnic disparities in bone outcomes and osteoporosis management. The primary objective of this review is to describe disparities in bone mineral density (BMD), prevalence of osteoporosis and fracture, as well as in screening and treatment of osteoporosis among non-Hispanic black (NHB), Hispanic, and Asian adults compared with NHW adults living on the US mainland. The following areas were reviewed: BMD, osteoporosis prevalence, fracture prevalence and incidence, postfracture outcomes, DXA screening, and osteoporosis treatments. Although there are limited studies on bone and fracture outcomes within Asian and Hispanic populations, findings suggest that there are differences in bone outcomes across NHW, NHB, Asian, and Hispanic populations. Further, NHB, Asian, and Hispanic populations may experience suboptimal osteoporosis management and postfracture care, although additional population-based studies are needed. There is also evidence that variation in BMD and osteoporosis exists within major racial and ethnic groups, highlighting the need for research in individual groups by origin or background. Although there is a clear need to prioritize future quantitative and qualitative research in these populations, initial strategies for addressing bone health disparities are discussed. © 2021 American Society for Bone and Mineral Research (ASBMR).

Bisphosphonate Treatment Beyond 5 Years and Hip Fracture Risk in Older Women

IMPORTANCE

Clinical trials have demonstrated the antifracture efficacy of bisphosphonate drugs for the first 3 to 5 years of therapy. However, the efficacy of continuing bisphosphonate for as long as 10 years is uncertain.

OBJECTIVE

To examine the association of discontinuing bisphosphonate at study entry, discontinuing at 2 years, and continuing for 5 additional years with the risk of hip fracture among women who had completed 5 years of bisphosphonate treatment at study entry.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included women who were members of Kaiser Permanente Northern and Southern California, 2 integrated health care delivery systems, and who had initiated oral bisphosphonate and completed 5 years of treatment by January 1, 2002, to September 30, 2014. Data analysis was conducted from January 2018 to August 2020.

EXPOSURE

Discontinuation of bisphosphonate at study entry (within a 6-month grace period), discontinuation at 2 years (within a 6-month grace period), and continuation for 5 additional years.

MAIN OUTCOMES AND MEASURES

The outcome was hip fracture determined by principal hospital discharge diagnoses. Demographic, clinical, and pharmacological data were ascertained from electronic health records.

RESULTS

Among 29 685 women (median [interquartile range] age, 71 [64-77] years; 17 778 [60%] non-Hispanic White individuals), 507 incident hip fractures were identified. Compared with bisphosphonate discontinuation at study entry, there were no differences in the cumulative incidence (ie, risk) of hip fracture if women remained on therapy for 2 additional years (5-year risk difference [RD], -2.2 per 1000 individuals; 95% CI, -20.3 to 15.9 per 1000 individuals) or if women continued therapy for 5 additional years (5-year RD, 3.8 per 1000 individuals; 95% CI, -7.4 to 15.0 per 1000 individuals). While 5-year differences in hip fracture risk comparing continuation for 5 additional years with discontinuation at 2 additional years were not statistically significant (5-year RD, 6.0 per 1000 individuals; 95% CI, -9.9 to 22.0 per 1000 individuals), interim hip fracture risk appeared lower if women discontinued after 2 additional years (3-year RD, 2.8 per 1000 individuals; 95% CI, 1.3 to 4.3 per 1000 individuals; 4-year RD, 9.3 per 1000 individuals; 95% CI, 6.3 to 12.3 per 1000 individuals) but not without a 6-month grace period to define discontinuation.

CONCLUSIONS AND RELEVANCE

In this study of women treated with bisphosphonate for 5 years, hip fracture risk did not differ if they discontinued treatment compared with continuing treatment for 5 additional years. If women continued for 2 additional years and then discontinued, their risk appeared lower than continuing for 5 additional years. Discontinuation at other times and fracture rates during intervening years should be further studied.

Bone Mineral Density in Older U.S. Filipino, Chinese, Japanese, and White Women

BACKGROUND/OBJECTIVES

Bone mineral density (BMD) reference data exist for U.S. White, Black, and Hispanic (Mexican American) populations but not for U.S. Asians. Few studies have compared BMD findings among different U.S. Asian ethnicities.

DESIGN

Retrospective observational study.

SETTING

Large northern California healthcare system.

PARTICIPANTS

Asian and White women aged 50 to 79 years with BMD testing from 1998 to 2017 excluding those with estrogen or osteoporosis treatment, recent fracture, or select disorders affecting skeletal health.

MEASUREMENTS

Femoral neck (FN)-BMD and height data.

