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| 2. |
- De Laet, Chris, et al.
(author)
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The impact of the use of multiple risk indicators for fracture on case-finding strategies: a mathematical approach.
- 2005
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In: Osteoporosis international. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 16:3, s. 313-8
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Journal article (peer-reviewed)abstract
- The value of bone mineral density (BMD) measurements to stratify fracture probability can be enhanced in a case-finding strategy that combines BMD measurement with independent clinical risk indicators. Putative risk indicators include age and gender, BMI or weight, prior fracture, the use of corticosteroids, and possibly others. The aim of the present study was to develop a mathematical framework to quantify the impact of using combinations of risk indicators with BMD in case finding. Fracture probability can be expressed as a risk gradient, i.e. a relative risk (RR) of fracture per standard deviation (SD) change in BMD. With the addition of other continuous or categorical risk indicators a continuous distribution of risk indicators is obtained that approaches a normal distribution. It is then possible to calculate the risk of individuals compared with the average risk in the population, stratified by age and gender. A risk indicator with a gradient of fracture risk of 2 per SD identified 36% of the population as having a higher than average fracture risk. In individuals so selected, the risk was on average 1.7 times that of the general population. Where, through the combination of several risk indicators, the gradient of risk of the test increased to 4 per SD, a smaller proportion (24%) was identified as having a higher than average risk, but the average risk in this group was 3.1 times that of the population, which is a much better performance. At higher thresholds of risk, similar phenomena were found. We conclude that, whereas the change of the proportion of the population detected to be at high risk is small, the performance of a test is improved when the RR per SD is higher, indicated by the higher average risk in those identified to be at risk. Case-finding strategies that combine clinical risk indicators with BMD have increased efficiency, while having a modest impact on the number of individuals requiring treatment. Therefore, the cost-effectiveness is enhanced.
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| 3. |
- Harvey, N. C., et al.
(author)
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FRAX predicts incident falls in elderly men : findings from MrOs Sweden
- 2016
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 27:1, s. 267-274
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Journal article (peer-reviewed)abstract
- A Summary Falls and fractures share several common risk factors. Although past falls is not included as an input variable in the FRAX calculator, we demonstrate that FRAX probability predicts risk of incident falls in the MrOs Sweden cohort. Introduction Although not included in the FRAXA (R) algorithm, it is possible that increased falls risk is partly dependent on other risk factors that are incorporated into FRAX. The aim of the present study was to determine whether fracture probability generated by FRAX might also predict risk of incident falls and the extent that a falls history would add value to FRAX. Methods We studied the relationship between FRAX probabilities and risk of falls in 1836 elderly men recruited to the MrOS study, a population-based prospective cohort of men from Sweden. Baseline data included falls history, clinical risk factors, bone mineral density (BMD) at femoral neck, and calculated FRAX probabilities. Incident falls were captured during an average of 1.8 years of follow-up. An extension of Poisson regression was used to investigate the relationship between FRAX, other risk variables, and the time-to-event hazard function of falls. All associations were adjusted for age and time since baseline. Results At enrolment, 15.5 % of the men had fallen during the preceding 12 months (past falls) and 39 % experienced one or more falls during follow-up (incident falls). The risk of incident falls increased with increasing FRAX probabilities at baseline (hazard ratio (HR) per standard deviation (SD), 1.16; 95 % confidence interval (95%CI), 1.06 to 1.26). The association between incident falls and FRAX probability remained after adjustment for past falls (HR per SD, 1.12; 95%CI, 1.03 to 1.22). High compared with low baseline FRAX score (>15 vs <15 % probability of major osteoporotic fracture) was strongly predictive of increased falls risk (HR, 1.64; 95%CI, 1.36 to 1.97) and remained stable with time. Whereas past falls were a significant predictor of incident falls (HR, 2.75; 95%CI, 2.32 to 3.25), even after adjustment for FRAX, the hazard ratio decreased markedly with increasing follow-up time. Conclusions Although falls are not included as an input variable, FRAX captures a component of risk for future falls and outperforms falls history with an extended follow-up time.
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| 4. |
- Johansson, Helena, 1981, et al.
