Oksana Pugach

Field validation of secondary commercial data sources on the retail food outlet environment in the U.S.

This study used direct field observations with interior assessments of outlets to validate food store and restaurant data from two commercial business lists conditional on classification of outlet type, including supermarkets, grocery stores, convenience stores, full-service restaurants and fast food restaurants. The study used a stratified random sample that included 274 urban census tracts across 9 counties from the Chicago Metropolitan Statistical Area (MSA) and 46 suburban and 61 rural census tracts across 13 counties from a 50-mile buffer surrounding the MSA. Results showed that agreement between the field observations and the commercial business lists for the food store and restaurant outlets was generally moderate (ranging from fair to good). However, when the listed data were validated based on an exact classification match, agreement was only fair (ranging from poor to moderate) and, in particular, poor for fast food restaurants. The study also found that agreement levels for some outlet types differed by tract characteristics. Commercial databases must be used with caution as substitutes for on the ground data collection.

Use of Tobacco Cessation Treatments Among Young Adult Smokers: 2005 National Health Interview Survey

OBJECTIVES We compared use of smoking cessation treatments and factors associated with treatment use among young adult smokers and other adult smokers. METHODS We used data from the 2005 National Health Interview Survey core and cancer control supplement. The sample consisted of 6511 current smokers, of whom 759 were aged 18-24 years. Our analyses were weighted to account for differential sampling probabilities and nonresponse rates. We compared continuous measures using the t test; logistic regression was used to obtain odds ratios and confidence intervals. Multiple logistic regression was used to identify correlates of treatment use. RESULTS Behavioral treatment use was infrequent among all smokers (4%-5%). Young adult smokers were less likely than other smokers to use pharmacotherapy (18% vs 32%). Correlates of pharmacotherapy use for young adult smokers were receiving advice from a health care provider, heavier smoking, and higher educational attainment. Compared with other smokers, young adult smokers were less likely to have received advice to quit from a health care provider (49% vs 60%). CONCLUSIONS Evidence-based tobacco cessation treatments are underused by young adult smokers.

Development and reliability testing of a food store observation form.

OBJECTIVE To develop a reliable food store observational data collection instrument to be used for measuring product availability, pricing, and promotion. DESIGN Observational data collection. SETTING A total of 120 food stores (26 supermarkets, 34 grocery stores, 54 gas/convenience stores, and 6 mass merchandise stores) in the Chicago metropolitan statistical area. MAIN OUTCOME MEASURES Inter-rater reliability for product availability, pricing, and promotion measures on a food store observational data collection instrument. ANALYSIS Cohens kappa coefficient and proportion of overall agreement for dichotomous variables and intra-class correlation coefficient for continuous variables. RESULTS Inter-rater reliability, as measured by average kappa coefficient, was 0.84 for food and beverage product availability measures, 0.80 for interior store characteristics, and 0.70 for exterior store characteristics. For continuous measures, average intra-class correlation coefficient was 0.82 for product pricing measures; 0.90 for counts of fresh, frozen, and canned fruit and vegetable options; and 0.85 for counts of advertisements on the store exterior and property. CONCLUSIONS AND IMPLICATIONS The vast majority of measures demonstrated substantial or almost perfect agreement. Although some items may require revision, results suggest that the instrument may be used to reliably measure the food store environment.

If You Build It Will They Come? Does Involving Community Groups in Playground Renovations Affect Park Utilization and Physical Activity?

In a sample of racially, ethnically, and socioeconomically diverse neighborhoods, using a quasi-experimental, prospective, longitudinal study design, we examined whether involvement of community groups in playground design selection, installation, and ongoing maintenance influences park utilization and moderate-to-vigorous physical activity (MVPA) post-playground renovations (N = 78 matched parks, 39 intervention/39control). Parks were matched on size, proximity, neighborhood socioeconomic status, and race/ethnicity. In summer/fall 2013 and 2014, baseline and 12-month follow-up data were collected on park utilization and physical activity, presence and condition of park features, incivilities, programming, and safety. Analyses were conducted using Poisson mixed-effects regression models. Significant increases between baseline and 12-month follow-up were found for park utilization and the number of people engaged in MVPA at the .05 significance level. Study results can provide communities with evidence to inform future policy decisions on how to increase park utilization in diverse neighborhoods.