METHODS

Differences in FN-BMD were examined by ethnicity and age, comparing Filipino, Chinese, and Japanese women and non-Hispanic White women. Differences in BMD were also examined after adjustment for height.

RESULTS

There were 37,224 Asian women (including 11,147 Filipino, 10,648 Chinese, and 2,519 Japanese) and 115,318 non-Hispanic White women. Mean height was similar among the Asian subgroups and about 6 to 8 cm lower than Whites. Mean FN-BMDs differed by less than 3% for Filipino, Chinese, and Japanese and all were lower than Whites, with smaller Asian-White differences among younger women (<3%; ages 50-59) and larger differences among older women (6-8%; ages 65-79). Adjusting FN-BMD for height reduced White-Asian differences by about 30% to 40%.

CONCLUSION

Mean FN-BMD and height for Filipino, Chinese, and Japanese women were similar but consistently lower than White women, especially among older women. Although Asian-White BMD differences were substantially attenuated after height adjustment; some differences persisted for older women. Future studies should investigate potential age-cohort effects and the extent to which these BMD differences influence fracture risk and clinical care.

Incidence, risk factors, and fracture healing of atypical femoral fractures: a multicenter case-control study

The incidence of atypical femoral fractures (AFFs) was 2.95% among 6644 hip and femoral fractures. Independent risk factors included the use of bisphosphonates (BPs), osteopenia or osteoporosis, rheumatoid arthritis, increased femoral curvatures, and thicker femoral cortices. Patients with AFFs and BP treatment were more likely to have problematic healing than those with typical femoral fractures (TFFs) and no BP treatment.

INTRODUCTION

To determine the incidence and risk factors of atypical femoral fractures (AFFs), we performed a multicenter case-control study. We also investigated the effects of bisphosphonates (BPs) on AFF healing.

METHODS

We retrospectively reviewed the medical records and radiographs of 6644 hip and femoral fractures of patients from eight tertiary referral hospitals. All the radiographs were reviewed to distinguish AFFs from TFFs. Univariate and multivariate logistic regression analyses were performed to identify risk factors, and interaction analyses were used to investigate the effects of BPs on fracture healing.

RESULTS

The incidence of AFFs among 6644 hip and femoral fractures was 2.95% (90 subtrochanter and 106 femoral shaft fractures). All patients were females with a mean age of 72 years, and 75.5% were exposed to BPs for an average duration of 5.2 years (range, 1-17 years). The use of BPs was significantly associated with AFFs (p < 0.001, odds ratio = 25.65; 95% confidence interval = 10.74-61.28). Other independent risk factors for AFFs included osteopenia or osteoporosis, rheumatoid arthritis, increased anterior and lateral femoral curvatures, and thicker lateral femoral cortex at the shaft level. Interaction analyses showed that patients with AFFs using BPs had a significantly higher risk of problematic fracture healing than those with TFFs and no BP treatment.

CONCLUSIONS

The incidence of AFFs among 6644 hip and femoral fractures was 2.95%. Osteopenia or osteoporosis, use of BPs, rheumatoid arthritis, increased anterior and lateral femoral curvatures, and thicker lateral femoral cortex were independent risk factors for the development of AFFs. Patients with AFFs and BP treatment were more likely to have problematic fracture healing than those with TFFs and no BP treatment.

Overexpression of GαS in Murine Osteoblasts In Vivo Leads to Increased Bone Mass and Decreased Bone Quality

Gα_S is a heterotrimeric G protein that transduces signals from activated G protein-coupled receptors on the cell surface to stimulate adenylyl cyclase/cyclic adenosine monophosphate (AMP) signaling. Gα_S plays a central role in mediating numerous growth and maintenance processes including osteogenesis and bone turnover. Decreased Gα_S expression or activating mutations in Gα_S both affect bone, suggesting that modulating Gα_S protein levels may be important for bone health and development. To examine the effects of increased osteoblastic Gα_S expression on bone development in vivo, we generated transgenic mice with Gα_S overexpression in osteoblasts (HOM-Gs mice) driven by the 3.6-kilobase (kb) Col1A1 promoter. Both male and female HOM-Gs mice exhibit increased bone turnover with overactive osteoblasts and osteoclasts, resulting in a high bone mass phenotype with significantly reduced bone quality. At 9 weeks of age, HOM-Gs mice have increased trabecular number, volumetric BMD (vBMD), and bone volume; however, the bone was woven and disorganized. There was also increased cortical bone volume despite an overall reduction in size in HOM-Gs mice along with increased cortical porosity and brittleness. The skeletal phenotype of HOM-Gs mice progressed into maturity at 26 weeks of age with further accrual of trabecular bone, whereas WT mice lost trabecular bone at this age. Although cortical bone volume and geometry were similar between mature HOM-Gs and WT mice, increased porosity persisted and the bone was weaker. At the cellular level, these alterations were mediated by an increase in bone resorption by osteoclasts and an overwhelmingly higher increase in bone formation by osteoblasts. In summary, our findings demonstrate that high osteoblastic Gα_S expression results in aberrant skeletal development in which bone production is favored at the cost of bone quality. © 2017 American Society for Bone and Mineral Research.

