Barbara Kilbourne

The Public Health Exposome: A Population-Based, Exposure Science Approach to Health Disparities Research

The lack of progress in reducing health disparities suggests that new approaches are needed if we are to achieve meaningful, equitable, and lasting reductions. Current scientific paradigms do not adequately capture the complexity of the relationships between environment, personal health and population level disparities. The public health exposome is presented as a universal exposure tracking framework for integrating complex relationships between exogenous and endogenous exposures across the lifespan from conception to death. It uses a social-ecological framework that builds on the exposome paradigm for conceptualizing how exogenous exposures “get under the skin”. The public health exposome approach has led our team to develop a taxonomy and bioinformatics infrastructure to integrate health outcomes data with thousands of sources of exogenous exposure, organized in four broad domains: natural, built, social, and policy environments. With the input of a transdisciplinary team, we have borrowed and applied the methods, tools and terms from various disciplines to measure the effects of environmental exposures on personal and population health outcomes and disparities, many of which may not manifest until many years later. As is customary with a paradigm shift, this approach has far reaching implications for research methods and design, analytics, community engagement strategies, and research training.

Group Therapy for Depressed Elderly Women

Abstract We describe and evaluate a group therapy program targeting depression among elderly residents (N=303) of subsidized high-rise apartments in Nashville, TN. This eclectic program was comprised of 12 sessions (a total of 24 hours) that included modules on exercise and preventive health behaviors, cognitive and re-motivation therapy, reminiscence and grief therapy, and social skills development. Our multivariate regression analyses of pre-post measures using the Geriatric Depression Scale (GDS) showed that the effects of the group therapy varied by race, age, and level of initial depression among the participants. The program was effective in reducing depression, but only among Caucasian women who reported at least moderate depression prior to the program, and it yielded greater benefits for women between 55 and 75 years of age.

Firearms, Youth Homicide, and Public Health

Homicide is seven times as common among U.S. non-Hispanic Black as among non-Hispanic White youth ages 15 to 24 years. In 83% of these youth homicides, the murder weapon is a firearm. Yet, for more than a decade, the national public health position on youth violence has been largely silent about the role of firearms, and tools used by public health professionals to reduce harm from other potential hazards have been unusable where guns are concerned. This deprives already underserved populations from the full benefits public health agencies might be able to deliver. In part, political prohibitions against research about direct measures of firearm control and the absence of valid public health surveillance are responsible. More refined epidemiologic theories as well as traditional public health methods are needed if the U.S. aims to reduce disparate Black-White youth homicide rates.

Exploration of preterm birth rates using the public health exposome database and computational analysis methods.

Recent advances in informatics technology has made it possible to integrate, manipulate, and analyze variables from a wide range of scientific disciplines allowing for the examination of complex social problems such as health disparities. This study used 589 county-level variables to identify and compare geographical variation of high and low preterm birth rates. Data were collected from a number of publically available sources, bringing together natality outcomes with attributes of the natural, built, social, and policy environments. Singleton early premature county birth rate, in counties with population size over 100,000 persons provided the dependent variable. Graph theoretical techniques were used to identify a wide range of predictor variables from various domains, including black proportion, obesity and diabetes, sexually transmitted infection rates, mother’s age, income, marriage rates, pollution and temperature among others. Dense subgraphs (paracliques) representing groups of highly correlated variables were resolved into latent factors, which were then used to build a regression model explaining prematurity (R-squared = 76.7%). Two lists of counties with large positive and large negative residuals, indicating unusual prematurity rates given their circumstances, may serve as a starting point for ways to intervene and reduce health disparities for preterm births.

Scalable combinatorial tools for health disparities research

Despite staggering investments made in unraveling the human genome, current estimates suggest that as much as 90% of the variance in cancer and chronic diseases can be attributed to factors outside an individual’s genetic endowment, particularly to environmental exposures experienced across his or her life course. New analytical approaches are clearly required as investigators turn to complicated systems theory and ecological, place-based and life-history perspectives in order to understand more clearly the relationships between social determinants, environmental exposures and health disparities. While traditional data analysis techniques remain foundational to health disparities research, they are easily overwhelmed by the ever-increasing size and heterogeneity of available data needed to illuminate latent gene x environment interactions. This has prompted the adaptation and application of scalable combinatorial methods, many from genome science research, to the study of population health. Most of these powerful tools are algorithmically sophisticated, highly automated and mathematically abstract. Their utility motivates the main theme of this paper, which is to describe real applications of innovative transdisciplinary models and analyses in an effort to help move the research community closer toward identifying the causal mechanisms and associated environmental contexts underlying health disparities. The public health exposome is used as a contemporary focus for addressing the complex nature of this subject.

