Bivariate Mapping of the Food Environment Index and Obesity in FloridaLEAH ATWELL , MPH

LAUREN PORTER, PHD, MPH

TERA ANDERSON, CHES

KELLIE O’DARE, PHD

Behavioral Risk Factor Surveillance System (BRFSS)•State-based telephone surveillance system

•Collaboration between the Centers for Disease Control and Prevention (CDC) and state

•Respondents ages 18+

•Collects data on individual risk behaviors and preventive health practices

•County level data collected every three years

Obesity •BRFSS uses Body Mass Index (BMI) to determine if a person is obese•BMI >30.0

•29.9% of adults in America are obese1

•27.4% of Florida adults are obese2

Consequences of Obesity•Increased risk for many diseases and health conditions

•Medical costs of obesity in the US were estimated to be $147 billion3

•In Florida, over the next 20 years, obesity is expected to contribute to millions of cases of chronic diseases costing the state an estimated $34 billion4

Food Deserts•Neighborhoods that lack access to affordable vegetables, fruits, low-fat milk, whole grains and other foods that make up a healthy diet5

Food Environment Index (FEI)6

•Developed by the Robert Wood Johnson Foundation (RWJF)•Data Source: 2015 USDA Food Environment Atlas and Feeding America’s Map the Meal Gap

•The FEI ranges from 0 (worst) to 10 (best)

•Based on two indicators (weighted equally):•Limited access to healthy foods

•Food insecurity

Limited Access to Food: Estimated percentage of the population that is low income and does not live close to a grocery store

Living close to a grocery store : • Rural: Lives less than 10 miles from a grocery store• Nonrural: Live less than 1 mile from a grocery store• Low Income: Annual family income is less than or

equal to 200% of the federal poverty threshold Food insecurity: Estimated percentage of the population who do not have access to a reliable source of food

Food Environment Atlas7

•Created by the United States Department of Agriculture (USDA)

•Contains over 275 variables, including indicators on Access, Supplemental Nutrition Assistance Program (SNAP) recipients and household food insecurity

•Data sources include 2010 Census and 2010-2014 American Community Survey

Methodology•We used 2016 Florida BRFSS obesity rates •Obesity rates ranged from a low of 15.3% in Martin county

to a high of 45.5% in Gadsden county

•We used the FEI from RWJF • It ranges from 0 (worst) to 10 (best)•Florida’s FEI ranged from 5.1 – 8.3

•We used ArcGIS to visualize the relationship between adult obesity and FEI creating a bivariate map

Methodology Continued•Food Environment Atlas indicators were represented by graduated symbols overlaid on the FEI and obesity bivariate map

•We used Food Environment Atlas indicators to look further at why certain counties may have better or worse outcomes

Obesity and FEI 9-Class Bivariate Color Scheme

2016 Obesity Rates and FEI Bivariate Map

Low Income, Low Access to Store

0.26% - 4.28%

4.28% - 7.46%

7.46% - 10.81%

10.81% - 15.00%

15.00% - 31.10%

2016 Obesity Rates and FEI Bivariate Map

With 2015 USDA Low Income, Low Access to Store

Indicator Represented by

Graduated Symbols

Households, No Car, Low Access to Store

0.35% - 1.36%

1.36% - 2.22%

2.22% - 3.40%

3.40% - 4.80%

4.80% - 8.20%

2016 Obesity Rates and FEI

Bivariate Map

With 2015 USDA Households with No Car, and Low Access to Store

Indicator Represented by

Graduated Symbols

SNAP Households, Low Access to Store

0.05% - 1.36%

1.36% - 2.59%

2.59% - 4.00%

4.00% - 6.30%

6.30% - 10.62%

2016 Obesity Rates and FEI Bivariate Map

With 2015 USDA SNAP Households,

Low Access to Store Indicator Represented

by Graduated Symbols

Poverty Rate

9.7%- 12.8%

12.8% - 16.0%

16.0% - 20.0%

20.0% - 24.8%

24.8% - 31.8%

2016 Obesity Rates and FEI Bivariate Map

With 2015 USDA Poverty Rates

Represented by Graduated Symbols

Results•Obesity rates are higher in rural areas throughout the state

•The majority of counties with poor rates are located in north Florida•13 out of 15

•Most counties with the lowest rates are in south Florida

Results Continued•The majority of Florida counties have obesity rates that fall into the mid-range of 26.6% - 35.5%

•The majority of counties in Florida have FEI scores in the range of 6.3 – 7.4

•When obesity and FEI are combined the majority of counties are mid-range

Results Continued•Alachua county is an outlier because it has a low FEI (bad) and low obesity rates

•Wakulla is an outlier because it has a high FEI (good) and high obesity rates

Conclusions•Bivariate county maps can serve as useful tools to visualize deviations in expected health patterns in Florida

•Bivariate maps may help identify counties that could be further studied at a sub-county level to determine why their health outcomes are better or worse than other counties with the same demographics

Limitations•Urban sprawl could lead to non-rural areas being assigned a low food index but it may be an artifact of the assigned distance and not a true indicator of limited access

•FEI does not take into consideration “Food Swamps”

References1. Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Population Health. BRFSS Prevalence & Trends Data [online]. 2015. [accessed Apr 16, 2018]. URL: https://www.cdc.gov/brfss/brfssprevalence/.

2. 2016 Florida Behavioral Risk Factor Surveillance System

3. Finkelstein EA1, Trogdon JG, Cohen JW, Dietz W. Annual medical spending attributable to obesity: payer-and service-specific estimates. Health Aff (Millwood). 2009 Sep-Oct;28(5):w822-31. doi: 10.1377/hlthaff.28.5.w822

4. Florida Department of Health. What is Healthiest Weight Florida? [online]. [accessed Apr 16, 2018]. URL: http://www.healthiestweightflorida.com/

5. United States Department of Agriculture, Economic Research Service. Documentation. [online]. [accessed Apr 16, 2018]. URL: https://www.ers.usda.gov/data-products/food-access-research-atlas/documentation/

6. A Robert Wood Johnson Foundation program, County Health Rankings & Roadmaps. Food Environment Index [online]. [accessed Apr 16, 2018]. URL: http://www.countyhealthrankings.org/explore-health-rankings/what-and-why-we-rank/health-factors/health-behaviors/diet-exercise/food-environment-index

7. Economic Research Service (ERS), U.S. Department of Agriculture (USDA). Food Environment Atlas. https://www.ers.usda.gov/data-products/food-environment-atlas/