Neighborhood disadvantage and racial disparities in colorectal cancer incidence: a population-based study in Louisiana.

PURPOSE: Colorectal cancer (CRC) continues to demonstrate racial disparities in incidence and survival in the United States. This study investigates the role of neighborhood concentrated disadvantage in racial disparities in CRC incidence in Louisiana. METHODS: Louisiana Tumor Registry and U.S. Census data were used to assess the incidence of CRC diagnosed in individuals 35 years and older between 2008 and 2012. Neighborhood concentrated disadvantage index (CDI) was calculated based on the PhenX Toolkit protocol. The incidence of CRC was modeled using multilevel binomial regression with individuals nested within neighborhoods. RESULTS: Our study included 10,198 cases of CRC. Adjusting for age and sex, CRC risk was 28% higher for blacks than whites (risk ratio [RR] = 1.28; 95% confidence interval [CI] = 1.22-1.33). One SD increase in CDI was associated with 14% increase in risk for whites (RR = 1.14; 95% CI = 1.10-1.18) and 5% increase for blacks (RR = 1.05; 95% CI = 1.02-1.09). After controlling for differential effects of CDI by race, racial disparities were not observed in disadvantaged areas. CONCLUSION: CRC incidence increased with neighborhood disadvantage and racial disparities diminished with mounting disadvantage. Our results suggest additional dimensions to racial disparities in CRC outside of neighborhood disadvantage that warrants further research.

Exploring racial disparity in obesity: A mediation analysis considering geo-coded environmental factors.

Research shows aconsistent racial disparity in obesity between white and black adults in the United States. Accounting for the disparity is a challenge given the variety of the contributing factors, the nature of the association, and the multilevel relationships among the factors. We used the multivariable mediation analysis (MMA) method to explore the racial disparity in obesity considering not only the individual behavior but also geospatially derived environmental risk factors. Results from generalized linear models (GLM) were compared with those from multiple additive regression trees (MART) which allow for hierarchical data structure, and fitting of nonlinear and complex interactive relationships. As results, both individual and geographically defined factors contributed to the racial disparity in obesity. MART performed better than GLM models in that MART explained a larger proportion of the racial disparity in obesity. However, there remained disparities that cannot be explained by factors collected in this study.

The Social Determinants of Health Core: Taking a Place-Based Approach.

INTRODUCTION: There is growing recognition that health disparities research needs to incorporate social determinants in the local environment into explanatory models. In the transdisciplinary setting of the Mid-South Transdisciplinary Collaborative Center (TCC), the Social Determinants of Health (SDH) Core developed an approach to incorporating SDH across a variety of studies. This place-based approach, which is geographically based, transdisciplinary, and inherently multilevel, is discussed. METHODS: From 2014 through 2016, the SDH Core consulted on a variety of Mid-South TCC research studies with the goal of incorporating social determinants into their research designs. The approach used geospatial methods (e.g., geocoding) to link individual data files with measures of the physical and social environment in the SDH Core database. Once linked, the method permitted various types of analysis (e.g., multilevel analysis) to determine if racial disparities could be explained in terms of social determinants in the local environment. RESULTS: The SDH Core consulted on five Mid-South TCC research projects. In resulting analyses for all the studies, a significant portion of the variance in one or more outcomes was partially explained by a social determinant from the SDH Core database. CONCLUSIONS: The SDH Core approach to addressing health disparities by linking neighborhood social and physical environment measures to an individual-level data file proved to be a successful approach across Mid-South TCC research projects.

Street Connectivity and Obesity Risk: Evidence From Electronic Health Records.

