Bridging the Gap Between Clinical and Community Research: Assessing the Association between Fracture Rates in Children and Neighborhood Factors Leticia Ryan, MD 1,2 , Jichuan Wang, PhD 2 , Mark Guagliardo, PhD 2 , Jennifer Marsh, PhD 2 , Steven Singer, MD 2 , Joseph Wright, MD,MPH 1,2,3 , Stephen Teach, MD, MPH 1,2 , James Chamberlain, MD 1,2 1 Division of Emergency Medicine, 2 Center 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
Transcript
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
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
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.
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.
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
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
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
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
Results
INITIAL:
361 CENSUS BLOCK
GROUPS
FINAL:
349 CENSUS BLOCK
GROUPS (97%)
Results
NEIGHBORHOOD FACTOR
ODDS RATIO 95% CONFIDENCE INTERVAL
F1- RACE/EDUCATION
1.271 1.139-1.418
F2- UNEMPLOY/POVERTY
0.947 0.891-1.007
F3- IMMIGRANTS 0.957 0.900-1.018
F4- RENTALS 1.021 0.968-1.077
F5- LARGE FAMILIES 1.114 1.056-1.176
F6- CROWDING 1.040 0.976-1.109
F7- SENIORS 0.907 0.856-0.963
Fracture Cases and Relationship to Factor 1- Race/Education
WASHINGTON DC
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
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.
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.
Acknowledgements
Primary Mentorship:James Chamberlain, MDDivision Chief, Division of Emergency MedicineChildren’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
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.
