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Integrating Fall Risk Assessment Into Routine Bone Density Testing
Journal of Clinical Densitometry: Assessment of Skeletal Health, vol. 15, no. 4, 480e505, 2012 Ó Copyright 2012 by The International Society for Clinical Densitometry 1094-6950/15:480e505/$36.00
2012 International Society of Clinical Densitometry Meeting Abstracts These abstracts were presented at the 2012 annual ISCD meeting and are reproduced as presented. No editorial changes have been made. measurements. Here we identify a confounder to radius BMD measurement and propose a technical approach to avoid this inaccuracy. Three technologists performed forearm BMD precision assessment in adults age 5 65 following ISCD recommendations using a GE Lunar iDXA. Each technologist scanned 30 men and 30 women (total n 5 180) twice with repositioning between scans. Mixed effects linear regression models were used to estimate least significant change (LSC). Upon demonstration of a larger than expected LSC and substantial difference between technologists, detailed visual examination of all 360 images, including bone, soft tissue, neutral and air point-typing was conducted. Potential causes of point-typing variability were explored. Upon identifying soft tissue point-typing errors, and potential causes of these errors, a second confirmatory cohort consisting of forearm scans from 62 postmenopausal women was similarly reviewed. An almost two-fold difference in one-third radius BMD LSC (0.038 to 0.073 g/cm2; p ! 0.001) was observed between technologists. Much of this appeared to result from automated soft tissue identification differences in scans from one technologist who often placed the forearm positioner with the long slots near the wrist instead of the elbow. Compared to the manufacturer’s ideal depiction, suboptimal soft tissue point-typing was present in 30/360 scans (8.3%) involving 27 individuals. The vast majority of these soft tissue point-typing errors appeared to result from inclusion of forearm positioner slots within the scan field; the others were due to clothing covering the forearm. In these 27 individuals, 24 had a paired scan correctly point-typed, thus allowing evaluation of the effect on BMD. In those with long forearm positioner slots located at the distal corners of the scan field, the mean one-third radius BMD was w7% higher (p ! 0.01). In the confirmatory cohort, a comparable frequency of soft tissue point-typing anomalies was observed, being present in 7/62 (11%).In conclusion, substantial variability in one-third radius BMD measurement reproducibility was observed between technologists. Inaccuracies in automated soft tissue detection contribute to this variability. As soft tissue point-typing errors are not visually evident on the image used for interpretation, it is probable that clinicians will not appreciate these occurrences, thereby leading to an incorrect reading. Technologists must evaluate point typing as part of routine forearm DXA analysis and, when suboptimal, immediately reacquire the scan to produce a valid measurement. Finally, ensuring the positioner is placed as recommended, with the short slots at the distal forearm, reduces likelihood of producing this long slot error.
001 Abstracts Selected as Best in Author Category INTEGRATING FALL RISK ASSESSMENT INTO ROUTINE BONE DENSITY TESTING Recipient of Best Clinician Abstract Kate Queen, Medical Director, Osteoporosis Center Cherie Shaffer, Coordinator, Osteoporosis Center; Mary Underwood, Densitometrist, Osteoporosis Center; Robyn Duncan, Physical Therapist, Osteoporosis Center Background: Most serious fractures, including 90% of hip fractures, occur in association with a fall; yet fall risk assessment is not routinely included in the clinical evaluation of fracture risk. This study was undertaken to determine if fall risk assessment could be integrated into the evaluation performed during routine bone density testing; and to evaluate the characteristics of those community dwelling adults identified to be at increased fall risk. Methods: All individuals referred to the Osteoporosis Center at MedwestHaywood for bone density testing between 4/19/10 and 8/31/11 were asked to perform Single Leg Stance, a validated tool for assessing risk of injurious falls in community dwelling older adults. Increased risk is associated with inability to stand unassisted on one foot for more than 5 seconds. History of falls over the prior 12 months based on recall was also obtained. Additional data obtained as part of routine bone density testing included: age, sex, height using stadiometer, peak height, weight, history of nonviolent fractures after the age of 40, current and prior osteoporosis medications,assessment of calcium and Vitamin D intake, risk factors for falls and VFA findings if performed. Results: 2932 individuals were evaluated. The 52 individuals for whom Z scores were reported were excluded from the analysis. Instruction in and performance of Single Leg Stance took no more than 2 minutes in this cohort of community dwelling older adults. 849 (29%) had ‘Poor Performance’ on Single Leg Stance with results ! or equal to 5 secs and 73 (3%) were ‘Too Frail To Assess’. Only 31 (1%) ‘Refused’ to perform the test. Of those 32% identified to be at increased risk for falls, 48% had Osteopenia and 28% Osteoporosis on DXA testing. 57% met NOF guidelines for pharmacologic treatment. If History of Falls based on recall was used only 230(25%)of those at risk using Single Leg Stance would have met the American Geriatric Society criteria for increased fall risk. In the 2880 individuals assessed, 60 had hip fractures and 235 had wrist fractures. Those with increased fall risk by Single Leg Stance had 42 of the 60 (70%) hip fractures; 152 of the 235 (65%) wrist fractures. Conclusions: Standardized testing for fall risk using Single Leg Stance, can be successfully integrated into routine assessment at the time of bone density testing; and used to identify a subset of community dwelling adults who are at increased risk for falls, as well as fractures, and in need of interventions focused on fall prevention strategies, in addition to standard osteoporosis therapy.
