Corrigendum: Development and validation of a prognostic model for predicting 30-day mortality risk in medical patients in emergency department (ED).

This corrects the article DOI: 10.1038/srep46474.

Development and validation of a prognostic model for predicting 30-day mortality risk in medical patients in emergency department (ED).

The primary aim of this prospective study is to develop and validate a new prognostic model for predicting the risk of mortality in Emergency Department (ED) patients. The study involved 1765 patients in the development cohort and 1728 in the validation cohort. The main outcome was mortality up to 30 days after admission. Potential risk factors included clinical characteristics, vital signs, and routine haematological and biochemistry tests. The Bayesian Model Averaging method within the Cox's regression model was used to identify independent risk factors for mortality. In the development cohort, the incidence of 30-day mortality was 9.8%, and the following factors were associated with a greater risk of mortality: male gender, increased respiratory rate and serum urea, decreased peripheral oxygen saturation and serum albumin, lower Glasgow Coma Score, and admission to intensive care unit. The area under the receiver operating characteristic curve for the model with the listed factors was 0.871 (95% CI, 0.844-0.898) in the development cohort and 0.783 (95% CI, 0.743-0.823) in the validation cohort. Calibration analysis found a close agreement between predicted and observed mortality risk. We conclude that the risk of mortality among ED patients could be accurately predicted by using common clinical signs and biochemical tests.

Contribution of Quadriceps Weakness to Fragility Fracture: A Prospective Study.

The association between muscle weakness and fracture is not well understood. This study sought to examine the contribution of muscle strength at baseline and change in muscle strength to the observed risk of fragility fracture in older people. The study involved 595 men and 1066 women aged 60+ years (median 69 years) who had been followed for a median of 11 years (range, 4 to 22 years). Quadriceps isometric muscle strength (MS) measured at baseline and biennially was adjusted for height. Femoral neck bone mineral density (FNBMD) was measured by DXA. Low-trauma fracture was ascertained from X-ray reports and interview. The relationship between baseline MS and serial MS and fracture assessed by time-invariant and time-variant Cox's regression models was expressed as hazard ratio (HR) and 95% confidence interval (CI). During the follow-up period, 282 (26%) women and 89 (15%) men sustained a fragility fracture. From age 60 years, women lost 0.28 kg/m (1.6%) of MS per year, whereas men lost 0.39 kg/m (1.5%) of MS per year. In the time-variant model, using serial MS, each 1 SD (4.7 kg/m) lower MS was associated with a 27% increase in the risk of fracture in women (HR 1.27; 95% CI, 1.11 to 1.43); and 46% increase in men (HR 1.46; 95% CI, 1.22 to 1.75). After adjusting for FNBMD, age and prior fracture, history of fall and smoking, HR per SD of lower MS was 1.13 (95% CI, 0.99 to 1.28) for women and 1.35 (95% CI, 1.18 to 1.64) for men. These data indicate that muscle weakness is an independent determinant of fracture risk in men, but not in women. This sex difference suggests that apart from mechanical load effect of muscle on bone, there are other muscle-bone interactions that need to be investigated in future studies. The accuracy of fracture risk prediction for men may be improved by incorporating muscle strength.

Prognostic performance of the Rapid Emergency Medicine Score (REMS) and Worthing Physiological Scoring system (WPS) in emergency department.

BACKGROUND: The Rapid Emergency Medicine Score (REMS) and Worthing Physiological Scoring system (WPS) have been developed for predicting in-hospital mortality in nonsurgical emergency department (ED) patients. The prognostic performance of the scoring systems in independent populations has not been clear. The aim of the study is to evaluate the prognostic accuracy of REMS and WPS systems in the estimation of 30-day mortality risk among medical patients in ED. METHODS: The study was designed as a prospective investigation, with the setting being the ED of the National Hospital of Can Tho, Vietnam. We enrolled medical patients aged 16+ years who met the study entry criteria. Clinical data were obtained as required for each scoring system. The primary outcome was mortality within 30 days since hospitalization. The association between each scoring system and mortality was assessed by the hazard ratio (HR) of the Cox's proportional hazard model. RESULTS: The study involved 1746 patients, average age 65.9 years (SD 17). During the period of follow-up, 172 patients (9.9 %) died. The risk of 30-day mortality was increased by 30 % for each additional REMS unit (HR: 1.28; 95 % confidence interval (CI): 1.23-1.34) and by 60 % for each additional WPS unit (HR: 1.6; 95 % CI: 1.5-1.7). The AUC of the REMS was 0.71 (95 % CI: 0.67-0.76) which was significantly lower than that of the WPS (0.80; 95 % CI: 0.76-0.83). CONCLUSIONS: Both REMS and WPS have good prognostic value in the prediction of death in ED patients. The WPS appeared to have a better prognostic performance than the REMS system.

