Variable Name	Description
Individual-level Variables
Gender	Male vs. female
Race	African American vs. white/other
Age	Years
Weight	Body weight was measured using a commercial-grade weight scale (lbs)
Height	Height was measured using a wall-mounted stadiometer (inches)
BMI	(kg/m2)
HbA1c	A1c was assessed from a fingerstick capillary blood sample using a DCA 2000/Vantage portable bench-top analyzer.
Self-Efficacy for Exercise	Self-Efficacy and Exercise Habits Survey;4 12-items scored from 1 (I know I cannot) to 5 (I know I can); Subscales include: Making Time to Exercise, scored as the mean of 8 individual items (range 1 to 5); and Sticking to an Exercise Program, scored as the mean of 4 individual items (range 1 to 5)a
Perceived Health Status	One item indicator of perceived health status. “In general, would you say your health is…excellent, very good, good, fair, poor.” Lower scores indicate stronger health perceptions. b
Risk Perception Survey for Developing Diabetes (RPS- DD)	The RPS-DD (Developing Diabetes) is a 43-item survey appropriate for people who are at risk for type 2 diabetes. RPS-DD assesses risk perceptions for developing diabetes and/or its complications, as well as environmental perceived risks. Subscales used: (1) Personal Control: (4 items) a higher score indicates greater perceived personal control over developing diabetes; (2) Worry about Developing Diabetes: (2 items) higher score indicates greater worry for developing diabetes; (3) Optimistic Bias: (2 items), a higher score describes more perceived risk for developing diabetes.c
Social Support and Exercise	Abbreviated Social Support and Exercise Survey;6 13-items each scored on a 1 (no support) to 5 (supported very often) Likert Scale; Family Participation scored as the sum of 10 items (range for total score 10 to 50); Family Punishment & Rewards scored as sum of 3 items (range for total score 3 to 15).d
Community-Level Variables
Food desert	The online Food Desert Locator, developed by the U.S. Department of Agriculture's (USDA) Economic Research Service (ERS) was used to assess the availability of nutritious food in food deserts, or low-income communities that lack ready access to healthy food. Census tracts in USDA’s food desert spreadsheet were compared to census tracts of study participants. Participants’ whose residential census tract matched a census tract in the USDA food desert dataset were flagged as living in a food desert. Data was downloaded in tabular form from the USDA Food Desert Locator Website in October of 2011. The data was obtained by using the “download the data” tool that leads to an Excel spreadsheet that has a list of all census tracts in the nation that USDA considers to be a food desert. The Healthy Food Financing Initiative Working Group considers a food desert as a low-income census tract (poverty rate is at least 20%) where a substantial number or share of residents has low access to a supermarket or large grocery store. Low access to a healthy food retail outlet is defined as more than 1 mile from a supermarket or large grocery store in urban areas.e
Walk Score	Walk Score’s mission is to promote walkable neighborhoods. It uses a patent-pending system to measure the “walkability” of an address. The Walk Score algorithm awards points based on the distance to resources or amenities. The Walk Score website provides an interface that allows users to enter an address or a set of geographic coordinates and returns a walkability score between 0 and 100, with 100 representing the highest level of walkability and zero representing a location that is completely car-dependent. Walk Score measures resource proximity and density. Resources include grocery stores, bars, movie theaters, libraries, schools, and more. Scores do not distinguish “health-friendly” resources from other types, and do not incorporate aspects like area crime or sidewalk quality. Amenities within .25 miles receive maximum points and no points are awarded for amenities further than one mile. Walk Score uses a variety of data sources including Google, Education.com, Open Street Map, and Localeze. Walking score data were obtained from WalkScore.com’s interface tool during October 2011. We entered geographic coordinates directly into the webpage that returned a walkability score. WalkScore.com also has a batch tool available, but we did not use this for data retrieval for this project.f
Crime	Uniform Crime Report (UCR) data were compiled by the Indianapolis Metropolitan Police Department (IMPD), Crime Analysis Section. These data were submitted by IPD as Part 1 crime statistics to the Federal Bureau of Investigations (FBI) for inclusion in the national Uniform Crime Report to assess and report crime trends in the IMPD jurisdiction.. We downloaded Uniform Crime Report data by 2000 census tracts for Marion County, IN from the SAVI Community Information System, October 2011. The original source was the Indianapolis Metropolitan Police Department (IMPD). Annual data for 2007 and for 2009 was downloaded. The downloaded census tract-level data were matched to the census tracts identified for each participant.g
Median Household Income and Use of Public Transportation	The American Community Survey (ACS) is a US Census Bureau program designed to supplement the decennial census. The advantage of ACS data is that it is released annually and is therefore more up-to-date than decennia census data. Median family income data was downloaded by 2000 census tracts for Marion County, October 2011. The original source is the 2005–2009 American Community Survey 5-year averages provided by the U.S. Census Bureau. The downloaded census tract data was matched to the census tracts identified for each participant.h
Vegetation Index	Normalized Differential Vegetation Index (NDVI) is a measure of the amount and health of vegetation on the ground as measured by aerial or satellite photography. The value of the index varies from a minimum of negative one in spots where there is no vegetation to a maximum of positive one in areas that have lush, dense vegetation. The measure is sometimes referred to as “greenness.”The raw image was downloaded from IndianaView, a website developed by 14 universities and institutions in Indiana. The Polis Center received the NDVI image from the IUPUI Dept. of Geography. Using ESRI ArcMap software, Polis then calculated the mean NDVI within each of Marion County’s 212 census tracts. The calculation was made using the Zonal Statistics tool within ArcMap’s Spatial Analyst extension, with the Statistics Type option set to Mean. It should be noted that the NDVI only measures the amount and health of the vegetation, not it’s aesthetic values. The raw imagery was obtained by the Landsat 5 satellite on September 30th, 2010. The IUPUI Dept. of Geography then performed the necessary processing to create the NDVI image.I

^aSallis JF, Pinski RB, Grossman RM, Patterson TL, Nader PR. The development of self-efficacy scales for health-related diet and exercise behaviors. Health Educ Res. 1988; 3: 283–292.

^bClark DO. Physical activity and its correlates among urban primary care patients aged 55 years and over. J Gerontol Soc Sci. 1999; 54B:S41–S48.

^cWalker EA, Mertz CK, Kalten MR, Flynn J. Risk perception for developing diabetes: comparative risk judgments of physicians. Diabetes Care. 2003; 26(9): 2543–8. PMID:12941716

^dSallis JF, Grossman RM, Pinski RB, Patterson TL, Nader PR. The development of scales to measure social support for diet and exercise behaviors. Prev Med. Nov 1987;16(6):825–836.

^eU.S. Department of Agriculture. Food Desert Locator, Economic Research Service. http://www.ers.usda.gov/data-products/food-access-research-atlas/documentation.aspx

^fWalk Score. Copyright 2012 Walk Score. https://www.walkscore.com/

^gIndianapolis Metropolitan Police Department. Crime Analysis Section, 50 N. Alabama Street, Room E303, Indianapolis, IN 46204, (317) 327–3525. www.indygov.org/eGov/City/DPS/IPD/home.htm

^hU.S. Census Bureau. American Community Survey: 5-year averages, 2005–2009. https://www.census.gov/programs-surveys/acs/

^IAmericaView. National Consortium for Remote Sensing Education, Research, and Applications. IndianaView. http://www.indianaview.org/pdf/IndianaView_FS_MultiSpec.pdf