Identifying the appropriate comparison group for HIV-infected individuals

Correlates of Breakthrough SARS-CoV-2 Infections in People with HIV: Results from the CIHR CTN 328 Study

COVID-19 breakthrough infection (BTI) can occur despite vaccination. Using a multi-centre, prospective, observational Canadian cohort of people with HIV (PWH) receiving ≥2 COVID-19 vaccines, we compared the SARS-CoV-2 spike (S) and receptor-binding domain (RBD)-specific IgG levels 3 and 6 months post second dose, as well as 1 month post third dose, in PWH with and without BTI. BTI was defined as positivity based on self-report measures (data up to last study visit) or IgG data (up to 1 month post dose 3). The self-report measures were based on their symptoms and either a positive PCR or rapid antigen test. The analysis was restricted to persons without previous COVID-19 infection. Persons without BTI remained COVID-19-naïve until ≥3 months following the third dose. Of 289 participants, 92 developed BTI (31.5 infections per 100 person-years). The median days between last vaccination and BTI was 128 (IQR 67, 176), with the most cases occurring between the third and fourth dose (n = 59), corresponding to the Omicron wave. In analyses adjusted for age, sex, race, multimorbidity, hypertension, chronic kidney disease, diabetes and obesity, a lower IgG S/RBD (log10 BAU/mL) at 1 month post dose 3 was significantly associated with BTI, suggesting that a lower IgG level at this time point may predict BTI in this cohort of PWH.

Predictive Risk Model for Serious Falls Among Older Persons Living With HIV

BACKGROUND

Older (older than 50 years) persons living with HIV (PWH) are at elevated risk for falls. We explored how well our algorithm for predicting falls in a general population of middle-aged Veterans (age 45-65 years) worked among older PWH who use antiretroviral therapy (ART) and whether model fit improved with inclusion of specific ART classes.

METHODS

This analysis included 304,951 six-month person-intervals over a 15-year period (2001-2015) contributed by 26,373 older PWH from the Veterans Aging Cohort Study who were taking ART. Serious falls (those falls warranting a visit to a health care provider) were identified by external cause of injury codes and a machine-learning algorithm applied to radiology reports. Potential predictors included a fall within the past 12 months, demographics, body mass index, Veterans Aging Cohort Study Index 2.0 score, substance use, and measures of multimorbidity and polypharmacy. We assessed discrimination and calibration from application of the original coefficients (model derived from middle-aged Veterans) to older PWH and then reassessed by refitting the model using multivariable logistic regression with generalized estimating equations. We also explored whether model performance improved with indicators of ART classes.

RESULTS

With application of the original coefficients, discrimination was good (C-statistic 0.725; 95% CI: 0.719 to 0.730) but calibration was poor. After refitting the model, both discrimination (C-statistic 0.732; 95% CI: 0.727 to 0.734) and calibration were good. Including ART classes did not improve model performance.

CONCLUSIONS

After refitting their coefficients, the same variables predicted risk of serious falls among older PWH nearly and they had among middle-aged Veterans.

CTN 328: immunogenicity outcomes in people living with HIV in Canada following vaccination for COVID-19 (HIV-COV): protocol for an observational cohort study

INTRODUCTION

Most existing vaccines require higher or additional doses or adjuvants to provide similar protection for people living with HIV (PLWH) compared with HIV-uninfected individuals. Additional research is necessary to inform COVID-19 vaccine use in PLWH.

METHODS AND ANALYSIS

This multicentred observational Canadian cohort study will enrol 400 PLWH aged >16 years from Montreal, Ottawa, Toronto and Vancouver. Subpopulations of PLWH of interest will include individuals: (1) >55 years of age; (2) with CD4 counts <350 cells/mm3; (3) with multimorbidity (>2 comorbidities) and (4) 'stable' or 'reference' PLWH (CD4 T cells >350 cells/mm3, suppressed viral load for >6 months and <1 comorbidity). Data for 1000 HIV-negative controls will be obtained via a parallel cohort study (Stop the Spread Ottawa), using similar time points and methods. Participants receiving >1 COVID-19 vaccine will attend five visits: prevaccination; 1 month following the first vaccine dose; and at 3, 6 and 12 months following the second vaccine dose. The primary end point will be the percentage of PLWH with COVID-19-specific antibodies at 6 months following the second vaccine dose. Humoral and cell-mediated immune responses, and the interplay between T cell phenotypes and inflammatory markers, will be described. Regression techniques will be used to compare COVID-19-specific immune responses to determine whether there are differences between the 'unstable' PLWH group (CD4 <350 cells/mm3), the stable PLWH cohort and the HIV-negative controls, adjusting for factors believed to be associated with immune response. Unadjusted analyses will reveal whether there are differences in driving factors associated with group membership.

