Food deserts, endometrial cancer survivors, and healthy food access: Is it equitable in rural America? - A geospatial analysis.

OBJECTIVE: To examine endometrial cancer survivors' access to healthy food resources recommended by the Society of Gynecologic Oncology (SGO) in relation to food deserts and social health determinants. METHODS: Participants included women seen for endometrial cancer treatment at an academic medical center in the Deep South from 2015 to 2020 who lived in South Carolina. Demographic and comorbidity data were abstracted from medical records. Food desert data were obtained from the United States Department of Agriculture (USDA). Each patient was assigned a socioeconomic (SES) score (SES-1 = low, SES-5 = high) using census data and a social vulnerability index (SVI) using Center for Disease Control and Prevention (CDC) data for neighborhood adverse health effects. Geospatial techniques assessed patients' driving distance from home to a healthy food resource. RESULTS: Of the 736 endometrial cancer survivors, 31% identified as African American, and 30% lived in low SES (SES-1, SES-2) census blocks. Most survivors had low grade disease (63%) and 76% with stage 1-2 disease. Seventy percent of patients were obese (BMI ≥30 kg/m2). Forty percent of survivors lived in a food desert. Survivors living in a food desert with low SES had significantly higher social vulnerability (p = 0.0001) and lower median income (p = 0.0001). Those with low SES and living in a food desert drove further (p = 0.05, range 0.017-12.0 miles). CONCLUSION: Obesity rates were high in endometrial cancer survivors living in the Deep South. Survivors with higher social vulnerability and lower SES were more likely to live in food deserts with decreased access to healthy food resources.

The Examination of Diffusion Effects on Modern Contraceptive Use in Nigeria.

This study uses data gathered for an evaluation of a Bill & Melinda Gates Foundation-funded initiative designed to increase modern contraceptive use in select urban areas of Nigeria. When the initiative was conceived, the hope was that any positive momentum in the cities would diffuse to surrounding areas. Using a variety of statistical methods, we study three aspects of diffusion and their effects on modern contraceptive use: spread through mass communications, social learning, and social influence. Using a dynamic causal model, we find strong evidence of social multiplier effects through social learning. The results for social influence and spread through mass communications are promising, but we are unable to identify definitive causal impacts.

Longitudinal examination of changing fertility intentions and behaviors over a four-year period in urban Senegal.

BACKGROUND: Fertility intentions and contraceptive use are often used to demonstrate gaps in programs and policies to meet the contraceptive needs of women and couples. Prior work demonstrated that fertility intentions are fluid and change over a woman's (or couple's) life course with changing marital status, childbearing, and education/employment opportunities. This study uses longitudinal data to better examine the fluidity of women's fertility intentions and disentangle the complex interrelationships between fertility and contraceptive use. METHODS: Using survey data from three time points and three urban sites in Senegal, this study examines how women's fertility intentions and contraceptive use in an earlier period affect pregnancy experience and the intentionality of experienced pregnancies among a sample of 1050 women who were in union at all three time points. We apply correlated random effect longitudinal regression methods to predict a subsequent birth by fertility intentions and modern contraceptive use at an earlier period addressing endogeneity concerns of earlier analyses that only include two time periods. RESULTS: Descriptive results demonstrate some change in fertility desires over time such that 6-8% of women who reported their pregnancy as intended (i.e., wanted to get pregnant at time of pregnancy) reported earlier that they did not want any(more) children. Multivariate analyses demonstrate that women who want to delay or avoid a pregnancy and are using modern contraception are the least likely to get pregnant. Among women who became pregnant, the only factor differentiating whether the pregnancy is reported as intended or unintended (mistimed or unwanted) was prior fertility intention. Women who wanted to delay a pregnancy previously were more likely to report the pregnancy as unintended compared to women who wanted to get pregnant soon. CONCLUSIONS: These results suggest some post-hoc rationalization among women who are getting pregnant. Women who say they do not want to get pregnant may be choosing not to use a contraceptive method in this urban Senegal context of high fertility. Programs seeking to reach these women need to consider their complex situations including their fertility intentions, family planning use, and the community norms within which they are reporting these intentions and behaviors.