Predicting Adherence and Persistence with Oral Bisphosphonate Therapy in an Integrated Health Care Delivery System

BACKGROUND

Examining drug exposure is essential to pharmacovigilance, especially for bisphosphonate (BP) therapy.

OBJECTIVE

To examine differences in 4 measures of oral BP exposure: treatment discontinuation, adherence, persistence, and nonpersistence.

METHODS

Among women aged ≥ 50 years who initiated oral BP therapy during 2002-2007 with at least 3 years of health plan membership follow-up, discontinuation was defined by evidence of no further treatment during the study observation period. Among those with at least 2 filled BP prescriptions during the study period, adherence was calculated for each year of follow-up using the (modified) proportion of days covered (mPDC) metric that allows for stockpiling of prescription/refills overlap ≤ 30 days supply. Persistence was quantified by treatment duration, allowing a gap of up to 60 days between prescription/refill days covered. Nonpersistence was quantified by the periods without drugs outside this allowable gap. Multivariable logistic regression was used to compare age and race groups and the relationships of early adherence (adherence during the first year) with subsequent adherence.

RESULTS

Among 48,390 women initiating oral BP therapy and followed for 3 years, 26.7% discontinued in year 1, and 14.7% of the remaining 35,456 women discontinued in year 2. Discontinuation rates were slightly higher (29.4%, P < 0.001) for women aged ≥ 75 years and somewhat lower (21.1%, P < 0.001) for Asian women. During the first year, 60.4% of the women achieved an mPDC of ≥ 75%, with demographic differences in adherence similar to that seen for treatment discontinuation. Over the 3 years, the median mPDC levels for BP therapy were 86%, 84%, and 85% in years 1, 2, and 3, respectively, for those receiving treatment. Cumulative persistence was 2.3 years (median, IQR = 1.0-3.0) overall and slightly greater for Asian versus white women and lower for older women. There were 18,174 (42.9%) women with at least 1 period of nonpersistence during 3 years follow-up in excess of the 60-day allowable gap between prescription/refills (median cumulative nonpersistence = 0.65, IQR = 0.30-1.25 years). Women with mPDC ≥ 75% during the first year had a 12-fold and 6-fold increased odds of mPDC ≥ 75% during year 2 and year 3, respectively.

CONCLUSIONS

BP discontinuation rates are highest for women during the first year. Among those continuing treatment in subsequent years, adherence rates were relatively stable. Persistence and adherence varied slightly by age and was somewhat higher in Asians, contributing to differences in cumulative BP exposure. We also found evidence that optimal adherence in the first year was highly predictive of optimal adherence in the subsequent 1-2 years. Hence, subgroups of patients receiving oral BP drugs may require different levels of support and monitoring to maximize treatment benefit, especially based on early patterns of use.

DISCLOSURES

This study was supported by grants from the Kaiser Permanente Northern California Community Benefit Program and the National Institutes of Health, 1R01AG047230-01A1. The opinions expressed in this publication are solely the responsibility of the authors and do not represent the official views of Kaiser Permanente or the National Institutes of Health. Hui, Yi, and Chandra have received past research funding from Amgen not related to the current study. Adams has received research funding from Amgen, Merck, and Otsuka not related to the current study. Niu has received research funding from Bristol-Myers Squibb not related to the current study. Ettinger has received past legal fees in litigation involving Fosamax. Lo has received past research funding from Amgen and current research funding from Sanofi not related to the current study. The data from this study were presented at the Academy of Managed Care Pharmacy Annual Meeting; April 19-22, 2016; San Francisco, California. Study concept and design were contributed primarily by Hui and Lo, along with Adams, Niu, Yi, and Ettinger. Hui took the lead in data collection, along with Chandra, and data interpretation was performed by Niu, Yi, and Lo, along with the other authors. The manuscript was written by Hui, Adams, and Lo, along with Niu, Yi, and Ettinger, and revised by Ettinger, Hui, Lo, and Niu, along with the other authors.

