Bridging the Gap Between Clinical and Community Research: Assessing the Association between Fracture Rates in Children and Neighborhood Factors

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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, Childrens National Medical
  Center, George Washington University School of
  Medicine and Health Sciences, Washington, DC

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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

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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.

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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.

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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 Childrens
  National Medical Center Emergency Department
  between January 1, 2003 and December 31, 2006

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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

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Design/Methods

• Unit of Analysis census block group (CBG)
• areas of DC with gt 80 catchment at our facility
• minimum CBG population of 250
• Fracture rate estimations Fracture rates
  calculated for each CBG using year 2000 census
  data

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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

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

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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.

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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.

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Acknowledgements

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

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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.