ETHICS AND DISSEMINATION

Research ethics boards at all participating institutions have granted ethics approval for this study. Written informed consent will be obtained from all study participants prior to enrolment. The findings will inform the design of future COVID-19 clinical trials, dosing strategies aimed to improve immune responses and guideline development for PLWH.

TRIAL REGISTRATION NUMBER

NCT04894448.

Mortality Among Persons Entering HIV Care Compared With the General U.S. Population : An Observational Study

BACKGROUND

Understanding advances in the care and treatment of adults with HIV as well as remaining gaps requires comparing differences in mortality between persons entering care for HIV and the general population.

OBJECTIVE

To assess the extent to which mortality among persons entering HIV care in the United States is elevated over mortality among matched persons in the general U.S. population and trends in this difference over time.

DESIGN

Observational cohort study.

SETTING

Thirteen sites from the U.S. North American AIDS Cohort Collaboration on Research and Design.

PARTICIPANTS

82 766 adults entering HIV clinical care between 1999 and 2017 and a subset of the U.S. population matched on calendar time, age, sex, race/ethnicity, and county using U.S. mortality and population data compiled by the National Center for Health Statistics.

MEASUREMENTS

Five-year all-cause mortality, estimated using the Kaplan-Meier estimator of the survival function.

RESULTS

Overall 5-year mortality among persons entering HIV care was 10.6%, and mortality among the matched U.S. population was 2.9%, for a difference of 7.7 (95% CI, 7.4 to 7.9) percentage points. This difference decreased over time, from 11.1 percentage points among those entering care between 1999 and 2004 to 2.7 percentage points among those entering care between 2011 and 2017.

LIMITATION

Matching on available covariates may have failed to account for differences in mortality that were due to sociodemographic factors rather than consequences of HIV infection and other modifiable factors.

CONCLUSION

Mortality among persons entering HIV care decreased dramatically between 1999 and 2017, although those entering care remained at modestly higher risk for death in the years after starting care than comparable persons in the general U.S. population.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Disparities in multimorbidity and mortality among people living with and without HIV across British Columbia's health regions: a population-based cohort study

OBJECTIVES

Longer survival has increased the likelihood of antiretroviral-treated people living with HIV (PLWH) developing age-associated comorbidities. We compared the burden of multimorbidity and all-cause mortality across HIV status in British Columbia (BC), and assessed the longitudinal effect of multimorbidity on all-cause mortality among PLWH.

METHODS

Antiretroviral-treated PLWH aged ≥19 years and 1:4 age-sex-matched HIV-negative individuals from a population-based cohort were followed for ≥1 year during 2001-2012. Diagnoses of seven age-associated comorbidities were identified from provincial administrative databases and grouped into 0, 1, 2, and ≥3 comorbidities. Multimorbidity prevalence and age-standardized mortality rates (ASMRs) in both populations were stratified by BC's health regions. Marginal structural models were used to estimate the effect of multimorbidity on mortality among PLWH, adjusted for time-varying confounders affected by prior multimorbidity.

RESULTS

Among 8031 PLWH and 32,124 HIV-negative individuals, 25% versus 11% developed multimorbidity, and 23.53 deaths/1000 person-years (95% confidence interval [95% CI]: 22.02-25.13) versus 3.04 (2.81-3.29) were observed, respectively. PLWH in Northern region had the highest ASMR, but those in South Vancouver Island experienced the greatest difference in mortality compared with HIV-negative individuals. Among PLWH, compared with those with zero comorbidities, adjusted hazard ratios for those with 1, 2, and ≥3 comorbidities were 3.36 (95% CI: 2.86-3.95), 6.92 (5.75-8.33), and 12.87 (10.45-15.85), respectively.

CONCLUSION

PLWH across BC's health regions experience excess multimorbidity and associated mortality. We highlight health disparities which are key when planning the distribution of healthcare resources across BC, and provide evidence for improved HIV care models integrating prevention and management of chronic diseases.