Access to public transportation and health facilities offering long-acting reversible contraceptives among residents of formal and informal settlements in two cities in Kenya.

BACKGROUND: Despite improved health facility access relative to rural areas, distance and transportation remain barriers in some urban areas. Using household and facility data linked to residential and transportation geographic information we describe availability of health facilities offering long-acting reversible contraceptive (LARC) methods and measure access via matatus (privately owned mid-size vehicles providing public transport) in urban Kenya. METHODS: Study data were collected by the Measurement, Learning and Evaluation (MLE) Project. Location information for clusters (2010) representative of city-level population were used to identify formal and informal settlement residents. We measured straight-line distances between clusters and facilities that participated in facility audits (2014) and offered LARCs. In Kisumu, we created a geographic database of matatu routes using Google Earth. In Nairobi, matatu route data were publicly available via the Digital Matatus Project. We measured straight-line distance between clusters and matatu stops on 'direct' routes (matatu routes with stop(s) ≤1 km from health facility offering LARCs). Facility and matatu access were compared by settlement status using descriptive statistics. We then used client exit interview data from a subset of facilities in Nairobi (N = 56) and Kisumu (N = 37) Kenya (2014) to examine the frequency of matatu use for facility visits. RESULTS: There were 141 (Informal = 71; Formal = 70) study clusters in Nairoibi and 73 (Informal = 37; Formal = 36) in Kisumu. On average, residential clusters in both cities were located ≤1 km from a facility offering LARCs and ≤ 1 km from approximately three or more matatu stops on direct routes regardless of settlement status. Client exit interview data in Nairobi (N = 1602) and Kisumu (N = 1158) suggest that about 25% of women use matatus to visit health facilities. On average, women who utilized matatus travelled 30 min to the facility, with 5% travelling more than 1 hour. Matatu use increased with greater household wealth. CONCLUSIONS: Overall, formal and informal settlement clusters were within walking distance of a facility offering LARCs, and multiple matatu stops were accessible to get to further away facilities. This level of access will be beneficial as efforts to increase LARC use expand, but the role of wealth and transportation costs on access should be considered, especially among urban poor.

On the sustainability of a family planning program in Nigeria when funding ends.

Few studies have examined the sustainability of family planning program outcomes in the post-program period. This article presents the results of a natural experiment where the Nigerian Urban Reproductive Health Initiative Phase I programming ended in early 2015 and Phase II activities continued in a subset of cities. Using data collected in 2015 and 2017, we compare contraceptive ideation and modern family planning use in two cities: Ilorin where program activities concluded in 2015 and Kaduna where program activities continued. The results demonstrate that exposure to program activities decreased in Ilorin but for those individuals reporting continuing exposure, the effect size of exposure on modern family planning use remained the same and was not significantly different from Kaduna. Modern family planning use continued to increase in both cites but at a lower rate than during Phase I. The results are useful for designing family planning programs that sustain beyond the life of the program.

Geospatial analyses identify regional hot spots of diffuse gastric cancer in rural Central America.

