Longitudinal Care Cascade Outcomes Among People Eligible for Antiretroviral Therapy Who Are Newly Linking to Care in Zambia: A Multistate Analysis

The HIV Care Cascade for Older Adults in Rural South Africa: A Longitudinal Cohort Study (2014-2019)

BACKGROUND

As people with HIV grow older, stable engagement in care is essential for healthy aging. We evaluate the HIV care cascade for older adults in rural South Africa at 2 time points cross-sectionally and assess movement in the cascade over time.

SETTING

We evaluated the cascade stage at waves 1 (2014-2015) and 2 (2018-2019) of Health and Aging in Africa: A Longitudinal Study of an INDPETH Community in South Africa, a population-based longitudinal cohort study in Mpumalanga Province, South Africa.

METHODS

Biomarker screening defined cascade stages [HIV+/no antiretroviral therapy (ART); ART+/unsuppressed viral load; ART+/suppressed viral load]. Between-wave probability of death, cascade progression, regression, cascade transitions, and sociodemographic predictors were assessed with Poisson regression. The impact of death was considered using the Fine and Gray competing risk model.

RESULTS

We observed a higher prevalence of antiretroviral therapy with viral suppression over time (50% in wave 1 vs. 70% in wave 2). Among those alive, the oldest age group (70+ years old) was most likely to have cascade progression [adjusted risk ratio for treatment initiation vs. 40-49 years old: 1.38 (95% confidence interval: 1.02 to 1.86)]. However, there was a significant risk of death and cascade regression. Death between waves reached 40% for 70+-year-olds who were ART+/unsuppressed. In competing risk models, older age was associated with equivalent or less cascade progression.

CONCLUSION

Older age groups who were unsuppressed on treatment and men had poorer cascade outcomes. Improvements observed in HIV treatment coverage over time for older adults must be interpreted in the context of the high risk of death for older HIV-positive adults, especially among those failing treatment.

Modeling the HIV Cascade of Care Using Routinely Collected Clinical Data to Guide Programmatic Interventions and Policy Decisions

BACKGROUND

The HIV care cascade is a framework to examine effectiveness of HIV programs and progress toward global targets to end the epidemic but has been conceptualized as a unidirectional process that ignores cyclical care patterns. We present a dynamic cascade that accounts for patient "churn" and apply novel analytic techniques to readily available clinical data to robustly estimate program outcomes and efficiently assess progress toward global targets.

METHODS

Data were assessed for 35,649 people living with HIV and receiving care at 78 clinics in East Africa between 2014 and 2020. Patients were aged ≥15 years and had ≥1 viral load measurements. We used multi-state models to estimate the probability of being in 1 of 5 states of a dynamic HIV cascade: (1) in HIV care but not on antiretroviral therapy (ART), (2) on ART, (3) virally suppressed, (4) in a gap-in-care, and (5) deceased and compared these among subgroups. To assess progress toward global targets, we summed those probabilities across patients and generated population-level proportions of patients on ART and virally suppressed in mid-2020.

RESULTS

One year after enrollment, 2.8% of patients had not initiated ART, 86.7% were receiving ART, 57.4% were virally suppressed, 10.2% were disengaged from care, and 0.3% had died. At 5 years, the proportion on ART remained steady but viral suppression increased to 77.2%. Of those aged 15-25, >20% had disengaged from care and <60% were virally suppressed. In mid-2020, 90.1% of the cohort was on ART, 90.7% of whom had suppressed virus.

CONCLUSIONS

Novel analytic approaches can characterize patient movement through a dynamic HIV cascade and, importantly, by capitalizing on readily available data from clinical cohorts, offer an efficient approach to estimate population-level proportions of patients on ART and virally suppressed. Significant progress toward global targets was observed in our cohort but challenges remain among younger patients.

HIV epidemiology, prevention, treatment, and implementation strategies for public health

The global HIV response has made tremendous progress but is entering a new phase with additional challenges. Scientific innovations have led to multiple safe, effective, and durable options for treatment and prevention, and long-acting formulations for 2-monthly and 6-monthly dosing are becoming available with even longer dosing intervals possible on the horizon. The scientific agenda for HIV cure and remission strategies is moving forward but faces uncertain thresholds for success and acceptability. Nonetheless, innovations in prevention and treatment have often failed to reach large segments of the global population (eg, key and marginalised populations), and these major disparities in access and uptake at multiple levels have caused progress to fall short of their potential to affect public health. Moving forward, sharper epidemiologic tools based on longitudinal, person-centred data are needed to more accurately characterise remaining gaps and guide continued progress against the HIV epidemic. We should also increase prioritisation of strategies that address socio-behavioural challenges and can lead to effective and equitable implementation of existing interventions with high levels of quality that better match individual needs. We review HIV epidemiologic trends; advances in HIV prevention, treatment, and care delivery; and discuss emerging challenges for ending the HIV epidemic over the next decade that are relevant for general practitioners and others involved in HIV care.

