Social capital and rates of gonorrhea and syphilis in the United States: Spatial regression analyses of state-level associations

A systematic review and meta-analysis of the relationship between economic inequality and prosocial behaviour

How does economic inequality relate to prosocial behaviour? Existing theories and empirical studies from multiple disciplines have produced mixed results. Here we conduct a systematic review and meta-analysis to systematically synthesize empirical studies. Results from 192 effect sizes and over 2.5 million observations in 100 studies show that the relationship varies from being negative to positive depending upon the study (95% prediction interval -0.450 to 0.343). However, on average, there is a small, negative relationship between economic inequality and prosocial behaviour (r = -0.064, P = 0.004, 95% confidence interval -0.106 to -0.021). There is generally no evidence that results depend upon characteristics of the studies, participants, the way prosocial behaviour and inequality were assessed, and the publication discipline. Given the prevalence of economic inequality and the importance of prosocial behaviour, this systematic review and meta-analysis provides a timely study on the relationship between economic inequality and prosocial behaviour.

Racial disparity in ART adherence is closed in states with high social trust: Results from the Medical Monitoring Project (MMP), 2015

Racial/ethnic disparities persist in antiretroviral therapy (ART) adherence and viral suppression. We examined associations between state-level social trust and individual-level ART adherence and viral suppression and assessed whether these relationships varied by race/ethnicity. The Medical Monitoring Project (MMP) annually reports nationally representative estimates of the behavioral and clinical characteristics of HIV-positive adults in primary care. A total of 3298 adults diagnosed with HIV between 2015 and 2016 from 16 US states were included. We used weighted logistic regression to model the association between state-level social trust, race/ethnicity (Non-Hispanic Black, White, and Hispanic/Latino), and cross-product interactions with ART adherence (a binary measure derived from three self-reported questions), and viral suppression (a binary measure corresponding to plasma HIV RNA < 200 copies/ml). Social trust was the percentage of people in each state who agreed that most people in their neighborhood could be trusted. A high level of social trust was associated with a higher likelihood of ART adherence (PR [prevalence ratio] = 1.17; 95% confidence interval [CI]: 1.05-1.30). In covariate-adjusted analyses, the association between state-level social trust and individual-level ART adherence significantly varied by race/ethnicity (Wald χ2  F = 9.8 [df = 4], p = 0.044). Social trust was positively associated with ART, but the effect was smaller for Blacks than for Whites (PR = 0.66; 95% CI: 0.57-0.82) in states with the lowest social trust. Black-White differences were closed and no longer significant above mean social trust (PP [predicted probability] = 0.50 vs. 0.53, at two standard deviations). Racial/ethnic disparities in ART adherence were closed among individuals living in states with high social trust. Understanding the mechanisms that promote social trust among neighbors may have downstream impacts on reducing disparities in ART adherence among people with HIV (PWH).

Spatiotemporal analysis of 11 years of Chlamydia trachomatis data from southern China

BACKGROUND

Urogenital Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection (STI) globally. Reviews suggest high and persistently endemic STI epidemics in low and middle income countries. However population-based prevalence estimates in these settings are less common, underscoring the need for analyses of available data to characterize patterns of disease burden. We identified spatio-temporal clusters and key behavioral, social, or environmental factors contribution to transmission in order to inform the prioritization and targeting of evidence based interventions.

METHODS

Using 11 years of data (2006-2016) from the chlamydia case report system of Guangdong, China, we identified county level spatio-temporal hot and cold spots using the Getis-Ord Gi* statistic and discrete Poisson models in SaTScan 9.6. We also estimated associations between observed distribution patterns and area-level demographic, social, and economic factors using quasi-Poisson regression models that controlled for annual counts of certified laboratories to account for fluctuations in location-specific detection capacity.

FINDINGS

Cluster analysis indicates an expanding chlamydia epidemic in Guangdong, with cases clustered in regions of greatest economic activity. Greater male-to-female sex ratio (RR, 3.63; 95% CI, 1.41-9.45) and greater urbanicity (RR, 2.44; 95% CI, 1.98-2.99) were predictive of higher chlamydia case occurrence.

INTERPRETATION

We found that chlamydia case occurrence in Guangdong province has been accelerating over the past 11 years and that its expansion is tied to indicators of social and economic development. These estimates not only identify high prevalence regions to target but also areas where data gaps potentially remain. The salience of sex ratios and urbanicity may best be understood through the lens of China's modern history of labor migration which has reshaped the gender dynamics and health access landscape of urban China. Future chlamydia control efforts will require a population-based approach focused on reengaging sexually active adults of diverse economic and migratory backgrounds.

FUNDING

This was an unfunded study using routinely collected public health data.

County-Level Social Capital and Bacterial Sexually Transmitted Infections in the United States

BACKGROUND

The association between county-level social capital indices (SCIs) and the 3 most commonly reported sexually transmitted infections (STIs) in the United States is lacking. In this study, we determined and examined the association between 2 recently developed county-level SCIs (ie, Penn State Social Capital Index [PSSCI] vs United States Congress Social Capital Index [USCSCI]) and the 3 most commonly reported bacterial STIs (chlamydia, gonorrhea, and syphilis) using spatial and nonspatial regression techniques.

METHODS

We assembled and analyzed multiyear (2012-2016) cross-sectional data on STIs and 2 SCIs (PSSCI vs USCSCI) on counties in all 48 contiguous states. We explored 2 nonspatial regression models (univariate and multiple generalized linear models) and 3 spatial regression models (spatial lag model, spatial error model, and the spatial autoregressive moving average model) for comparison.

RESULTS

Without exception, all the SCIs were negatively associated with all 3 STI morbidities. A 1-unit increase in the SCIs was associated with at least 9% (P < 0.001) decrease in each STI. Our test of the magnitude of the estimated associations indicated that the USCSCI was at least 2 times higher than the estimates for the PSSCI for all STIs (highest P value = 0.01).