External validation of the Garvan nomograms for predicting absolute fracture risk: the Tromsø study.

BACKGROUND: Absolute risk estimation is a preferred approach for assessing fracture risk and treatment decision making. This study aimed to evaluate and validate the predictive performance of the Garvan Fracture Risk Calculator in a Norwegian cohort. METHODS: The analysis included 1637 women and 1355 aged 60+ years from the Tromsø study. All incident fragility fractures between 2001 and 2009 were registered. The predicted probabilities of non-vertebral osteoporotic and hip fractures were determined using models with and without BMD. The discrimination and calibration of the models were assessed. Reclassification analysis was used to compare the models performance. RESULTS: The incidence of osteoporotic and hip fracture was 31.5 and 8.6 per 1000 population in women, respectively; in men the corresponding incidence was 12.2 and 5.1. The predicted 5-year and 10-year probability of fractures was consistently higher in the fracture group than the non-fracture group for all models. The 10-year predicted probabilities of hip fracture in those with fracture was 2.8 (women) to 3.1 times (men) higher than those without fracture. There was a close agreement between predicted and observed risk in both sexes and up to the fifth quintile. Among those in the highest quintile of risk, the models over-estimated the risk of fracture. Models with BMD performed better than models with body weight in correct classification of risk in individuals with and without fracture. The overall net decrease in reclassification of the model with weight compared to the model with BMD was 10.6% (p = 0.008) in women and 17.2% (p = 0.001) in men for osteoporotic fractures, and 13.3% (p = 0.07) in women and 17.5% (p = 0.09) in men for hip fracture. CONCLUSIONS: The Garvan Fracture Risk Calculator is valid and clinically useful in identifying individuals at high risk of fracture. The models with BMD performed better than those with body weight in fracture risk prediction.

Association between fat-mass-and-obesity-associated (FTO) gene and hip fracture susceptibility.

OBJECTIVE: Common variants in the fat-mass-and-obesity-associated (FTO) gene are related to body mass index (BMI), which is a predictor of hip fracture risk. This study sought to examine the association between variants in the FTO gene and hip fracture risk. DESIGN AND PARTICIPANTS: This is a prospective study including 934 postmenopausal women aged 60 years and above living in Dubbo, Australia (Dubbo Osteoporosis Epidemiology Study), followed up between 1989 and 2007. MEASUREMENTS: Six single nucleotide polymorphisms (SNPs) (rs1421085, rs1558902, rs1121980, rs17817449, rs9939609 and rs9930506) of the FTO gene were genotyped using Taqman assay. Bone mineral density at the lumbar spine and femoral neck was measured by DXA (GE-Lunar) at baseline. Incidence of hip fractures during the follow-up was ascertained by reviewing X-ray reports. We used Cox's models to estimate the association between the genetic variants and hip fracture risk. We also utilized Bayes factor to evaluate the association. RESULTS: One hundred and two women (11%) had sustained a hip fracture. The incidence of hip fracture was greater in women homozygous for the minor allele of all SNPs. Women homozygous for the minor allele (AA) of rs1121980 had significantly higher risk of hip fracture (hazard ratio, 2.06; 95% CI 1.17-3.62) than women homozygous for the major allele (TT). The observed data favoured the hypothesis of FTO gene and fracture association over the hypothesis of nonassociation by a factor of nine. CONCLUSION: Common variations in the FTO gene are associated with hip fracture risk in women and that FTO gene may help improve the predictive value of hip fracture risk.

