Transcript Slide 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
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
FRACTURE VISITS IDENTIFIED
INITIAL:
361 CENSUS
BLOCK
GROUPS
4343
FRACTURE VISITS MAPPED
4081 (94%)
FINAL:
349 CENSUS
BLOCK
GROUPS (97%)
FRACTURE VISITS AFTER CHART REVIEW
3900 (90%)
FRACTURE VISITS PRESENT IN STUDY CBGs
3462 (80%)
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, 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
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 casecontrol 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.