Communities of Excellence

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• Communities of Excellence
• in Nutrition, Physical Activity,
• and Obesity Prevention

CX3
Use of GIS to Map Low-Income Food
Environments APHA November 6, 2006
Alyssa Ghirardelli, MPH, RD Research
Associate Cancer Prevention and Nutrition
Section California Department of Health Services
Co-Authors Valerie Quinn, M.Ed., Ellen
Feighery, R.N., M.S., Mathew Stone, M.P.H.,
Sharon Sugerman, M.S., R.D., F.A.D.A.
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CX3 Defined

• Documents the physical environment
• and empowers local action to change the
  environment to support individual behaviors
• A planning model that involves assessing
  communities in relation to a variety of obesity
  prevention benchmarks known as community
  indicators and assets.
• Based on CX- Communities of Excellence model
  developed by California Tobacco Control Section
• 3 nutrition, physical activity and obesity
  prevention

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CX3 Goals

• Empower communities
• Assess a communitys strengths, assets, gaps
  weaknesses
• Set priorities based on data
• Develop strategic local data-driven action plans
• Broaden participation at local level
• Evaluate progress
• Policy Action at the Local Level

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CX3 Standardized Indicators Assets

• Indicators organized in 6 Community Environments
• Neighborhood
• Preschool
• School
• After-school
• Worksite
• Government

• Assets organized into
• Health department infrastructure
• Political will
• Community infrastructure

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GIS Mapping PhaseMapped CX3 Indicators

• Neighborhood Environment
• Access to Supermarkets
• Markets with 20 employees
• Transit to supermarkets
• Farmers Markets
• Density of Fast Food
• Fast food chain/not chain
• Pizza
• Deli

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CX3 Pilot ProjectSites

• Six Sites
• Sites are all Health Departments
• Dense urban, suburban, rural, and remote areas

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CX3 Pilot ProjectNeighborhood Selection

• Chose 3-7 low-income neighborhoods
• Each neighborhood comprised of
• 1-5 census tracts
• 50 of population in census tract at or below
  185 Federal Poverty Level (FPL)
• Other selection factors
• Established partnerships
• Race/Ethnic make-up
• Rural and Urban (for some sites)
• Obesity rates (used by one site)

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GIS Mapping Phase On-line System California
Nutrition Network Map Viewer Developed in 2003
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Supermarkets ½ Mile Buffer
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Density of Fast Food Outlets
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Farmers Markets in Neighborhood or Within 5 Miles
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GIS Mapping Process Usability

• All sites either attended the GIS
• training or had used GIS previously
• Also received detailed instructions as part of
  CX3
• A few were highly skilled at GIS
• Usability of the GIS system ranged from
  difficult to very easy
• What users liked about the GIS
• Number and types of layers available
• Buffers
• Ability to zoom and pan
• Seeing which markets accept WIC EBT
• Ability to visually see where things are located

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GIS Mapping Process Challenges

• Initially used for statewide perspective, now
  adapting for use at neighborhood level
• Retail store data layer from industry source,
  only as accurate as provided from source
• Categories for stores not always accurate
• Difficulties with using the number of employees
  as way to designate supermarkets
• Sometimes data missing categories/locations for
  fast foods

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GIS Mapping Process Interesting Findings

• 19 low-income neighborhoods
• (not representative sample for California)
• No food deserts identified
• Decent access to supermarkets with 9
  neighborhoods having ½ mile or less as average
  distance to supermarkets
• Most residents travel on average supermarket (only 1 neighborhood with average
  distance of 4 miles)

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GIS Mapping Process Interesting Findings

• Two Bay Area pilot sites have
• good access to farmers markets
• Other 4 counties have mixed access to farmers
  markets, with 1 county having no access in any of
  the CX3 neighborhoods
• Several neighborhoods saturated with fast food
  outlets
• 5 neighborhoods have between 12-22 outlets, with
  several outlets within 1000 ft. of schools

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GIS Mapping Process Questions/Issues Raised...

• Wonderful tool with power,
• however....
• Does our GIS system provide
• data necessary to answer neighborhood level
  questions?
• Need to examine quality of retail data source
  (markets and fast food outlets) and how to
  improve in quickly changing landscape of data
• How to compare low-income neighborhoods with
  average/median neighborhood

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GIS Mapping Process Conclusions

• If using data for local action
• with policy makers and community partners,
  accurate data needed at neighborhood level
• GIS is great first step to neighborhood
  assessment, but it is essential
• to get into the community to
• really capture food environment

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For more information or to make connection
Alyssa Ghirardelli, MPH, RD Research Associate,
California Department of Health Services, Cancer
Prevention and Nutrition Section
aghirard_at_dhs.ca.gov 916-449-5342