CONCLUSIONS

Overall, our results highlight the potential benefits of applying/incorporating social capital concepts to STI control and prevention efforts. In addition, our results suggest that for the purpose of planning, designing, and implementing effective STI control and prevention interventions/programs, understanding the communities' associational life (as indicated by the factors/data used to develop the USCSCI) may be important.

Social capital and physical health: An updated review of the literature for 2007-2018

PURPOSE

Social capital is frequently indicated as a determinant of population health. Despite an increase in the frequency of public health studies including such measures, our understanding of social capital's effects on health remains unclear. In 2008, a systematic review of the "first decade" of research on social capital and health was published in the textbook Social Capital and Health. Our study intends to update and expand upon this original review to account for developments in the literature over the second decade of research on social capital and health.

METHODS

We employed a systematic review of empirical studies investigating the relationship between measures of social capital and physical health outcomes published between January 1, 2007 and December 31, 2018. To identify potential studies, we conducted searches of PubMed, Embase, and PsychINFO databases in January 2019 using combinations of "social capital" and "physical health" search terms.

RESULTS

We identified 1,608 unique articles and reviewed 145 studies meeting our inclusion criteria. The most frequently examined health condition was self-reported health (57%), followed by mortality (12%), cardiovascular diseases (10%), obesity (7%), diabetes (6%), infectious diseases (5%), and cancers (3%). Of these studies, 127 (88%) reported at least partial support for a protective association between social capital and health. However, only 41 (28%) reported exclusively positive findings. The majority (59%) of results were mixed, suggesting a nuanced relationship between social capital and health. This finding could also be indicative of differences in study design, which showed substantial variation.

CONCLUSIONS

Despite limitations in the literature, our review chronicles an evolution in the field of social capital and health in terms of size and sophistication. Overall, these studies suggest that social capital may be an important protective factor for some physical health outcomes, but further research is needed to confirm and clarify these findings.

Applying core theory and spatial analysis to identify hepatitis C virus infection "core areas" in British Columbia, Canada

"Core areas" of transmission for bacterial sexually transmitted infections have been identified. However, it is unclear whether core areas apply to viral infections, such as hepatitis C virus (HCV). We used geographic mapping and spatial analysis to identify distinct core areas of HCV infection in British Columbia (BC) using the BC Hepatitis Testers Cohort (BC-HTC), 1990-2013. The BC-HTC includes all BC residents tested for HCV (~1.5 million; 1990-2013). Core HCV infection areas were identified spatially and temporally for five time periods (1990-1993, 1994-1998, 1999-2003, 2004-2008 and 2009-2013) through thematic mapping, Kernel Density Estimation, Hotspot analysis and cluster analysis at the Census dissemination area level in ArcGIS and SatScan. HCV infection core areas were consistently identified. HCV core areas expanded from the downtown of major cities in different regions of BC (Metro Vancouver, Vancouver Island, and Northern BC; 1990-1998), to smaller cities in Metro Vancouver and Interior BC (2000 onwards). Statistically significant clusters, or hotspots, were also observed for downtown Vancouver, Northern BC (Prince George) and Vancouver Island from 1990 to 2008 with expansion to other urban areas in Metro Vancouver from 1990-2013. Statistically significant clusters persisted after adjustment for injection drug use, number of HCV tests, age, sex, material and social deprivation. Persistence of areas with high HCV diagnoses rates in Vancouver and Prince George supports the theory of core areas of HCV transmission. Identification of core areas can inform prevention, care and treatment programme interventions and evaluate their impact over time.

The Spatial Association Between Federally Qualified Health Centers and County-Level Reported Sexually Transmitted Infections: A Spatial Regression Approach

BACKGROUND

The number of categorical sexually transmitted disease (STD) clinics is declining in the United States. Federally qualified health centers (FQHCs) have the potential to supplement the needed sexually transmitted infection (STI) services. In this study, we describe the spatial distribution of FQHC sites and determine if reported county-level nonviral STI morbidity were associated with having FQHC(s) using spatial regression techniques.

METHODS

We extracted map data from the Health Resources and Services Administration data warehouse on FQHCs (ie, geocoded health care service delivery [HCSD] sites) and extracted county-level data on the reported rates of chlamydia, gonorrhea and, primary and secondary (P&S) syphilis (2008-2012) from surveillance data. A 3-equation seemingly unrelated regression estimation procedure (with a spatial regression specification that controlled for county-level multiyear (2008-2012) demographic and socioeconomic factors) was used to determine the association between reported county-level STI morbidity and HCSD sites.

RESULTS

Counties with HCSD sites had higher STI, poverty, unemployment, and violent crime rates than counties with no HCSD sites (P < 0.05). The number of HCSD sites was associated (P < 0.01) with increases in the temporally smoothed rates of chlamydia, gonorrhea, and P&S syphilis, but there was no significant association between the number of HCSD per 100,000 population and reported STI rates.

CONCLUSIONS

There is a positive association between STI morbidity and the number of HCSD sites; however, this association does not exist when adjusting by population size. Further work may determine the extent to which HCSD sites can meet unmet needs for safety net STI services.

Association of Neighborhood Geographic Spatial Factors With Rates of Childhood Obesity

IMPORTANCE

Childhood obesity is a principal public health concern. Understanding the geographic distribution of childhood obesity can inform the design and delivery of interventions.

OBJECTIVE

To better understand the causes of spatial dependence in rates of childhood obesity across neighborhoods.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from a legislatively mandated body mass index screening program for public school children in Arkansas from the 2003-2004 through 2014-2015 academic years. Spatial autoregressive moving average (SARMA) models for panel data were used to estimate spatial dependency in childhood obesity at 2 levels of spatial aggregation. Data were analyzed from August 2017 to February 2018.

EXPOSURES

The SARMA models included geographic fixed effects to capture time-invariant differences in neighborhood characteristics along with controls for the mean age of children and the proportion of children by race/ethnicity, school meal status, and sex.

