Timothy L. Barnes

Validation of 3 Food Outlet Databases: Completeness and Geospatial Accuracy in Rural and Urban Food Environments

Despite interest in the built food environment, little is known about the validity of commonly used secondary data. The authors conducted a comprehensive field census identifying the locations of all food outlets using a handheld global positioning system in 8 counties in South Carolina (2008–2009). Secondary data were obtained from 2 commercial companies, Dun & Bradstreet, Inc. (D&B) (Short Hills, New Jersey) and InfoUSA, Inc. (Omaha, Nebraska), and the South Carolina Department of Health and Environmental Control (DHEC). Sensitivity, positive predictive value, and geospatial accuracy were compared. The field census identified 2,208 food outlets, significantly more than the DHEC (n = 1,694), InfoUSA (n = 1,657), or D&B (n = 1,573). Sensitivities were moderate for DHEC (68%) and InfoUSA (65%) and fair for D&B (55%). Combining InfoUSA and D&B data would have increased sensitivity to 78%. Positive predictive values were very good for DHEC (89%) and InfoUSA (86%) and good for D&B (78%). Geospatial accuracy varied, depending on the scale: More than 80% of outlets were geocoded to the correct US Census tract, but only 29%–39% were correctly allocated within 100 m. This study suggests that the validity of common data sources used to characterize the food environment is limited. The marked undercount of food outlets and the geospatial inaccuracies observed have the potential to introduce bias into studies evaluating the impact of the built food environment.

Characterizing the food retail environment: Impact of count, type, and geospatial error in 2 secondary data sources

OBJECTIVE Commercial listings of food retail outlets are increasingly used by community members and food policy councils and in multilevel intervention research to identify areas with limited access to healthier food. This study quantified the amount of count, type, and geospatial error in 2 commercial data sources. METHODS InfoUSA and Dun and Bradstreet were compared with a validated field census and validity statistics were calculated. RESULTS Considering only completeness, Dun and Bradstreet data undercounted 24% of existing supermarkets and grocery stores, and InfoUSA, 29%. In addition, considering accuracy of outlet type assignment increased the undercount error to 42% and 39%, respectively. Marked overcount existed as well, and only 43% of existing supermarkets were correctly identified with respect to presence, outlet type, and location. CONCLUSIONS AND IMPLICATIONS Relying exclusively on secondary data to characterize the food environment will result in substantial error. Whereas extensive data cleaning can offset some error, verification of outlets with a field census is still the method of choice.

An efficacy trial of 'Steps to Your Health', a health promotion programme for adults with intellectual disability

Objective: Although there are evaluation and effectiveness studies of health promotion interventions for adults with intellectual disabilities (ID), randomized efficacy trials of such interventions are lacking. Design: A randomized active control intervention trial. Setting: The participants attended the health promotion classes in local disability agency service facilities. Method: We enrolled 443 individuals and randomly assigned them to one of two eight-week participatory classes. The ‘Steps to Your Health’ (STYH) classes emphasized moderate to vigorous physical activity (MVPA), healthy eating and body mass index (BMI) reduction. The control intervention focused on hygiene and safety. Results: We did not find a statistically significant difference in mean MVPA or BMI change between completers of the STYH group compared to the control group one year after the intervention was completed. We did find that participation in STYH classes had a non-significant association with odds of reduction in BMI (odds ratio [OR] 2.87, 95% confidence interval [CI] 0.91–9.11) and completers who lived in group homes were more likely than their counterparts who lived with families or in apartments to decrease their BMI (OR 4.61; 95% CI 1.14–18.64). Conclusions: This trial did not demonstrate a significant effect of STYH participation on change in mean minutes of MVPA or mean BMI 12 months after classes ended, although there was a non-significant association with odds of reduction of BMI (p = 0.07). This study has implications for design of intervention studies in people with intellectual disability (ID).

Snacking Behaviors, Diet Quality, and Body Mass Index in a Community Sample of Working Adults