Quantification of the relative contribution of estrogen to bone mineral density in men and women.

BACKGROUND: The study quantified the relative contributions of estrogen (E2) and total testosterone (TT) to variation in bone mineral density in men and women. METHODS: This was a cross-sectional study which involved 200 men and 415 women aged 18 to 89 years. BMD at the lumbar spine (LS) and femoral neck (FN) was measured by DXA. Serum levels of E2 and TT were measured by electrochemiluminescence immunoassays. The association between E2, TT, and BMD was analyzed by the multiple linear regression model, adjusting for age and BMI. The contribution of each hormone to the variation in BMD was quantified by the bootstrap method. RESULTS: In women, higher serum levels of E2, but not TT, were significantly associated with greater BMD at the FN (P = 0.001) and LS (P < 0.0001). In men, higher serum levels of E2 were independently associated with greater FNBMD (P = 0.008) and LSBMD (P = 0.086). In the multiple linear regression model, age, body weight and E2 accounted for 50-55% variance in FNBMD, and 25% (in men) and 48% (in women) variance in LSBMD. Variation in E2 accounted for 2.5% (95% CI 0.4-7.8%) and 11.3% (95% CI 8.1-15.3%) variation in FNBMD in men and women, respectively. Moreover, E2 contributed 1.2% (95% CI 0.1-5.8%) and 11.7% (95% CI 8.5-15.9%) variation in LSBMD in men and women, respectively. CONCLUSIONS: Estrogen is more important than testosterone in the determination of age-related bone mineral density men and women of Vietnamese background. However, the relative contributions of estrogen to bone mineral density in men are likely modest.

Excess mortality attributable to hip-fracture: a relative survival analysis.

INTRODUCTION: Individuals with hip fracture are at substantially increased risk of mortality. The aim of this study was to estimate the excess mortality attributable to hip fracture in elderly men and women. METHODS: The Dubbo Osteoporosis Epidemiology Study was designed as a prospective epidemiologic investigation, in which more than 2000 men and women aged 60+ as of 1989 had been followed for 21 years. During the follow-up period, the incidence of atraumatic hip fractures was ascertained by X-ray reports, and mortality was ascertained by the New South Wales Birth, Death and Marriage Registry. Relative survival ratios were estimated by taking into account the age-and-sex specific expected survival in the general Australian population from 1989 to 2010. RESULTS: During the follow-up period 151 women and 55 men sustained a hip fracture. Death occurred in 86 (57%) women and 36 (66%) men. In women, the cumulative relative survival post hip-fracture at 1, 5 and 10 years was 0.83 (95% confidence interval (CI) 0.76-0.89), 0.59 (95% CI 0.48-0.68), and 0.31 (95% CI 0.20-0.43), respectively; in men, the corresponding estimates of relative survival were: 0.63 (95% CI 0.48-0.75), 0.48 (95% CI 0.32-0.63), and 0.36 (95% CI 0.18-0.56). On average post hip-fracture women died 4 years earlier (median: 4.1, inter-quartile range (IQR) 1.7-7.8) and men died 5 years earlier (median = 4.8, IQR 2.4-7.0) than expected. For every six women and for every three men with hip fracture one extra death occurred above that expected in the background population. CONCLUSION: Hip fracture is associated with reduced life expectancy, with men having a greater reduction than women, even after accounting for time-related changes in background mortality in the population. These data underscore that hip fracture is an independent clinical risk factor for mortality.

Association between abdominal obesity and fracture risk: a prospective study.