Classification Tree Analysis as a Method for Uncovering Relations between CHRNA5A3B4 and CHRNB3A6 in Predicting Smoking Progression in Adolescent Smokers

Introduction Prior research suggests the CHRNA5A3B4 and CHRNB3A6 gene clusters have independent effects on smoking progression in young smokers. Here classification tree analysis uncovers conditional relations between these genes. Methods Conditional classification tree and random forest analyses were employed to predict daily smoking at 6-year follow-up in a longitudinal sample of young smokers (N = 480) who had smoked at least one puff at baseline and were of European ancestry. Potential predictors included gender, lifetime smoking, Nicotine Dependence Syndrome Scale (NDSS), and five single nucleotide polymorphisms (SNPs) tagging CHRNB3A6 and CHRNA5A3B4 Haplotypes A, B, and C. Conditional random forest analysis was used to calculate variable importance. Results The classification tree identified NDSS, the CHRNB3A6 SNP rs2304297, and the CHRNA5A3B4 Haplotype C SNP rs6495308 as predictive of year 6 daily smoking with the baseline NDSS identified as the strongest predictor. The CHRNB3A6 protective effect was contingent on a lower level of baseline NDSS, whereas the CHRNA5A3B4 Haplotype C protective effect was seen at a higher level of baseline NDSS. A CHRNA5A3B4 Haplotype C protective effect also was observed in participants with low baseline NDSS who had no CHRNB3A6 rs2304297 minor allele. Conclusions The protective effects of CHRNA5A3B4 Haplotype C and CHRNB3A6 on smoking progression are conditional on different levels of baseline cigarette use. Also, duplicate dominant epistasis between SNPs indicated the minor allele of either SNP afforded comparable protective effects in the absence of a minor allele at the other locus. Possible mechanisms underlying these conditional relations are discussed. Implications The substantive contributions of this paper are the demonstration of a difference in the protective effects of CHRNB3A6 and CHRNA5A3B4 Haplotype C in young smokers attributable to level of cigarette use, as well as observation of duplicate dominant epistasis between the two markers. The methodological contribution is demonstrating that classification tree and random forest statistical methods can uncover conditional relations among genetic effects not detected with more common regression methods.

Modeling Mood Variation and Covariation Among Adolescent Smokers: Application of a Bivariate Location-Scale Mixed-Effects Model

INTRODUCTION Ecological momentary assessments (EMAs) are useful for understanding both between- and within-subject dynamic changes in smoking and mood. Modeling 2 moods (positive affect [PA] and negative affect [NA], PA and NA) simultaneously will better enable researchers to explore the association between mood variables and what influences them at both the momentary and subject level. METHODS The EMA component of a natural history study of adolescent smoking was analyzed with a bivariate location-scale mixed-effects model. The proposed model separately estimates the between- and within-subject variances and jointly models the 2 mood constructs. A total of 461 adolescents completed the baseline EMA wave, which resulted in 14,105 random prompts. Smoking level, represented by the number of smoking events on EMA, entered the model as 2 predictors: one that compared nonsmokers during the EMA week to 1-cigarette smokers, and the second one that estimated the effect of smoking level on mood among smokers. RESULTS Results suggest that nonsmokers had more consistent positive and negative moods compared to 1-cigarette smokers. Among those who smoked, both moods were more consistent at higher smoking levels. The effects of smoking level were greater for NA than for PA. The within-subject association between mood constructs was negative and strongest among 1-cigarette smokers; the within-subject association between positive and negative moods was negatively associated with smoking. CONCLUSIONS Mood variation and association between mood constructs varied across smoking levels. The most infrequent smokers were characterized with more inconsistent moods, whereas mood was more consistent for subjects with higher smoking levels.

A Comparison of Mandated Versus Volunteer Adolescent Participants in Youth Tobacco Cessation Programs

A national evaluation of community-based youth cessation programs delivered in group format provided the opportunity to compare mandated and volunteer program participants on demographics, smoking patterns, other health behaviors and motivation to quit. A total of 857 youth participants completed surveys prior to the start of their treatment program. Mandated youth comprised 24% of the sample (n=202). Both bivariate and multivariate comparisons were conducted. Mandated participants reported lower levels of stress, higher extrinsic motivation and lower intrinsic motivation to quit, and were more likely to be in the earlier (precontemplation) stage of readiness to quit. Mandated and volunteer smokers did not differ in their smoking patterns, school-related smoking behaviors, or binge drinking. Rates of smoking, school problems, and binge drinking were higher among cessation program participants than in general samples of youth. Programs with mixed voluntary-mandatory participation may benefit from extra attention to motivational issues.