BACKGROUND Snacking behaviors have been linked with higher energy intake and excess weight. However, results have been inconsistent. In addition, few data are available on the extent to which snacking affects diet quality. OBJECTIVE This study describes snacking behaviors, including total snacking energy, frequency, time of day, and percentage of snacking energy intake by food groups, and their associations with diet quality and body mass index (BMI; calculated as kg/m(2)). DESIGN Snacking behaviors and dietary intake were examined cross-sectionally among 233 adults participating in a community-based worksite nutrition intervention from September 2010 through February 2013. Three telephone-administered 24-hour dietary recalls were collected (2 weekdays; 1 weekend day). Diet quality was characterized by the Healthy Eating Index 2010 and BMI was computed using measured height and weight. SETTING The setting was a large metropolitan medical complex in Minneapolis, Minnesota. MAIN OUTCOME MEASURES Outcome measures included diet quality and BMI. STATISTICAL ANALYSES General linear regression models were used to examine associations between each of the snacking behaviors as independent variables, and diet quality and BMI as dependent variables. RESULTS Percent of snacking energy from fruit and juice (β=.13; P=0.001) and nuts (β=.16; P=0.008) were significantly positively associated with diet quality. Percent of snacking energy from desserts and sweets (β=-.16; P<0.001) and sugar-sweetened beverages (β=-.22; P=0.024) were significantly inversely associated. Percent of snacking energy from vegetables (β=-.18; P=0.044) was significantly associated with lower BMI. Percent snacking energy from desserts and sweets was significantly associated with a higher BMI (β=.04; P=0.017). CONCLUSIONS Snack food choices, but not total energy from snacks, frequency, or time of day, were significantly associated with diet quality and BMI.

Environmental influences on fruit and vegetable intake: results from a path analytic model.

OBJECTIVE Fruit and vegetable (F&V) intake is influenced by behavioural and environmental factors, but these have rarely been assessed simultaneously. We aimed to quantify the relative influence of supermarket availability, perceptions of the food environment and shopping behaviour on F&V intake. DESIGN A cross-sectional study. SETTING Eight counties in South Carolina, USA, with verified locations of all supermarkets. SUBJECTS A telephone survey of 831 household food shoppers ascertained F&V intake with a seventeen-item screener, primary food store location, shopping frequency and perceptions of healthy food availability, and supermarket availability was calculated with a geographic information system. Path analysis was conducted. We report standardized beta coefficients on paths significant at the 0·05 level. RESULTS Frequency of grocery shopping at primary food store (β = 0·11) was the only factor exerting an independent, statistically significant direct effect on F&V intake. Supermarket availability was significantly associated with distance to utilized food store (β = -0·24) and shopping frequency (β = 0·10). Increased supermarket availability was significantly and positively related to perceived healthy food availability in the neighbourhood (β = 0·18) and ease of shopping access (β = 0·09). Collectively considering all model paths linked to perceived availability of healthy foods, this measure was the only other factor to have a significant total effect on F&V intake. CONCLUSIONS While the majority of the literature to date has suggested an independent and important role of supermarket availability for F&V intake, our study found only indirect effects of supermarket availability and suggests that food shopping frequency and perceptions of healthy food availability are two integral components of a network of influences on F&V intake.

Trichomoniasis in Pregnancy and Mental Retardation in Children

PURPOSE Trichomoniasis is a highly prevalent sexually transmitted infection and is associated with premature rupture of membranes, preterm birth, and low birth weight. This study examines the association between maternal trichomoniasis and intellectual disability (ID) in children. METHODS This study utilized linked maternal, infant, and child records for 134,596 Medicaid-insured singleton births in South Carolina from 1996 through 2002. Data were obtained from Medicaid billing records, birth certificates, and administrative data from the South Carolina Department of Education (DOE) and the Department of Disabilities and Special Needs (DDSN). Pregnancies during which women were diagnosed with urinary tract infection, chlamydia, gonorrhea, or vulvovaginal candidiasis were excluded, as were children diagnosed with a known cause of mental retardation. Odds of diagnosed ID in children were modeled using population averaged generalized estimating equation models. RESULTS Controlling for potential confounders, women with trichomoniasis were significantly more likely to have a child with ID (hazard ratio [HR] = 1.28; 95% confidence interval [CI], 1.12-1.46). The association was stronger for moderate to severe ID documented by the school system or DDSN (HR = 1.84; 95% CI, 1.35-2.51). Second-trimester trichomoniasis was associated with more than a three-fold increase in the odds a child was identified as trainable mentally handicapped or profoundly mentally handicapped in the public school system, or was receiving ID services from DDSN. There was not a significant difference in the risk of ID in children of women with treated versus untreated trichomoniasis. CONCLUSION Maternal trichomoniasis may be a preventable risk factor for ID.

Do people really know what food retailers exist in their neighborhood? Examining GIS-based and perceived presence of retail food outlets in an eight-county region of South Carolina.

