Human immunodeficiency virus infection and older adults: A retrospective single-site cohort study from Johannesburg, South Africa

Introduction: HIV-infected adults aged over 50 years in South Africa are increasing. This study explored differences between baseline characteristics and 12-month outcomes of younger and older HIV-infected adults initiated on antiretroviral therapy (ART). Additionally, associations with outcomes within the older group were sought.Methods: We retrospectively reviewed treatment-naive HIV-infected adult patients at ART initiation. Patients aged 18.0–39.9 years were compared to patients aged over 50 years using log-binomial regression for baseline characteristics and 12-month outcomes. Within the older group, outcome associations were found using multivariate regression.Results: The older cohort (n = 1635) compared to the younger cohort (n = 10726) comprised more males (47.2% vs. 35.4%, PR 1.52, p < 0.05), smokers (12.9% vs. 9.7%, PR 1.32, p < 0.05) and overweight patients (26.0% vs. 20.0%, PR 1.32, p < 0.05). Fewer older patients had tuberculosis (10.2% vs. 15.3%, PR 0.67, p < 0.05), other opportunistic infections (16.9% vs. 23.3%, PR 0.70, p < 0.05), World Health Organization stage 3/4 disease (39.9% vs. 43.2%, PR 0.89, p < 0.05), anaemia (22.8% vs. 28.4%, PR 0.77, p < 0.05), liver dysfunction (17.1% vs. 21.3%, PR 0.83, p < 0.05) or low CD4+ count < 100 cells/mm3 (56.3% vs. 59.9%, PR 0.71, p < 0.05).Mortality was higher in the older cohort (11.3% vs. 7.5%, PR 1.48, p < 0.05). Virological suppression was greater in the older cohort (89.5% vs. 86.5%, PR 1.28, p < 0.05) but CD4+ restitution was lower (62.8% vs. 75.0%, PR 0.61, p < 0.05). There was no difference in treatment complications between the groups.Within the older cohort, associations with death were as follows: age > 55 years (PR 1.47, p < 0.05), an AIDS-defining condition (PR 2.28, p < 0.05), raised ALT (PR 1.53, p < 0.05) and CD4+ < 100 cells/mm3 (PR 2.15, p < 0.05). Associations with favourable treatment response at 12 months were unemployment (PR 1.18, p < 0.05) and raised ALT (PR 1.19, p < 0.05). Associations with a treatment complication at 12 months were unemployment (PR 1.12, p < 0.05), smoking (PR 1.20, p < 0.05) and nevirapine use (PR 1.36, p < 0.05) but secondary education was protective (PR 0.87, p < 0.05).Conclusion: HIV-infected South African adults aged over 50 years differ in characteristics and outcomes compared to their younger counterparts and justify specialised management within HIV treatment facilities

Long term outcomes of antiretroviral therapy in a large HIV/AIDS care clinic in urban South Africa: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Clinical, immunologic and virologic outcomes at large HIV/AIDS care clinics in resource poor settings are poorly described beyond the first year of highly active antiretroviral treatment (HAART). We aimed to prospectively evaluate long-term treatment outcomes at a large scale HIV/AIDS care clinic in South Africa.</p> <p>Methods</p> <p>Cohort study of patients initiating HAART between April 1, 2004 and March 13, 2007, and followed up until April 1, 2008 at a public HIV/AIDS care clinic in Johannesburg, South Africa. We performed time to event analysis on key treatment outcomes and program impact parameters including mortality, retention in care, CD4 count gain, virologic success and first line regimen durability.</p> <p>Results</p> <p>7583 HIV-infected patients initiated care and contributed to 161,000 person months follow up. Overall mortality rate was low (2.9 deaths per 100 person years, 95% CI 2.6-3.2), but high in the first three months of HAART (8.4 per 100 person years, 95% CI 7.2-9.9). Long-term on-site retention in care was relatively high (74.4% at 4 years, 95%CI 73.2-75.6). CD4 count was above 200 cells/mm³after 6 months of treatment in almost all patients. By the fourth year of HAART, the majority (59.6%, 95%CI 57.8-61.4) of patients had at least one first line drug (mainly stavudine) substituted. Women were twice as likely to experience drug substitution (OR 1.97, 95% CI 1.80-2.16). By 6 months of HAART, 90.8% suppressed virus below 400 copies. Among those with initial viral suppression, 9.4% (95% CI 8.5-10.3%) had viral rebound within one year of viral suppression, 16.8% (95% CI 15.5-18.1) within 2 years, and 20.6% (95% CI 18.9-22.4) within 3 years of initial suppression. Only 10% of women and 13% of men initiated second line HAART.</p> <p>Conclusion</p> <p>Despite advanced disease presentation and a very large-scale program, high quality care was achieved as indicated by good long-term clinical, immunologic and virologic outcomes and a low rate of second line HAART initiation. High rates of single drug substitution suggest that the public health approach to HAART could be further improved by the use of a more durable first line regimen.</p