BACKGROUND: Geospatial technology has facilitated the discovery of disease distributions and etiology and helped target prevention programs. Globally, gastric cancer is the leading infection-associated cancer, and third leading cause of cancer mortality worldwide, with marked geographic variation. Central and South America have a significant burden, particularly in the mountainous regions. In the context of an ongoing population-based case-control study in Central America, our aim was to examine the spatial epidemiology of gastric cancer subtypes and H. pylori virulence factors. METHODS: Patients diagnosed with gastric cancer from 2002 to 2013 in western Honduras were identified in the prospective gastric cancer registry at the principal district hospital. Diagnosis was based on endoscopy and confirmatory histopathology. Geospatial methods were applied using the ArcGIS v10.3.1 and SaTScan v9.4.2 platforms to examine regional distributions of the gastric cancer histologic subtypes (Lauren classification), and the H. pylori CagA virulence factor. Getis-Ord-Gi hot spot and Discrete Poisson SaTScan statistics, respectively, were used to explore spatial clustering at the village level (30-50 rural households), with standardization by each village's population. H. pylori and CagA serologic status was determined using the novel H. pylori multiplex assay (DKFZ, Germany). RESULTS: Three hundred seventy-eight incident cases met the inclusion criteria (mean age 63.7, male 66.3%). Areas of higher gastric cancer incidence were identified. Significant spatial clustering of diffuse histology adenocarcinoma was revealed both by the Getis-Ord-GI* hot spot analysis (P-value < 0.0015; range 0.00003-0.0014; 99%CI), and by the SaTScan statistic (P-value < 0.006; range 0.0026-0.0054). The intestinal subtype was randomly distributed. H. pylori CagA had significant spatial clustering only in association with the diffuse histology cancer hot spot (Getis-Ord-Gi* P value ≤0.001; range 0.0001-0.0010; SaTScan statistic P value 0.0085). In the diffuse gastric cancer hot spot, the lowest age quartile range was 21-46 years, significantly lower than the intestinal cancers (P = 0.024). CONCLUSIONS: Geospatial methods have identified a significant cluster of incident diffuse type adenocarcinoma cases in rural Central America, suggest of a germline genetic association. Further genomic and geospatial analyses to identify potential spatial patterns of genetic, bacterial, and environmental risk factors may be informative.

Exploring the spatial relationship between primary road distance to antenatal clinics and HIV prevalence in pregnant females of Lilongwe, Malawi.

While urbanization in a sub-Saharan African (SSA) context can lead to greater independence in women, various sociological, biological, and geographical factors in urban areas may keep women at a higher risk for HIV than men. Access to major roads during Malawi's transition into rapid urbanization may leave women disproportionately vulnerable to HIV infection. It is not well established whether women who report to health clinics closer to major roads have higher or lower levels of HIV. In this study we explored the spatial heterogeneity of HIV prevalence among pregnant females in Lilongwe District, Malawi. Using Geographic Information Systems, we visually represented patterns of HIV prevalence in relation to primary roads. HIV prevalence data for 2015 were obtained from 44 antenatal clinics (ANC) in Lilongwe District. ANC prevalence data were aggregated to the administrative area and mapped. Euclidean distance between clinics and two primary roads that run through Lilongwe District were measured. A correlation was run to assess the relationship between area-level ANC HIV prevalence and clinic distance to the nearest primary road. ANC HIV prevalence ranged from 0% to 10.3%. Clinic to major road distance ranged from 0.1 to 35 km. Correlation results ( r= -0.622, p = 0.002) revealed a significant negative relationship between clinic distance to primary road and HIV prevalence, indicating that the farther the clinics stood from primary roads, the lower the reported antenatal HIV prevalence. Overall, the clinic catchments through which the major roads run reported higher ANC HIV prevalence. Antenatal HIV prevalence decreases as ANC distance from primary roads increases in Lilongwe, Malawi. As urbanization continues to grow in this region, road distance may serve as a good indicator of HIV burden and help to guide targeted prevention and treatment efforts.

Geospatial patterns of access to self-care resources for obesity among endometrial cancer survivors in a high poverty urban community.

OBJECTIVE: To examine endometrial cancer survivors' access to recommended obesity-related self-care resources. METHODS: Participants included women treated 2010-2015 for endometrial cancer at an academic medical center who lived in the surrounding 16 ZIP code area on Chicago's South Side. Demographic and health data were abstracted from medical records. A socioeconomic status (SES) score (SES-1 = low, SES-5 = high) was generated for each patient using census block group-level data. Self-care resources for exercise, healthy weight, and diet were obtained from a community resource census. Geospatial techniques assessed "walkable access" (~½-mile radius around a patient's home) to obesity-related resources. Multivariable logistic regression investigated associations between access to obesity-related resources and patient characteristics. RESULTS: Of 195 endometrial cancer survivors, 81% identified as Black/African American and 34% lived in an SES-1 census block. Two thirds (68%) had Stage I or II endometrial cancer. Nearly two thirds (62%) were obese (BMI ≥ 30 kg/m2). Obesity was inversely associated with SES (p = 0.05). Two thirds of survivors had access to at least one of all three recommended resource types. Access was lower in low SES regions and among Black/African American women. Lower SES was associated with lower odds of walkable access to recommended resources (AOR for access to two of each resource type 0.75, 95%CI 0.59, 0.97; AOR for access to three or more of each 0.44, 95%CI 0.32, 0.61). CONCLUSIONS: Obesity rates were higher and access to recommended resources was lower for Black/African American endometrial cancer survivors living in high poverty areas in Chicago.