MAIN OUTCOMES AND MEASURES

The proportion of obese schoolchildren in Arkansas neighborhoods by year, defined at larger (census tract) and smaller (census block group) spatial scales.

RESULTS

The geographic aggregations were based on 935 800 children with a mean (SD) age of 132 (39) months. Of these children, 51% were male; 65% were white, 21% were black, 10% were Hispanic, 2% were Asian, and the remainder were of other or unidentified race/ethnicity. In models without geographic fixed effects, there was evidence of positive and significant spatial autocorrelation in obesity rates across tracts (ρ = 0.511; 95% CI, 0.469-0.553) and block groups (ρ = 0.569; 95% CI, 0.543-0.595). When geographic fixed effects were included, spatial autocorrelation diminished at the census tract level (ρ = 0.271; 95% CI, 0.147-0.396) and disappeared at the census block group level (ρ = -0.075; 95% CI, -0.264 to 0.114).

CONCLUSIONS AND RELEVANCE

Because block groups are smaller than tracts, children in neighboring block groups were more likely to attend the same schools and interact through neighborhood play. Thus, geographic-based social networks were more likely to span block group boundaries. The lack of evidence of spatial autocorrelation in block group-level models suggests that social contagion may be less important than differences in neighborhood context across space. Caution should be used in interpreting significant spatial autocorrelation as evidence of social contagion in obesity.

Spatiotemporal distribution and determinants of gonorrhea infections in mainland China: a panel data analysis

OBJECTIVES

Gonorrhea remains a major public health concern worldwide. This study aims to explore the spatiotemporal distribution and sociodemographic determinants of gonorrhea rates during 2004-2014 in mainland China.

STUDY DESIGN

Space-time scan statistics and spatial panel regression model.

METHODS

The gonorrhea infection data and sociodemographic data during 2004-2014 at the provincial level in mainland China were extracted from the China Public Health Science Data Center and China Statistical Yearbooks, respectively. The space-time scan statistics were used to identify the high-risk clusters of gonorrhea, and the spatial panel regression model was adopted to examine the sociodemographic determinants.

RESULTS

One most likely and five secondary high-risk clusters of gonorrhea rates were identified, which were mainly located in southern and eastern China. The regions with higher GDP per capita, larger floating population, less access to healthcare, higher male-female ratio, and higher divorce rate were more likely to become high-risk areas of gonorrhea.

CONCLUSIONS

Gonorrhea rates were distributed unevenly through space and time and affected by various sociodemographic variables. The space-time scan statistics and spatial panel regression are viable tools for identifying clusters and examining determinants of gonorrhea rates. The findings provide valuable implications for developing targeted prevention and control programs in public health practice.

How Do Social Capital and HIV/AIDS Outcomes Geographically Cluster and Which Sociocontextual Mechanisms Predict Differences Across Clusters?

BACKGROUND

Place of residence has been associated with HIV transmission risks. Social capital, defined as features of social organization that improve efficiency of society by facilitating coordinated actions, often varies by neighborhood, and hypothesized to have protective effects on HIV care continuum outcomes. We examined whether the association between social capital and 2 HIV care continuum outcomes clustered geographically and whether sociocontextual mechanisms predict differences across clusters.

METHODS

Bivariate Local Moran's I evaluated geographical clustering in the association between social capital (participation in civic and social organizations, 2006, 2008, 2010) and [5-year (2007-2011) prevalence of late HIV diagnosis and linkage to HIV care] across Philadelphia, PA, census tracts (N = 378). Maps documented the clusters and multinomial regression assessed which sociocontextual mechanisms (eg, racial composition) predict differences across clusters.

RESULTS

We identified 4 significant clusters (high social capital-high HIV/AIDS, low social capital-low HIV/AIDS, low social capital-high HIV/AIDS, and high social capital-low HIV/AIDS). Moran's I between social capital and late HIV diagnosis was (I = 0.19, z = 9.54, P < 0.001) and linkage to HIV care (I = 0.06, z = 3.274, P = 0.002). In multivariable analysis, median household income predicted differences across clusters, particularly where social capital was lowest and HIV burden the highest, compared with clusters with high social capital and lowest HIV burden.

DISCUSSION

The association between social participation and HIV care continuum outcomes cluster geographically in Philadelphia, PA. HIV prevention interventions should account for this phenomenon. Reducing geographic disparities will require interventions tailored to each continuum step and that address socioeconomic factors such as neighborhood median income.

Assessing Spatial Relationships between Race, Inequality, Crime, and Gonorrhea and Chlamydia in the United States

Incidence rates of chlamydia and gonorrhea reached unprecedented levels in 2015 and are concentrated in southern counties of the USA. Using incidence data from the Center for Disease Control, Moran's I analyses assessed the data for statistically significant clusters of chlamydia and gonorrhea at the county level in 46 states of the USA. Lagrange multiplier diagnostics justified selection of the spatial Durbin regression model for chlamydia and the spatial error model for gonorrhea. Rates of chlamydia (Moran's I = .37, p < .001) and gonorrhea (Moran's I = .38, p < .001) were highly clustered particularly in the southern region of the USA. Logged percent in poverty (B = .49, p < .001 and B = .48, p < .001) and racial composition of African-Americans (B = .16, p < .001 and B = .40, p < .001); Native Americans (B = .12, p < .001 and B = .20, p < .001); and Asians (B = .14, p < .001 and B = .09, p < .001) were significantly associated with greater rates of chlamydia and gonorrhea, respectively, after accounting for spatial dependence in the data. Logged rates of rates violent crimes were associated with chlamydia (B = .053, p < .001) and gonorrhea (B = .10, p < .001). Logged rates of drug crimes (.052, p < .001) were only associated with chlamydia. Metropolitan census designation was associated with logged rates of chlamydia (B = .12, p < .001) and gonorrhea (B = .24, p < .001). Spatial heterogeneity in the distribution of rates of chlamydia and gonorrhea provide important insights for strategic public health interventions in the USA and inform the allocation of limited resources for the prevention of chlamydia and gonorrhea.

