How to find discrete contact symmetries

This paper describes a new algorithm for determining all discrete contact symmetries of any differential equation whose Lie contact symmetries are known. The method is constructive and is easy to use. It is based upon the observation that the adjoint action of any contact symmetry is an automorphism of the Lie algebra of generators of Lie contact symmetries. Consequently, all contact symmetries satisfy various compatibility conditions. These conditions enable the discrete symmetries to be found systematically, with little effort

Internalized HIV Stigma Predicts Suboptimal Retention in Care among People Living with HIV in the United States

HIV-related stigma is a known barrier to retention in care. However, no large-scale, multi-site studies have prospectively evaluated the effect of internalized stigma on retention in care. The Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort study integrates medical record and survey data from people living with HIV (PLWH) seen in HIV primary care clinics across the United States, and assesses internalized stigma yearly using a validated 4-item Likert scale. We used multivariable logistic regression models to evaluate associations between mean internalized stigma and two prospective retention in care outcomes: keeping the next primary care appointment and keeping all scheduled primary care appointments in the 12 months following stigma assessment. From February 2016 to November 2017, 5968 PLWH completed the stigma assessment and had adequate follow-up time. Mean stigma was 1.9 (standard deviation 1.08). Increased mean stigma scores were associated with decreased odds of attending the next primary care appointment [adjusted odds ratio (aOR) = 0.93, 95% confidence interval (CI) 0.88-0.99, p = 0.02], and all primary care appointments in the subsequent 12 months (aOR = 0.94, 95% CI 0.89-0.99, p = 0.02). In both models, younger age and Black race were also independently associated with suboptimal appointment attendance. There was no support for interactions between internalized stigma and covariates. Internalized HIV stigma had an independent negative effect on the odds of subsequent appointment attendance. This study highlights the importance of identifying even low levels of internalized stigma. Interventions to address internalized HIV stigma are critical to supporting retention in care and improving clinical outcomes

The Human Immunodeficiency Virus (HIV) Index: Using a Patient-Reported Outcome on Engagement in HIV Care to Explain Suboptimal Retention in Care and Virologic Control

Background: We investigated the prospective association between a brief self-report measure of engagement in human immunodeficiency virus (HIV) care (the Index of Engagement in HIV Care; hereafter "Index") and suboptimal retention and viral suppression outcomes. Methods: The Centers for AIDS Research Network of Integrated Clinical Systems cohort study combines medical record data with patient-reported outcomes from 8 HIV clinics in the United States, which from April 2016 to March 2017 included the 10-item Index. Multivariable logistic regression was used to estimate the risk and odds ratios of mean Index scores on 2 outcomes in the subsequent year: (1) not keeping ≥75% of scheduled HIV care appointments; and (2) for those with viral suppression at Index assessment, having viral load >200 copies/mL on ≥1 measurement. We also used generalized linear mixed models (GLMMs) to estimate the risk and odds ratios of appointment nonattendance or unsuppressed viral load at any given observation. We generated receiver operating characteristic curves for the full models overlaid with the Index as a sole predictor. Results: The mean Index score was 4.5 (standard deviation, 0.6). Higher Index scores were associated with lower relative risk of suboptimal retention (n = 2576; logistic regression adjusted risk ratio [aRR], 0.88 [95% confidence interval,. 87-.88]; GLMM aRR, 0.85 [.83-.87]) and lack of sustained viral suppression (n = 2499; logistic regression aRR, 0.75 [.68-.83]; GLMM aRR, 0.74 [.68-.80]). The areas under the receiver operating characteristic curve for the full models were 0.69 (95% confidence interval,. 67-.71) for suboptimal retention and 0.76 (.72-.79) for lack of sustained viral suppression. Conclusions: Index scores are significantly associated with suboptimal retention and viral suppression outcomes

Detecting Disengagement from HIV Care before It Is Too Late: Development and Preliminary Validation of a Novel Index of Engagement in HIV Care