CONTEXT: Higher body weight is associated with greater bone mineral density (BMD) and lower fracture risk. However, the relationship between abdominal fat mass (aFM) and fracture risk is unclear because of limited prospective data. The present study sought to examine the association between aFM, BMD, and fracture risk. METHODS: The study was designed as a prospective investigation, in which a sample of 1126 participants (360 men and 766 women) aged 50 years or older had been continuously followed up for an average of 5 years. The mean age of participants was 71 years (range, 57-94 years). At baseline, BMD at the femoral neck and lumbar spine and aFM were measured by dual-energy X-ray absorptiometry. The incidence of low-trauma and nonpathological fractures was ascertained prospectively from X-ray reports. RESULTS: During the follow-up period, 19 men and 107 women had sustained a fracture. In women, each 1-kg lower aFM was associated with a 50% higher risk of fracture (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.10-2.05) after adjustment for age, femoral neck BMD, falls, stature, physical activity, and prior fracture. Subgroup analysis by fracture type found that the association was mainly observed in clinical vertebral fracture (HR, 1.96; 95% CI, 1.22-3.13). In men, although there was no statistically significant association between aFM and fracture risk (HR, 1.15; 95% CI, 0.58-2.25), the strength of this finding is affected negatively by the low number of fractures. CONCLUSIONS: Lower abdominal fat was significantly associated with an higher fracture risk in women.

Progressively increasing fracture risk with advancing age after initial incident fragility fracture: the Tromsø study.

The risk of subsequent fracture is increased after initial fractures; however, proper understanding of its magnitude is lacking. This population-based study examines the subsequent fracture risk in women and men by age and type of initial incident fracture. All incident nonvertebral fractures between 1994 and 2009 were registered in 27,158 participants in the Tromsø Study, Norway. The analysis included 3108 subjects with an initial incident fracture after the age of 49 years. Subsequent fracture (n = 664) risk was expressed as rate ratios (RR) and absolute proportions irrespective of death. The rates of both initial and subsequent fractures increased with age, the latter with the steepest curve. Compared with initial incident fracture rate of 30.8 per 1000 in women and 12.9 per 1000 in men, the overall age-adjusted RR of subsequent fracture was 1.3 (95% CI, 1.2-1.5) in women, and 2.0 (95% CI, 1.6-2.4) in men. Although the RRs decreased with age, the absolute proportions of those with initial fracture who suffered a subsequent fracture increased with age; from 9% to 30% in women and from 10% to 26% in men, between the age groups 50-59 to 80+ years. The type of subsequent fracture varied by age from mostly minor fractures in the youngest to hip or other major fractures in the oldest age groups, irrespective of type and severity of initial fracture. In women and men, 45% and 38% of the subsequent hip or other major fractures, respectively, were preceded by initial minor fractures. The risk of subsequent fracture is high in all age groups. At older age, severe subsequent fracture types follow both clinically severe and minor initial incident fractures. Any fragility fracture in the elderly reflects the need for specific osteoporosis management to reduce further fracture risk.

Compound risk of high mortality following osteoporotic fracture and refracture in elderly women and men.

After fracture there is increased risk of refracture and premature mortality. These outcomes, particularly premature mortality following refracture, have not previously been studied together to understand overall mortality risk. This study examined the long-term cumulative incidence of subsequent fracture and total mortality with mortality calculated as a compound risk and separated according to initial and refracture. Community-dwelling participants aged 60+ years from Dubbo Osteoporosis Epidemiology Study with incident fractures, followed prospectively for further fractures and deaths from 1989 to 2010. Subsequent fracture and mortality ascertained using cumulative incidence competing risk models allowing four possible outcomes: death without refracture; death following refracture; refracture but alive, and event-free. There were 952 women and 343 men with incident fracture. Within 5 years following initial fracture, 24% women and 20% men refractured; and 26% women and 37% men died without refracture. Of those who refractured, a further 50% of women and 75% of men died, so that total 5-year mortality was 39% in women and 51% in men. Excess mortality was 24% in women and 27% in men. Although mortality following refracture occurred predominantly in the first 5 years post-initial fracture, total mortality (post-initial and refracture) was elevated for 10 years. Most of the 5-year to 10-year excess mortality was associated with refracture. The long-term (>10 years) refracture rate was reduced, particularly in the elderly as a result of their high mortality rate. The 30% alive beyond 10 years postfracture were at low risk of further adverse outcomes. Refractures contribute substantially to overall mortality associated with fracture. The majority of the mortality and refractures occurred in the first 5 years following the initial fracture. However, excess mortality was observed for up to 10 years postfracture, predominantly related to that after refracture.

Ten-year risk of second hip fracture. A NOREPOS study.