Influences of heatwave, rainfall, and tree cover on cholera in Bangladesh.

Cholera is a severe diarrheal disease and remains a global threat to public health. Climate change and variability have the potential to increase the distribution and magnitude of cholera outbreaks. However, the effect of heatwave on the occurrence of cholera at individual level is still unclear. It is also unknown whether the local vegetation could potentially mitigate the effects of extreme heat on cholera outbreaks. In this study, we designed a case-crossover study to examine the association between the risk of cholera and heatwaves as well as the modification effects of rainfall and tree cover. The study was conducted in Matlab, a cholera endemic area of rural Bangladesh, where cholera case data were collected between January 1983 and April 2009. The association between the risk of cholera and heatwaves was examined using conditional logistic regression models. The results showed that there was a higher risk of cholera two days after heatwaves (OR = 1.53, 95% CI: 1.07-2.19) during wet days (rainfall > 0 mm). For households with less medium-dense tree cover, the heatwave after a 2-day lag was positively associated (OR = 1.80, 95% CI: 1.01-3.22) with the risk of cholera during wet days. However, for households with more medium-dense tree cover, the association between the risk of cholera and heatwave in 2-day lag was not significant. These findings suggest that heatwaves might promote the occurrence of cholera, while this relationship was modified by rainfall and tree cover. Further investigations are needed to explore major mechanisms underlying the association between heatwaves and cholera as well as the beneficial effects of tree cover.

The Role of Distance and Quality on Facility Selection for Maternal and Child Health Services in Urban Kenya.

Universal access to health care requires service availability and accessibility for those most in need of maternal and child health services. Women often bypass facilities closest to home due to poor quality. Few studies have directly linked individuals to facilities where they sought maternal and child health services and examined the role of distance and quality on this facility choice. Using endline data from a longitudinal survey from a sample of women in five cities in Kenya, we examine the role of distance and quality on facility selection for women using delivery, facility-based contraceptives, and child health services. A survey of public and private facilities offering reproductive health services was also conducted. Distances were measured between household cluster location and both the nearest facility and facility where women sought care. A quality index score representing facility infrastructure, staff, and supply characteristics was assigned to each facility. We use descriptive statistics to compare distance and quality between the nearest available facility and visited facility among women who bypassed the nearest facility. Facility distance and quality comparisons were also stratified by poverty status. Logistic regression models were used to measure associations between the quality and distance to the nearest facility and bypassing for each outcome. The majority of women bypassed the nearest facility regardless of service sought. Women bypassing for delivery traveled the furthest and had the fewest facility options near their residential cluster. Poor women bypassing for delivery traveled 4.5 km further than non-poor women. Among women who bypassed, two thirds seeking delivery and approximately 46% seeking facility-based contraception or child health services bypassed to a public hospital. Both poor and non-poor women bypassed to higher quality facilities. Our findings suggest that women in five cities in Kenya prefer public hospitals and are willing to travel further to obtain services at public hospitals, possibly related to free service availability. Over time, it will be important to examine service quality and availability in public sector facilities with reduced or eliminated user fees, and whether it lends itself to a continuum of care where women can visit one facility for multiple services reducing travel burden.

Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.

