Demographic, risk, and spatial factors associated with over-the-counter syringe purchase among injection drug users

Geographic information science and the United States opioid overdose crisis: A scoping review of methods, scales, and application areas

BACKGROUND

The Opioid Overdose Crisis (OOC) continues to generate morbidity and mortality in the United States, outpacing other prominent accident-related reasons. Multiple disciplines have applied geographic information science (GIScience) to understand geographical patterns in opioid-related health measures. However, there are limited reviews that assess how GIScience has been used.

OBJECTIVES

This scoping review investigates how GIScience has been used to conduct research on the OOC. Specific sub-objectives involve identifying bibliometric trends, the location and scale of studies, the frequency of use of various GIScience methodologies, and what direction future research can take to address existing gaps.

METHODS

The review was pre-registered with the Open Science Framework ((https://osf.io/h3mfx/) and followed the PRISMA-ScR guidelines. Scholarly research was gathered from the Web of Science Core Collection, PubMed, IEEE Xplore, ACM Digital Library. Inclusion criteria was defined as having a publication date between January 1999 and August 2021, using GIScience as a central part of the research, and investigating an opioid-related health measure.

RESULTS

231 studies met the inclusion criteria. Most studies were published from 2017 onward. While many (41.6%) of studies were conducted using nationwide data, the majority (58.4%) occurred at the sub-national level. California, New York, Ohio, and Appalachia were most frequently studied, while the Midwest, north Rocky Mountains, Alaska, and Hawaii lacked studies. The most common GIScience methodology used was descriptive mapping, and county-level data was the most common unit of analysis across methodologies.

CONCLUSIONS

Future research of GIScience on the OOC can address gaps by developing use cases for machine learning, conducting analyses at the sub-county level, and applying GIScience to questions involving illicit fentanyl. Research using GIScience is expected to continue to increase, and multidisciplinary research efforts amongst GIScientists, epidemiologists, and other medical professionals can improve the rigor of research.

Examining the spatial risk environment tied to the opioid crisis through a unique public health, EMS, and academic research collaborative: Lowell, Massachusetts, 2008–2018

Between 2015 and 2018, Lowell Massachusetts experienced outbreaks in opioid overdoses, HIV, and hepatitis C virus infections (HCV) among people who inject drugs. Through an innovative collaboration between emergency medical services (EMS), public health, and academic partners, we assessed the geographic distribution of opioid-related risks to inform intervention efforts. We analyzed data from three unique data sources for publicly discarded syringes, opioid-related incidents (ORIs), and fatal opioid overdoses in Lowell between 2008 and 2018. We assessed the risk environment over time using a geographic information system to identify and characterize hotspots and noted parallel trends within the syringe discard and ORI data. We identified two notable increases in ORIs per day: the first occurring between 2008 and 2010 (from 0.3 to 0.5), and the second between 2011 and 2014 (from 0.9 to 1.3), following the introduction of fentanyl within local drug markets. We also identified seasonal patterns in the syringe discard, ORI, and overdose data. Through our spatial analyses, we identified significant clusters of discarded syringes, ORIs, and fatal overdoses (p < 0.05), and neighborhoods where high densities of these outcomes overlapped. We found that areas with the highest densities shifted over time, expanding beyond the epicenter of the Downtown neighborhood. Data sharing and analyses among EMS, public health, and academic partners can foster better assessments of local risk environments. Our work, along with new public health efforts in Lowell, led to a city-funded position to improve pick-up and proper disposal of publicly discarded syringes, and better targeted harm reduction services.

The Role of Pharmacies in the HIV Prevention and Care Continuums: A Systematic Review

The role of pharmacists in the treatment of HIV has expanded beyond medication dispensing to include a host of cost-effective, evidence-based strategies across the HIV prevention and care continuums. However, wide-scale adoption of pharmacy-based HIV prevention and treatment interventions has been slow. We conducted a systematic review to evaluate the evidence on the role of pharmacists across the HIV prevention and care continuums. Thirty-two studies were identified, most of which provided evidence of feasibility of HIV testing and efficacy of non-prescription syringe sale services in pharmacies. However, only two studies implemented an experimental design to rigorously test pharmacy-based strategies. Notably, no pharmacy-based strategies have specifically targeted the highest HIV risk populations such as black and Latinx men who have sex with men, women, or trans populations. Efficacy trials and effectiveness studies should rigorously test existing pharmacy-based strategies to build greater support for wide-scale adoption and implementation. Moreover, in order to integrate pharmacies into the strategy to end the HIV epidemic, studies are needed to ensure that pharmacy-based HIV prevention and treatment services can reach the highest risk populations.

