Generalized Jacobi identities and ball-box theorem for horizontally regular vector fields

We consider a family of vector fields and we assume a horizontal regularity on their derivatives. We discuss the notion of commutator showing that different definitions agree. We apply our results to the proof of a ball-box theorem and Poincar\'e inequality for nonsmooth H\"ormander vector fields.Comment: arXiv admin note: material from arXiv:1106.2410v1, now three separate articles arXiv:1106.2410v2, arXiv:1201.5228, arXiv:1201.520

The effect of unstable housing on HIV treatment biomarkers: An instrumental variables approach

Unstable housing, including homelessness, is a public policy concern for all populations, and more critically for people with a serious health condition such as HIV. We measure the effect of unstable housing on HIV treatment biomarkers: viral suppression (viral load < 200 HIV RNA copies per ml) and adequate CD4+ T-cell count (CD4>350 cells per μl). We use panel data (1995–2015) from 3082 participants of the Women's Interagency HIV Study (WIHS) sites in Bronx and Brooklyn (NY), Chicago (IL), Los Angeles and San Francisco (CA), and Washington (DC). The instrumental variable (IV) measures allocations for the Housing Opportunities for People with AIDS (HOPWA) per person newly infected with HIV, and it represents actual availability of housing assistance for HIV-positive persons at the metropolitan area level. Using an extended probit model with the IV, we find that unstable housing reduces the likelihood of viral suppression by 51 percentage points, and decreases the probability of having adequate CD4 cell count by 53 percentage points. The endogeneity-corrected results are larger than naïve probits, which show decreases of 8.1 and 7.8 percentage points, respectively. The hypothesized pathways for the effect are: decreased use of mental healthcare/counseling, any healthcare, and less continuity of care. Increasing efforts to improve housing assistance, including HOPWA, and other interventions to make housing more affordable for low-income populations, and HIV-positive populations in particular, may be warranted not only for the benefits of stable housing, but also to improve HIV-related biomarkers

The effects of viral load burden on pregnancy loss among HIV-infected women in the United States

Background. To evaluate the effects of HIV viral load, measured cross-sectionally and cumulatively, on the risk of miscarriage or stillbirth (pregnancy loss) among HIV-infected women enrolled in the Women's Interagency HIV Study between 1994 and 2013. Methods. We assessed three exposures: most recent viral load measure before the pregnancy ended, log10 copy-years viremia from initiation of antiretroviral therapy (ART) to conception, and log10 copy-years viremia in the two years before conception. Results. The risk of pregnancy loss for those with log10 viral load >4.00 before pregnancy ended was 1.59 (95% confidence interval (CI): 0.99, 2.56) times as high as the risk for women whose log10 viral load was ≤1.60. There was not a meaningful impact of log10 copy-years viremia since ART or log10 copy-years viremia in the two years before conception on pregnancy loss (adjusted risk ratios (aRRs): 0.80 (95% CI: 0.69, 0.92) and 1.00 (95% CI: 0.90, 1.11), resp.). Conclusions. Cumulative viral load burden does not appear to be an informative measure for pregnancy loss risk, but the extent of HIV replication during pregnancy, as represented by plasma HIV RNA viral load, predicted loss versus live birth in this ethnically diverse cohort of HIV-infected US women

Impacts of Medicaid Expansion on Health Insurance and Coverage Transitions among Women with or at Risk for HIV in the United States

Background: As employment, financial status, and residential location change, people can gain, lose, or switch health insurance coverage, which may affect care access and health. Among Women's Interagency HIV Study participants with HIV and participants at risk for HIV attending semiannual visits at 10 U.S. sites, we examined whether the prevalence of coverage types and rates of coverage changes differed by HIV status and Medicaid expansion in their states of residence. Methods: Geocoded addresses were merged with dates of Medicaid expansion to indicate, at each visit, whether women lived in Medicaid expansion states. Age-adjusted rate ratios (RRs) and rate differences of self-reported insurance changes were estimated by Poisson regression. Results: From 2008 to 2018, 3,341 women (67% Black, 71% with HIV) contributed 43,329 visits at aged less than 65 years (27% under Medicaid expansion). Women with and women without HIV differed in their proportions of visits at which no coverage (14% vs. 19%; p < .001) and Medicaid enrollment (61% vs. 51%; p < .001) were reported. Women in Medicaid expansion states reported no coverage and Medicaid enrollment at 4% and 69% of visits, respectively, compared with 20% and 53% of visits for those in nonexpansion states. Women with HIV had a lower rate of losing coverage than those without HIV (RR, 0.81; 95% confidence interval [CI], 0.70 to 0.95). Compared with nonexpansion, Medicaid expansion was associated with lower coverage loss (RR, 0.62; 95% CI, 0.53 to 0.72) and greater coverage gain (RR, 2.32; 95% CI, 2.02 to 2.67), with no differences by HIV status. Conclusions: Both women with HIV and women at high risk for HIV in Medicaid expansion states had lower coverage loss and greater coverage gain; therefore, Medicaid expansion throughout the United States should be expected to stabilize insurance for women and improve downstream health outcomes