BACKGROUND: Second hip fracture risk is elevated after the first, however whether risk differs with age, by sex or over time is not well known. OBJECTIVE: To examine the risk of second hip fracture by sex, age and time after first hip fracture. DESIGN: Data on all hip fractures in subjects 50 years and older and treated in Norwegian hospitals during 1999-2008 were retrieved. Surgical procedure codes and additional diagnosis codes were used to define incident fractures. Survival analyses with and without adjustment for competing risk of death were used to estimate the risk of second hip fracture. RESULTS: Among the 81,867 persons who sustained a first hip fracture, 6161 women and 1782 men suffered a second hip fracture during follow-up. The overall age-adjusted hazard ratio (HR) of a second hip fracture did not differ between the sexes (women versus men, HR=1.03; 95% confidence interval (CI): 0.98-1.09). Taking competing risk of death into account, the corresponding age-adjusted HR of a second hip fracture was 1.40 (95% CI: 1.33-1.47) in women compared to men. The greater risk in women was due to a higher mortality in men. Based on competing risk analyses, we estimate that 15% of women and 11% of men will have suffered a second hip fracture within 10 years after the first hip fracture. The ten-year cumulative incidence was above 10% in all age-groups, except in men 90 years and older. CONCLUSION: Fracture preventive strategies have a large potential in both women and men who suffer their first hip fracture due to the high risk of another hip fracture.

Serum level of under-carboxylated osteocalcin and bone mineral density in early menopausal Norwegian women.

PURPOSE: Serum level of under-carboxylated osteocalcin (ucOC) is considered a sensitive measure of vitamin K status, and ucOC levels are associated with bone mineral density (BMD) and fracture risk in elderly persons. The aim of this study was to assess the relationship between ucOC and BMD in early menopausal women. METHODS: The data reported here come from the enrollment in a double-blinded placebo-controlled randomized trial comprising 334 healthy Norwegian women between 50 and 60 years, 1-5 years after menopause, not using warfarin or medication known to affect bone metabolism. Total hip, femoral neck, lumbar spine, and total body BMD and serum level of ucOC and total osteocalcin were measured, and information of lifestyle was collected through questionnaires. The association between ucOC and BMD at all measurement sites was assessed by multiple regression analyses adjusting for possible confounding variables. RESULTS: The absolute serum level of ucOC was significantly and negatively associated with BMD at all measurements sites, both in univariate analyses (p < 0.01) and in multivariate analyses adjusting for years since menopause, smoking status and weight (p < 0.01). However, serum ucOC, expressed as percentage of the total osteocalcin level, was not associated with BMD at any site. CONCLUSIONS: Achievement of adequate vitamin K nutritional intake is important, but ucOC expressed as percentage of total osteocalcin levels as reflection of vitamin K status does not seem to play a central role in determining BMD levels in early menopausal women.

Reference ranges for vertebral heights and prevalence of asymptomatic (undiagnosed) vertebral fracture in Vietnamese men and women.

UNLABELLED: Based on quantitative measurements of vertebral heights, the prevalence of undiagnosed vertebral fracture in Vietnamese men and women aged 50 years and older was 23 and 26 %, respectively. BACKGROUND: The present study sought to develop reference ranges for vertebral heights and to determine the prevalence of asymptomatic vertebral fracture in Vietnamese men and women. METHODS: The study included 312 men and 657 women aged over 18 who were randomly selected from the community. The ImageJ software program was used to measure anterior height (H(a)), middle height (H(m)), and posterior height (H(p)) for each vertebra (T4 to T12 and L1 to L5). Four vertebral ratios were determined: H(a)/H(p), H(m)/H(p), H(p)/H(p + 1), and H(p)/H(p − 1). Reference ranges for the ratios were then developed by the method of Winsorized mean. Vertebral fracture was diagnosed as a ratio lower than three standard deviations from the normal mean. RESULTS: For any given vertebra, H(a), H(m), and H(p) in men were higher than in women. In both sexes, H(a) and H(m) increased in a stepwise fashion from T4 to L3 and then gradually reduced in L4­L5. Vertebral heights for T4­T9 tended to decrease, while vertebral height for T10­L5 tended to increase with advancing age. Among those aged over 50 years, the prevalence of vertebral fracture in men was 23.3 % (95 % confidence interval (CI) 16.8­31.3 %) which was lower than that in women (26.5 %; 95 % CI 22.4­31.1 %). The prevalence increased with advancing age, such that from the age of over 70, 41 % of men and 42 % women had at least one vertebral fracture. CONCLUSION: One fourth of Vietnamese men and women aged 50 years and older have a symptomatic vertebral fracture. This prevalence is equivalent to that in Caucasian populations.