003
Abstracts Invited for Oral Presentation
A COMPARISON OF THE AUSTRALIAN FRAX AND THE GARVAN HIP FRACTURE PREDICTION MODELS USING A 10 PROSPECTIVE STUDY OF 1127 ELDERLY AUSTRALIAN WOMEN Mingxiang Yu, Shanghai Zhongshan Hospital & University of Western Australia Satvinder Dhaliwal, Curtin University; Kun Zhu, University of Western Australia & Sir Charles Gairdner Hospital; Josh Lewis, University of Western Australia & Dept of Endocrinology and Diabetes; Richard Prince, University of Western Australia & Sir Charles Gairdner Hospital
002 Abstracts Selected as Best in Author Category POSITIONER AND CLOTHING ARTIFACT CAN AFFECT ONE-THIRD RADIUS BMD MEASUREMENT Recipient of Best Technologist Abstract
Background: Fracture risk calculators have been developed to improve DXA a BMD structural measures as predictors of future fracture risk. We compared Australian FRAX and the Garvan hip fracture prediction models using a long running cohort study of older women. Methods: The study population used was the CAREES study, an ongoing population based cohort study of 1500 women with a mean age of 75 years at baseline in 1998. In this paper we report hip fracture risk prediction in a sub population of 1127 women who had a hip aBMD measurement in 1999 and in whom complete ascertainment of hip fracture incidence over 10 years is available.
Diane Krueger, University of Wisconsin Nellie Vallarta-Ast, University of Wisconsin; Jessie Libber, University of Wisconsin; Mary Checovich, University of Wisconsin; Ronald Gangnon, University of Wisconsin; Neil Binkley, University of Wisconsin Radius BMD is a valuable cortical bone measurement in clinical trials, patients with hyperparathyroidism and adults with spinal degenerative changes. However, we have observed substantial variability upon repeat of one-third radius BMD
480
2012 International Society of Clinical Densitometry Meeting Abstracts These abstracts were presented at the 2012 annual ISCD meeting and are reproduced as presented. No editorial changes have been made. measurements. Here we identify a confounder to radius BMD measurement and propose a technical approach to avoid this inaccuracy. Three technologists performed forearm BMD precision assessment in adults age 5 65 following ISCD recommendations using a GE Lunar iDXA. Each technologist scanned 30 men and 30 women (total n 5 180) twice with repositioning between scans. Mixed effects linear regression models were used to estimate least significant change (LSC). Upon demonstration of a larger than expected LSC and substantial difference between technologists, detailed visual examination of all 360 images, including bone, soft tissue, neutral and air point-typing was conducted. Potential causes of point-typing variability were explored. Upon identifying soft tissue point-typing errors, and potential causes of these errors, a second confirmatory cohort consisting of forearm scans from 62 postmenopausal women was similarly reviewed. An almost two-fold difference in one-third radius BMD LSC (0.038 to 0.073 g/cm2; p ! 0.001) was observed between technologists. Much of this appeared to result from automated soft tissue identification differences in scans from one technologist who often placed the forearm positioner with the long slots near the wrist instead of the elbow. Compared to the manufacturer’s ideal depiction, suboptimal soft tissue point-typing was present in 30/360 scans (8.3%) involving 27 individuals. The vast majority of these soft tissue point-typing errors appeared to result from inclusion of forearm positioner slots within the scan field; the others were due to clothing covering the forearm. In these 27 individuals, 24 had a paired scan correctly point-typed, thus allowing evaluation of the effect on BMD. In those with long forearm positioner slots located at the distal corners of the scan field, the mean one-third radius BMD was w7% higher (p ! 0.01). In the confirmatory cohort, a comparable frequency of soft tissue point-typing anomalies was observed, being present in 7/62 (11%).In conclusion, substantial variability in one-third radius BMD measurement reproducibility was observed between technologists. Inaccuracies in automated soft tissue detection contribute to this variability. As soft tissue point-typing errors are not visually evident on the image used for interpretation, it is probable that clinicians will not appreciate these occurrences, thereby leading to an incorrect reading. Technologists must evaluate point typing as part of routine forearm DXA analysis and, when suboptimal, immediately reacquire the scan to produce a valid measurement. Finally, ensuring the positioner is placed as recommended, with the short slots at the distal forearm, reduces likelihood of producing this long slot error.
