title: Measuring the retail food environment in rural and urban North Carolina counties.
abstract: BACKGROUND
  Development of accurate and sensitive methods to characterize the food environment is needed. Thus, we examined convergent and criterion validity of 2 retail food environment data sources and then examined differences in predictive validity between 3 ways of measuring the rural and urban food environment.
  
  
  METHODS
  Ten counties were selected in each of 3 North Carolina regions (n = 30). Number of fast-food restaurants and chain supermarkets were calculated using 2 data sources. Convergent validity was percent agreement between the 2 sources. Criterion validity was percent agreement between each source and the most accurate venue count. Predictive validity of food environment measures (Retail Food Environment Index, fast-food restaurants/capita, and supermarkets/capita) was calculated by associations with county-level mean-weighted body mass index (BMI).
  
  
  RESULTS
  Percent agreement for fast-food restaurants ranged from 50% to 100% (mean = 87%) and for supermarkets ranged from 58% to 100% (mean = 89%). The 2 data sources had similar percent agreement with the most accurate count. Retail Food Environment Index was positively associated with BMI, while fast-food restaurants per capita were negatively associated with BMI.
  
  
  CONCLUSIONS
  Our results lend support to studies using both food environment data sources examined.
authors.affiliation: Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27858, USA. jilcotts@ecu.edu
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Jilcott
authors.forename: Jared T
authors.initials: JT
authors.lastname: McGuirt
authors.forename: Satomi
authors.initials: S
authors.lastname: Imai
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
mesh_terms: D015992:Body Mass Index; D003132:Commerce; D003625:Data Collection; D005260:Female; D005504:Food Analysis; D005523:Food Supply / Q000145:classification* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D009657:North Carolina; D009749:Nutrition Surveys; D015203:Reproducibility of Results; D012147:Restaurants / Q000145:classification* / Q000706:statistics & numerical data; D012424:Rural Population; D014505:Urban Population