Racial-Ethnic Differences in Fall Prevalence among Older Women: A Cross-Sectional Survey Study

Background

Falls are the leading cause of hip fracture in older women, with important public health implications. Fall risk increases with age and other clinical factors, and varies by race/ethnicity. International studies suggest that fall risk is lower in Asians, although data are limited in U.S. populations. This study examines racial/ethnic differences in fall prevalence among older U.S. women within a large integrated healthcare delivery system.

Methods

This cross-sectional study used data from 6277 women ages 65–90 who responded to the 2008 or 2011 Kaiser Permanente Northern California Member Health Survey (KPNC-MHS). The KPNC-MHS is a mailed questionnaire sent to a random sample of adult members stratified by age, gender, and geographic location, representing a population estimate of >200,000 women age ≥65 years. Age, race/ethnicity, self-reported health status, presence of diabetes, arthritis or prior stroke, mobility limitations and number of falls in the past year were obtained from the KPNC-MHS. The independent association of race/ethnicity and recent falls was examined, adjusting for known risk factors.

Results

The weighted sample was 76.7% non-Hispanic white, 6.2% Hispanic, 6.8% black and 10.3% Asian. Over 20% reported having fallen during the past year (28.5% non-Hispanic white, 27.8% Hispanic, 23.4% black and 20.1% Asian). Older age was associated with greater fall risk, as was having diabetes (OR 1.24, CI 1.03–1.48), prior stroke (OR 1.51, CI 1.09–2.07), arthritis (OR 1.61, CI 1.39–1.85) and mobility limitations (OR 2.82, CI 2.34–3.39), adjusted for age. Compared to whites, Asian (OR 0.64, CI 0.50–0.81) and black (OR 0.73, CI 0.55–0.95) women were much less likely to have ≥1 fall in the past year, adjusting for age, comorbidities, mobility limitation and poor health status. Asians were also less likely to have ≥2 falls (OR 0.62, CI 0.43–0.88).

Conclusions

Among older women, the risk of having a recent fall was substantially lower for black and Asian women when compared to white women. This may contribute to their lower rates of hip fracture. Future studies should examine cultural and behavioral factors that contribute to these observed racial/ethnic differences in fall risk among U.S. women.

Applying ethnic-specific bone mineral density T-scores to Chinese women in the USA

Caucasian reference data are used to classify bone mineral density in US women of all races. However, use of Chinese American reference data yields lower osteoporosis prevalence in Chinese women. The reduction in osteoporosis labeling may be relevant for younger Chinese women at low fracture risk.

INTRODUCTION

Caucasian reference data are used for osteoporosis classification in US postmenopausal women regardless of race, including Asians who tend to have lower bone mineral density (BMD) than women of white race. This study examines BMD classification by ethnic T-scores for Chinese women.

METHODS

Using BMD data in a Northern California healthcare population, Chinese women aged 50-79 years were compared to age-matched white women (1:5 ratio), with femoral neck (FN), total hip (TH), and lumbar spine (LS) T-scores calculated using Caucasian versus Chinese American reference data.

RESULTS

Comparing 4039 Chinese and 20,195 white women (44.8 % age 50-59 years, 37.5 % age 60-69 years, 17.7 % age 70-79 years), Chinese women had lower BMD T-scores at the FN, TH, and LS (median T-score 0.29-0.72 units lower across age groups, p < 0.001) using Caucasian reference data. Using Chinese American BMD reference data resulted in an average +0.47, +0.36, and +0.48 units higher FN, TH, and LS T-scores, respectively, reducing the prevalence of osteoporosis (T-score ≤ -2.5) in Chinese women at the FN (16.7 to 6.6 %), TH (9.8 to 3.2 %), and LS (23.2 to 8.9 %); osteoporosis prevalence at any one of three sites fell from 29.6 to 12.6 % (22.4 to 8.1 % for age 50-64 years and 43.2 to 21.0 % for age 65-79 years).

CONCLUSION

Use of Chinese American BMD reference data yields higher (ethnic) T-scores by 0.4-0.5 units, with a large proportion of Chinese women reclassified from osteoporosis to osteopenia. The reduction in osteoporosis labeling with ethnic T-scores may be relevant for younger Chinese women at low fracture risk.

Outcomes of trauma admission for falls: influence of race and age on inhospital and post-discharge mortality

BACKGROUND

Racial disparities in trauma outcomes occur, but disparities in fall mortality are unknown. The objective of this study was to determine inhospital and 1-year fall mortality among patients discharged from an urban trauma center.

METHODS

We conducted a retrospective analysis of fall patients in our trauma registry (1997 to 2008) linked to the National Death Index to determine postdischarge mortality. Statistical analysis included chi-square tests, multivariable logistic regression, and Cox proportional hazards models.