The relationship between higher social trust and lower late HIV diagnosis and mortality differs by race/ethnicity: results from a state-level analysis

INTRODUCTION

Black men who have sex with men (MSM) continue to suffer a disproportionate burden of new HIV diagnoses and mortality. To better understand some of the reasons for these profound disparities, we examined whether the association between social trust and late HIV diagnosis and mortality differed by race/ethnicity, and investigated potential indirect effects of any observed differences.

METHODS

We performed generalized structural equation modelling to assess main and interaction associations between trust among one's neighbours in 2009 (i.e. social trust) and race/ethnicity (Black, White, and Hispanic) predicting late HIV diagnosis (a CD4 count ≤200 cell/µL within three months of a new HIV diagnosis) rates and all-cause mortality rates of persons ever diagnosed late with HIV, across 47 American states for the years 2009-2013. We examined potential indirect effects of state-level HIV testing between social trust and late HIV diagnosis. Social trust data were from the Gallup Healthways Survey, HIV data from the Centers for Disease Control and Prevention, and HIV testing from the Behavioral Risk Factor Surveillance System. Covariates included state-level structural, healthcare, and socio-demographic factors including income inequality, healthcare access, and population density. We stratified analysis by transmission group (male-to-male, heterosexual, and injection drug use (IDU)).

RESULTS

States with higher levels of social trust had lower late HIV diagnosis rates: Adjusted Rate Ratio [aRR] were consistent across risk groups (0.57; 95%CI 0.53-0.62, male-to-male), (aRR 0.58; 95%CI 0.54-0.62, heterosexual) and (aRR 0.64; 95%CI 0.60-0.69, IDU). Those associations differed by race/ethnicity (all p < 0.001). The associations were most protective for Blacks followed by Hispanics, and least protective for Whites. HIV testing mediated between 18 and 32% of the association between social trust and late HIV diagnosis across transmission group but for Blacks relative to Whites only. Social trust was associated with lower all-cause mortality rates and that association varied by race/ethnicity within the male-to-male and IDU transmission groups only.

CONCLUSION

Social trust may promote timely HIV testing, which can facilitate earlier HIV diagnosis, thus it can be a useful determinant to monitor the relationship with HIV care continuum outcomes especially for racial/ethnic minority groups disproportionately infected by HIV.

Correlates of county-level nonviral sexually transmitted infection hot spots in the US: application of hot spot analysis and spatial logistic regression

PURPOSE

We used a combination of hot spot analysis (HSA) and spatial regression to examine county-level hot spot correlates for the most commonly reported nonviral sexually transmitted infections (STIs) in the 48 contiguous states in the United States (US).

METHODS

We obtained reported county-level total case rates of chlamydia, gonorrhea, and primary and secondary (P&S) syphilis in all counties in the 48 contiguous states from national surveillance data and computed temporally smoothed rates using 2008-2012 data. Covariates were obtained from county-level multiyear (2008-2012) American Community Surveys from the US census. We conducted HSA to identify hot spot counties for all three STIs. We then applied spatial logistic regression with the spatial error model to determine the association between the identified hot spots and the covariates.

RESULTS

HSA indicated that ≥84% of hot spots for each STI were in the South. Spatial regression results indicated that, a 10-unit increase in the percentage of Black non-Hispanics was associated with ≈42% (P < 0.01) [≈22% (P < 0.01), for Hispanics] increase in the odds of being a hot spot county for chlamydia and gonorrhea, and ≈27% (P < 0.01) [≈11% (P < 0.01) for Hispanics] for P&S syphilis. Compared with the other regions (West, Midwest, and Northeast), counties in the South were 6.5 (P < 0.01; chlamydia), 9.6 (P < 0.01; gonorrhea), and 4.7 (P < 0.01; P&S syphilis) times more likely to be hot spots.

CONCLUSION

Our study provides important information on hot spot clusters of nonviral STIs in the entire United States, including associations between hot spot counties and sociodemographic factors.

Influence of Detection Method and Study Area Scale on Syphilis Cluster Identification in North Carolina

BACKGROUND

Identifying geographical clusters of sexually transmitted infections can aid in targeting prevention and control efforts. However, detectable clusters can vary between detection methods because of different underlying assumptions. Furthermore, because disease burden is not geographically homogenous, the reference population is sensitive to the study area scale, affecting cluster outcomes. We investigated the influence of cluster detection method and geographical scale on syphilis cluster detection in Mecklenburg County, North Carolina.

METHODS

We analyzed primary and secondary syphilis cases reported in North Carolina (2003-2010). Primary and secondary syphilis incidence rates were estimated using census tract-level population estimates. We used 2 cluster detection methods: local Moran's I using an areal adjacency matrix and Kulldorff's spatial scan statistic using a variable size moving circular window. We evaluated 3 study area scales: North Carolina, Piedmont region, and Mecklenburg County. We focused our investigation on Mecklenburg, an urban county with historically high syphilis rates.

RESULTS

Syphilis clusters detected using local Moran's I and Kulldorff's scan statistic overlapped but varied in size and composition. Because we reduced the scale to a high-incidence urban area, the reference syphilis rate increased, leading to the identification of smaller clusters with higher incidence. Cluster demographic characteristics differed when the study area was reduced to a high-incidence urban county.

CONCLUSIONS

Our results underscore the importance of selecting the correct scale for analysis to more precisely identify areas with high disease burden. A more complete understanding of high-burden cluster location can inform resource allocation for geographically targeted sexually transmitted infection interventions.