Important risk factors and attributable risk of vertebral fractures in the population-based Tromsø study.

BACKGROUND: Vertebral fractures, the most common type of osteoporotic fractures, are associated with increased risk of subsequent fracture, morbidity, and mortality. The aim of this study was to examine the contribution of important risk factors to the variability in vertebral fracture risk. METHODS: Vertebral fracture was ascertained by VFA method (DXA, GE Lunar Prodigy) in 2887 men and women, aged between 38 and 87 years, in the population-based Tromsø Study 2007/2008. Bone mineral density (BMD; g/cm2) at the hip was measured by DXA. Lifestyle information was collected by questionnaires. Multivariable logistic regression model, with anthropometric and lifestyle factors included, was used to assess the association between each or combined risk factors and vertebral fracture risk. Population attributable risk was estimated for combined risk factors in the final multivariable model. RESULTS: In both sexes, age (odds ratio [OR] per 5 year increase: 1.32; 95% CI 1.19-1.45 in women and 1.21; 95% CI 1.10-1.33 in men) and BMD (OR per SD decrease: 1.60; 95% CI 1.34-1.90 in women and1.40; 95% CI 1.18-1.67 in men) were independent risk factors for vertebral fracture. At BMD levels higher than 0.85 g/cm2, men had a greater risk of fracture than women (OR 1.52; 95% CI 1.14-2.04), after adjusting for age. In women and men, respectively, approximately 46% and 33% of vertebral fracture risk was attributable to advancing age (more than 70 years) and low BMD (less than 0.85 g/cm2), with the latter having a greater effect than the former. CONCLUSIONS: These data confirm that age and BMD are major risk factors for vertebral fracture risk. However, in both sexes the two factors accounted for less than half of fracture risk. The identification of individuals with vertebral fracture is still a challenge.

Association between beta-blockers and fracture risk: a Bayesian meta-analysis.

BACKGROUND: The association between beta-blockers (BB) and fracture risk is controversial, due largely to conflicting findings from previous studies. The present study sought to evaluate the effect of BB on fracture risk by using a Bayesian meta-analysis approach. METHODS AND RESULTS: We systematically retrieved 13 observational studies on the association between BB use and fracture risk. This meta-analysis involved more than 907,000 men and women with mean/median age of individual studies ranging from 43 to 81 years. We used a hierarchical Bayesian random effects model to synthesize the results. BB use was associated with an average 17% reduction in the risk of any fracture (risk ratio [RR] 0.83; 95% credible interval [CrI]: 0.71-0.93), hip fracture (RR 0.83; 95% CrI: 0.70-0.92) and vertebral fracture (RR 0.81; 95% CrI: 0.61-0.99). The probability that BB use reduces fracture risk by at least 10% was 0.91. CONCLUSIONS: Beta-blockers are associated with reduced risk of fracture in older adults, but the effect size is likely to be modest.

Prevalence of vertebral fractures in women and men in the population-based Tromsø Study.