Human Immunodeficiency Virus Is Associated with Elevated FibroScan-Aspartate Aminotransferase (FAST) Score

Background: Whether human immunodeficiency virus (HIV) infection is associated with the development of nonalcoholic steatohepatitis (NASH) remains unclear. The FibroScan-aspartate aminotransferase (FAST) score was developed to identify patients who have histologic NASH with high nonalcoholic fatty liver disease activity score (NAS ≥4) and significant liver fibrosis (≥F2), which has been associated with higher risk of end-stage liver disease. We examined whether HIV infection is associated with elevated FAST score in a large United States (US) cohort. Methods: Vibration-controlled transient elastography was performed in 1309 women without history of chronic viral hepatitis enrolled from 10 US sites: 928 women with HIV (WWH) and 381 women without HIV (WWOH). We used multivariable logistic regression to evaluate associations of HIV, demographic, lifestyle, and metabolic factors with an elevated (>0.35) FAST score. Results: Median age of WWH and WWOH was 51 years and 48 years, respectively. Most (90%) WWH were on antiretroviral therapy and 72% had undetectable HIV RNA. Prevalence of elevated FAST score was higher among WWH compared to WWOH (6.3% vs 1.8%, respectively; P =. 001). On multivariable analysis, HIV infection was associated with 3.7-fold higher odds of elevated FAST score (P =. 002), and greater waist circumference (per 10 cm) was associated with 1.7-fold higher odds (P <. 001). In analysis limited to WWH, undetectable HIV RNA and current protease inhibitor use were independently associated with lower odds of elevated FAST score. Conclusions: Our findings suggest that HIV is an independent risk factor for NASH with significant activity and fibrosis. Studies validating FAST score in persons with HIV are warranted

Associations between Medicare Part D and Out-of-Pocket Spending, HIV Viral Load, Adherence, and ADAP Use in Dual Eligibles with HIV

Background: The implementation of Medicare part D on January 1, 2006 required all adults who were dually enrolled in Medicaid and Medicare (dual eligibles) to transition prescription drug coverage from Medicaid to Medicare part D. Changes in payment systems and utilization management along with the loss of Medicaid protections had the potential to disrupt medication access, with uncertain consequences for dual eligibles with human immunodeficiency virus (HIV) who rely on consistent prescription coverage to suppress their HIV viral load (VL). Objective: To estimate the effect of Medicare part D on self-reported out-of-pocket prescription drug spending, AIDS Drug Assistance Program (ADAP) use, antiretroviral adherence, and HIV VL suppression among dual eligibles with HIV. Methods: Using 2003–2008 data from the Women’s Interagency HIV Study, we created a propensity score–matched cohort and used a difference-in-differences approach to compare dual eligibles’ outcomes pre-Medicare and post-Medicare part D to those enrolled in Medicaid alone. Results: Transition to Medicare part D was associated with a sharp increase in the proportion of dual eligibles with self-reported out-of-pocket prescription drug costs, followed by an increase in ADAP use. Despite the increase in out-of-pocket costs, both adherence and HIV VL suppression remained stable. Conclusions: Medicare part D was associated with increased out-of-pocket spending, although the increased spending did not seem to compromise antiretroviral therapy adherence or HIV VL suppression. It is possible that increased ADAP use mitigated the increase in out-of-pocket spending, suggesting successful coordination between Medicare part D and ADAP as well as the vital role of ADAP during insurance transitions

The Longitudinal Association between Social Support on HIV Medication Adherence and Healthcare Utilization in the Women’s Interagency HIV Study

Social support is associated with HIV-related health outcomes. However, few studies have explored this longitudinally. We assessed psychometric properties of the Medical Outcomes Study’s Social Support Survey among women in the Women’s Interagency HIV Study, and explored the longitudinal effects of social support on HIV medication adherence (HIV-positive women) and healthcare utilization (HIV-positive and negative women). The 15 questions loaded into two factors, with Cronbach’s Alpha > 0.95. Over 3 years, perceived emotional support was associated with optimal medication adherence (OR 1.19, 95% CI 1.10–1.28) and healthcare utilization (OR 1.16, 95% CI 1.05–1.27), and tangible social support with adherence only (OR 1.18, 95% CI 1.08–1.27) when controlling for covariates, including core sociodemographic characteristics and depressive symptoms. Interventions to further understand the drivers of sub-types of social support as well as enhance sustained social support may assist with optimizing care of women with and at risk for HIV