Geographic Variation in Condom Availability and Accessibility

Identifying predictors that contribute to geographic disparities in sexually transmitted infections (STIs) is necessary in order to reduce disparities. This study assesses the spatial relationship condom availability and accessibility in order to better identify determinants of geographic disparities in STIs. We conducted a telephone-based audit among potential-condom selling establishments. Descriptive analyses were conducted to detect differences in condom-selling characteristics by stores and by store type. Geocoding, mapping, and spatial analysis were conducted to measure the availability of condoms. A total of 850 potential condom-selling establishments participated in the condom availability and accessibility audit in St. Louis city; 29 % sold condoms. There were several significant geographic clusters of stores identified across the study area. The first consisted of fewer convenience stores and gas stations that sold condoms in the northern section of the city, whereas condoms were less likely to be sold in non-convenience store settings in the southwestern and central parts of the city. Additionally, locations that distributed free condoms clustered significantly in city center. However, there was a dearth of businesses that were neither convenience stores nor gas stations in the northern region of the city, which also had the highest concentration of condoms sold. This initial study was conducted to provide evidence that condom availability and accessibility differ by geographic region, and likely are a determinant of social norms surrounding condom use and ultimately impact STI rates.

Per capita incidence of sexually transmitted infections increases systematically with urban population size: a cross-sectional study

OBJECTIVES

Rampant urbanisation rates across the globe demand that we improve our understanding of how infectious diseases spread in modern urban landscapes, where larger and more connected host populations enhance the thriving capacity of certain pathogens.

METHODS

A data-driven approach is employed to study the ability of sexually transmitted diseases (STDs) to thrive in urban areas. The conduciveness of population size of urban areas and their socioeconomic characteristics are used as predictors of disease incidence, using confirmed-case data on STDs in the USA as a case study.

RESULTS

A superlinear relation between STD incidence and urban population size is found, even after controlling for various socioeconomic aspects, suggesting that doubling the population size of a city results in an expected increase in STD incidence larger than twofold, provided that all other socioeconomic aspects remain fixed. Additionally, the percentage of African-Americans, income inequalities, education and per capita income are found to have a significant impact on the incidence of each of the three STDs studied.

CONCLUSIONS

STDs disproportionately concentrate in larger cities. Hence, larger urban areas merit extra prevention and treatment efforts, especially in low-income and middle-income countries where urbanisation rates are higher.

Condom deserts: geographical disparities in condom availability and their relationship with rates of sexually transmitted infections

BACKGROUND

Identifying predictors that contribute to geographical disparities in sexually transmitted infections (STIs) is necessary. This study assesses the spatial relationship between condom availability to locations of STIs in order to better understand these geographical disparities.

OBJECTIVES

We conducted a condom availability audit among potential condom-selling establishments. New gonorrhoea and chlamydia cases in 2011 (n=6034) and HIV infection cases from 2006 to 2011 (n=565) were collected by census tract in St Louis, Missouri. 829 potential condom-selling establishments participated in the condom availability audit in St Louis City; 242 of which sold condoms.

RESULTS

A negative linear relationship exists between condom vendors and cases of gonorrhoea and chlamydia, after adjusting for concentrated disadvantage and free condom locations. Higher concentrated disadvantage, higher proportions of convenience vendors and free locations were associated with higher rates of HIV.

CONCLUSIONS

This study was conducted to provide evidence that lack of condom availability is associated with STI rates, and likely is an integral component to influencing the subjective norms surrounding condom use and STI rates. Condom distribution interventions may be addressing availability needs and social norms, yet are more likely to be effective when placed in locations with the highest STI rates.

Neighborhoods at risk: estimating risk of higher Neisseria gonorrhoeae incidence among women at the census tract level

BACKGROUND

The association between area-based social factors and sexually transmitted diseases has been demonstrated in numerous studies. Such associations have not previously been explored for their potential to quantify likelihood of higher transmission of gonorrhea in small geographic areas.

METHODS

Aggregate census tract-level sociodemographic factors in 4 domains (demographics, educational attainment, household income, and housing characteristics) were merged with female gonorrhea incidence data from 113 counties in 10 US states. Multivariate models were constructed, and a tract-level composite gonorrhea risk index was calculated. This composite risk index was validated against gonorrhea incidence among women from 2 independent states.

RESULTS

Seven tract-level factors were found to be most strongly correlated with female gonorrhea incidence: educational attainment, proportion of female headed households, annual household income below US $20,000, proportion of population non-Hispanic black, proportion of housing units currently vacant, proportion of population reporting moving in last year, and proportion of households that are nonfamily units. Composite index was highly correlated with female gonorrhea in the study area and validated with independent data.

CONCLUSIONS

Social factors predict gonorrhea incidence at the census tract level and identify small areas at risk for higher morbidity. These data may be used by health departments and health care practices to develop geographically based disease prevention and control efforts. This is especially useful because gonorrhea incidence data are not routinely available below the county level in many states.

Spatial epidemiology of the syphilis epidemic in Toronto, Canada

BACKGROUND

Urban centers across Canada and the United States have battled syphilis epidemics with high rates of human immunodeficiency virus (HIV) coinfection for over a decade. We examined the spatial epidemiology of syphilis over time for Toronto (Canada) with the intention of forming new insights and strategies for restoring low syphilis rates.

METHODS

Syphilis incidence rates, HIV-syphilis coinfection, and sexual risk behavior prevalences were estimated and mapped from primary, secondary, early latent syphilis cases reported to Toronto Public Health between January 1, 2006, and December 31, 2010, using ArcGIS 9.0. Geographic clusters of significantly elevated syphilis incidence rates were identified using SaTScan 9.0. The relationship between syphilis incidence rates and sociocultural factors was modeled using the Besag, York, and Mollie model.

RESULTS

Between 2006 and 2010, syphilis incidence rates were high in Toronto's downtown core area, intensified, and spread outward initiating 3 independent outbreak areas. HIV coinfection was high (47%); however, no spatial clustering was identified. Syphilis incidence rates, HIV coinfection, and behavioral risk factors promoting sexually transmitted infection transmission were high outside the core area, suggesting that peripheral sexual networks may be influencing high syphilis infection rates both inside and outside the core.

CONCLUSIONS

Toronto's syphilis epidemic is mature. Response, resources, and intervention activities should target core and noncore areas.