Statistical methods applied for the assessment of the HIV cascade and continuum of care: a systematic scoping review

OBJECTIVES

This scoping review aims to identify and synthesise existing statistical methods used to assess the progress of HIV treatment programmes in terms of the HIV cascade and continuum of care among people living with HIV (PLHIV).

DESIGN

Systematic scoping review.

DATA SOURCES

Published articles were retrieved from PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete and Excerpta Medica dataBASE (EMBASE) databases between April and July 2022. We also strategically search using the Google Scholar search engine and reference lists of published articles.

ELIGIBILITY CRITERIA

This scoping review included original English articles that estimated and described the HIV cascade and continuum of care progress in PLHIV. The review considered quantitative articles that evaluated either HIV care cascade progress in terms of the Joint United Nations Programme on HIV and AIDS targets or the dynamics of engagement in HIV care.

DATA EXTRACTION AND SYNTHESIS

The first author and the librarian developed database search queries and screened the retrieved titles and abstracts. Two independent reviewers and the first author extracted data using a standardised data extraction tool. The data analysis was descriptive and the findings are presented in tables and visuals.

RESULTS

This review included 300 articles. Cross-sectional study design methods were the most commonly used to assess the HIV care cascade (n=279, 93%). In cross-sectional and longitudinal studies, the majority used proportions to describe individuals at each cascade stage (276/279 (99%) and 20/21 (95%), respectively). In longitudinal studies, the time spent in cascade stages, transition probabilities and cumulative incidence functions was estimated. The logistic regression model was common in both cross-sectional (101/279, 36%) and longitudinal studies (7/21, 33%). Of the 21 articles that used a longitudinal design, six articles used multistate models, which included non-parametric, parametric, continuous-time, time-homogeneous and discrete-time multistate Markov models.

CONCLUSIONS

Most literature on the HIV cascade and continuum of care arises from cross-sectional studies. The use of longitudinal study design methods in the HIV cascade is growing because such methods can provide additional information about transition dynamics along the cascade. Therefore, a methodological guide for applying different types of longitudinal design methods to the HIV continuum of care assessments is warranted.

Understanding the effects of universal test and treat on longitudinal HIV care outcomes among South African youth: a retrospective cohort study

INTRODUCTION

Little is known about the effects of universal test and treat (UTT) policies on HIV care outcomes among youth living with HIV (YLHIV). Moreover, there is a paucity of information regarding when YLHIV are most susceptible to disengagement from care under the newest treatment guidelines. The longitudinal HIV care continuum is an underutilized tool that can provide a holistic understanding of population-level HIV care trajectories and be used to compare treatment outcomes across groups. We aimed to explore effects of the UTT policy on longitudinal outcomes among South African YLHIV and identify temporally precise opportunities for re-engaging this priority population in the UTT era.

METHODS

Using medical record data, we conducted a retrospective cohort study among youth aged 18-24 diagnosed with HIV from August 2015-December 2018 in nine health care facilities in South Africa. We used Fine and Gray sub-distribution proportional hazards models to characterize longitudinal care continuum outcomes in the population overall and stratified by treatment era of diagnosis. We estimated the proportion of individuals in each stage of the continuum over time and the restricted mean time spent in each stage in the first year following diagnosis. Sub-group estimates were compared using differences.

RESULTS

A total of 420 YLHIV were included. By day 365 following diagnosis, just 23% of individuals had no 90-or-more-day lapse in care and were virally suppressed. Those diagnosed in the UTT era spent less time as ART-naïve (mean difference=-19.3 days; 95% CI: -27.7, -10.9) and more time virally suppressed (mean difference = 17.7; 95% CI: 1.0, 34.4) compared to those diagnosed pre-UTT. Most individuals who were diagnosed in the UTT era and experienced a 90-or-more-day lapse in care disengaged between diagnosis and linkage to care or ART initiation and viral suppression.

CONCLUSIONS

Implementation of UTT yielded modest improvements in time spent on ART and virally suppressed among South African YLHIV- however, meeting UNAIDS' 95-95-95 targets remains a challenge. Retention in care and re-engagement interventions that can be implemented between diagnosis and linkage to care and between ART initiation and viral suppression (e.g., longitudinal counseling) may be particularly important to improving care outcomes among South African YLHIV in the UTT era.

Novel Longitudinal Methods for Assessing Retention in Care: a Synthetic Review

PURPOSE OF REVIEW

Retention in care is both dynamic and longitudinal in nature, but current approaches to retention often reduce these complex histories into cross-sectional metrics that obscure the nuanced experiences of patients receiving HIV care. In this review, we discuss contemporary approaches to assessing retention in care that captures its dynamic nature and the methodological and data considerations to do so.

