Leticia Ryan, MD 1,2 , Jichuan Wang, PhD 2 , Mark Guagliardo, PhD 2 ,

1. Bridging the Gap Between Clinical and Community Research: Assessing the Association between Fracture Rates in Children and Neighborhood Factors Leticia Ryan, MD1,2, Jichuan Wang, PhD2, Mark Guagliardo, PhD2, Jennifer Marsh, PhD2, Steven Singer, MD2 , Joseph Wright, MD,MPH1,2,3, Stephen Teach, MD, MPH1,2, James Chamberlain, MD1,2 1Division of Emergency Medicine, 2Center for Clinical and Community Research, 3 Child Health Advocacy Institute, Children’s National Medical Center, George Washington University School of Medicine and Health Sciences, Washington, DC

2. Background: • Pediatric bone fractures • Are increasing in incidence1 • Person-level factors • Are associated with increased risk • Relate to lower bone mineral density • physical inactivity2/obesity3 • poor nutrition4 • poor vitamin D status5 • May not account for all population variation in risk

3. Background • Neighborhood factors • Have been found for many diseases including adult hip fracture. 6 • No published studies have evaluated the role of neighborhood factors in childhood fractures.

4. Study Overview • OBJECTIVE: • to evaluate the relationship between fracture rates in children and neighborhood factors • HYPOTHESIS: • Certain neighborhood factors will be either positively or negatively associated with local fracture rates.

5. Design/Methods • Retrospective cohort study with IRB approval • Billing records used to identify fracture visits: • ages 0-17 • residence in Washington DC • evaluated for bone fracture in the Children’s National Medical Center Emergency Department between January 1, 2003 and December 31, 2006

6. Design/Methods • Addresses converted to point locations using Geographical Information Systems (GIS) software • Chart review of multiple fracture visits for an individual subject to exclude: • Visits of patients with bone mineralization disorders • Follow up visits for the same fracture event

7. Design/Methods • Unit of Analysis: census block group (CBG) • areas of DC with > 80% catchment at our facility • minimum CBG population of 250 • Fracture rate estimations: Fracture rates calculated for each CBG using year 2000 census data

8. Design/Methods • Neighborhood factor analysis: • Variables extracted from year 2000 census data • Correlation matrix searched to identify clusters of variables • Each cluster represented as a linear combination of its constituent variables (factor) • Factor scores served as predictor variables in regression models of fracture rate with control for race, sex and age within the CBGs

9. Results INITIAL: 361 CENSUS BLOCK GROUPS FINAL: 349 CENSUS BLOCK GROUPS (97%)

10. Results

11. Fracture Cases and Relationship to Factor 1- Race/Education WASHINGTON DC

12. Discussion • A race and education factor was significantly associated with increased fracture risk. • This factor correlated to neighborhoods with long term blue collar African American residents with lower education levels. • ? Vitamin D insufficiency • ? Lower dietary intake of calcium • ? obesity

13. Conclusions • These preliminary results demonstrate that neighborhood factors are associated with risk patterns for bone fracture in children. • This is an essential first step in the development of targeted community-based strategies for fracture prevention.

14. Future direction • Because forearm fractures may represent a particular fracture location reflecting bone health deficit, future analysis will focus on the subgroup of approximately 1000 children with isolated forearm fracture. • Additionally, we are conducting a case-control study to evaluate person-level risk factors for childhood fracture related to bone health.

15. Acknowledgements Primary Mentorship: James Chamberlain, MD Division Chief, Division of Emergency Medicine Children’s National Medical Center This study is funded in part by: • National Institutes of Health National Center for Research Resources (1K23 RR024467-01) • Children’s Research Institute Children’s National Medical Center Research Advisory Council Grant

16. Selected References 1. Khosla S, et al. Incidence of childhood distal forearm fractures over 30 years: a population-based study. JAMA. 2003; 290: 1479-1485. 2. McKay HA, et al. Augmented trochanteric bone mineral density after modified physical education classes: a randomized school-based exercise intervention study in prepubescent and early pubescent children. J Pediatr 2000; 136: 156-162. 3. Goulding A, et al. Bone mineral density and body composition in boys with distal forearm fractures: a dual-energy x-ray absorptiometry study. J Pediatr 2001; 139: 509-515. 4. Ma D, Jones G. The association between bone mineral density, metacarpal morphometry, and upper limb fractures in children: a population-based case-control study. J Clin Endocrinol Metab. 2003; 88: 1486-1491. 5. Valimaki VV, et al. Vitamin D status as a determinant of peak bone mass in young Finnish men. J Clin Endocrinol Metab 2004; 89: 76-80. 6. Reimers A, Laflamme L. Hip fractures among the elderly. J Trauma. 2007; 62: 365-369.