Using empirical Bayes methods to rank counties on population health measures

The University of Wisconsin Population Health Institute has published County Health Rankings (The Rankings) since 2010. These rankings use population-based data to highlight variation in health and encourage health assessment for all US counties. However, the uncertainty of estimates remains a limitation. We sought to quantify the precision of TheRankings for selected measures. We developed hierarchical models for 5 health outcome measures and applied empirical Bayes methods to obtain county rank estimates for a composite health outcome measure. We compared results using models with and without demographic fixed effects to determine whether covariates improved rank precision. Counties whose rank had wide confidence intervals had smaller populations or ranked in the middle of all counties for health outcomes. Incorporating covariates in the models produced narrower intervals, but rank estimates remained imprecise for many counties. Local health officials, especially in smaller population and mid-performing communities, should consider these limitations when interpreting the results of TheRankings.

The association between racial disparity in income and reported sexually transmitted infections

OBJECTIVES

We examined the association between racial disparity in income and reported race-specific county-level bacterial sexually transmitted infections (STIs) in the United States focusing on disparities between Blacks and Whites.

METHODS

Data are from the US 2000 decennial census. We defined 2 race-income county groups (high and low race-income disparity) on the basis of the difference between Black and White median household incomes. We used 2 approaches to examine disparities in STI rates across the groups. In the first approach, we computed and compared race-specific STI rates for the groups. In the second approach, we used spatial regression analyses to control for potential confounders.

RESULTS

Consistent with the STI literature, chlamydia, gonorrhea, and syphilis rates for Blacks were substantially higher than were those for Whites. We also found that racial disparities in income were associated with racial disparities in chlamydia and gonorrhea rates and, to a lesser degree, syphilis rates.

CONCLUSIONS

Racial disparities in household income may be a more important determinant of racial disparities in reported STI morbidity than are absolute levels of household income.

Does core area theory apply to sexually transmitted diseases in rural environments?

BACKGROUND

Our objective was to determine the extent to which geographical core areas for gonorrhea and syphilis are located in rural areas as compared with urban areas.

METHODS

Incident gonorrhea (January 1, 2005-December 31, 2010) and syphilis (January 1, 1999-December 31, 2010) rates were estimated and mapped by census tract and quarter. Rurality was measured using percent rural and rural-urban commuting area (rural, small town, micropolitan, or urban). SaTScan was used to identify spatiotemporal clusters of significantly elevated rates of infection. Clusters lasting 5 years or longer were considered core areas; clusters of shorter duration were considered outbreaks. Clusters were overlaid on maps of rurality and qualitatively assessed for correlation.

RESULTS

Twenty gonorrhea core areas were identified: 65% were in urban centers, 25% were in micropolitan areas, and the remaining 10% were geographically large capturing combinations of urban, micropolitan, small town, and rural environments. Ten syphilis core areas were identified with 80% in urban centers and 20% capturing 2 or more rural-urban commuting areas. All 10 (100%) of the syphilis core areas overlapped with gonorrhea core areas.

CONCLUSIONS

Gonorrhea and syphilis rates were high for rural parts of North Carolina; however, no core areas were identified exclusively for small towns or rural areas. The main pathway of rural sexually transmitted disease (STI) transmission may be through the interconnectedness of urban, micropolitan, small town, and rural areas. Directly addressing STIs in urban and micropolitan communities may also indirectly help address STI rates in rural and small town communities.

Infections and obstetric outcomes in opioid-dependent pregnant women maintained on methadone or buprenorphine

AIMS

To characterize infections and compare obstetric outcomes in opioid-dependent pregnant women who participated in a randomized clinical trial comparing agonist medications, methadone and buprenorphine.

DESIGN

Incidence of infections was identified as part of the screening medical assessment. As part of a planned secondary analysis, analysis of variance and polytomous logistic regressions were conducted on obstetric outcome variables using treatment randomization condition (maternal maintenance with either methadone or buprenorphine) as the predictor variable, controlling for differences between study sites.

SETTING

Six United States sites and one European site that provided comprehensive treatment to opioid-dependent pregnant women.

PARTICIPANTS

Pregnant opioid-dependent women (n = 131) who delivered while participating in the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study.

MEASUREMENTS

Obstetric, infectious and other maternal medical complications captured by medical records, physical examination, blood tests and self-report. Neonatal medical complications captured by medical records.

FINDINGS

Hepatitis C was the most common infection (32.3%), followed by hepatitis B (7.6%) and chlamydia (6.1%) among participants at study enrollment. Maternal methadone versus buprenorphine maintenance was associated with a higher incidence of preterm labor (P = 0.04) and a significantly higher percentage of signs of respiratory distress in neonates at delivery (P = 0.05). Other medical and obstetric complications were infrequent in the total sample, as well as in both methadone and buprenorphine conditions.

CONCLUSIONS

Buprenorphine appears to have an acceptable safety profile for use during pregnancy.

Disparities in sexually transmitted disease rates across the "eight Americas"

BACKGROUND

The purpose of this study was to examine rates of 3 bacterial sexually transmitted diseases (STDs; syphilis, gonorrhea, and chlamydia) in 8 subpopulations (known as the "eight Americas") defined by race and a small number of county-level sociodemographic and geographical characteristics. The eight Americas are (1) Asians and Pacific Islanders in specific counties; (2) Northland low-income rural white; (3) Middle America; (4) Low-income whites in Appalachia and Mississippi Valley; (5) Western Native American; (6) Black middle America; (7) Southern low-income rural black; and (8) High-risk urban black.

METHODS

A list of the counties comprising each of the eight Americas was obtained from the corresponding author of the original eight Americas project, which examined disparities in mortality rates across the eight Americas. Using county-level STD surveillance data, we calculated syphilis, gonorrhea, and chlamydia rates (new cases per 100,000) for each of the eight Americas.

RESULTS

Reported STD rates varied substantially across the eight Americas. STD rates were generally lowest in Americas 1 and 2 and highest in Americas 6, 7, and 8.