INTRODUCTION: This study aimed to determine the feasibility of using electronic health record (EHR) data from a federally qualified health center (FQHC) to assess the association between street connectivity, a measure of walkability for the local environment, and BMI obtained from EHRs. METHODS: The study included patients who visited Daughters of Charity clinics in 2012-2013. A total of 31,297 patients were eligible, of which 28,307 were geocoded. BMI and sociodemographic information were compiled into a de-identified database. The street connectivity measure was intersection density, calculated as the number of three-way or greater intersections per unit area. Multilevel analyses of BMI, measured on 17,946 patients who were aged ≥20 years, not pregnant, had complete sociodemographic information, and a BMI value that was not considered an outlier, were conducted using random intercept models. RESULTS: Overall, on average, patients were aged 44.1 years, had a BMI of 30.2, and were mainly non-Hispanic black (59.4%). An inverse association between BMI and intersection density was observed in multilevel models controlling for age, gender, race, and marital status. Tests for multiple interactions were conducted and a significant interaction between race and intersection density indicated the decrease in BMI was strongest for non-Hispanic whites (decreased by 2) compared with blacks or Hispanics (decreased by 0.6) (p=0.0121). CONCLUSIONS: EHRs were successfully used to assess the relationship between street connectivity and BMI in a multilevel framework. Increasing street connectivity levels measured as intersection density were inversely associated with directly measured BMI obtained from EHRs, demonstrating the feasibility of the approach.

An ecological analysis of alcohol-outlet density and campus-reported violence at 32 U.S. colleges.

OBJECTIVE: The purpose of this study was to assess the relationships among campus violence, student drinking levels, and the physical availability of alcohol at off-campus outlets in a multisite design. METHOD: An ecological analysis of on-campus violence was conducted at 32 U.S. colleges. Dependent variables included campus-reported rates of rape, robbery, assault, and burglary obtained from a U.S. Department of Education online database for the years 2000-2004. Measures of student alcohol use and demographics were obtained from student surveys conducted for the Social Norms Marketing Research Project from 2000 to 2004. Measures of alcohol-outlet density within 3 miles of each campus were obtained from state alcohol-licensing authorities for 2004. RESULTS: Both on- and off-premise alcohol-outlet densities were associated with the campus rape-offense rate but not with the assault or robbery rates. Student drinking level was associated with both campus rape and assault rates but not with the campus robbery rate. The apparent effect of on-premise outlet density on campus rape-offense rates was reduced when student drinking level was included in the model, suggesting that the effect of on-premise outlet density may be mediated by student drinking level. Separate analyses revealed a similar mediational role for off-premise outlet density. CONCLUSIONS: These findings demonstrate that there is a campus-level association between sexual violence and the campus-community alcohol environment.

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.

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

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.

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

OBJECTIVE: An 18-site randomized trial was conducted to determine the effectiveness of social norms marketing (SNM) campaigns in reducing college student drinking. The SNM campaigns are intended to correct misperceptions of subjective drinking norms and thereby drive down alcohol consumption. METHOD: Institutions of higher education were randomly assigned to treatment and control groups. At the treatment group institutions, SNM campaigns delivered school-specific, data-driven messages through a mix of campus media venues. Cross-sectional student surveys were conducted by mail at baseline (n = 2,771) and at posttest 3 years later (n = 2,939). Hierarchical linear modeling was applied to examine multiple drinking outcomes, taking intraclass correlation into account. RESULTS: Controlling for other predictors, having an SNM campaign was significantly associated with lower perceptions of student drinking levels and lower alcohol consumption, as measured by a composite drinking scale, recent maximum consumption, blood alcohol concentration for recent maximum consumption, drinks consumed when partying, and drinks consumed per week. A moderate mediating effect of normative perceptions on student drinking was demonstrated by an attenuation of the Experimental Group x Time interaction, ranging from 16.4% to 39.5% across measures. Additional models that took into account the intensity of SNM campaign activity at the treatment institutions suggested that there was a dose-response relationship. CONCLUSIONS: This study is the most rigorous evaluation of SNM campaigns conducted to date. Analysis revealed that students attending institutions that implemented an SNM campaign had a lower relative risk of alcohol consumption than students attending control group institutions.

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.

BACKGROUND: Polymorphisms in several genes (NOD2, MDR1, SLC22A4) have been associated with susceptibility to Crohn's disease. Identification of the remaining Crohn's 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 Crohn's susceptibility gene. The CSF1R gene is involved in monocyte to macrophage differentiation and in innate immunity. METHODS: Patients 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 Crohn's disease and 108 controls. We also stained paraffin-embedded, ileal and colonic tissue sections from patients with Crohn's disease and controls with a polyclonal antibody raised against the human CSF1R protein. RESULTS: A 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 Crohn's 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. CONCLUSIONS: We conclude that the colony stimulating factor receptor 1 gene may be a susceptibility gene for Crohn's disease.