BACKGROUND: Osteoporotic vertebral fractures are, as the hip fractures, associated with increased morbidity and mortality. Norway has one of the highest reported incidences of hip fractures in the world. Because of methodological challenges, vertebral fractures are not extensively studied. The aim of this population based study was to describe, for the first time, the age- and sex specific occurrence of osteoporotic vertebral fractures in Norway. METHODS: Data was collected in the Tromso Study, 2007/8 survey. By the use of dual x-ray absorptiometry (GE Lunar Prodigy) vertebral fracture assessments were performed in 2887 women and men aged from 38 to 87 years, in addition to measurements of bone mineral density at the femoral sites. Information on lifestyle was collected through questionnaires. Comparisons between fractures and non-fractures were done sex stratified, by univariate analyses, adjusting for age when relevant. RESULTS: The prevalence of vertebral fractures varied from about 3% in the age group below 60 to about 19% in the 70+ group in women, and from 7.5% to about 20% in men, with an overall prevalence of 11.8% in women and 13.8% in men (p = 0.07). Among those with fractures, only one fracture was the most common; two and more fractures were present in approximately 30% of the cases. Fractures were seen from the fourth lumbar to the fifth thoracic vertebrae, most common between first lumbar and sixth thoracic vertebrae. The most common type of fracture was the wedge type in both sexes. Bone mineral density at the hip differed significantly according to type of fracture, being highest in those with wedge fractures and lowest in those with compression fractures. CONCLUSIONS: The prevalence of vertebral fractures increased by age in women and men, but the overall prevalence was lower than expected, considering the high prevalence of hip and forearm fractures in Norway. In both sexes, the wedge type was the fracture type most frequently observed and most common in the thoracic region.

Absolute fracture-risk prediction by a combination of calcaneal quantitative ultrasound and bone mineral density.

Quantitative ultrasound measurement (QUS) and bone mineral density (BMD) have each been shown to predict fracture risk in women. The present study examined whether a combination of QUS and BMD could improve the predictive accuracy of fracture risk. This is a population-based prospective study which involved 454 women and 445 men aged 62-89 years. Femoral neck BMD (FNBMD) was measured by DXA and calcaneal QUS was measured as broadband ultrasound attenuation (BUA) by a CUBA sonometer. Fragility fracture was ascertained by X-ray reports during the follow-up period, which took place between mid-1989 and 2009. During the follow-up period (median 13 years, range 11-15), 75 men and 154 women sustained a fragility fracture. In women, the model with FNBMD and BUA had a higher AUC compared to that without BUA (0.73 vs. 0.71 for any fracture, 0.81 vs. 0.77 for hip fracture, and 0.72 vs. 0.70 for vertebral fracture). Reclassification analysis yielded a total net reclassification improvement of 7.3%, 11.1%, and 5.2% for any, hip, and vertebral fractures, respectively. For men, the addition of BUA to FNBMD did not improve the predictive power for any, hip, or vertebral fracture. These results suggest that calcaneal QUS is an independent predictor of fracture risk and that a combination of QUS and BMD measurement could improve the predictive accuracy of fracture risk in elderly women.

Reference ranges for bone mineral density and prevalence of osteoporosis in Vietnamese men and women.

BACKGROUND: The aim of this study was to examine the effect of different reference ranges in bone mineral density on the diagnosis of osteoporosis. METHODS: This cross-sectional study involved 357 men and 870 women aged between 18 and 89 years, who were randomly sampled from various districts within Ho Chi Minh City, Vietnam. BMD at the femoral neck, lumbar spine and whole body was measured by DXA (Hologic QDR4500). Polynomial regression models and bootstraps method were used to determine peak BMD and standard deviation (SD). Based on the two parameters, we computed T-scores (denoted by TVN) for each individual in the study. A similar diagnosis was also done based on T-scores provided by the densitometer (TDXA), which is based on the US White population (NHANES III). We then compared the concordance between TVN and TDXA in the classification of osteoporosis. Osteoporosis was defined according to the World Health Organization criteria. RESULTS: In post-menopausal women, the prevalence of osteoporosis based on femoral neck TVN was 29%, but when the diagnosis was based on TDXA, the prevalence was 44%. In men aged 50+ years, the TVN-based prevalence of osteoporosis was 10%, which was lower than TDXA-based prevalence (30%). Among 177 women who were diagnosed with osteoporosis by TDXA, 35% were actually osteopenia by TVN. The kappa-statistic was 0.54 for women and 0.41 for men. CONCLUSION: These data suggest that the T-scores provided by the Hologic QDR4500 over-diagnosed osteoporosis in Vietnamese men and women. This over-diagnosis could lead to over-treatment and influence the decision of recruitment of participants in clinical trials.