Neighbourhood food, physical activity, and educational environments and black/white disparities in obesity: a complex systems simulation analysis.

BACKGROUND: Multiple approaches that can contribute to reducing obesity have been proposed. These policies may share overlapping pathways, and may have unanticipated consequences, creating considerable complexity. Aiming to illuminate the use of agent-based models to explore the consequences of key policies, this paper simulates the effects of increasing neighbourhood availability of good food stores, physical activity infrastructure and higher school quality on the reduction of black/white disparities in body mass index (BMI) in the USA. METHODS: We used an agent-based model, with parameters derived from the empirical literature, which included individual and neighbourhood characteristics over the life course as determinants of behaviours thought to impact BMI. We systematically varied the strength of the 3 policy interventions, examining the impact of 125 different policy scenarios on black/white BMI disparities. RESULTS: In the absence of any of these policies, black/white BMI disparities generally increased over time. However, we found that some combinations of these policies resulted in reductions in BMI, yielding decreases in the black/white BMI disparity as large as a 90%. CONCLUSIONS: Within the structure of relationships captured in this simulation model, there is support for the further use of agent-based simulation models to explore upstream policies as plausible candidates for the reduction of black/white disparities in BMI. These results highlight the potential insights into important public health problems, such as obesity, that can come from uniting the systems science approach with policy analysis.

Mass fatality preparedness among medical examiners/coroners in the United States: a cross-sectional study.

BACKGROUND: In the United States (US), Medical Examiners and Coroners (ME/Cs) have the legal authority for the management of mass fatality incidents (MFI). Yet, preparedness and operational capabilities in this sector remain largely unknown. The purpose of this study was twofold; first, to identify appropriate measures of preparedness, and second, to assess preparedness levels and factors significantly associated with preparedness. METHODS: Three separate checklists were developed to measure different aspects of preparedness: MFI Plan Elements, Operational Capabilities, and Pre-existing Resource Networks. Using a cross-sectional study design, data on these and other variables of interest were collected in 2014 from a national convenience sample of ME/C using an internet-based, anonymous survey. Preparedness levels were determined and compared across Federal Regions and in relation to the number of Presidential Disaster Declarations, also by Federal Region. Bivariate logistic and multivariable models estimated the associations between organizational characteristics and relative preparedness. RESULTS: A large proportion (42%) of respondents reported that less than 25 additional fatalities over a 48-hour period would exceed their response capacities. The preparedness constructs measured three related, yet distinct, aspects of preparedness, with scores highly variable and generally suboptimal. Median scores for the three preparedness measures also varied across Federal Regions and as compared to the number of Presidential Declared Disasters, also by Federal Region. Capacity was especially limited for activating missing persons call centers, launching public communications, especially via social media, and identifying temporary interment sites. The provision of staff training was the only factor studied that was significantly (positively) associated (p < .05) with all three preparedness measures. Although ME/Cs ranked local partners, such as Offices of Emergency Management, first responders, and funeral homes, as the most important sources of assistance, a sizeable proportion (72%) expected federal assistance. CONCLUSIONS: The three measures of MFI preparedness allowed for a broad and comprehensive assessment of preparedness. In the future, these measures can serve as useful benchmarks or criteria for assessing ME/Cs preparedness. The study findings suggest multiple opportunities for improvement, including the development and implementation of national strategies to ensure uniform standards for MFI management across all jurisdictions.

Reducing racial disparities in obesity: simulating the effects of improved education and social network influence on diet behavior.

PURPOSE: Understanding how to mitigate the present black-white obesity disparity in the United States is a complex issue, stemming from a multitude of intertwined causes. An appropriate but underused approach to guiding policy approaches to this problem is to account for this complexity using simulation modeling. METHODS: We explored the efficacy of a policy that improved the quality of neighborhood schools in reducing racial disparities in obesity-related behavior and the dependence of this effect on social network influence and norms. We used an empirically grounded agent-based model to generate simulation experiments. We used a 2 × 2 × 2 factorial design that represented the presence or absence of improved neighborhood school quality, the presence or absence of social influence, and the type of social norm (healthy or unhealthy). Analyses focused on time trends in sociodemographic variables and diet quality. RESULTS: First, the quality of schools and social network influence had independent and interactive effects on diet behavior. Second, the black-white disparity in diet behavior was considerably reduced under some conditions, but never completely eliminated. Third, the degree to which the disparity in diet behavior was reduced was a function of the type of social norm that was in place; the reduction was the smallest when the type of social norm was healthy. CONCLUSIONS: Improving school quality can reduce, but not eliminate racial disparities in obesity-related behavior, and the degree to which this is true depends partly on social network effects.

Potentially modifiable deployment characteristics and new-onset alcohol abuse or dependence in the US National Guard.