CYP2A6 effects on subjective reactions to initial smoking attempt

INTRODUCTION In very novice smokers, CYP2A6 genotypes that reduce nicotine metabolism to an intermediate rate may increase smoking risk, relative to both normal and slow rates. The present study examined the hypothesis that intermediate metabolism variants are associated with greater pleasurable effects of the initial smoking attempt than either normal or slow metabolism variants. METHODS Participants were novice smokers (N = 261, 65% female) of European descent. Predicted nicotine metabolic rate based on CYP2A6 diplotypes (CYP2A6 Diplotype Predicted Rate [CDPR]) was partitioned into Normal, Intermediate, and Slow categories using a metabolism metric. Subjective reactions to the initial smoking attempt were assessed by the Pleasurable Smoking Experiences (PSE) scale, which was collected within 3 years of the initial smoking attempt. The effect of CDPR on PSE was tested using a generalized linear model in which CDPR was dummy coded and Intermediate CDPR was the reference condition. Gender was included in the model as a control for higher PSE scores by males. RESULTS Lower PSE scores were associated with Normal CDPR, β = -0.34, P = .008, and Slow CDPR, β = -0.52, P = .001, relative to Intermediate CDPR. CONCLUSIONS Intermediate CDPR-enhanced pleasurable effects of the initial smoking attempt relative to other CYP2A6 variants. This finding is consistent with the hypothesis that the risk effect of Intermediate CDPR on early smoking is a function of optimal pleasurable effects. IMPLICATIONS This study supports our recent hypothesis that CYP2A6 diplotypes that encode intermediate nicotine metabolism rate are associated with enhanced pleasurable events following the initial smoking attempt, compared with diplotypes that encode either normal or slow metabolism. This hypothesis was offered to account for our unexpected previous finding of enhanced smoking risk in very novice smokers associated with intermediate metabolism rate. Our new finding encourages further investigation of time-dependent relations between CYP2A6 effects and smoking motives, and it encourages laboratory study of the mechanisms underlying the initial smoking enhancement in novice smokers associated with intermediate metabolism.

Associations between fiber intake and Body Mass Index (BMI) among African-American women participating in a randomized weight loss and maintenance trial

INTRODUCTION African-American women are at increased risk for obesity, and therefore it is important to identify dietary factors that have the potential to prevent weight gain within this population. The purpose of the current study was to examine associations between daily fiber intake and Body Mass Index (BMI) over the course of an 18-month weight loss intervention for African-American women. METHODS Anthropometric measures and the Block Food Frequency Questionnaire were administered at baseline, 6-month, and 18-month follow-up between 2008 and 2010. A mixed-effects linear regression model with random intercept and time slope was used to model associations between fiber consumption and BMI controlling for time trend. RESULTS Associations between fiber consumption and BMI were significantly different over time (β̂Fiber∗Time=-0.07,p-value=0.003). There was no association between fiber intake and BMI at baseline; however, there was a significant inverse relation between fiber consumption and BMI at 6 months, and the association was even stronger at 18 months. CONCLUSIONS Results from this study suggest that dietary fiber consumption may be particularly important within weight loss interventions tailored for African-American women.

A Bivariate Mixed-Effects Location-Scale Model with application to Ecological Momentary Assessment (EMA) data

A bivariate mixed-effects location-scale model is proposed for estimation of means, variances, and covariances of two continuous outcomes measured concurrently in time and repeatedly over subjects. Modeling the two outcomes jointly allows examination of BS and WS association between the outcomes and whether the associations are related to covariates. The variance–covariance matrices of the BS and WS effects are modeled in terms of covariates, explaining BS and WS heterogeneity. The proposed model relaxes assumptions on the homogeneity of the within-subject (WS) and between-subject (BS) variances. Furthermore, the WS variance models are extended by including random scale effects. Data from a natural history study on adolescent smoking are used for illustration. 461 students, from 9th and 10th grades, reported on their mood at random prompts during seven consecutive days. This resulted in 14,105 prompts with an average of 30 responses per student. The two outcomes considered were a subject’s positive affect and a measure of how tired and bored they were feeling. Results showed that the WS association of the outcomes was negative and significantly associated with several covariates. The BS and WS variances were heterogeneous for both outcomes, and the variance of the random scale effects were significantly different from zero.