Negative Consequences of Alcohol Use among People Living with HIV

Introduction: Among people living with HIV (PLWH), alcohol use can have negative impacts beyond HIV-related outcomes. The objectives of this study are to identify the most common alcohol-related consequences among PLWH in Florida and describe factors associated with experiencing more alcohol-related consequences. Methods: Data were collected from PLWH in the Florida Cohort study who drank at least monthly in the past year (n=397). Self-reported consequences were assessed by the 15-item Short Inventory of Problems Revised (SIP-2R). Nonparametric tests and a generalized estimating equation model with inverse probability of exposure weighting were used to evaluate associations between the total SIP-2R score and socio-demographics, mental health, and substance use while controlling for alcohol use. Results: Over half (56%) endorsed at least one consequence and 29% endorsed 5 or more consequences. The most common consequences were doing something they regretted and taking foolish risks (both endorsed by 37% of participants), both in the impulse control domain. After controlling for alcohol use and other covariates, homelessness and injection drug use remained significantly associated with greater SIP-2R scores. Conclusion: PLWH who are experiencing homelessness or injecting drugs could benefit from receiving additional screening for alcohol-related consequences if they report any alcohol use.

Accounting for HIV Health Disparities: Risk and Protective Factors Among Older Gay and Bisexual Men

Objective: This study examines whether disparities exist in poor health and depressive symptomatology among older gay/bisexual men (50+) with (n = 371) and without (n = 973) HIV. If so, what risk/promoting factors account for those disparities? Method: These cross-sectional analyses used 2014 data from the Aging With Pride: National Health, Aging, and Sexuality/Gender Study. Results: Those with HIV reported poorer health and more depressive symptomatology accounted for by lower income, resilience and social support, and more lifetime victimization. Poorer health among those with HIV was associated with more chronic conditions. Higher depressive symptomatology was associated with diagnosed anxiety and drug addiction. Community engagement reduced disparities in poor health and depression. Implications: Older gay/bisexual men living with HIV infection are at greater risk for physical and mental health issues. Assessments should be conducted with attention to these risk factors. Interventions for improving social support, resilience, and community engagement are warranted.

The Changing Science of HIV Epidemiology in the United States

In 1984, a large prospective study of the natural history of human immunodeficiency virus (HIV) infection, the Multicenter AIDS Cohort Study (MACS), was established; 10 years later, the Women's Interagency HIV Study (WIHS) was launched. Motivated by the merger and redesign of these long-standing HIV cohort studies in 2019, we review ways in which HIV epidemiology in the United States has transformed over the lives of these studies and how this evolution has influenced planning for enrollment and follow-up. We highlight changes that have occurred in the 3 major domains that are central to epidemiologic science: changes to key populations at highest risk for HIV, refinements in measurement and shifts in the outcomes of interest, and a new era in the tools and approaches that epidemiologists use to synthesize evidence from measurements made on populations. By embracing foundational principles with modern methods, the epidemiologic approach of analyzing the causes and distributions of diseases in contemporaneous populations will continue to advance HIV science over the next decade.

Cancer Risk in Older Persons Living With Human Immunodeficiency Virus Infection in the United States

Background

Cancer risk is increased in persons living with human immunodeficiency virus (HIV) (PLWH). Improved survival has led to an aging of PLWH. We evaluated the cancer risk in older PLWH (age ≥50 years).

Methods

We included data from the HIV/AIDS Cancer Match Study (1996-2012) and evaluated risks of Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL), Hodgkin lymphoma, and cervical, anal, lung, liver, oral cavity/pharyngeal, breast, prostate, and colon cancers in older PLWH with risk in the general population by calculating standardized incidence ratios (SIRs) and excess absolute risks (EARs). Cancer risk by time since HIV diagnosis was estimated using Poisson regression.

Results

We identified 10371 cancers among 183542 older PLWH. Risk was significantly increased for KS (SIR, 103.34), NHL (3.05), Hodgkin lymphoma (7.61), and cervical (2.02), anal (14.00), lung (1.71), liver (2.91), and oral cavity/pharyngeal (1.66) cancers, and reduced for breast (0.61), prostate (0.47), and colon (0.63) cancers. SIRs declined with age for all cancers; however, EARs increased with age for anal, lung, liver, and oral cavity/pharyngeal cancers. Cancer risk was highest for most cancers within 5 years after HIV diagnosis; risk decreased with increasing time since HIV diagnosis for KS, NHL, lung cancer, and Hodgkin lymphoma.