CONCLUSIONS

Although disparities in STDs across the eight Americas are generally similar to the well-established disparities in STDs across race/ethnicity, the grouping of counties into the eight Americas does offer additional insight into disparities in STDs in the United States. The high STD rates we found for black Middle America are consistent with the assertion that sexual networks and social factors are important drivers of racial disparities in STDs.

Understanding social capital and HIV risk in rural African American communities

BACKGROUND

African Americans (AA) and rural communities often suffer disproportionately from poorer health. Theory-guided research examining how individual- and community-level factors influence health behaviors and contribute to disparities is needed.

OBJECTIVE

To understand how a social network model that captures the interplay between individual and community factors might inform community-based interventions to reduce HIV risk in rural AA communities.

DESIGN

Qualitative study.

SETTING AND PARTICIPANTS

Eleven focus groups with 38 AA 16-24 year olds, 42 adults over age 25, and 13 formerly incarcerated individuals held in community settings in two rural, predominantly AA counties in North Carolina. Thirty-seven semi-structured interviews with multiethnic key informants.

APPROACH

Semi-structured interviews and focus groups with open-ended questions assessed a) perceptions of multi-level HIV risk determinants from a social network model (individual, interpersonal, social, economic, political and structural) identified through literature review and b) community needs and assets affecting local HIV rates. Qualitative data was analyzed using directive content analysis guided by a social network model.

RESULTS

We identified four themes regarding the interaction between individuals and their communities that mediate HIV risk: interpersonal processes, community structural environment, social disorder, and civic engagement. Communities were characterized as having a high degree of cohesiveness, tension, and HIV-related stigma. The community structural environment-characterized by neighborhood poverty, lack of skilled jobs, segregation, political disenfranchisement and institutional racism-was felt to reduce the availability and accessibility of resources to combat HIV. Adults noted an inability to combat social problems due to social disorder, which fuels HIV risk behaviors. Civic engagement as a means of identifying community concerns and developing solutions is limited by churches' reluctance to address HIV-related issues.

CONCLUSION

To combat HIV-related stigma, physicians should follow recommendations for universal HIV testing. Besides asking about individual health behaviors, physicians should ask about the availability of support and local community resources. Physicians might consider tailoring their treatment recommendations based on available community resources. This strategy may potentially improve patient adherence and clinical outcomes.

Sexually transmitted disease core theory: roles of person, place, and time

The authors' purpose was to expand sexually transmitted disease core theory by examining the roles of person, place, and time in differentiating geographic core areas from outbreak areas. The authors mapped yearly census-tract-level syphilis rates for San Francisco, California, based on new primary and secondary syphilis cases reported to the San Francisco City sexually transmitted disease surveillance program between January 1, 1985, and December 31, 2007. SaTScan software (Information Management Services, Inc., Silver Spring, Maryland) was used to identify geographic clusters of significantly elevated syphilis rates over space and time. The authors graphed epidemic curves for 1) core areas, 2) outbreak areas, 3) neither core nor outbreak areas, and 4) noncore areas, where noncore areas included outbreaks, and stratified these curves according to demographic characteristics. Five clusters of significantly elevated primary and secondary syphilis rates were identified. A 5-year threshold was useful for differentiating core clusters from outbreak clusters. Epidemic curves for core areas, outbreak areas, neither core nor outbreak areas, and noncore areas were perfectly synchronized in phase trends and wavelength over time, even when broken down by demographic characteristics. Between epidemics, the occurrence of syphilis affected all demographic groups equally. During an epidemic, a temporary disparity in syphilis occurrence arose and a homogeneous core group of cases could be defined.

Are neighborhood sociocultural factors influencing the spatial pattern of gonorrhea in North Carolina?

PURPOSE

To determine if the spatial pattern of gonorrhea observed for North Carolina was influenced by neighborhood-level sociocultural determinants of health, including race/ethnicity.

METHODS

A generalized linear mixed model with spatially correlated random effects was fit to measure the influence of socio-cultural factors on the spatial pattern of gonorrhea reported to the North Carolina State Health Department (January 1, 2005 to March 31, 2008).

RESULTS

Neighborhood gonorrhea rates increased as the percent single mothers increased (25th to 75th neighborhood percentile Relative Rate 1.18, 95% CI 1.12, 1.25), and decreased as socioeconomic status increased (Relative Rate 0.89, 95% CI 0.84, 0.95). Increasing numbers of men in neighborhoods with more women than men did not change the gonorrhea rate, but was associated with decreased rates in neighborhoods with more men than women. Living in the mountains was protective for all race/ethnicities. Rurality was associated with decreased rates for Blacks and increased rates for Native Americans outside the mountains.

PURPOSE

Neighborhood-level sociocultural factors, primarily those indicative of neighborhood deprivation, explained a significant proportion of the spatial pattern of gonorrhea in both urban and rural communities. Race/ethnicity was an important proxy for social and cultural factors not captured by measures of socioeconomic status.

Design of a faith-based HIV intervention: successful collaboration between a university and a church

This article describes the development of a gender-specific and culturally tailored, theoretically derived, faith-based HIV intervention created to reduce HIV vulnerability among African American women. This innovative culturally congruent approach to HIV prevention involves one of the most influential social structures in the African American community-the African American church. Using the ADAPT-ITT model, and principles of community-based participatory research, this faith-based HIV intervention was adapted from a CDC-defined evidence-based HIV prevention intervention for young African American women. Results of data assessing the feasibility of implementing this faith-based HIV intervention suggests that young African American women are receptive and willing to participate in a faith-based HIV intervention. Results show that fidelity to intervention implementation (97%) and participant attendance to both sessions (92%) was high, and the HIV risk behaviors targeted in the faith-based intervention matched the participants' HIV behavioral risk profile. Given the vulnerability of young African American women to HIV sustainable efforts, in particular, the institutionalization of this intervention within the church structure could halt the persistent increase in HIV infections within this community.