The role of socio-demographic determinants in the geo-spatial distribution of newly diagnosed HIV infections in small areas of Catalonia (Spain)

BACKGROUND

Spatial visualization of HIV surveillance data could improve the planning of programs to address the HIV epidemic. The objectives of the study were to describe the characteristics and the spatial distribution of newly diagnosed HIV infection in Catalonia and to identify factors associated with HIV infection rates.

METHODS

Surveillance data from the national registry were presented in the form of descriptive and ring maps and used to study the spatial distribution of new HIV diagnoses in Catalonia (2012-2016) and associated risk factors at the small area level (ABS, acronym for "basic health area" in Catalan). Incident cases were modeled using the following as predictors: type of municipality, prevalence of young men and migrant groups, GBMSM activity indicators, and other variables at the aggregated level.

RESULTS

New HIV diagnoses are heterogeneously distributed across Catalonia. The predictors that proved to be significantly associated with a higher rate of new HIV diagnoses were ABS located in the city of Barcelona (IRR, 2.520; P < 0.001), a higher proportion of men aged 15-44 years (IRR, 1.193; P = 0.003), a higher proportion of GBMSM (IRR, 1.230; P = 0.030), a higher proportion of men from Western Europe (IRR, 1.281; P = 0.003), a higher proportion of men from Latin America (IRR, 1.260; P = 0.003), and a higher number of gay locations (IRR, 2.665; P < 0.001). No association was observed between the HIV diagnosis rate and economic deprivation.

CONCLUSIONS

Ring maps revealed substantial spatial associations for the rate of new HIV diagnoses. New HIV diagnoses are concentrated in ABS located in urban areas. Our results show that, in the case of HIV infection, the socioeconomic deprivation index on which the Catalan government bases its budget allocation policies among the ABS should not be the only criterion used.

HIV Clustering in Mississippi: Spatial Epidemiological Study to Inform Implementation Science in the Deep South

BACKGROUND

In recent years, more than half of new HIV infections in the United States occur among African Americans in the Southeastern United States. Spatial epidemiological analyses can inform public health responses in the Deep South by identifying HIV hotspots and community-level factors associated with clustering.

OBJECTIVE

The goal of this study was to identify and characterize HIV clusters in Mississippi through analysis of state-level HIV surveillance data.

METHODS

We used a combination of spatial epidemiology and statistical modeling to identify and characterize HIV hotspots in Mississippi census tracts (n=658) from 2008 to 2014. We conducted spatial analyses of all HIV infections, infections among men who have sex with men (MSM), and infections among African Americans. Multivariable logistic regression analyses identified community-level sociodemographic factors associated with HIV hotspots considering all cases.

RESULTS

There were HIV hotspots for the entire population, MSM, and African American MSM identified in the Mississippi Delta region, Southern Mississippi, and in greater Jackson, including surrounding rural counties (P<.05). In multivariable models for all HIV cases, HIV hotspots were significantly more likely to include urban census tracts (adjusted odds ratio [AOR] 2.01, 95% CI 1.20-3.37) and census tracts that had a higher proportion of African Americans (AOR 3.85, 95% CI 2.23-6.65). The HIV hotspots were less likely to include census tracts with residents who had less than a high school education (AOR 0.95, 95% CI 0.92-0.98), census tracts with residents belonging to two or more racial/ethnic groups (AOR 0.46, 95% CI 0.30-0.70), and census tracts that had a higher percentage of the population living below the poverty level (AOR 0.51, 95% CI 0.28-0.92).

CONCLUSIONS

We used spatial epidemiology and statistical modeling to identify and characterize HIV hotspots for the general population, MSM, and African Americans. HIV clusters concentrated in Jackson and the Mississippi Delta. African American race and urban location were positively associated with clusters, whereas having less than a high school education and having a higher percentage of the population living below the poverty level were negatively associated with clusters. Spatial epidemiological analyses can inform implementation science and public health response strategies, including improved HIV testing, targeted prevention and risk reduction education, and tailored preexposure prophylaxis to address HIV disparities in the South.

Patterns of Twitter Behavior Among Networks of Cannabis Dispensaries in California

Background

Twitter represents a social media platform through which medical cannabis dispensaries can rapidly promote and advertise a multitude of retail products. Yet, to date, no studies have systematically evaluated Twitter behavior among dispensaries and how these behaviors influence the formation of social networks.

Objectives

This study sought to characterize common cyberbehaviors and shared follower networks among dispensaries operating in two large cannabis markets in California.

Methods

From a targeted sample of 119 dispensaries in the San Francisco Bay Area and Greater Los Angeles, we collected metadata from the dispensary accounts using the Twitter API. For each city, we characterized the network structure of dispensaries based upon shared followers, then empirically derived communities with the Louvain modularity algorithm. Principal components factor analysis was employed to reduce 12 Twitter measures into a more parsimonious set of cyberbehavioral dimensions. Finally, quadratic discriminant analysis was implemented to verify the ability of the extracted dimensions to classify dispensaries into their derived communities.