Demographic and Geographic Variations in Breast Cancer Mortality among U.S. Hispanics

This paper examines demographic and geographic differences in breast cancer mortality (1999 to 2009) between U.S. Hispanic and non-Hispanic women from different racial groups. Data were publically available from the U.S. Centers for Disease Control and Prevention (CDC). Four racial groups are included: American Indian/Alaska Natives, Asian/Pacific Islanders, Blacks/African Americans, and Whites. Age-adjusted rates were obtained for women ages 35–64 and 65 years and older. Hispanic mortality was generally lower than non-Hispanic mortality regardless of age, race, Census Region, State, or county. The lone exception was Hispanic Asian/Pacific Islanders residing in Hawaii. Despite generally lower rates, there was considerable variation in Hispanic breast cancer mortality within the country. Poverty, percentage of renters, and educational attainment were important explanatory factors. Analytic epidemiologic studies might explain social, cultural, and other reasons for the observed geographic variations. Such studies, in turn, could support a stronger theoretical basis for public health policy.

Alcohol diagnoses among older Tennessee Medicare beneficiaries: race and gender differences

These analyses bolster a sparse body of research focusing on the rate of alcohol disorders among older adults, particularly race and gender subgroups.

Mammography Screening Among the Elderly: A Research Challenge

BACKGROUND Randomized trials demonstrate clear benefits of mammography screening in women through age 74 years. We explored age- and race-specific rates of mammography screening and breast cancer mortality among women aged 69 to 84 years. METHODS We analyzed Medicare claims data for women residing within Surveillance, Epidemiology and End Results geographic areas from 1995 to 2009 from 64,384 non-Hispanic women (4886 black and 59,498 white) and ascertained all primary breast cancer cases diagnosed between ages 69 and 84 years. The exposure was annual or biennial screening mammography during the 4 years immediately preceding diagnosis. The outcome was breast cancer mortality during the 10 years immediately after diagnosis. RESULTS After adjustment for stage at diagnosis, radiation therapy, chemotherapy, comorbid conditions, and contextual socioeconomic status, hazard ratios (and 95% confidence intervals) for breast cancer mortality relative to no/irregular mammography at 10 years for women aged 69 to 84 years at diagnosis were 0.31 (0.29-0.33) for annual mammography and 0.47 (0.44-0.51) for biennial mammography among whites and 0.36 (0.29-0.44) for annual mammography and 0.47 (0.37-0.58) for biennial mammography among blacks. Trends were similar at 5 years overall and stratified by ages 69 to 74 years, 75 to 78 years, and 79 to 84 years. CONCLUSIONS In these Medicare claims and Surveillance, Epidemiology and End Results data, elderly non-Hispanic women who self-selected for annual mammography had lower 10-year breast cancer mortality than corresponding women who self-selected for biennial or no/irregular mammography. These findings were similar among black and white women. The data highlight the evidentiary limitations of data used for current screening mammography recommendations.

A multifactorial obesity model developed from nationwide public health exposome data and modern computational analyses

STATEMENT OF THE PROBLEM Obesity is both multifactorial and multimodal, making it difficult to identify, unravel and distinguish causative and contributing factors. The lack of a clear model of aetiology hampers the design and evaluation of interventions to prevent and reduce obesity. METHODS Using modern graph-theoretical algorithms, we are able to coalesce and analyse thousands of inter-dependent variables and interpret their putative relationships to obesity. Our modelling is different from traditional approaches; we make no a priori assumptions about the population, and model instead based on the actual characteristics of a population. Paracliques, noise-resistant collections of highly-correlated variables, are differentially distilled from data taken over counties associated with low versus high obesity rates. Factor analysis is then applied and a model is developed. RESULTS AND CONCLUSIONS Latent variables concentrated around social deprivation, community infrastructure and climate, and especially heat stress were connected to obesity. Infrastructure, environment and community organisation differed in counties with low versus high obesity rates. Clear connections of community infrastructure with obesity in our results lead us to conclude that community level interventions are critical. This effort suggests that it might be useful to study and plan interventions around community organisation and structure, rather than just the individual, to combat the nations obesity epidemic.

Neighbourhood deprivation and lung cancer risk: a nested case–control study in the USA

Objectives To examine the association between neighbourhood deprivation and lung cancer risk. Design Nested case–control study. Setting Southern Community Cohort Study of persons residing in 12 states in the southeastern USA. Participants 1334 cases of lung cancer and 5315 controls. Primary outcome measure Risk of lung cancer. Results After adjustment for smoking status and other confounders, and additional adjustment for individual-level measures of socioeconomic status (SES), there was no monotonic increase in risk with worsening deprivation score overall or within sex and race groups. There was an increase among current and shorter term former smokers (p=0.04) but not among never and longer term former smokers. There was evidence of statistically significant interaction by sex among whites, but not blacks, in which the effect of worsening deprivation on lung cancer existed in males but not in females. Conclusions Area-level measures of SES were associated with lung cancer risk in current and shorter term former smokers only in this population.