Patrick Habecker

The Interaction of Risk Network Structures and Virus Natural History in the Non-spreading of HIV Among People Who Inject Drugs in the Early Stages of the Epidemic

This article explores how social network dynamics may have reduced the spread of HIV-1 infection among people who inject drugs during the early years of the epidemic. Stochastic, discrete event, agent-based simulations are used to test whether a “firewall effect” can arise out of self-organizing processes at the actor level, and whether such an effect can account for stable HIV prevalence rates below population saturation. Repeated simulation experiments show that, in the presence of recurring, acute, and highly infectious outbreaks, micro-network structures combine with the HIV virus’s natural history to reduce the spread of the disease. These results indicate that network factors likely played a significant role in the prevention of HIV infection within injection risk networks during periods of peak prevalence. They also suggest that social forces that disturb network connections may diminish the natural firewall effect and result in higher rates of HIV.ResumenEste artículo explora cómo las dinámicas de redes sociales pueden haber reducido la propagación de la infección por VIH-1 entre las personas que se inyectan drogas durante los primeros años de la epidemia. Estocásticas, eventos discretos, las simulaciones basadas en agentes se utilizan para probar la de si un “efecto cortafuegos” puede surgir de los procesos de auto-organización, al nivel de actor, y si este efecto puede dar cuenta de las tasas estables de la prevalencia del VIH por debajo de la saturación de la población. Repetidos experimentos de simulación muestran que, en la presencia de brotes recurrentes, agudos, y altamente infecciosos, las estructuras micro-red se combinan con la historia natural del virus del VIH para reducir la propagación de la enfermedad. Estos resultados indican que los factores de la red probablemente jugaron un papel importante en la prevención de la infección por el VIH dentro de las redes de riesgo de inyección durante los períodos de pico de prevalencia. Además, sugieren que las fuerzas sociales que perturban las conexiones de red pueden disminuir el efecto cortafuegos natural y resultan en tasas más altas de VIH.

Improving the Network Scale-Up Estimator: Incorporating Means of Sums, Recursive Back Estimation, and Sampling Weights.

Researchers interested in studying populations that are difficult to reach through traditional survey methods can now draw on a range of methods to access these populations. Yet many of these methods are more expensive and difficult to implement than studies using conventional sampling frames and trusted sampling methods. The network scale-up method (NSUM) provides a middle ground for researchers who wish to estimate the size of a hidden population, but lack the resources to conduct a more specialized hidden population study. Through this method it is possible to generate population estimates for a wide variety of groups that are perhaps unwilling to self-identify as such (for example, users of illegal drugs or other stigmatized populations) via traditional survey tools such as telephone or mail surveys—by asking a representative sample to estimate the number of people they know who are members of such a “hidden” subpopulation. The original estimator is formulated to minimize the weight a single scaling variable can exert upon the estimates. We argue that this introduces hidden and difficult to predict biases, and instead propose a series of methodological advances on the traditional scale-up estimation procedure, including a new estimator. Additionally, we formalize the incorporation of sample weights into the network scale-up estimation process, and propose a recursive process of back estimation “trimming” to identify and remove poorly performing predictors from the estimation process. To demonstrate these suggestions we use data from a network scale-up mail survey conducted in Nebraska during 2014. We find that using the new estimator and recursive trimming process provides more accurate estimates, especially when used in conjunction with sampling weights.

Differential access to syringe exchange and other prevention activities among people who inject drugs in rural and urban areas of Puerto Rico

BACKGROUND Injection drug use and its associated blood-borne infections has become a rapidly increasing problem in rural areas of the US recently. Syringe exchange programs have been shown to be effective for reducing transmission of blood borne infections, however access to these prevention efforts may be limited in rural areas. METHODS This paper utilizes two separate community samples of people who inject drugs (PWID) in Puerto Rico to achieve the following research objectives: (1) compare rural and urban access to syringe exchange programs, free sterile syringes and other HIV/HCV prevention activities, and (2) examine whether utilization of prevention activities is associated with lower injection risk behaviors. Two samples were recruited with RDS (n=315 rural sample; n=512 urban sample) and included adults aged 18 years and older who have injected drugs within the past month. RESULTS 78.5% of the urban sample utilized a syringe exchange program in the past year, compared to 58.4% of the rural sample (p<.001). 71.4% of the urban sample received free sterile needles, compared to 58.4% of the rural sample (p<.001). 66% of the urban sample received free works compared to 59% of the rural sample (p=.034). 29% of urban PWID had a conversation with an outreach worker about HIV prevention compared to 18% of the rural sample (p<0.001). Receiving free needles significantly increases the frequency of using a sterile needle to inject (p<.001). CONCLUSION Urban PWID were significantly more likely to have utilized syringe exchange programs, received free sterile needles, received free works, and to have talked about HIV prevention with an outreach worker during the past year than PWID residing in rural areas. Individuals who accessed these prevention activities were significantly less likely to exhibit risky injection behavior. Policy implications call for increasing access to prevention services in rural areas to reduce disease transmission.