Results

The modularity algorithm yielded three communities in each city with distinct network structures. The principal components factor analysis reduced the 12 cyberbehaviors into five dimensions that encompassed account age, posting frequency, referencing, hyperlinks, and user engagement among the dispensary accounts. In the quadratic discriminant analysis, the dimensions correctly classified 75% (46/61) of the communities in the San Francisco Bay Area and 71% (41/58) in Greater Los Angeles.

Conclusions

The most centralized and strongly connected dispensaries in both cities had newer accounts, higher daily activity, more frequent user engagement, and increased usage of embedded media, keywords, and hyperlinks. Measures derived from both network structure and cyberbehavioral dimensions can serve as key contextual indicators for the online surveillance of cannabis dispensaries and consumer markets over time.

Nonprescription naloxone and syringe sales in the midst of opioid overdose and hepatitis C virus epidemics: Massachusetts, 2015

OBJECTIVES

To determine the prevalence of nonprescription naloxone and sterile syringe sales, factors associated with nonprescription sales, geospatial access to nonprescription naloxone and syringe-selling pharmacies, and targets for potential interventions.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Massachusetts has experienced steep increases in reported opioid overdoses and hepatitis C virus cases in the past decade. Pharmacists have the potential to play a substantial role in increasing access to nonprescription naloxone and sterile syringes, which can reverse opioid overdoses and decrease hepatitis C virus transmission, respectively. We completed brief telephone surveys with 809 of 1042 retail pharmacies across Massachusetts (response rate = 77.6%) during 2015 to assess experience with nonprescription sales of naloxone and sterile syringes.

OUTCOME MEASURES

Our primary outcomes were the stocking and selling of naloxone in the pharmacy (yes or no) for nonprescription sales and nonprescription syringe sales (yes or no). We conducted multivariable regression analyses and created maps using a geographic information system to identify factors associated with nonprescription sales of naloxone and sterile syringes, and to improve our understanding of geospatial access to pharmacy-based naloxone and syringe sales.

RESULTS

More than 97% of pharmacies reported selling sterile syringes without requiring a prescription, and 45% of pharmacies reported stocking and selling naloxone. Factors associated with nonprescription sales included hours of operation, experience with and interest in harm reduction activities, and presence in an opioid overdose hotspot. Geographic access to nonprescription sale of sterile syringes is widespread, whereas geospatial access to naloxone is limited. Training to understand the benefits, applications, and distribution needs of naloxone is of interest to surveyed pharmacists.

CONCLUSION

Access to sterile syringes through nonprescription sales is strong across Massachusetts, and although more than 350 pharmacies (45%) reported stocking and selling naloxone to prevent opioid overdose deaths, there is much room for improvement in access and training among pharmacy staff members.

Neighborhood-Level and Spatial Characteristics Associated with Lay Naloxone Reversal Events and Opioid Overdose Deaths

There were over 23,000 opioid overdose deaths in the USA in 2013, and opioid-related mortality is increasing. Increased access to naloxone, particularly through community-based lay naloxone distribution, is a widely supported strategy to reduce opioid overdose mortality; however, little is known about the ecological and spatial patterns of the distribution and utilization of lay naloxone. This study aims to investigate the neighborhood-level correlates and spatial relationships of lay naloxone distribution and utilization and opioid overdose deaths. We determined the locations of lay naloxone distribution sites and the number of unintentional opioid overdose deaths and reported reversal events in San Francisco census tracts (n = 195) from 2010 to 2012. We used Wilcoxon rank-sum tests to compare census tract characteristics across tracts adjacent and not adjacent to distribution sites and multivariable negative binomial regression models to assess the association between census tract characteristics, including distance to the nearest site, and counts of opioid overdose deaths and naloxone reversal events. Three hundred forty-two opioid overdose deaths and 316 overdose reversals with valid location data were included in our analysis. Census tracts including or adjacent to a distribution site had higher income inequality, lower percentage black or African American residents, more drug arrests, higher population density, more overdose deaths, and more reversal events (all p < 0.05). In multivariable analysis, greater distance to the nearest distribution site (up to a distance of 4000 m) was associated with a lower count of Naloxone reversals [incidence rate ratio (IRR) = 0.51 per 500 m increase, 95% CI 0.39-0.67, p < 0.001] but was not significantly associated with opioid overdose deaths. These findings affirm that locating lay naloxone distribution sites in areas with high levels of substance use and overdose risk facilitates reversals of opioid overdoses in those immediate areas but suggests that alternative delivery methods may be necessary to reach individuals in other areas with less concentrated risk.

