Neal Simonsen

A multisite randomized trial of social norms marketing campaigns to reduce college student drinking: A replication failure.

ABSTRACT A 14-site randomized trial tested the effectiveness of social norms marketing (SNM) campaigns, which present accurate student survey data in order to correct misperceptions of subjective drinking norms and thereby drive down alcohol use. Cross-sectional student surveys were conducted by mail at baseline and at posttest 3 years later. Hierarchical linear modeling was applied to examine multiple drinking outcomes, taking into account the nonindependence of students grouped in the same college. Controlling for other predictors, having a SNM campaign was not significantly associated with lower perceptions of student drinking levels or lower self-reported alcohol consumption. This study failed to replicate a previous multisite randomized trial of SNM campaigns, which showed that students attending institutions with a SNM campaign had a lower relative risk of alcohol consumption than students attending control group institutions (W. DeJong et al. J Stud Alcohol. 2006;67:868–879). Additional research is needed to explore whether SNM campaigns are less effective in campus communities with relatively high alcohol retail outlet density.

Impact of small group size on neighbourhood influences in multilevel models

Background Given the growing availability of multilevel data from national surveys, researchers interested in contextual effects may find themselves with a small number of individuals per group. Although there is a growing body of literature on sample size in multilevel modelling, few have explored the impact of group sizes of less than five. Methods In a simulated analysis of real data, the impact of a group size of less than five was examined on both a continuous and dichotomous outcome in a simple two-level multilevel model. Models with group sizes one to five were compared with models with complete data. Four different linear and logistic models were examined: empty models; models with a group-level covariate; models with an individual-level covariate and models with an aggregated group-level covariate. The study evaluated further whether the impact of small group size differed depending on the total number of groups. Results When the number of groups was large (N=459), neither fixed nor random components were affected by small group size, even when 90% of tracts had only one individual per tract and even when an aggregated group-level covariate was examined. As the number of groups decreased, the SE estimates of both fixed and random effects were inflated. Furthermore, group-level variance estimates were more affected than were fixed components. Conclusions Datasets in which there is a small to moderate number of groups, with the majority of very small group size (n<5), size may fail to find or even consider a group-level effect when one may exist and also may be underpowered to detect fixed effects.

Social Capital in the College Setting: The Impact of Participation in Campus Activities on Drinking and Alcohol-Related Harms

Objective: The authors aimed to replicate previous findings on social capital and harmful alcohol outcomes in the college setting and to ascertain the protective effects of additional indicators of social capital. Methods: Over 4 years (2000-2004), the authors conducted annual cross-sectional, random-sample student surveys at 32 US institutions of higher education (N = 15,875) and constructed multilevel models to examine the association between individual- and campus-level participation in campus activities and harmful drinking outcomes. Results: At the individual level, community volunteerism was protective against harmful drinking outcomes. In contrast to past research, campus-level volunteerism was not significantly associated with the outcome measures. At both the individual and campus levels, participation in a religious organization was protective. Greek membership and varsity athletic participation were risk factors at the individual level. Conclusions: Results did not corroborate previous findings and revealed mixed results for other measures of participation at the campus level. The influence of social capital on college alcohol consumption deserves further attention.

Environmental Exposure to Emissions from Petrochemical Sites and Lung Cancer: The Lower Mississippi Interagency Cancer Study

To investigate potential links between environmental exposure to petrochemical plant emissions and lung cancer, a population-based case-control study (LMRICS) was conducted in eleven Louisiana parishes bordering the Mississippi River. Cases and age, gender, and race-matched controls were interviewed regarding potential risk factors. Residential history was geocoded to provide indices of long-term proximity to industrial sites. Cases were more likely to have lived near a petrochemical site. Models adjusted for other risk factors, however, showed small or no association with lung cancer (odds ratio for residence within a half-mile of a site = 1.10, 95% confidence interval 0.58–2.08). While associations were strongest for exposures exceeding 15 years, none approached statistical significance and there was no clear dose-response across exposure duration, distance categories, or when sites were grouped according to carcinogenicity rating of chemical releases. Residential proximity to petrochemical plants along the lower Mississippi thus showed no significant association with lung cancer.