Conclusions

Cancer risk is elevated among older PLWH. Although SIRs decrease with age, EARs are higher for some cancers, reflecting a greater absolute excess in cancer incidence among older PLWH. High risk in the first 5 years after HIV diagnosis for some cancers highlights the need for early HIV diagnosis and rapid treatment initiation.

Multimorbidity Among Persons Living with Human Immunodeficiency Virus in the United States

Background

Age-associated conditions are increasingly common among persons living with human immunodeficiency virus (HIV) (PLWH). A longitudinal investigation of their accrual is needed given their implications on clinical care complexity. We examined trends in the co-occurrence of age-associated conditions among PLWH receiving clinical care, and differences in their prevalence by demographic subgroup.

Methods

This cohort study was nested within the North American AIDS Cohort Collaboration on Research and Design. Participants from HIV outpatient clinics were antiretroviral therapy-exposed PLWH receiving clinical care (ie, ≥1 CD4 count) in the United States during 2000-2009. Multimorbidity was irreversible, defined as having ≥2: hypertension, diabetes mellitus, chronic kidney disease, hypercholesterolemia, end-stage liver disease, or non-AIDS-related cancer. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CIs) comparing demographic subgroups were obtained by Poisson regression with robust error variance, using generalized estimating equations for repeated measures.

Results

Among 22969 adults, 79% were male, 36% were black, and the median baseline age was 40 years (interquartile range, 34-46 years). Between 2000 and 2009, multimorbidity prevalence increased from 8.2% to 22.4% (Ptrend < .001). Adjusting for age, this trend was still significant (P < .001). There was no difference by sex, but blacks were less likely than whites to have multimorbidity (aPR, 0.87; 95% CI, .77-.99). Multimorbidity was the highest among heterosexuals, relative to men who have sex with men (aPR, 1.16; 95% CI, 1.01-1.34). Hypertension and hypercholesterolemia most commonly co-occurred.

Conclusions

Multimorbidity prevalence has increased among PLWH. Comorbidity prevention and multisubspecialty management of increasingly complex healthcare needs will be vital to ensuring that they receive needed care.

Excess Clinical Comorbidity Among HIV-Infected Patients Accessing Primary Care in US Community Health Centers

OBJECTIVES

As the life expectancy of people infected with human immunodeficiency virus (HIV) infection has increased, the spectrum of illness has evolved. We evaluated whether people living with HIV accessing primary care in US community health centers had higher morbidity compared with HIV-uninfected patients receiving care at the same sites.

METHODS

We compared data from electronic health records for 12 837 HIV-infected and 227 012 HIV-uninfected patients to evaluate the relative prevalence of diabetes mellitus, hypertension, chronic kidney disease, dyslipidemia, and malignancies by HIV serostatus. We used multivariable logistic regression to evaluate differences. Participants were patients aged ≥18 who were followed for ≥3 years (from January 2006 to December 2016) in 1 of 17 community health centers belonging to the Community Health Applied Research Network.

RESULTS

Nearly two-thirds of HIV-infected and HIV-uninfected patients lived in poverty. Compared with HIV-uninfected patients, HIV-infected patients were significantly more likely to be diagnosed and/or treated for diabetes (odds ratio [OR] = 1.18; 95% confidence interval [CI], 1.22-1.41), hypertension (OR = 1.38; 95% CI, 1.31-1.46), dyslipidemia (OR = 2.30; 95% CI, 2.17-2.43), chronic kidney disease (OR = 4.75; 95% CI, 4.23-5.34), lymphomas (OR = 4.02; 95% CI, 2.86-5.67), cancers related to human papillomavirus (OR = 5.05; 95% CI, 3.77-6.78), or other cancers (OR = 1.25; 95% CI, 1.10-1.42). The prevalence of stroke was higher among HIV-infected patients (OR = 1.32; 95% CI, 1.06-1.63) than among HIV-uninfected patients, but the prevalence of myocardial infarction or coronary artery disease did not differ between the 2 groups.

CONCLUSIONS

As HIV-infected patients live longer, the increasing burden of noncommunicable diseases may complicate their clinical management, requiring primary care providers to be trained in chronic disease management for this population.