BACKGROUND: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. METHODS: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. RESULTS: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2 surveys (ORs: 0.63, 0.68, 1.03, 1.78) with lower risk of malaria infection. CONCLUSION: Local PfPR differed substantially between sites and age groups. In children 6 months-4 years old, a significant decrease in prevalence over the 3 years was observed in 4 out of the 8 study sites. Trial registration Clinical Trials.gov identifier: NCT01190202:NCT. GSK Study ID numbers: 114001.

Effects of community-level bed net coverage on malaria morbidity in Lilongwe, Malawi.

BACKGROUND: The protective effect of insecticide-treated bed nets against individual-level malaria transmission is well known, however community-level effects are less understood. Protective effects from community-level bed net use against malaria transmission have been observed in clinical trials, however, the relationship is less clear outside of a controlled research setting. The objective of this research was to investigate the effect of community-level bed net use against malaria transmission outside of a bed net clinical trial setting in Lilongwe, Malawi following national efforts to scale-up ownership of long-lasting, insecticide-treated bed nets. METHODS: An annual, cross-sectional, household-randomized, malaria transmission intensity survey was conducted in Lilongwe, Malawi (2011-2013). Health, demographic, and geographic-location data were collected. Participant blood samples were tested for Plasmodium falciparum presence. The percentage of people sleeping under a bed net within 400-m and 1-km radii of all participants was measured. Mixed effects logistic regression models were used to measure the relationship between malaria prevalence and surrounding bed net coverage. Each year, 800 people were enrolled (400 <5 years; 200 5-19 years; 200 ≥20 years; total n = 2400). RESULTS: From 2011 to 2013, malaria prevalence declined from 12.9 to 5.6%, while bed net use increased from 53.8 to 78.6%. For every 1% increase in community bed net coverage, malaria prevalence decreased among children under 5 years old [adjusted odds ratio: 0.98 (0.96, 1.00)]. Similar effects were observed in participants 5-19 years [unadjusted odds ratio: 0.98 (0.97, 1.00)]; the effect was attenuated after adjusting for individual-level bed net use. Community coverage was not associated with malaria prevalence among adults ≥20 years. Supplemental analyses identified more pronounced indirect protective effects from community-level bed net use against malaria transmission among children under 5 years who were sleeping under a bed net [adjusted odds ratio: 0.97 (0.94, 0.99)], compared to children who were not sleeping under a bed net [adjusted odds ratio: 0.99 (0.97, 1.01)]. CONCLUSIONS: Malawi's efforts to scale up ownership of long-lasting, insecticide-treated bed nets are effective in increasing reported use. Increased community-level bed net coverage appears to provide additional protection against malaria transmission beyond individual use in a real-world context.

CommunityRx: A Population Health Improvement Innovation That Connects Clinics To Communities.

The CommunityRx system, a population health innovation, combined an e-prescribing model and community engagement to strengthen links between clinics and community resources for basic, wellness, and disease self-management needs in Chicago. The components of CommunityRx were a youth workforce, whose members identified 19,589 public-serving entities in the 106-square-mile implementation region between 2012 and 2014; community health information specialists, who used the workforce's findings to generate an inventory of 14,914 health-promoting resources; and a health information technology (IT) platform that was integrated with three electronic health record systems at thirty-three clinical sites. By mapping thirty-seven prevalent social and medical conditions to community resources, CommunityRx generated 253,479 personalized HealtheRx prescriptions for more than 113,000 participants. Eighty-three percent of the recipients found the HealtheRx very useful, and 19 percent went to a place they learned about from the HealtheRx. All but one organization continued using the CommunityRx system after the study period ended. This study demonstrates the feasibility of using health IT and workforce innovation to bridge the gap between clinical and other health-promoting sectors.

Health-Specific Information and Communication Technology Use and Its Relationship to Obesity in High-Poverty, Urban Communities: Analysis of a Population-Based Biosocial Survey.