Healthcare Empowerment and HIV Viral Control: Mediating Roles of Adherence and Retention in Care

Introduction: This study assessed longitudinal relationships between patient healthcare empowerment, engagement in care, and viral control in the Women's Interagency HIV Study, a prospective cohort study of U.S. women living with HIV. Methods: From April 2014 to March 2016, four consecutive 6-month visits were analyzed among 973 women to assess the impact of Time 1 healthcare empowerment variables (Tolerance for Uncertainty and the state of Informed Collaboration Committed Engagement) on Time 2 reports of ≥95% HIV medication adherence and not missing an HIV primary care appointment since last visit; and on HIV RNA viral control across Times 3 and 4, controlling for illicit drug use, heavy drinking, depression symptoms, age, and income. Data were analyzed in 2017. Results: Adherence of ≥95% was reported by 83% of women, 90% reported not missing an appointment since the last study visit, and 80% were categorized as having viral control. Logistic regression analyses revealed a significant association between the Informed Collaboration Committed Engagement subscale and viral control, controlling for model covariates (AOR=1.08, p=0.04), but not for the Tolerance for Uncertainty subscale and viral control (AOR=0.99, p=0.68). In separate mediation analyses, the indirect effect of Informed Collaboration Committed Engagement on viral control through adherence (β=0.04, SE=0.02, 95% CI=0.02, 0.08), and the indirect effect of Informed Collaboration Committed Engagement on viral control through retention (β=0.01, SE=0.008, 95% CI=0.001, 0.030) were significant. Mediation analyses with Tolerance for Uncertainty as the predictor did not yield significant indirect effects. Conclusions: The Informed Collaboration Committed Engagement healthcare empowerment component is a promising pathway through which to promote engagement in care among women living with HIV

Trends in Bacterial Vaginosis Prevalence in a Cohort of U.S. Women with and at Risk for HIV

Background: Women with human immunodeficiency virus (HIV) often have bacterial vaginosis (BV). The goal of this analysis was to assess how BV prevalence changed over time and across U.S. regions in enrollment cohorts of the Women's Interagency HIV Study. Methods: In a multisite study, BV was diagnosed retrospectively when pH and two of three other Amsel criteria were met. Prevalence was determined across four recruitment waves: 1994-5, 2001-2, 2011-2, and 2013-5. Generalized estimating equation multivariable logistic regression models assessed changes in visit prevalence across waves after controlling for HIV disease severity and other risks. Results: Among 4,790 women (3,539 with HIV and 1,251 without HIV), BV was diagnosed at 7,870 (12%) of 64,444 visits. Baseline prevalence across enrollment waves was 15.0%-19.2%, but declined in all cohorts, with prevalence in the initial cohort falling to 3.9% in the 1994-5 cohort after up to 21 years of continuous observation. Prevalence varied within U.S. regions. HIV status was not associated with BV. Conclusion: BV prevalence decreased with time in study. Prevalence varied across sites, but was not uniformly increased or decreased in any U.S. region. Clinical Trials.gov identifier: NCT00000797

Health Disparities and the Digital Divide: The Relationship between Communication Inequalities and Quality of Life among Women in a Nationwide Prospective Cohort Study in the United States

Background: Communication inequalities can affect health-seeking behaviors yet the relationship between Internet use and overall health is inconclusive. Communication-related inequalities vary by race/ethnicity and SES but existing research primarily includes middle-class Whites. We therefore examined the relationship between communication-related inequalities—measured by daily Internet use—and health-related quality of life (QOL) using a nationwide prospective cohort study in the United States that consists of primarily low income, minority women. Methods: We examined Internet use and QOL among participants in the Women’s Interagency HIV Study. Data collection occurred from October 2014-September 2015 in Chicago, New York, Washington DC, San Francisco, Atlanta, Chapel Hill, Birmingham/Jackson and Miami. We used multi-variable analyses to examine the relationship between daily Internet use and QOL. Results: The sample of 1,915 women was 73% African American and 15% Hispanic; 53% reported an annual income of ≤$12,000. Women with daily Internet use reported a higher QOL at six months, as did women with at least a high school diploma, income >$12,000, and non-White race; older women and those with reported drug use, depressive symptoms and loneliness had lower QOL. Conclusions: Overcoming communication inequalities may be one pathway through which to improve overall QOL and address public health priorities. Reducing communication-related inequalities—e.g, by providing reliable Internet access—and thus improving access to health promoting information, may lead to improved health outcomes