Background:Engagement in care is critical to achieving and sustaining optimal benefits of efficacious antiretroviral therapies for HIV infection. Current metrics of engagement in care, including problematic patterns of retention in care, adherence to treatment, and viral suppression, are often detected late in the disengagement process. We sought to develop and validate a patient-centered screener of engagement in care that can be used to identify deficits in patient perceptions of engagement before the development of poor outcomes, including loss to follow-up, treatment nonadherence, virologic failure, and the resulting increased likelihood of HIV-associated morbidity and mortality and onward transmission of HIV.Setting and Methods:Using input from patients, providers, and researchers through in-person focus groups and an online Delphi process, we developed a self-report measure of engagement in care that was validated with 3296 patients from 7 clinics across the United States.Results:Results supported a single dimension of engagement in care measured by 10 items. Lower scores on the HIV Index were related to higher depression and anxiety symptoms, greater use of alcohol and stimulants, and increased likelihood of reporting internalized HIV stigma. Higher Index scores were positively associated with self-report measures of antiretroviral therapy adherence, corroborative clinic records documenting appointment attendance, and increased likelihood of recent viral load suppression.Conclusions:The HIV Index offers promise as a patient-centered diagnostic and prognostic screener for engagement in care that can be used to trigger interventions to promote better clinical outcomes for persons living with HIV

Measuring engagement in HIV care: Measurement invariance in three racial/ethnic patient groups

Objective: The objective of the study was to evaluate a novel measure of HIV care engagement in a large sample of non-Latino White, Latino, and African American patients. The Index of Engagement in HIV care (the Index) measures the degree to which a patient feels engaged/disengaged from HIV care. However, its measurement invariance, or the degree to which observed scores can be meaningfully compared across racial/ethnic groups, has not been established. Methods: The 10-item Index is a self-report measure initially validated in the Center for AIDS Research Network of Integrated Systems cohort study. Using Center for AIDS Research Network of Integrated Systems survey data, Index scores were linked to patients' electronic medical records, which included viral load (VL) and appointment attendance data. We conducted measurement invariance analyses to test the Index's performance in the 3 racial/ethnic groups and its cross-sectional association with VL and retention in HIV care (2 primary outcomes). Results: A total of 3,127 patients completed the Index, which showed good reliability across the 3 groups (alphas >.84). Confirmatory factor analysis model fit statistics showed that the Index demonstrated configural, metric, and scalar invariance, supporting the conclusion that the Index is a single factor construct. Lastly, lower Index scores associated with a concurrent detectable VL and poor retention in HIV care for all 3 groups. Conclusion: Having demonstrated invariance, the Index scores can be used to compare engagement levels across non-Latino Whites, Latinos, and African Americans in HIV care settings. Improving HIV care retention requires tools that can accurately identify people struggling to stay engaged in HIV care, especially racial/ethnic minorities

Cumulative Human Immunodeficiency Viremia, Antiretroviral Therapy, and Incident Myocardial Infarction

Background: People living with HIV are at risk of increased myocardial infarction (MI). Cumulative HIV viral load (VL) has been proposed as a better measure of HIV inflammation than other measures of VL, like baseline VL, but its associations with MI are not known. Methods: The multisite Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort includes clinical data and centrally adjudicated MI with distinction between atheroembolic MI (type 1) and MI related to supply-demand mismatch (type 2). We examined CNICS participants who were not on antiretroviral therapy (ART) at enrollment. Cumulative VL (copy-days of virus) from 6 months after enrollment was estimated with a time-weighted sum using the trapezoidal rule. We modeled associations of cumulative and baseline VL with MI by type using marginal structural Cox models. We contrasted the 75% percentile of the VL distribution with the 25% percentile. Results: Among 11,324 participants, 218 MIs occurred between 1996 and 2016. Higher cumulative VL was associated with risk of all MI (hazard ratio [HR] = 1.72; 95% confidence interval [CI] = 1.26, 2.36), type 1 MI (HR = 1.23; 95% CI = 0.78, 1.96), and type 2 MI (HR = 2.52; 95% CI = 1.74, 3.66). While off ART, cumulative VL had a stronger association with type 1 MI (HR = 2.13; 95% CI = 1.15, 3.94) than type 2 MI (HR = 1.25; 95% CI = 0.70, 2.25). Baseline VL was associated with all MI (HR = 1.60; 95% CI = 1.28, 2.01), type 1 MI (HR = 1.73; 95% CI = 1.26, 2.38), and type 2 MI (HR = 1.51; 95% CI = 1.10, 2.08). Conclusions: Higher cumulative and baseline VL is associated with all MI, with a particularly strong association between cumulative VL and type 2 MI

