Spatial accessibility to HIV testing, treatment, and prevention services in Illinois and Chicago, USA.

Accomplishing the goals outlined in "Ending the HIV (Human Immunodeficiency Virus) Epidemic: A Plan for America Initiative" will require properly estimating and increasing access to HIV testing, treatment, and prevention services. In this research, a computational spatial method for estimating access was applied to measure distance to services from all points of a city or state while considering the size of the population in need for services as well as both driving and public transportation. Specifically, this study employed the enhanced two-step floating catchment area (E2SFCA) method to measure spatial accessibility to HIV testing, treatment (i.e., Ryan White HIV/AIDS program), and prevention (i.e., Pre-Exposure Prophylaxis [PrEP]) services. The method considered the spatial location of MSM (Men Who have Sex with Men), PLWH (People Living with HIV), and the general adult population 15-64 depending on what HIV services the U.S. Centers for Disease Control (CDC) recommends for each group. The study delineated service- and population-specific accessibility maps, demonstrating the method's utility by analyzing data corresponding to the city of Chicago and the state of Illinois. Findings indicated health disparities in the south and the northwest of Chicago and particular areas in Illinois, as well as unique health disparities for public transportation compared to driving. The methodology details and computer code are shared for use in research and public policy.

State health policies and interest in PrEP: evidence from Google Trends.

This study investigated the association between interest in Pre-exposure Prophylaxis (PrEP) in the US using Google Health Trends as a source of big data and state policy variables of Medicaid expansions under the Affordable Care Act (ACA) and initiation of PrEP Assistance Programs (PrEP-AP). As of December 2019, thirty-three states and the District of Columbia have accepted federal Medicaid funding provided through the ACA to expand eligibility to low-income adults. Among these expansion states, eight states also implemented PrEP-AP, a program that finances PrEP. A difference-in-differences approach estimated how changes in Google search for PrEP before and after the expansion differed across expansion and non-expansion states. Analyses also gauged whether the magnitude of the correlation between Medicaid expansions and Google searches was higher in states that also initiated PrEP-AP. Findings indicated that the Medicaid expansions were associated with a higher share of Google searches for PrEP keywords (ß=1.536, S.E. =.36, p<.001). Moreover, the magnitude of correlation for some keywords was higher in states that also implemented PrEP-APs.

Are spatial models advantageous for predicting county-level HIV epidemiology across the United States?

Predicting human immunodeficiency virus (HIV) epidemiology is vital for achieving public health milestones. Incorporating spatial dependence when data varies by region can often provide better prediction results, at the cost of computational efficiency. However, with the growing number of covariates available that capture the data variability, the benefit of a spatial model could be less crucial. We investigate this conjecture by considering both non-spatial and spatial models for county-level HIV prediction over the US. Due to many counties with zero HIV incidences, we utilize a two-part model, with one part estimating the probability of positive HIV rates and the other estimating HIV rates of counties not classified as zero. Based on our data, the compound of logistic regression and a generalized estimating equation outperforms the candidate models in making predictions. The results suggest that considering spatial correlation for our data is not necessarily advantageous when the purpose is making predictions.

The demand for preventive and restorative dental services among older adults.

Many older Americans have poor access to dental care, resulting in a high prevalence of oral health problems. Because traditional Medicare does not include dental care benefits, only older Americans who are employed, have post-retirement dental benefits or spousal coverage, or enroll in certain Medicare Advantage plans are able to obtain dental care coverage. We seek to determine the extent to which poor access to dental insurance and high out-of-pocket costs affect dental service use by the elderly. Using the 2007-2015 Medical Expenditure Panel Survey and supplemental data on dental care prices, we estimate a demand system for preventive dental services and basic and major restorative services. Selection into dental and medical insurance is addressed using a correlated random effects panel data specification. Consistent with prior studies of the nonelderly population, dental service use was not sensitive to out-of-pocket prices. However, private dental insurance increased preventive service use by 25%, and dental coverage through Medicaid increased basic and major service use by 23% and 36%, respectively. The use of services was more responsive to dental insurance for women than men. These estimates suggest that a Medicare dental benefit could significantly increase dental service use by older Americans.