Misspecification of the effect of race in fixed effects models of health inequalities

The purpose of this study is to characterize the different results obtained when analyzing health inequalities data in which individuals are nested within their neighborhoods and a single level model is used to characterize risk rather than a multilevel model. The inability of single level models to characterize between neighborhood variance in risk may affect the level of risk attributed to black race if blacks are differentially distributed in high risk neighborhoods. The research replicates in Los Angeles an approach applied by a different group of researchers in Massachusetts (Subramanian, Chen, Rehkopf, Waterman, & Krieger, 2005). Single level and multilevel models were used to analyze Los Angeles County, California, US all-cause mortality data for the years 1989-1991, modeled as 29,936 cells (deaths and population denominators cross-tabulated by age, gender, and race/ethnicity) nested within 1552 census tracts. Overall blacks had 1.27 times the risk of mortality compared to whites. However, multilevel models demonstrated considerable between census tract variance in mortality for both blacks and whites which was partially explained by neighborhood poverty. Comparing the results of equivalent single level and multilevel models, the mortality odds ratio for blacks compared to the white reference group reversed itself, indicating greater risk for blacks in the single level model and lower risk in the multilevel model. Adding an area based socioeconomic measure (ABSM) to the single level model reduced but did not remove the discrepancy. Predictions of mortality risk for the interaction of race and age group demonstrate that all single level models exaggerated the mortality risk associated with black race. We conclude that characterizing health inequalities in mortality for blacks using single level models, which do not account for the cross level interaction created by the greater likelihood of black residence in neighborhoods where the risk of mortality is greater regardless of race, can exaggerate the risk of mortality attributable to the individual level effects of black race.

Racial/Ethnic Disparities in Health-Related Quality of Life among Participants with Self-Reported Diabetes from NHANES 2001-2010

Purpose The purpose of this study is to investigate the racial/ethnic disparities in health-related quality of life (HRQOL) among adults with self-reported diabetes and identify the different risk factors related to HRQOL for specific racial/ethnic groups in the United States. Methods National Health and Nutrition Examination Survey (NHANES) 2001-2010 participants (ages 20 years and older) who were self-identified as non-Hispanic white, non-Hispanic black, or Hispanic and with self-reported diabetes were included in the analysis (n = 2594). The Centers for Disease Control and Prevention’s HRQOL-4 was used to assess factors associated with HRQOL through multivariate logistic regression models with survey weighting. Stepwise model selection was applied to select the most significant factors for HRQOL in each racial/ethnic group. Results Hispanic participants were less likely to report 14 or more mentally unhealthy days and activity-limited days compared to non-Hispanic white counterparts, adjusting for age, sex, education, marital status, family poverty–income ratio (PIR), body mass index, smoking status, insurance coverage, and diabetes duration. Current smoking status and obesity were significantly associated with worse HRQOL among whites and blacks. Marital status predicted better HRQOL only among Hispanics. Having insurance coverage predicted better HRQOL among both blacks and Hispanics. Increased family PIR had a favorable association with the 4 HRQOL domains consistently among all races/ethnicities. Conclusion Minimal racial/ethnic disparities in HRQOL were observed among US adults with self-reported diabetes. Support is offered for more individualized health care and communication with patients to target care and interventions that improve health and quality-of-life indicators.

Multilevel spatiotemporal change-point models for evaluating the effect of an alcohol outlet control policy on changes in neighborhood assaultive violence rates.

Many previous studies have suggested a link between alcohol outlets and assaultive violence rates. In 1997 the City of New Orleans adopted a series of policies, e.g., increased license fee, additional enforcement staff, and expanded powers for the alcohol license board. The policies were specifically enacted to address the proliferation of problem alcohol outlets believed to be the source of a variety of social problems including assaultive violence. In this research, we evaluate the impact of a city level policy in New Orleans to address the problem alcohol outlets and their influence on assaultive violence. The spatial association between rates of assaultive violence at the census tract level (n=170) over a ten year period raises a challenge in statistical analysis. To meet this challenge we developed a hierarchical change-point model that controls for important covariates of assaultive violence and accounts for unexplained spatial and temporal variability. While our model is somewhat complex, its hierarchical Bayesian analysis is accessible via the WinBUGS software program. Keeping other effects fixed, the implementation of the new city level policy was associated with a decrease in the positive association between census tract level rates of assaultive violence and alcohol outlet density. Comparing several candidate change-point models using the DIC criterion, the positive association began decreasing the year of the policy implementation. The magnitude of the association continued to decrease for roughly two years and then stabilized. We also created maps of the fitted assaultive violence rates in New Orleans, as well as spatial residual maps which, together with Morans Is, suggest that the spatial variation of the data is well accounted for by our model. We reach the conclusion that the implementation of the policy is associated with a significant decrease in the positive relationship between assaultive violence and the off-sale alcohol outlet density.