BACKGROUND: More than 35% of American adults are obese. For African American and Hispanic adults, as well as individuals residing in poorer or more racially segregated urban neighborhoods, the likelihood of obesity is even higher. Information and communication technologies (ICTs) may substitute for or complement community-based resources for weight management. However, little is currently known about health-specific ICT use among urban-dwelling people with obesity. OBJECTIVE: We describe health-specific ICT use and its relationship to measured obesity among adults in high-poverty urban communities. METHODS: Using data collected between November 2012 and July 2013 from a population-based probability sample of urban-dwelling African American and Hispanic adults residing on the South Side of Chicago, we described patterns of ICT use in relation to measured obesity defined by a body mass index (BMI) of ≥30 kg/m(2). Among those with BMI≥30 kg/m(2), we also assessed the association between health-specific ICT use and diagnosed versus undiagnosed obesity as well as differences in health-specific ICT use by self-reported comorbidities, including diabetes and hypertension. RESULTS: The survey response rate was 44.6% (267 completed surveys/598.4 eligible or likely eligible individuals); 53.2% were African American and 34.6% were Hispanic. More than 35% of the population reported an annual income of less than US $25,000. The population prevalence of measured obesity was 50.2%. People with measured obesity (BMI≥30 kg/m(2)) were more likely to report both general (81.5% vs 67.0%, P=.04) and health-specific (61.1% vs 41.2%, P=.01) ICT use. In contrast, among those with measured obesity, being told of this diagnosis by a physician was not associated with increased health-specific ICT use. People with measured obesity alone had higher rates of health-specific use than those with comorbid hypertension and/or diabetes diagnoses (77.1% vs 60.7% vs 47.4%, P=.04). CONCLUSIONS: In conclusion, ICT-based health resources may be particularly useful for people in high-poverty urban communities with isolated measured obesity, a population that is at high risk for poor health outcomes.

Distance to testing sites and its association with timing of HIV diagnosis.

Early HIV diagnosis enables prompt treatment initiation, thereby contributing to decreased morbidity, mortality, and transmission. We aimed to describe the association between distance from residence to testing sites and HIV disease stage at diagnosis. Using HIV surveillance data, we identified all new HIV diagnoses made at publicly funded testing sites in central North Carolina during 2005-2013. Early-stage HIV was defined as acute HIV (antibody-negative test with a positive HIV RNA) or recent HIV (normalized optical density <0.8 on the BED assay for non-AIDS cases); remaining diagnoses were considered post-early-stage HIV. Street distance between residence at diagnosis and (1) the closest testing site and (2) the diagnosis site was dichotomized at 5 miles. We fit log-binomial models using generalized estimating equations to estimate prevalence ratios (PR) and robust 95% confidence intervals (CI) for post-early-stage diagnoses by distance. Models were adjusted for race/ethnicity and testing period. Most of the 3028 new diagnoses were black (N = 2144; 70.8%), men who have sex with men (N = 1685; 55.7%), and post-early-stage HIV diagnoses (N = 2010; 66.4%). Overall, 1145 (37.8%) cases traveled <5 miles for a diagnosis. Among cases traveling ≥5 miles for a diagnosis, 1273 (67.6%) lived <5 miles from a different site. Residing ≥5 miles from a testing site was not associated with post-early-stage HIV (adjusted PR, 95% CI: 0.98, 0.92-1.04), but traveling ≥5 miles for a diagnosis was associated with higher post-early HIV prevalence (1.07, 1.02-1.13). Most of the elevated prevalence observed in cases traveling ≥5 miles for a diagnosis occurred among those living <5 miles from a different site (1.09, 1.03-1.16). Modest increases in post-early-stage HIV diagnosis were apparent among persons living near a site, but choosing to travel longer distances to test. Understanding reasons for increased travel distances could improve accessibility and acceptability of HIV services and increase early diagnosis rates.

Adult BMI and Access to Built Environment Resources in a High-Poverty, Urban Geography.