(author)
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BMD, clinical risk factors and their combination for hip fracture prevention
- 2009
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 20:10, s. 1675-1682
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Journal article (peer-reviewed)abstract
- This study examined the effects of the use of clinical risk factors (CRFs) alone, BMD alone or the combination using the FRAXA (R) tool for the detection of women at risk of hip fracture. BMD tests alone selected women at higher risk and a greater number of hip fracture cases were identified compared to the use of CRFs alone. The combined use of CRFs and BMD identified fewer women above a threshold risk than the use of BMD alone, but with a higher hip fracture risk and thus had the more favourable positive predictive value (PPV) and number needed to treat (NNT). Algorithms have recently become available for the calculation of hip fracture probability from CRFs with and without information on femoral neck BMD. The aim of this study was to examine the effects of the use of CRFs alone, BMD alone or their combination using the FRAXA (R) tool for the detection of women at risk of hip fracture. Data from 10 prospective population based cohorts, in which BMD and CRFs were documented, were used to compute the 10-year probabilities of hip fracture calibrated to the fracture and death hazards of the UK. The effects of the use of BMD tests were examined in simulations where BMD tests were used alone, CRFs alone or their combined use. The base case examined the effects in women at the age of 65 years. The principal outcome measures were the number of women identified above an intervention threshold, the number of hip fracture cases that would be identified, the positive predicted value and the NNT to prevent a hip fracture during a hypothetical treatment with an effectiveness of 35% targeted to those above the threshold fracture risk. We also examined BMD values in women selected for treatment. Sensitivity analysis examined the effect of age and limited use of BMD resources. BMD tests alone selected women at higher risk of hip fracture than the use of CRFs alone (6.1% versus 5.3%). BMD tests alone also identified a greater number of hip fracture cases (219/1,000) compared to the use of CRFs alone (140/1,000). The combined use of CRFs and BMD identified fewer women above a threshold risk than the use of BMD alone (168/1,000 versus 219/1,000, respectively), but with a higher hip fracture risk (PPV, 8.6% versus 6.1%), and consequently a lower number needed to treat (NNT) (33 versus 47). In sensitivity analyses, the PPV and NNT were always better for the combination than either BMD or CRFs alone across all ages studied (50-70 years). The use of FRAXA (R) in combination with BMD increases the performance characteristics of fracture risk assessment.
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| 5. |
- Johansson, Helena, 1981, et al.
(author)
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High serum adiponectin predicts incident fractures in elderly men: Osteoporotic fractures in men (MrOS) Sweden
- 2012
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In: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 27:6, s. 1390-1396
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Journal article (peer-reviewed)abstract
- Adipocytes and osteoblasts share a common progenitor, and there is, therefore, potential for both autocrine and endocrine effects of adiponectin on skeletal metabolism. The aim of the present study was to determine whether high serum adiponectin was associated with an increased risk of fracture in elderly men. We studied the relationship between serum adiponectin and the risk of fracture in 999 elderly men drawn from the general population and recruited to the Osteoporotic Fractures in Men (MrOS) study in Gothenburg, Sweden. Baseline data included general health questionnaires, lifestyle questionnaires, body mass index (BMI), bone mineral density (BMD), serum adiponectin, osteocalcin, and leptin. Men were followed for up to 7.4 years (average, 5.2 years). Poisson regression was used to investigate the relationship between serum adiponectin, other risk variables and the time-to-event hazard function of fracture. Median levels of serum adiponectin at baseline were 10.4 mu g/mL (interquartile range, 7.714.3). During follow-up, 150 men sustained one or more fractures. The risk of fracture increased in parallel with increasing serum adiponectin (hazard ratio [HR]/SD, 1.46; 95% confidence interval [CI], 1.231.72) and persisted after multivariate-adjusted analysis (HR/SD, 1.30; 95% CI, 1.091.55). Serum adiponectin shows graded stepwise association with a significant excess risk of fracture in elderly men that was independent of several other risk factors for fracture. Its measurement holds promise as a risk factor for fracture in men. (C) 2012 American Society for Bone and Mineral Research.
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| 6. |
- Johansson, Helena, 1981, et al.
