1. Chapter 47 Assessing Fracture Risk: Who Should Be Screened? © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

2. Overall Approach to Fracture Risk Assessment Initial Assessment Based on Evident Clinical Risk Factors Bone Densitometry to Improve Fracture Risk Assessment Additional options to further refine fracture risk assessment –Vertebral fracture assessment –Measurement of bone turnover Final Assessment based on combination of clinical risk factors, bone densitometry, and other tests (if done) © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

3. Strong Clinical Risk Factors for Fracture* Advance Age Caucasian Race Prior Fracture Maternal or paternal history of hip fracture Weight loss Low physical activity Self-reported general poor health High pulse rate (age 65 and older) Impaired neuromuscular function Falls Hyperthyroidism Parkinson’s Disease Medications –Glucocorticoids –Anti-convulsants –Benzodiazepines * Confer 1.5 fold or greater risk of fracture relative to those without the factor independent of bone mineral density © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

4. Additional Clinical Risk Factors for Fracture Female gender Maternal history of any clinical fracture Low body weight or body mass index Greater height Cigarette smoking Protein/calorie intake Heavy alcohol intake Poor vision Anti-depressants Eating Disorders Hyperparathyroidism Hypercortisolism Gonadal hormone deficiency Autoimmune diseases Chronic lung disease Diabetes Mellitus © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

5. Indications for Bone Densitometry For all –Prior fracture with minor trauma –Chronic glucocorticoid therapy –Other illnesses associated with fracture Post-menopausal women –Age > 65 –Maternal/paternal history of fracture –Recent substantial weight loss –Osteoporosis Self-Assessment Tool (OST) score < 1 –Long-term use of benzodiazeopines or anticonvulsants Men –Hypogonadism –OST score < 1 © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

6. Components of Decision Rules to Guide Decisions Regarding Use of Bone Densitometry for Post-Menopausal Women ORAI (Osteoporosis Risk Assessment Instrument) –Age, Weight –Use of estrogen replacement SCORE (Simple Calculated Osteoporosis Risk Estimation) –Age, Weight –Use of estrogen replacement –Prior hip, wrist, or rib fracture –Rheumatoid arthritis OST (Osteoporosis Self-Assessment Tool) –Age, Weight © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

7. Risk of Osteoporosis According to Age and Weight: Osteoporosis Self-Assessment Tool From Cadarette SM, et. al. Osteoporos Int. May 2004;15(5):361-366. © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

8. Algorithm: Is Bone Densitometry Indicated © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

9. Additional Tests to Assess Fracture Risk Vertebral Fracture Assessment –With lateral spine radiography or lateral DXA imaging –Fracture risk independent of BMD for those with vertebral deformity relative to those with no deformity 4.0 for incident vertebral fracture 1.8 for incident hip fracture 1.6 for incident non-spine fracture Markers of Bone Turnover –High levels may indicate a higher risk of fracture independent of BMD –Routine use hampered by imprecision of the tests, and lack of agreement among studies as to which markers are associated with incident vertebral and non-vertebral fractures Heel Ultrasound –Unclear if ultrasound plus DXA defines a sharper gradient of fracture risk compared to DXA alone © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

10. Fracture Risk Assessment Combining Clinical Risk Factors, Bone Densitometry, & Other Tests Key features of integrating effect of multiple factors on fracture risk Accounting for prevalence (prev) of the risk factor in the base population –Relative risk in those with risk factor vs whole population: RR with vs whole –Relative risk on those with risk factor vs those without risk factor: RR with vs without Formula: –RRwith vs whole = RRwith vs without / [1 + (RRwith vs without -1)*prev] © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud

11. Fracture Risk Assessment Combining Clinical Risk Factors, Bone Densitometry, & Other Tests Theoretical example: assume risk of incident fracture in base population of 10% –4.0-fold risk for incident vertebral fracture in those with vertebral deformity on lateral imaging compared to those without deformity –If prevalence of risk factor in population is 25%: Relative risk of fracture in those with risk factor compared to base population: –4.0 / [1 + (4.0-1)*prevalencedeformity] = –4 / (1+3*0.25) = 4/1.75 = 2.3 Therefore, the risk of incident vertebral fracture among the subset with a prevalent vertebral deformity is 0.1*2.3 = 23% © American Society for Bone and Mineral Research Contributed by John Schousboe, Brent Taylor, and Kristine Enrud