INTRODUCTION: The purpose of this study is to examine the relationship between BMI and access to built environment resources in a high-poverty, urban geography. METHODS: Participants (aged ≥35 years) were surveyed between November 2012 and July 2013 to examine access to common health-enabling resources (grocers, outpatient providers, pharmacies, places of worship, and physical activity resources). Survey data were linked to a contemporaneous census of built resources. Associations between BMI and access to resources (potential and realized) were examined using independent t-tests and multiple linear regression. Data analysis was conducted in 2014-2015. RESULTS: Median age was 53.8 years (N=267, 62% cooperation rate). Obesity (BMI ≥30) prevalence was 54.9%. BMI was not associated with potential access to resources located nearest to home. Nearly all participants (98.1%) bypassed at least one nearby resource type; half bypassed nearby grocers (realized access >1 mile from home). Bypassing grocers was associated with a higher BMI (p=0.03). Each additional mile traveled from home to a grocer was associated with a 0.9-higher BMI (95% CI=0.4, 1.3). Quality and affordability were common reasons for bypassing resources. CONCLUSIONS: Despite potential access to grocers in a high-poverty, urban region, half of participants bypassed nearby grocers to access food. Bypassing grocers was associated with a higher BMI.

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.

Implementation and Operational Research: Distance From Household to Clinic and Its Association With the Uptake of Prevention of Mother-to-Child HIV Transmission Regimens in Rural Zambia.

BACKGROUND: In rural settings, HIV-infected pregnant women often live significant distances from facilities that provide prevention of mother-to-child transmission (PMTCT) services. METHODS: We offered universal maternal combination antiretroviral regimens in 4 pilot sites in rural Zambia. To evaluate the impact of services, we conducted a household survey in communities surrounding each facility. We collected information about HIV status and antenatal service utilization from women who delivered in the past 2 years. Using household Global Positioning System coordinates collected in the survey, we measured Euclidean (i.e., straight line) distance between individual households and clinics. Multivariable logistic regression and predicted probabilities were used to determine associations between distance and uptake of PMTCT regimens. RESULTS: From March to December 2011, 390 HIV-infected mothers were surveyed across four communities. Of these, 254 (65%) had household geographical coordinates documented. One hundred sixty-eight women reported use of a PMTCT regimen during pregnancy including 102 who initiated a combination antiretroviral regimen. The probability of PMTCT regimen initiation was the highest within 1.9 km of the facility and gradually declined. Overall, 103 of 145 (71%) who lived within 1.9 km of the facility initiated PMTCT versus 65 of 109 (60%) who lived farther away. For every kilometer increase, the association with PMTCT regimen uptake (adjusted odds ratio: 0.90, 95% confidence interval: 0.82 to 0.99) and combination antiretroviral regimen uptake (adjusted odds ratio: 0.88, 95% confidence interval: 0.80 to 0.97) decreased. CONCLUSIONS: In this rural African setting, uptake of PMTCT regimens was influenced by distance to health facility. Program models that further decentralize care into remote communities are urgently needed.

Sampling at community level by using satellite imagery and geographical analysis.

PROBLEM: Traditional random sampling at community level requires a list of every individual household that can be randomly selected in the study community. The longitudinal demographic surveillance systems often used as sampling frames are difficult to create in many resource-poor settings. APPROACH: We used Google Earth imagery and geographical analysis software to develop a sampling frame. Every household structure within the catchment area was digitized and assigned coordinates. A random sample was then generated from the list of households. LOCAL SETTING: The sampling took place in Lilongwe, Malawi and formed a part of an investigation of the intensity of Plasmodium falciparum transmission in a multi-site Phase III trial of a candidate malaria vaccine. RELEVANT CHANGES: Creation of a complete list of household coordinates within the catchment area allowed us to generate a random sample representative of the population. Once the coordinates of the households in that sample had been entered into the hand-held receivers of a global positioning system device, the households could be accurately identified on the ground and approached. LESSONS LEARNT: In the development of a geographical sampling frame, the use of Google Earth satellite imagery and geographical software appeared to be an efficient alternative to the use of a demographic surveillance system. The use of a complete list of household coordinates reduced the time needed to locate households in the random sample. Our approach to generate a sampling frame is accurate, has utility beyond morbidity studies and appears to be a cost-effective option in resource-poor settings.