BACKGROUND: There is a limited amount of data examining the relation between the onset of alcohol abuse/dependence and the experiences of soldiers prior to (pre), during (peri) and after (post) military deployment. Some deployment characteristics, e.g., military unit cohesion, are potentially modifiable in the context of reducing alcohol abuse/dependence peri-/post deployment. We investigated the associations between potentially modifiable deployment characteristics and peri-/post (incident) alcohol abuse/dependence among deployed Ohio Army National Guard (OHARNG) soldiers. METHODS: Using a sample of OHARNG (June, 2008 to February, 2009), eligible participants were ever been deployed and did not report alcohol abuse/dependence prior to deployment (final sample size=963). Interviews assessed soldiers' alcohol abuse/dependence, depression, PTSD, deployment related factors (e.g., exposure to warzone stressors) and three deployment characteristics (pre-deployment preparedness, unit support during deployment, and post-deployment social support). Associations between the three deployment characteristics and incident alcohol abuse/dependence (defined as abuse or dependence at any point during or after deployment) were estimated using logistic regression. RESULTS: Only pre-deployment preparedness was associated with incident alcohol abuse/dependence (a non-linear inverted-u shaped relation) when controlling for demographics, deployment related factors (e.g., exposure to warzone stressors), and the presence of psychopathology that exhibited peri-/post-deployment. We present these results graphically, plotting incident alcohol abuse/dependence over the levels of pre-deployment preparedness. CONCLUSIONS: The association between pre-deployment preparedness and alcohol abuse/dependence may be characterized as an inverted-U shaped function. Suggestions for how and whether to modify pre-deployment preparedness in an effort to reduce peri-/post-deployment alcohol abuse or dependence should await further research.

Complex systems and health behavior change: insights from cognitive science.

OBJECTIVE: To provide proof-of-concept that quantum health behavior can be instantiated as a computational model that is informed by cognitive science, the Theory of Reasoned Action, and quantum health behavior theory. METHODS: We conducted a synthetic review of the intersection of quantum health behavior change and cognitive science. We conducted simulations, using a computational model of quantum health behavior (a constraint satisfaction artificial neural network) and tested whether the model exhibited quantum-like behavior. RESULTS: The model exhibited clear signs of quantum-like behavior. CONCLUSIONS: Quantum health behavior can be conceptualized as constraint satisfaction: a mitigation between current behavioral state and the social contexts in which it operates. We outlined implications for moving forward with computational models of both quantum health behavior and health behavior in general.

The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

Behavioral, biological, and demographic risk and protective factors for new HIV infections among youth in Rakai, Uganda.

BACKGROUND: Prevalence of HIV infection is considerable among youth, although data on risk factors for new (incident) infections are limited. We examined incidence of HIV infection and risk and protective factors among youth in rural Uganda, including the role of gender and social transitions. METHODS: Participants were sexually experienced youth (15-24 years old) enrolled in the Rakai Community Cohort Study, 1999-2008 (n = 6741). Poisson regression with robust standard errors was used to estimate incident rate ratios (IRR) and 95% confidence intervals (CI) of incident HIV infection. RESULTS: HIV incidence was greater among young women than young men (14.1 vs. 8.3 per 1000 person-years, respectively); this gender disparity was greater among teenagers (14.9 vs. 3.6). Beyond behavioral (multiple partners and concurrency) and biological factors (sexually transmitted infection symptoms), social transitions such as marriage and staying in school influenced HIV risk. In multivariate analyses among women, HIV incidence was associated with living in a trading village (adjusted IRR (aIRR) = 1.48; 95% CI: 1.04 to 2.11), being a student (aIRR = 0.22; 95% CI: 0.07 to 0.72), current marriage (aIRR = 0.55; 95% CI: 0.37 to 0.81), former marriage (aIRR = 1.73; 95% CI: 1.01 to 2.96), having multiple partners, and sexually transmitted infection symptoms. Among men, new infections were associated with former marriage (aIRR = 5.57; 95% CI: 2.51 to 12.36), genital ulceration (aIRR = 3.56; 95% CI: 1.97 to 6.41), and alcohol use (aIRR = 2.08; 95% CI: 1.15 to 3.77). CONCLUSIONS: During the third decade of the HIV epidemic in Uganda, HIV incidence remains considerable among youth, with young women particularly at risk. The risk for new infections was strongly shaped by social transitions such as leaving school, entrance into marriage, and marital dissolution; the impact of marriage was different for young men than women.

Topology of local health officials' advice networks: mind the gaps.