The Historical Loss Scale: Longitudinal measurement equivalence and prospective links to anxiety among North American indigenous adolescents.

OBJECTIVES Thoughts of historical loss (i.e., the loss of culture, land, and people as a result of colonization) are conceptualized as a contributor to the contemporary distress experienced by North American Indigenous populations. Although discussions of historical loss and related constructs (e.g., historical trauma) are widespread within the Indigenous literature, empirical efforts to understand the consequence of historical loss are limited, partially because of the lack of valid assessments. In this study we evaluated the longitudinal measurement properties of the Historical Loss Scale (HLS)-a standardized measure that was developed to systematically examine the frequency with which Indigenous individuals think about historical loss-among a sample of North American Indigenous adolescents. We also test the hypothesis that thoughts of historical loss can be psychologically distressing. METHODS Via face-to-face interviews, 636 Indigenous adolescents from a single cultural group completed the HLS and a measure of anxiety at 4 time-points, which were separated by 1- to 2-year intervals (Mage = 12.09 years, SD = .86, 50.0% girls at baseline). RESULTS Responses to the HLS were explained well by 3-factor (i.e., cultural loss, loss of people, and cultural mistreatment) and second-order factor structures. Both of these factor structures held full longitudinal metric (i.e., factor loadings) and scalar (i.e., intercepts) equivalence. In addition, using the second-order factor structure, more frequent thoughts of historical loss were associated with increased anxiety. CONCLUSIONS The identified 3-factor and second-order HLS structures held full longitudinal measurement equivalence. Moreover, as predicted, our results suggest that historical loss can be psychologically distressing for Indigenous adolescents.

Relocation Redux: Labrador Inuit Population Movements and Inequalities in the Land Claims Era

The importance of community relocation experiences for aboriginal land claims movements is well documented; the role played by successful land claims in prompting ongoing out-migration is not. Data collected in 2011 on the lives of migrants are used to test three hypotheses: H1, Inuit leaving the land claims area for a nearby nonaboriginal city show markedly different social outcomes based on the length of time since migration; H2, these social outcomes map onto patterns of intergroup boundaries in their new communities; and H3, both of these outcomes are better explained by migration patterns after the land claims than by the ethnic/racial exclusion that has been the focus of past research on inequality in the region. This analysis takes advantage of social network techniques used to study hard-to-reach populations, showing how these methods can be used to address broader questions of community structure and cohesion during rapid social change. Conclusions focus on the experiences of migrants on the margins of sending and receiving communities and what they can tell us about the role played by aboriginal land claims in the culture politics of industrial resource extraction.

Network Approaches to Substance Use and HIV/Hepatitis C Risk among Homeless Youth and Adult Women in the United States: A Review

During the United States economic recession of 2008–2011, the number of homeless and unstably housed people in the United States increased considerably. Homeless adult women and unaccompanied homeless youth make up the most marginal segments of this population. Because homeless individuals are a hard to reach population, research into these marginal groups has traditionally been a challenge for researchers interested in substance abuse and mental health. Network analysis techniques and research strategies offer means for dealing with traditional challenges such as missing sampling frames, variation in definitions of homelessness and study inclusion criteria, and enumeration/population estimation procedures. This review focuses on the need for, and recent steps toward, solutions to these problems that involve network science strategies for data collection and analysis. Research from a range of fields is reviewed and organized according to a new stress process framework aimed at understanding how homeless status interacts with issues related to substance abuse and mental health. Three types of network innovation are discussed: network scale-up methods, a network ecology approach to social resources, and the integration of network variables into the proposed stress process model of homeless substance abuse and mental health. By employing network methods and integrating these methods into existing models, research on homeless and unstably housed women and unaccompanied young people can address existing research challenges and promote more effective intervention and care programs.