RECENT FINDINGS

Enhancing retention measurements either through patient tracing or "big data" approaches (including probabilistic matching) to link databases from different sources can be used to assess longitudinal retention from the perspective of the patient when they transition in and out of care and access care at different facilities. Novel longitudinal analytic approaches such as multi-state and group-based trajectory analyses are designed specifically for assessing metrics that can change over time such as retention in care. Multi-state analyses capture the transitions individuals make in between different retention states over time and provide a comprehensive depiction of longitudinal population-level outcomes. Group-based trajectory analyses can identify patient subgroups that follow distinctive retention trajectories over time and highlight the heterogeneity of retention patterns across the population. Emerging approaches to longitudinally measure retention in care provide nuanced assessments that reveal unique insights into different care gaps at different time points over an individuals' treatment. These methods help meet the needs of the current scientific agenda for retention and reveal important opportunities for developing more tailored interventions that target the varied care challenges patients may face over the course of lifelong treatment.

The HIV care cascade in sub-Saharan Africa: systematic review of published criteria and definitions

INTRODUCTION

The HIV care cascade examines the attrition of people living with HIV from diagnosis to the use of antiretroviral therapy (ART) and suppression of viral replication. We reviewed the literature from sub-Saharan Africa to assess the definitions used for the different steps in the HIV care cascade.

METHODS

We searched PubMed, Embase and CINAHL for articles published from January 2004 to December 2020. Longitudinal and cross-sectional studies were included if they reported on at least one step of the UNAIDS 90-90-90 cascade or two steps of an extended 7-step cascade. A step was clearly defined if authors reported definitions for numerator and denominator, including the description of the eligible population and methods of assessment or measurement. The review protocol has been published and registered in Prospero.

RESULTS AND DISCUSSION

Overall, 3364 articles were screened, and 82 studies from 19 countries met the inclusion criteria. Most studies were from Southern (38 studies, 34 from South Africa) and East Africa (29 studies). Fifty-eight studies (71.6%) were longitudinal, with a median follow-up of three years. The medium number of steps covered out of 7 steps was 3 (interquartile range [IQR] 2 to 4); the median year of publication was 2015 (IQR 2013 to 2019). The number of different definitions for the numerators ranged from four definitions (for step "People living with HIV") to 21 (step "Viral suppression"). For the denominators, it ranged from three definitions ("Diagnosed and aware of HIV status") to 14 ("Viral suppression"). Only 12 studies assessed all three of the 90-90-90 steps. Most studies used longitudinal data, but denominator-denominator or denominator-numerator linkages over several steps were rare. Also, cascade data are lacking for many countries. Our review covers the academic literature but did not consider other data, such as government reports on the HIV care cascade. Also, it did not examine disengagement and reengagement in care.

CONCLUSIONS

The proportions of patients retained at each step of the HIV care cascade cannot be compared between studies, countries and time periods, nor meta-analysed, due to the many different definitions used for numerators and denominators. There is a need for standardization of methods and definitions.

The Clinical Course of Coronavirus Disease 2019 in a US Hospital System: A Multistate Analysis

There are limited data on longitudinal outcomes for coronavirus disease 2019 (COVID-19) hospitalizations that account for transitions between clinical states over time. Using electronic health record data from a hospital network in the St. Louis, Missouri, region, we performed multistate analyses to examine longitudinal transitions and outcomes among hospitalized adults with laboratory-confirmed COVID-19 with respect to 15 mutually exclusive clinical states. Between March 15 and July 25, 2020, a total of 1,577 patients in the network were hospitalized with COVID-19 (49.9% male; median age, 63 years (interquartile range, 50–75); 58.8% Black). Overall, 34.1% (95% confidence interval (CI): 26.4, 41.8) had an intensive care unit admission and 12.3% (95% CI: 8.5, 16.1) received invasive mechanical ventilation (IMV). The risk of decompensation peaked immediately after admission; discharges peaked around days 3–5, and deaths plateaued between days 7 and 16. At 28 days, 12.6% (95% CI: 9.6, 15.6) of patients had died (4.2% (95% CI: 3.2, 5.2) had received IMV) and 80.8% (95% CI: 75.4, 86.1) had been discharged. Among those receiving IMV, 35.1% (95% CI: 28.2, 42.0) remained intubated after 14 days; after 28 days, 37.6% (95% CI: 30.4, 44.7) had died and only 37.7% (95% CI: 30.6, 44.7) had been discharged. Multistate methods offer granular characterizations of the clinical course of COVID-19 and provide essential information for guiding both clinical decision-making and public health planning.