Racial Differences of Pediatric Hypertension in Relation to Birth Weight and Body Size in the United States.

Background The prevalence of hypertension is known to differ by racial group in adults in the United States (US), but findings in children are scarce and inconsistent. The objective of this study was to assess the racial differences in pediatric hypertension and to explore whether these differences, if any, can be explained by low birth weight (LBW) and obesity. Methods Analyses were performed for participants aged 8–17 years (N = 9,250) included in the 1999–2010 National Health and Nutrition Examination Survey. Multivariate logistic regressions and weighted analysis were carried out considering the complex survey design. Results Compared to non-Hispanic White youth, the crude prevalence of hypertension was significantly higher in non-Hispanic Blacks (7.1% vs. 5.6%; P = 0.04), but not in Mexican Americans (5.4% vs. 5.6%; P = 0.77). Blacks also had higher rates of LBW (14.6% vs. 5.9%; P <0.001) and obesity (22.9% vs. 15.8%; P <0.001) than Whites. In stratified analysis by age-sex groups, the Black-White difference in hypertension prevalence was only significant in boys aged 13–17 (9.6% vs. 6.6%). After controlling for age, Black boys had a 51% higher odds of having hypertension (Odds ratio = 1.51; 95% confidence interval: 1.03, 3.43; P = 0.04) compared to White youth at ages 13–17. This racial difference persisted with additional adjustment for birth weight (odds ratio (OR) = 2.00; P = 0.02) and for current body mass index (OR = 1.50; P = 0.04). Mexican American youth had no difference in hypertension prevalence as compared to White youth after adjusting for age, sex, birth weight and obesity (Odds ratio = 0.82; P = 0.16) and in age-sex stratified subgroups. Conclusions Non-Hispanic Black adolescent boys have a significantly higher hypertension rate than their non-Hispanic White counterparts in the US. This racial difference cannot be explained by LBW and current obesity status within the Black population.

Forecasting the Effect of the Amethyst Initiative on College Drinking

BACKGROUND A number of college presidents have endorsed the Amethyst Initiative, a call to consider lowering the minimum legal drinking age (MLDA). Our objective is to forecast the effect of the Amethyst Initiative on college drinking. METHODS A system model of college drinking simulates MLDA changes through (i) a decrease in heavy episodic drinking (HED) because of the lower likelihood of students drinking in unsupervised settings where they model irresponsible drinking (misperception), and (ii) an increase in overall drinking among currently underage students because of increased social availability of alcohol (wetness). RESULTS For the proportion of HEDs on campus, effects of large decreases in misperception of responsible drinking behavior were more than offset by modest increases in wetness. CONCLUSIONS For the effect of lowering the MLDA, it appears that increases in social availability of alcohol have a stronger impact on drinking behavior than decreases in misperceptions.

Association of the T allele of an intronic single nucleotide polymorphism in the colony stimulating factor 1 receptor with Crohn's disease: a case-control study

BackgroundPolymorphisms in several genes (NOD2, MDR1, SLC22A4) have been associated with susceptibility to Crohns disease. Identification of the remaining Crohns susceptibility genes is essential for the development of disease-specific targets for immunotherapy. Using gene expression analysis, we identified a differentially expressed gene on 5q33, the colony stimulating factor 1 receptor (CSF1R) gene, and hypothesized that it is a Crohns susceptibility gene. The CSF1R gene is involved in monocyte to macrophage differentiation and in innate immunity.MethodsPatients provided informed consent prior to entry into the study as approved by the Institutional Review Board at LSU Health Sciences Center. We performed forward and reverse sequencing of genomic DNA from 111 unrelated patients with Crohns disease and 108 controls. We also stained paraffin-embedded, ileal and colonic tissue sections from patients with Crohns disease and controls with a polyclonal antibody raised against the human CSF1R protein.ResultsA single nucleotide polymorphism (A2033T) near a Runx1 binding site in the eleventh intron of the colony stimulating factor 1 receptor was identified. The T allele of this single nucleotide polymorphism occurred in 27% of patients with Crohns disease but in only 13% of controls (X2 = 6.74, p < 0.01, odds ratio (O.R.) = 2.49, 1.23 < O.R. < 5.01). Using immunohistochemistry, positive staining with a polyclonal antibody to CSF1R was observed in the superficial epithelium of ileal and colonic tissue sections.ConclusionsWe conclude that the colony stimulating factor receptor 1 gene may be a susceptibility gene for Crohns disease.