(author)
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Low bone mineral density is associated with increased mortality in elderly men : MrOS Sweden
- 2011
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 22:5, s. 1411-1418
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Journal article (peer-reviewed)abstract
- We studied the nature of the relationship between bone mineral density (BMD) and the risk of death among elderly men. BMD was associated with mortality risk and was independent of adjustments for other co-morbidities. A piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD was associated with a substantial excess risk of death, whilst a higher than average BMD had little impact on mortality. Previous studies have demonstrated an association between low BMD and an increased risk of death among men and women. The aim of the present study was to examine the pattern of the risk in men and its relation to co-morbidities. We studied the nature of the relationship between BMD and death among 3,014 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health questionnaires, life style questionnaires and BMD measured using DXA. Men were followed for up to 6.5 years (average 4.5 years). Poisson regression was used to investigate the relationship between BMD, co-morbidities and the hazard function of death. During follow-up, 382 men died (all-cause mortality). Low BMD at all measured skeletal sites was associated with increased mortality. In multivariate analyses, the relationship between BMD and mortality was non-linear, and a piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD is associated with a substantial excess risk of death compared to an average BMD, whereas a higher than average BMD has a more modest effect on mortality. These findings, if confirmed elsewhere, have implications for the constructing of probability-based fracture risk assessment tools.
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| 7. |
- Johansson, Helena, 1981, et al.
(author)
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Low serum vitamin D is associated with increased mortality in elderly men: MrOS Sweden
- 2012
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 23:3, s. 991-999
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Journal article (peer-reviewed)abstract
- In elderly man, low serum 25-hydroxyvitamin D (25(OH)D) was associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuated with time. The aim of the present study was to determine whether poor vitamin D status was associated with an increase in the risk of death in elderly men. We studied the relationship between serum 25(OH)D and the risk of death in 2,878 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health and lifestyle measures and serum 25(OH)D measured by competitive RIA. Men were followed for up to 8.2 years (average 6.0 years). Mortality adjusted for comorbidities decreased by 5% for each SD increase in 25(OH)D overall (gradient of risk 1.05; 95% confidence interval 0.96-1.14). The predictive value of 25(OH)D for death was greatest below a threshold value of 50-70 nmol/l, was greatest at approximately 3 years after baseline and thereafter decreased with time. Low serum 25(OH)D is associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuates with time. These findings, if causally related, have important implications for intervention in elderly men.
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| 8. |
- Johansson, Helena, 1981, et al.
(author)
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Optimization of BMD measurements to identify high risk groups for treatment--a test analysis.
- 2004
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In: Journal of bone and mineral research. - : Wiley. - 0884-0431 .- 1523-4681. ; 19:6, s. 906-13
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Journal article (peer-reviewed)abstract
- INTRODUCTION: The aim of this study was to develop a methodology to optimize the role of BMD measurements in a case finding strategy. We studied 2113 women > or = 75 years of age randomly selected from Sheffield, UK, and adjacent regions. Baseline assessment included hip BMD and clinical risk factors. Outcomes included death and fracture in women followed for 6723 person-years. MATERIALS AND METHODS: Poisson models were used to identify significant risk factors for all fractures and for death with and without BMD and the hazard functions were used to compute fracture probabilities. Women were categorized by fracture probability with and without a BMD assessment. A 10-year fracture probability threshold of 35% was taken as an intervention threshold. Discordance in categorization of risk (i.e., above or below the threshold probability) between assessment with and without BMD was examined by logistic regression as probabilities of re-classification. Age, prior fracture, use of corticosteroids, and low body mass index were identified as significant clinical risk factors. RESULTS: A total of 16.8% of women were classified as high risk based on these clinical risk factors. The average BMD in these patients was approximately 1 SD lower than in low-risk women; 21.5% of women were designated to be at high risk with the addition of BMD. Fifteen percent of all women were reclassified after adding BMD to clinical risk factors, most of whom lay near the intervention threshold. When a high probability of reclassification was accepted (without a BMD test) for high risk to low risk (p1< or = 0.8) and a low probability accepted for low to high risk (P2 < or = 0.2), BMD tests would be required in only 21% of the population. CONCLUSION: We conclude that the use of clinical risk factors can identify elderly women at high fracture risk and that such patients have a low average BMD. BMD testing is required, however, in a minority of women--a fraction that depends on the probabilities accepted for classification and the thresholds of risk chosen. These findings need to be validated in other cohorts at different ages and from different regions of the world.
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| 9. |
- Johansson, Helena, 1981, et al.