001 Abstracts Selected as Best in Author Category INTEGRATING FALL RISK ASSESSMENT INTO ROUTINE BONE DENSITY TESTING Recipient of Best Clinician Abstract Kate Queen, Medical Director, Osteoporosis Center Cherie Shaffer, Coordinator, Osteoporosis Center; Mary Underwood, Densitometrist, Osteoporosis Center; Robyn Duncan, Physical Therapist, Osteoporosis Center Background: Most serious fractures, including 90% of hip fractures, occur in association with a fall; yet fall risk assessment is not routinely included in the clinical evaluation of fracture risk. This study was undertaken to determine if fall risk assessment could be integrated into the evaluation performed during routine bone density testing; and to evaluate the characteristics of those community dwelling adults identified to be at increased fall risk. Methods: All individuals referred to the Osteoporosis Center at MedwestHaywood for bone density testing between 4/19/10 and 8/31/11 were asked to perform Single Leg Stance, a validated tool for assessing risk of injurious falls in community dwelling older adults. Increased risk is associated with inability to stand unassisted on one foot for more than 5 seconds. History of falls over the prior 12 months based on recall was also obtained. Additional data obtained as part of routine bone density testing included: age, sex, height using stadiometer, peak height, weight, history of nonviolent fractures after the age of 40, current and prior osteoporosis medications,assessment of calcium and Vitamin D intake, risk factors for falls and VFA findings if performed. Results: 2932 individuals were evaluated. The 52 individuals for whom Z scores were reported were excluded from the analysis. Instruction in and performance of Single Leg Stance took no more than 2 minutes in this cohort of community dwelling older adults. 849 (29%) had ‘Poor Performance’ on Single Leg Stance with results ! or equal to 5 secs and 73 (3%) were ‘Too Frail To Assess’. Only 31 (1%) ‘Refused’ to perform the test. Of those 32% identified to be at increased risk for falls, 48% had Osteopenia and 28% Osteoporosis on DXA testing. 57% met NOF guidelines for pharmacologic treatment. If History of Falls based on recall was used only 230(25%)of those at risk using Single Leg Stance would have met the American Geriatric Society criteria for increased fall risk. In the 2880 individuals assessed, 60 had hip fractures and 235 had wrist fractures. Those with increased fall risk by Single Leg Stance had 42 of the 60 (70%) hip fractures; 152 of the 235 (65%) wrist fractures. Conclusions: Standardized testing for fall risk using Single Leg Stance, can be successfully integrated into routine assessment at the time of bone density testing; and used to identify a subset of community dwelling adults who are at increased risk for falls, as well as fractures, and in need of interventions focused on fall prevention strategies, in addition to standard osteoporosis therapy.
003
Abstracts Invited for Oral Presentation
A COMPARISON OF THE AUSTRALIAN FRAX AND THE GARVAN HIP FRACTURE PREDICTION MODELS USING A 10 PROSPECTIVE STUDY OF 1127 ELDERLY AUSTRALIAN WOMEN Mingxiang Yu, Shanghai Zhongshan Hospital & University of Western Australia Satvinder Dhaliwal, Curtin University; Kun Zhu, University of Western Australia & Sir Charles Gairdner Hospital; Josh Lewis, University of Western Australia & Dept of Endocrinology and Diabetes; Richard Prince, University of Western Australia & Sir Charles Gairdner Hospital
002 Abstracts Selected as Best in Author Category POSITIONER AND CLOTHING ARTIFACT CAN AFFECT ONE-THIRD RADIUS BMD MEASUREMENT Recipient of Best Technologist Abstract
Background: Fracture risk calculators have been developed to improve DXA a BMD structural measures as predictors of future fracture risk. We compared Australian FRAX and the Garvan hip fracture prediction models using a long running cohort study of older women. Methods: The study population used was the CAREES study, an ongoing population based cohort study of 1500 women with a mean age of 75 years at baseline in 1998. In this paper we report hip fracture risk prediction in a sub population of 1127 women who had a hip aBMD measurement in 1999 and in whom complete ascertainment of hip fracture incidence over 10 years is available.
Diane Krueger, University of Wisconsin Nellie Vallarta-Ast, University of Wisconsin; Jessie Libber, University of Wisconsin; Mary Checovich, University of Wisconsin; Ronald Gangnon, University of Wisconsin; Neil Binkley, University of Wisconsin Radius BMD is a valuable cortical bone measurement in clinical trials, patients with hyperparathyroidism and adults with spinal degenerative changes. However, we have observed substantial variability upon repeat of one-third radius BMD
480