Primary syphilis cases in Guangdong Province 1995-2008: opportunities for linking syphilis control and regional development

BACKGROUND

Syphilis cases have risen in many parts of China, with developed regions reporting the greatest share of cases. Since syphilis increases in these areas are likely driven by both increased screening and changes in sexual behaviours, distinguishing between these two factors is important. Examining municipal-level primary syphilis cases with spatial analysis allows a more direct understanding of changing sexual behaviours at a more policy-relevant level.

METHODS

In this study we examined all reported primary syphilis cases from Guangdong Province, a southern province in China, since the disease was first incorporated into the mandatory reporting system in 1995. Spatial autocorrelation statistics were used to correlate municipal-level clustering of reported primary syphilis cases and gross domestic product (GDP).

RESULTS

A total of 52,036 primary syphilis cases were reported over the period 1995-2008, and the primary syphilis cases increased from 0.88 per 100,000 population in 1995 to 7.61 per 100,000 in 2008. The Pearl River Delta region has a disproportionate share (44.7%) of syphilis cases compared to other regions. Syphilis cases were spatially clustered (p = 0.01) and Moran's I analysis found that syphilis cases were clustered in municipalities with higher GDP (p = 0.004).

CONCLUSIONS

Primary syphilis cases continue to increase in Guangdong Province, especially in the Pearl River Delta region. Considering the economic impact of syphilis and its tendency to spatially cluster, expanded syphilis testing in specific municipalities and further investigating the costs and benefits of syphilis screening are critical next steps.

Sexuality education policies and sexually transmitted disease rates in the United States of America

Summary

The aim of the study was to test for relationships between state-level sex educational policies and sexually transmitted disease (STD) rates. We analysed US case reports of gonorrhoea and chlamydial infection for 2001–2005 against state policies for abstinence coverage in sexuality education, using the proportion of the population per state who identified as black (aged 15–24 years) as a covariate. We also tested for effects on 15–19 year olds versus 35–39 year olds and tuberculosis rates (the latter to ensure findings applied only to STD). States with no mandates for abstinence had the lowest mean rates of infection among the overall population and among adolescents. States with mandates emphasizing abstinence had the highest rates; states with mandates to cover (but not emphasize) abstinence fell in between. Rates in some states covering abstinence changed faster than in others, as reflected in sharper declines (gonorrhoea) or slower increases (chlamydial infection). These effects were not shown for tuberculosis or 35–39 year olds. Having no abstinence education policy has no apparent effect on STD rates for adolescents. For states with elevated rates, policies mandating coverage may be useful, although policies emphasizing abstinence show no benefit.

Using spatial regression methods to examine the association between county-level racial/ethnic composition and reported cases of Chlamydia and gonorrhea: an illustration with data from the state of Texas

BACKGROUND

Several studies have reported racial/ethnic disparities in the incidence of sexually transmitted diseases. However, very few studies have accounted for potential spatial dependence. Additionally, little is known about the relative magnitudes of the associations between county-level racial/ethnic composition and the 2 most commonly reported sexually transmitted diseases.

METHODS

We used county-level data from the National Electronic Telecommunications System for Surveillance and the 2000 Census data to investigate the association between county-level racial/ethnic composition and reported cases of the 2 most commonly reported sexually transmitted diseases (chlamydia and gonorrhea) in Texas. We also estimated ordinary least square (OLS) models for comparison.

RESULTS

Preliminary results from the spatial regression models indicated that the choice of spatial relationships criteria was important for model specification. The spatial error model (SEM) was superior to the spatial autoregressive model, spatial Durbin model, and OLS. The SEM for the 2 disease equations were further analyzed using a seemingly unrelated regression estimation (SURE) procedure. Although the SEM was superior to all models (using standard criteria), the coefficients were fairly stable across models. Our results showed that a unit change in percent black was associated with 1.6 (1.1 for Hispanic) and 3.3 (0.5 for Hispanic) percent change in chlamydia and gonorrhea rates (on average), respectively, compared with percent white.

CONCLUSION

Although there were no substantial differences in the magnitude of the estimated parameters, spatial regression models are potentially superior to OLS models and should be explored in future sexually transmitted disease studies.

Association between widowhood and risk of diagnosis with a sexually transmitted infection in older adults

OBJECTIVES

We assessed whether widowhood is associated with risk of diagnosis with a sexually transmitted infection (STI) among older adults in the United States and whether the associations observed in men differed before and after the introduction of sildenafil, the first oral erectile dysfunction medication approved by the Food and Drug Administration.

METHODS

We used Cox proportional hazards regression to analyze the time to first STI diagnosis in a random sample of married, Medicare-eligible couples aged 67 to 99 years in 1993 (N = 420 790 couples).

RESULTS

Twenty-one percent of male and 43% of female participants lost a spouse during the 9-year study period. Only 0.65% of men and 0.97% of women were diagnosed with an STI. Widowhood was associated with an increased risk of STI diagnosis for men only, with the largest effects found 0.5 to 1 year after a wife's death. Effects for men were larger after the introduction of sildenafil.

CONCLUSIONS

Widowhood in older men, but not women, increased the risk for STIs, especially in the postsildenafil era. Clinicians should address sexual health issues with older patients, especially bereaved men taking erectile dysfunction medications.

Why housing?

Housing/lack of housing and HIV are powerfully linked. Housing occupies an important place in the causal chains linking poverty and inequality, and HIV risk and outcomes of infection. The articles in this Special Supplement of AIDS and Behavior confirm the impact of homelessness, and poor or unstable housing, on HIV/AIDS, and challenge scientists to test and policy makers to implement the promise of housing as an innovative response to the epidemic. In order to influence the development of policies on housing to benefit at-risk or HIV-infected persons, however, proponents must justify why this association exists, and how housing can help end the epidemic as well as improve the care and health of persons living with HIV/AIDS. We introduce this supplement with a discussion of the "why" question.