(author)
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Waning predictive value of serum adiponectin for fracture risk in elderly men: MrOS Sweden
- 2014
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 25:7, s. 1831-1836
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Journal article (peer-reviewed)abstract
- Serum adiponectin is a risk factor for fracture. The predictive value attenuates with time in elderly men so that its use for the risk assessment in the long term is questionable. The study underlines the importance of testing the long-term stability of potential risk factors. High serum adiponectin is associated with an increased risk of fracture in elderly men. The aim of the present study was to determine the impact of adiponectin on the probability of fracture as a function of time. The probability of osteoporotic fracture was computed in 989 elderly men from the MrOS study in Sweden. Baseline data included clinical risk factors for fracture, femoral neck BMD and serum adiponectin. Men were followed for up to 7.4 years with a mean follow up of 5.3 years (range 0.0-7.4 years). Poisson regression was used to model the hazard function for osteoporotic fracture and death to determine the 10 year probability of fracture. During follow up, 124 men sustained one or more osteoporotic fracture. There was a significant interaction between adiponectin and time since baseline (p = 0.026) such that the longer time since baseline, the lower the gradient of fracture risk. When using this interaction in the calculation of 10-year probability of fracture, the probabilities of osteoporotic fracture varied little over the range of adiponectin values. Serum adiponectin is a risk factor for fracture. Nevertheless, the predictive value attenuates with time so that its use for the risk assessment in the long term is questionable. This study underlines the importance of testing the long-term stability of potential risk factors that might be used in fracture risk assessment.
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| 10. |
- Johnell, Olof, et al.
(author)
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Predictive value of BMD for hip and other fractures.
- 2005
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In: Journal of bone and mineral research. - 0884-0431 .- 1523-4681. ; 20:7, s. 1185-94
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Journal article (peer-reviewed)abstract
- The relationship between BMD and fracture risk was estimated in a meta-analysis of data from 12 cohort studies of approximately 39,000 men and women. Low hip BMD was an important predictor of fracture risk. The prediction of hip fracture with hip BMD also depended on age and z score. INTRODUCTION: The aim of this study was to quantify the relationship between BMD and fracture risk and examine the effect of age, sex, time since measurement, and initial BMD value. MATERIALS AND METHODS: We studied 9891 men and 29,082 women from 12 cohorts comprising EVOS/EPOS, EPIDOS, OFELY, CaMos, Rochester, Sheffield, Rotterdam, Kuopio, DOES, Hiroshima, and 2 cohorts from Gothenburg. Cohorts were followed for up to 16.3 years and a total of 168,366 person-years. The effect of BMD on fracture risk was examined using a Poisson model in each cohort and each sex separately. Results of the different studies were then merged using weighted coefficients. RESULTS: BMD measurement at the femoral neck with DXA was a strong predictor of hip fractures both in men and women with a similar predictive ability. At the age of 65 years, risk ratio increased by 2.94 (95% CI = 2.02-4.27) in men and by 2.88 (95% CI = 2.31-3.59) in women for each SD decrease in BMD. However, the effect was dependent on age, with a significantly higher gradient of risk at age 50 years than at age 80 years. Although the gradient of hip fracture risk decreased with age, the absolute risk still rose markedly with age. For any fracture and for any osteoporotic fracture, the gradient of risk was lower than for hip fractures. At the age of 65 years, the risk of osteoporotic fractures increased in men by 1.41 per SD decrease in BMD (95% CI = 1.33-1.51) and in women by 1.38 per SD (95% CI = 1.28-1.48). In contrast with hip fracture risk, the gradient of risk increased with age. For the prediction of any osteoporotic fracture (and any fracture), there was a higher gradient of risk the lower the BMD. At a z score of -4 SD, the risk gradient was 2.10 per SD (95% CI = 1.63-2.71) and at a z score of -1 SD, the risk was 1.73 per SD (95% CI = 1.59-1.89) in men and women combined. A similar but less pronounced and nonsignificant effect was observed for hip fractures. Data for ultrasound and peripheral measurements were available from three cohorts. The predictive ability of these devices was somewhat less than that of DXA measurements at the femoral neck by age, sex, and BMD value. CONCLUSIONS: We conclude that BMD is a risk factor for fracture of substantial importance and is similar in both sexes. Its validation on an international basis permits its use in case finding strategies. Its use should, however, take account of the variations in predictive value with age and BMD.
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