Injection Partners, HCV, and HIV Status among Rural Persons Who Inject Drugs in Puerto Rico

ABSTRACT Background: The prevalence of hepatitis C (HCV) and HIV among persons who inject drugs (PWID) and the ability of these diseases to spread through injection networks are well documented in urban areas. However, less is known about injection behaviors in rural areas. Objectives: This study focuses on the association between the number of self-reported injection partners with the PWIDs self-reported HCV and HIV status. Injection networks provide paths for infection and information to flow, and are important to consider when developing prevention and intervention strategies. Methods: Respondent driven sampling was used to conduct 315 interviews with PWID in rural Puerto Rico during 2015. Negative binomial regression was used to test for associations between the number of self-reported injection partners and self-reported HCV and HIV statuses. Multinomial logistic regression was used to test for associations with the participants self-reported HCV and HIV statuses. Results: Self-reported HCV status is significantly associated with injection risk network size. Injection partner networks of self-reported HCV− respondents are half what is reported by those with a positive or unknown status. Self-reported HIV statuses are not associated with different numbers of injection partners. Conclusions: Smaller injection networks among those who self-report a HCV− status suggests that those who believe their status to be negative may take protective action by reducing their injection network compared to those have a self-reported HCV+ or an unknown status. Although the cross-sectional design of the study makes it difficult verify, such behavior has implications for prevention programs attempting to prevent HCV transmission.

Injection-related hepatitis C serosorting behaviors among people who inject drugs: An urban/rural comparison

ABSTRACT Although previous research has focused on injection drug use behaviors in both urban and rural settings, few have drawn direct comparisons between adjacent rural and urban areas. Using data from the National HIV Behavioral Surveillance study as well as original data collected in a similar fashion, we compare the risk behaviors of people who inject drugs (PWID) in San Juan, Puerto Rico, with those of PWID in nearby rural areas. Specifically, we examine whether one’s own hepatitis C (HCV) infection status can be used to predict whether one asked their most recent co-injection partner about their HCV status. Acquiring such information allows injectors to seek out co-injection partners of concordant status as a way to minimize the risk of viral transmission. Results indicate that urban PWID with a known HCV+ status were more likely to know their last co-injector partner’s HCV status than were their peers with a negative or unknown HCV status. However, this relationship was not present in the rural data. These findings suggest that there are different risk norms in rural and urban PWID communities and that interventions successful in one type of community may not be so in others.

Rural and Urban Differences in Nebraskans’ Access to Marijuana, Methamphetamine, Heroin, and Prescription Pills

The ability of a user to access a given type of drug is related to the configuration of the market for that drug, and a range of economic and criminal justice concerns. This study focuses on Nebraskan’s “ready access” to four types of drugs (marijuana, methamphetamine, heroin, and prescription pills) in 2016, using a statewide survey of housed Nebraskan adults. Ready access is defined as a participant knowing at least one person from whom they could obtain a given type of drug if they wanted to. We found that 35% of adult Nebraskans knew at least one person from whom they could obtain marijuana, 8.9% for methamphetamine, 4.5% for heroin, and 17.8% knew at least one source for prescription pills. Relationships between knowing a source for each type of drug and rurality, sex, race, religious attendance, mental health symptoms, and education are explored.

Framing and Cultivating the Story of Crime: The Effects of Media Use, Victimization, and Social Networks on Attitudes About Crime

The current study extended prior research by considering the effects of media, victimization, and network experiences on attitudes about crime and justice, drawing on the problem frame, cultivation, real-word, and interpersonal diffusion theses. Data were from a survey of Nebraska adults (n = 550) who were asked about their social networks; beliefs about media reliability; use of newspaper and news on TV, radio, and the Internet; and exposure to violence on TV, movies, and the Internet. Results indicated that viewing TV violence predicted worry and anger about crime. Believing the media are a reliable source of information about crime predicted more anger and more support for the justice system. Personal and network members’ victimization was also linked to attitudes. Other network contacts, including knowing police or correctional officers or knowing someone who had been arrested or incarcerated, had limited effects. The results support the problem frame and cultivation theses in that media framing and media consumption influence attitudes about crime, as do certain real-world experiences.