HIV viral suppression trends over time among HIV-infected patients receiving care in the United States, 1997 to 2015 a cohort study

Background: Because HIV viral suppression is essential for optimal outcomes and prevention efforts, understanding trends and predictors is imperative to inform public health policy. Objective: To evaluate viral suppression trends in people living with HIV (PLWH), including the relationship of associated factors, such as demographic characteristics and integrase strand transfer inhibitor (ISTI) use. Design: Longitudinal observational cohort study. Setting: 8 HIV clinics across the United States. Participants: PLWH receiving clinical care. Measurements: To understand trends in viral suppression (≤400 copies/mL), annual viral suppression rates from 1997 to 2015 were determined. Analyses were repeated with tests limited to 1 random test per person per year and using inverse probability of censoring weights to address loss to follow-up. Joint longitudinal and survival models and linear mixed models of PLWH receiving antiretroviral therapy (ART) were used to examine associations between viral suppression or continuous viral load (VL) levels and demographic factors, substance use, adherence, and ISTI use. Results: Viral suppression increased from 32% in 1997 to 86% in 2015 on the basis of all tests among 31 930 PLWH. In adjusted analyses, being older (odds ratio [OR], 0.76 per decade [95% CI, 0.74 to 0.78]) and using an ISTI-based regimen (OR, 0.54 [CI, 0.51 to 0.57]) were associated with lower odds of having a detectable VL, and black race was associated with higher odds (OR, 1.68 [CI, 1.57 to 1.80]) (P < 0.001 for each). Similar patterns were seen with continuous VL levels; when analyses were limited to 2010 to 2015; and with adjustment for adherence, substance use, or depression. Limitation: Results are limited to PLWH receiving clinical care. Conclusion: HIV viral suppression rates have improved dramatically across the United States, which is likely partially attributable to improved ART, including ISTI-based regimens. However, disparities among younger and black PLWH merit attention

Reduced use of illicit substances, even without abstinence, is associated with improved depressive symptoms among people living with HIV

Purpose: Substance use is linked with poor outcomes among people living with HIV (PLWH) and is associated with mental health disorders. This analysis examines the impact of decreasing substance use, even without abstinence, on depressive symptoms among PLWH. Methods: Data are from PLWH enrolled in the Centers for AIDS Research Network of Integrated Clinical Sites cohort. Participants completed longitudinal assessments of substance use (modified ASSIST) and depressive symptoms (PHQ-9). Changes in substance use frequency were categorized as abstinence, reduced use, and nondecreasing use. Adjusted linear mixed models with time-updated change in substance use frequency and depressive symptom scores were used to examine associations between changes in the use of individual substances and depressive symptoms. Analyses were repeated using joint longitudinal survival models to examine associations with a high (PHQ-9 ≥10) score. Results: Among 9905 PLWH, 728 used cocaine/crack, 1016 used amphetamine-type substances (ATS), 290 used illicit opiates, and 3277 used marijuana at baseline. Changes in ATS use were associated with the greatest improvements in depressive symptoms: stopping ATS led to a mean decrease of PHQ-9 by 2.2 points (95% CI: 1.8 to 2.7) and a 61% lower odds of PHQ-9 score ≥10 (95% CI: 0.30 to 0.52), and decreasing ATS use led to a mean decrease of 1.7 points (95% CI: 1.2 to 2.3) and a 62% lower odds of PHQ-9 score ≥10 (95% CI: 0.25 to 0.56). Stopping and reducing marijuana and stopping cocaine/crack use were also associated with improvement in depressive symptoms. Conclusions: We demonstrated that both substance use reduction and abstinence are associated with improvements in depressive symptoms over time