RESULTS

There were 7,541 fall admissions. There was no clinically significant difference in inhospital mortality between blacks and whites with age stratification. One year after discharge, blacks younger than 65 years were more likely to die of disease (hazard ratio, 1.37; 95% confidence interval, 1.14 to 1.62).

CONCLUSIONS

Although rates of inhospital mortality are similar, blacks younger than 65 years have a higher risk of dying after discharge due to disease when stratified by age highlighting the need for continued medical follow-up and prevention efforts.

Trends in the incidence of atypical femoral fractures and bisphosphonate therapy

PURPOSE

To report the trends in the incidence of typical and atypical femoral fractures (AFF) in patients aged >50 years from 2009 to 2014 and in the prescription of bisphosphonates for osteoporosis from 2001 to 2013 in Australia.

METHODS

175 patients aged >50 years presenting to our hospital with an AO type 32 femoral shaft fracture between October 2009 and October 2014 were identified using a trauma database. Of them, 21 male and 110 female patients with a mean age of 75 years were reviewed. Radiographs were reviewed by 2 investigators blinded to the use of bisphosphonates. The femoral shaft fractures were classified as typical or atypical using the American Society of Bone and Mineral Research definition, and their annual incidence was compared. The trend and number of prescriptions for various bisphosphonates in Australia was determined using the Pharmaceutical Benefits Scheme statistics from 2001 to 2013.

RESULTS

Of the 131 femoral shaft fractures, 65 were typical and 66 were atypical subtrochanteric (n=19) or diaphyseal (n=47) fractures that were complete (n=60) or incomplete (n=6). Four patients had sequential bilateral AFF. The 66 AFFs accounted for 5% of hip and shaft fractures. Women accounted for 80% of all femoral shaft fractures and 95% of AFF. The proportion of AFF was higher in women than men (63/110 vs. 3/21, relative risk=3.95, 95% CI=1.37- 11.39, p=0.0006). The mean length of hospital stay was 9.7 days shorter in the AFF patients (14.1 vs. 23.8 days, 95% CI=2.6-16.8 days, p=0.008). Patients with AFF were 8 years younger than those with proximal femoral fracture (73 vs. 81 years, p<0.0001). There was no trend in the annual incidence or proportion of AFF from 2009 to 2014 (p=0.70). The bisphosphonate usage was highest in 2007 with 260 000 yearly patient treatments and had declined by 30% by the end of 2013.

CONCLUSION

AFF accounted for half of all femoral shaft fractures in patients aged >50 years. Women accounted for 80% of all femoral shaft fractures and 95% of AFF. The incidence of AFF was no longer increasing possibly related to decreased prescription of bisphosphonates in preceding years.

The association of race/ethnicity and risk of atypical femur fracture among older women receiving oral bisphosphonate therapy

PURPOSE

Several epidemiologic studies suggest that compared to white women, Asians have a greater propensity to suffer an atypical femur fracture (AFF) while taking bisphosphonate therapy. This study examines the relative risk of AFF following bisphosphonate initiation for Asian compared to white women.

METHODS

Using data from a large integrated northern California healthcare delivery system, we examined diaphyseal femur fracture outcomes among women age≥50years old who initiated oral bisphosphonate therapy during 2002-2007. An AFF was defined by the 2013 American Society of Bone and Mineral Research Task Force criteria. The risk of radiographically-confirmed AFF was examined for Asian compared to white women, adjusting for differences in bisphosphonate exposure and other potential risk factors.

RESULTS

Among 48,390 women (65.3% white, 17.1% Asian) who newly initiated bisphosphonate therapy and were followed for a median of 7.7years, 68 women experienced an AFF. The rate of AFF was 18.7 per 100,000 person-years overall and eight-fold higher among Asian compared to white women (64.2 versus 7.6 per 100,000 person-years). Asians were also more likely to have longer bisphosphonate treatment duration compared to whites (median 3.8 versus 2.7years). The age-adjusted relative hazard for AFF was 8.5 (95% confidence interval 4.9-14.9) comparing Asian to white women, and was only modestly reduced to 6.6 (3.7-11.5) after adjusting for bisphosphonate duration and current use.

CONCLUSIONS

Our study confirms marked racial disparity in AFF risk that should be further investigated, particularly the mechanisms accounting for this difference. These findings also underscore the need to further examine the association of bisphosphonate duration and AFF in women of Asian race, as well as differential risk across Asian subgroups. In the interim, counseling of Asian women about osteoporosis drug continuation should include consideration of their potentially higher AFF risk.