Elevated Markers of Vascular Remodeling and Arterial Stiffness Are Associated With Neurocognitive Function in Older HIV+ Adults on Suppressive Antiretroviral Therapy

BACKGROUND

HIV is associated with elevated markers of vascular remodeling that may contribute to arterial fibrosis and stiffening and changes in pulse pressure (PP). These changes may, in turn, deleteriously affect autoregulation of cerebral blood flow and neurocognitive function.

METHODS

To evaluate these mechanisms, we studied markers of vascular remodeling, PP, and neurocognitive function among older (≥50 years of age) HIV-infected (HIV+, n = 72) and HIV-seronegative (HIV-, n = 36) adults. Participants completed standardized neurobehavioral and neuromedical assessments. Neurocognitive functioning was evaluated using a well-validated comprehensive battery. Three plasma biomarkers of vascular remodeling (ie, angiopoietin 2, Tie-2, and vascular endothelial growth factor, VEGF) were collected.

RESULTS

HIV+ and HIV- participants had similar levels of plasma angiopoietin 2 (P = 0.48), Tie-2 (P = 0.27), VEGF (P = 0.18), and PP (P = 0.98). In a multivariable regression model, HIV interacted with Tie-2 (β = 0.41, P < 0.01) and VEGF (β = -0.43, P = 0.01) on neurocognitive function, such that lower Tie-2 and higher VEGF values were associated with worse neurocognitive function for HIV+ participants. Greater Tie-2 values were associated with increased PP (r = 0.31, P < 0.01). In turn, PP demonstrated a quadratic association with neurocognitive function (β = -0.33, P = 0.01), such that lower and higher, relative to mean sample, PP values were associated with worse neurocognitive function.

CONCLUSIONS

These findings indicate that vascular remodeling and altered cerebral blood flow autoregulation contribute to neurocognitive function. Furthermore, HIV moderates the association between vascular remodeling and neurocognitive function but not the association between PP and neurocognitive function.

Social, Economic, and Health Disparities Among LGBT Older Adults

LGBT older adults are a heterogeneous population with collective and unique strengths and challenges. Health, personal, and economic disparities exist in this group when compared to the general population of older adults, yet subgroups such as transgender and bisexual older adults and individuals living with HIV are at greater risk for disparities and poorer health outcomes. As this population grows, further research is needed on factors that contribute to promoting health equity, while decreasing discrimination and improving competent service delivery.

HIV and aging

With the wider availability of antiretrovirals, the world's HIV population is aging. More than 10% of the 34.5 million HIV-positive individuals worldwide are over the age of 50 years and the average age continues to increase. In the USA more than 50% of the 1.3 million people with HIV are over 50 years old and by the year 2030 it is estimated that 70% will be over the age of 50 years. Although the life expectancy of HIV-positive people has increased dramatically, it still lags behind that of HIV-negative individuals. There is controversy about whether HIV itself accelerates the aging process. Elevated rates of inflammation seen in people with HIV, even if their viral loads are suppressed and their CD4 counts are preserved, are associated with greater rates of cardiovascular, renal, neurocognitive, oncological, and osteoporotic disease. These conditions increase exponentially in the elderly and will represent a major challenge for HIV patients. In addition, conditions such as geriatric syndromes including frailty are also seen at higher rates. Management of the aging HIV patient includes an emphasis on early diagnosis and treatment, preventative measures for co-morbidities, and avoiding polypharmacy. Finally, the issue of quality of life, prioritization of medical issues, and end of life care become increasingly important as the patient grows older.

From Smallpox to Big Data: The Next 100 Years of Epidemiologic Methods

For more than a century, epidemiology has seen major shifts in both focus and methodology. Taking into consideration the explosion of "big data," the advent of more sophisticated data collection and analytical tools, and the increased interest in evidence-based solutions, we present a framework that summarizes 3 fundamental domains of epidemiologic methods that are relevant for the understanding of both historical contributions and future directions in public health. First, the manner in which populations and their follow-up are defined is expanding, with greater interest in online populations whose definition does not fit the usual classification by person, place, and time. Second, traditional data collection methods, such as population-based surveillance and individual interviews, have been supplemented with advances in measurement. From biomarkers to mobile health, innovations in the measurement of exposures and diseases enable refined accuracy of data collection. Lastly, the comparison of populations is at the heart of epidemiologic methodology. Risk factor epidemiology, prediction methods, and causal inference strategies are areas in which the field is continuing to make significant contributions to public health. The framework presented herein articulates the multifaceted ways in which epidemiologic methods make such contributions and can continue to do so as we embark upon the next 100 years.