Assessing Syringe Exchange Program Access among Persons Who Inject Drugs (PWID) in the District of Columbia

Prior research has explored spatial access to syringe exchange programs (SEPs) among persons who inject drugs (PWID), but these studies have been based on limited data from short periods of time. No research has explored changes in spatial access to SEPs among PWID longitudinally. The purpose of this research is to examine spatial access to SEPs among PWID who accessed services at a SEP in Washington, District of Columbia (DC), from 1996 to 2010. The geometric point distance estimation technique was used to calculate the mean walking distance PWID traveled from the centroid point of their zip code of home residence to the mobile exchange site where they accessed SEP services. Analysis of variance (ANOVA) was used to examine differences in walking distance measures by year. The results of this research suggest that the distance DC PWID traveled to access SEP services remained relatively constant (approximately 2.75 mi) from 2003 to 2008, but increased to just over 4 mi in 2010. This research provides support for expanding SEP operations such that PWID have increased access to their services. Increasing SEP accessibility may help resolve unmet needs among injectors.

Acceptability of Global Positioning System technology to survey injecting drug users' movements and social interactions: a pilot study from San Francisco, USA

BACKGROUND

Despite potential applications for improving health services using GPS technology, little is known about ethical concerns, acceptability, and logistical barriers for their use, particularly among marginalized groups.

OBJECTIVES

We garnered the insights of people who inject drug (PWID) in San Francisco on these topics.

METHODS

PWID were enrolled through street-outreach (n=20) and an ongoing study (n=4) for 4 focus group discussions. Participants also completed a self-administered questionnaire on demographic characteristics and their numbers and types of interactions with other PWID.

RESULTS

Median age was 30.5 years, majorities were male (83.3%) and white (68.2%). Most interacted with other PWID for eating meals and purchasing drugs over the last week; fewer reported interactions such as sexual contact, drug treatment, or work. Participants identified several concerns about carrying GPS devices, including what authorities might do with the data, that other PWID and dealers may suspect them as informants, and adherence to carrying and use. Most felt concerns were surmountable with detailed informed consent on the purpose of the study and practical ways to carry, charge, and hide devices.

CONCLUSIONS

PWID felt data collection on their movements and social interactions with other PWID using GPS can be acceptable with addressing specific concerns. The technology is now in hand to greatly expand the ability to monitor health conditions with respect to the environment and improve the location of prevention, care, and treatment facilities to serve hard to reach, mobile, and hidden populations.

Spatial analysis of HIV positive injection drug users in San Francisco, 1987 to 2005

Spatial analyses of HIV/AIDS related outcomes are growing in popularity as a tool to understand geographic changes in the epidemic and inform the effectiveness of community-based prevention and treatment programs. The Urban Health Study was a serial, cross-sectional epidemiological study of injection drug users (IDUs) in San Francisco between 1987 and 2005 (N = 29,914). HIV testing was conducted for every participant. Participant residence was geocoded to the level of the United States Census tract for every observation in dataset. Local indicator of spatial autocorrelation (LISA) tests were used to identify univariate and bivariate Census tract clusters of HIV positive IDUs in two time periods. We further compared three tract level characteristics (% poverty, % African Americans, and % unemployment) across areas of clustered and non-clustered tracts. We identified significant spatial clustering of high numbers of HIV positive IDUs in the early period (1987-1995) and late period (1996-2005). We found significant bivariate clusters of Census tracts where HIV positive IDUs and tract level poverty were above average compared to the surrounding areas. Our data suggest that poverty, rather than race, was an important neighborhood characteristic associated with the spatial distribution of HIV in SF and its spatial diffusion over time.

Activity spaces among injection drug users in San Francisco

BACKGROUND

Representations of activity spaces, defined as the local areas within which people move or travel in the course of their daily activities, are unexplored among injection drug users (IDUs). The purpose of this paper is to use an activity space framework to study place and drug user health.

METHODS

Data for this analysis is from an epidemiological study of street-recruited IDUs in San Francisco (N=1084). Study participants reported geographic intersections of where they most often slept at night, hung out during the day, and used drugs during a 6 month time period. We used GIS software to construct and map activity space routes of street-based network paths between these intersections. We further identified if syringe exchange program (SEP) locations intersected with, participant activity space routes. We used logistic regression to estimate associations between activity space variables and HIV serostatus, syringe sharing, and non-fatal overdose, after adjusting for individual and Census tract covariates.

RESULTS

Mean activity space distance for all participants was 1.5miles. 9.6% of participants had a SEP located along their activity space. An increase in activity space distance was associated with a decrease in odds of being HIV positive. An increase in residential transience, or the number of different locations slept in by participants in a 6 month time period, was associated with higher odds of syringe sharing. Activity space distance was not independently associated with overdose or syringe sharing.

DISCUSSION

Research that locates individuals in places of perceived importance is needed to inform placement and accessibility of HIV and overdose prevention programs. More attention needs to be given to the logistics of collecting sensitive geospatial data from vulnerable populations as well as how to maximize the use of GIS software for visualizing and understanding how IDUs interact with their environment.