OBJECTIVE: To determine how a health officials' advice network might contribute to a high-performing public health systems by facilitating diffusion of innovation and best practices. DESIGN: A secondary analysis of cross-sectional data obtained from the National Association of County and City Health Officials 2010 Profile of local health departments (LHDs) using network analysis. SETTING: The Profile survey is distributed biannually to all 2565 LHDs in the United States. In 2010, it included a network question: "In thinking about your peers who lead other local health departments in the U.S., list the five LHDs whose leaders you communicate with most frequently about administrative, professional, and leadership issues in public health." PARTICIPANTS: The network question was answered only by the top executive. The subjects are 1522 health officials who answered the network question plus 477 named as contacts (n = 1999). MAIN OUTCOME MEASURES: Measurements to assess network topology were density, centralization, transitivity, and reciprocity. At the node level, average centrality, clustering, effective network size, and clique count were measured. The convergence of iterated correlations algorithm was used to detect subgroups. RESULTS: : A sparsely connected core periphery network exhibited minimal evidence of unified communication. Mutually connected small groups tend to clump within state boundaries suggesting gaps in information flow. The pattern persisted at the regional level with an average health official having an effective network of only 2 others. CONCLUSIONS: Communication between peers may not be the primary way professional information diffuses among local health officials. National groups involved in performance improvement may wish to consider strategies to increase the diffusion of best practices and innovations through this network.

Baseline assessment of community knowledge and attitudes toward drug use and harm reduction in Kabul, Afghanistan.

INTRODUCTION AND AIMS: Problem drug use has been identified as a significant public health problem in Afghanistan. The study aim was to assess community knowledge and attitude toward drug use and harm reduction in Kabul, Afghanistan. DESIGN AND METHODS: A cross-sectional convenience sample of community representatives of 10 possible professions were recruited, distributed between the 17 Kabul city districts in 2007. A questionnaire measured sociodemographic characteristics and awareness, knowledge, and attitudes toward drug use and harm reduction. Logistic regression and cluster analysis were performed to test for associations with participant attitude. RESULTS: Of 210 participants, mean age was 36.7 years. Most (98.6%) were Afghan and employed (87.6%). Most (88.6%) were aware of problem drug use in Afghanistan, primarily attributed to unemployment. The majority of participants agreed that addiction is a disease (88.6%) and believed more and better treatment and vocational training facilities were needed (90.5%). Use of only punitive measures in response to drug use was favoured by few (7.1%) participants. Only 33.3% of participants could correctly identify legal consequences of drug use. DISCUSSION AND CONCLUSIONS: Community acknowledgement of problem drug use and support for addiction treatment are present in Kabul, Afghanistan. However, knowledge gaps concerning drug laws and harm reduction should be addressed in efforts to introduce culturally appropriate harm reduction programming.

Pregnancy risk among black, white, and Hispanic teen girls in New York City public schools.

Disparities in teen pregnancy rates are explained by different rates of sexual activity and contraceptive use. Identifying other components of risk such as race/ethnicity and neighborhood can inform strategies for teen pregnancy prevention. Data from the 2005 and 2007 New York City Youth Risk Behavior Surveys were used to model demographic differences in odds of recent sexual activity and birth control use among black, white, and Hispanic public high school girls. Overall pregnancy risk was calculated using pregnancy risk index (PRI) methodology, which estimates probability of pregnancy based on current sexual activity and birth control method at last intercourse. Factors of race/ethnicity, grade level, age, borough, and school neighborhood were assessed. Whites reported lower rates of current sexual activity (23.4%) than blacks (35.4%) or Hispanics (32.7%), and had lower predicted pregnancy risk (PRI = 5.4% vs. 9.0% and 10.5%, respectively). Among sexually active females, hormonal contraception use rates were low in all groups (11.6% among whites, 7.8% among blacks, and 7.5% among Hispanics). Compared to white teens, much of the difference in PRI was attributable to poorer contraceptive use (19% among blacks and 50% among Hispanics). Significant differences in contraceptive use were also observed by school neighborhood after adjusting for age group and race/ethnicity. Interventions to reduce teen pregnancy among diverse populations should include messages promoting delayed sexual activity, condom use and use of highly effective birth control methods. Access to long-acting contraceptive methods must be expanded for all sexually active high school students.

Toward a multidimensional measure of pregnancy intentions: evidence from the United States.

Widely used dichotomous categorical measures of pregnancy intentions do not represent well the complexity of factors involved in women's intentions. We used a variety of exploratory statistical methods to examine measures of pregnancy intention in the 2002 National Survey of Family Growth (N = 3,032 pregnancies). Factor analyses identified two key dimensions of pregnancy intentions (desire and mistiming) and two smaller nondimensional categories (overdue and don't care). Desire included both affective and cognitive variables, as well as partner-specific factors. Similar pregnancy-intention dimensions were found for adolescent and adult women, across socioeconomic status, and among racial and ethnic groups. Both desire and mistiming were highly predictive of the decision to abort or continue the pregnancy. These analyses strongly support prior demographic thinking about the importance of both the timing of pregnancy and wanting a baby, but suggest that multidimensional rather than simple categorical measures of pregnancy intentions should be used.