Measures of neighborhood food environments have been linked to diet and obesity. However, the appropriate measurement methods and how people actually perceive their food environments are still unclear. In a cross-sectional study of 939 adults, the perceived presence of food outlets was compared to the geographic-based presence of outlets within a participants neighborhood, utilizing percent agreement and Kappa statistics. Perceived presence was based on survey-administered questions, and geographic-based presence was characterized using 1-, 2-, 3- and 5-mile (1-mile=1.6km) Euclidean- and network-based buffers centered on each participants residence. Analyses were also stratified by urban and non-urban designations. Overall, an individuals perceived neighborhood food environment was moderately correlated with the geographic-based presence of outlets. The performance of an individuals perception was most optimal using a 2- or 3-mile geographic-based neighborhood boundary and/or when the participant lived in a non-urban neighborhood. This study has implications for how researchers measure the food environment.

Test-retest reliability of a questionnaire measuring perceptions of neighborhood food environment.

There is a lack of validated and reliable instruments on perception of the food environment, in particular for rural environments. We estimated the test-retest reliability of a questionnaire assessing perceptions of the food environment. A total of 101 primary food shoppers in South Carolina were interviewed by phone to assess their perceptions of the food environment and presence of different food outlet types in their neighborhood. The survey was repeated approximately one month after the initial administration. The intra-class correlation (ICC) and Phi coefficient are reported as measures of reliability. The majority of questions on perceptions of the neighborhood food environment appear highly reliable (ICCs range from 0.55 to 0.71), including the 3-item scale on healthy food availability (ICC 0.71). Compared to participants in rural areas, those in urban areas demonstrated better reliability for questions on opportunities to purchase fast food and perceived presence of a supercenter. More research is needed to evaluate potential rural-urban differences in reliability.

Neighborhood fast food availability and fast food consumption

Recent nutritional and public health research has focused on how the availability of various types of food in a persons immediate area or neighborhood influences his or her food choices and eating habits. It has been theorized that people living in areas with a wealth of unhealthy fast-food options may show higher levels of fast-food consumption, a factor that often coincides with being overweight or obese. However, measuring food availability in a particular area is difficult to achieve consistently: there may be differences in the strict physical locations of food options as compared to how individuals perceive their personal food availability, and various studies may use either one or both of these measures. The aim of this study was to evaluate the association between weekly fast-food consumption and both a persons perceived availability of fast-food and an objective measure of fast-food presence - Geographic Information Systems (GIS) - within that persons neighborhood. A randomly selected population-based sample of eight counties in South Carolina was used to conduct a cross-sectional telephone survey assessing self-report fast-food consumption and perceived availability of fast food. GIS was used to determine the actual number of fast-food outlets within each participants neighborhood. Using multinomial logistic regression analyses, we found that neither perceived availability nor GIS-based presence of fast-food was significantly associated with weekly fast-food consumption. Our findings indicate that availability might not be the dominant factor influencing fast-food consumption. We recommend using subjective availability measures and considering individual characteristics that could influence both perceived availability of fast food and its impact on fast-food consumption. If replicated, our findings suggest that interventions aimed at reducing fast-food consumption by limiting neighborhood fast-food availability might not be completely effective.

Fast-food consumption, diet quality and body weight: Cross-sectional and prospective associations in a community sample of working adults

OBJECTIVE To examine the association between fast-food consumption, diet quality and body weight in a community sample of working adults. DESIGN Cross-sectional and prospective analysis of anthropometric, survey and dietary data from adults recruited to participate in a worksite nutrition intervention. Participants self-reported frequency of fast-food consumption per week. Nutrient intakes and diet quality, using the Healthy Eating Index-2010 (HEI-2010), were computed from dietary recalls collected at baseline and 6 months. SETTING Metropolitan medical complex, Minneapolis, MN, USA. SUBJECTS Two hundred adults, aged 18-60 years. RESULTS Cross-sectionally, fast-food consumption was significantly associated with higher daily total energy intake (β=72·5, P=0·005), empty calories (β=0·40, P=0·006) and BMI (β=0·73, P=0·011), and lower HEI-2010 score (β=-1·23, P=0·012), total vegetables (β=-0·14, P=0·004), whole grains (β=-0·39, P=0·005), fibre (β=-0·83, P=0·002), Mg (β=-6·99, P=0·019) and K (β=-57·5, P=0·016). Over 6 months, change in fast-food consumption was not significantly associated with changes in energy intake or BMI, but was significantly inversely associated with total intake of vegetables (β=-0·14, P=0·034). CONCLUSIONS Frequency of fast-food consumption was significantly associated with higher energy intake and poorer diet quality cross-sectionally. Six-month change in fast-food intake was small, and not significantly associated with overall diet quality or BMI.