Comparison of Pharmacy-Based Measures of Adherence to Antiretroviral Therapy as Predictors of Virological Failure

We compared multiple pharmacy refill-based adherence indicators for antiretroviral therapy, as well as thresholds for defining non-adherent behavior, based on ability to predict virological failure. A total of 29,937 pharmacy visits with corresponding viral load assessments were contributed by 8,695 patients attending a large clinic in Johannesburg, South Africa. Indicators based on pill coverage and timing of refill pickup performed comparably using the strictest thresholds for adherence [100 % pill coverage: odds ratio (OR) (95 % confidence interval (CI)) : 1.26 (1.15, 1.39); prescription picked up on or before scheduled refill date: 1.27 (1.16,1.38)]. For both types of indicators, the association between non-adherence and virological failure increased as the threshold defining adherent behavior was lowered. All measures demonstrated high specificity (range 84–98 %), but low sensitivity (5–19 %). In this setting, patients identified as non-adherent using pharmacy-based indicators are likely correctly classified and in need of interventions to improve compliance. Pharmacy based measures alone, however, are inadequate for identifying most cases of nonadherence

Tuberculosis Treatment and Risk of Stavudine Substitution in First‐Line Antiretroviral Therapy

Treatment for tuberculosis (TB) is common among individuals receiving stavudine-containing highly active antiretroviral therapy (HAART), but the effect of TB treatment on stavudine toxicity has received little attention. We estimated the effect of TB treatment on risk of stavudine substitution among individuals receiving first-line HAART

Applying machine learning and predictive modeling to retention and viral suppression in South African HIV treatment cohorts

HIV treatment programs face challenges in identifying patients at risk for loss-to-follow-up and uncontrolled viremia. We applied predictive machine learning algorithms to anonymised, patientlevel HIV programmatic data from two districts in South Africa, 2016–2018. We developed patient risk scores for two outcomes: (1) visit attendance≤ 28 days of the next scheduled clinic visit and (2) suppression of the next HIV viral load (VL). Demographic, clinical, behavioral and laboratory data were investigated in multiple models as predictor variables of attending the next scheduled visit and VL results at the next test. Three classifcation algorithms (logistical regression, random forest and AdaBoost) were evaluated for building predictive models. Data were randomly sampled on a 70/30 split into a training and test set. The training set included a balanced set of positive and negative examples from which the classifcation algorithm could learn. The predictor variable data from the unseen test set were given to the model, and each predicted outcome was scored against known outcomes. Finally, we estimated performance metrics for each model in terms of sensitivity, specifcity, positive and negative predictive value and area under the curve (AUC). In total, 445,636 patients were included in the retention model and 363,977 in the VL model. The predictive metric (AUC) ranged from 0.69 for attendance at the next scheduled visit to 0.76 for VL suppression, suggesting that the model correctly classifed whether a scheduled visit would be attended in 2 of 3 patients and whether the VL result at the next test would be suppressed in approximately 3 of 4 patients. Variables that were important predictors of both outcomes included prior late visits, number of prior VL tests, time since their last visit, number of visits on their current regimen, age, and treatment duration. For retention, the number of visits at the current facility and the details of the next appointment date were also predictors, while for VL suppression, other predictors included the range of the previous VL value. Machine learning can identify HIV patients at risk for disengagement and unsuppressed VL. Predictive modeling can improve the targeting of interventions through diferentiated models of care before patients disengage from treatment programmes, increasing costefectiveness and improving patient outcomes.The American People and the President’s Emergency Plan for AIDS Relief (PEPFAR) through the United States Agency for International Development (USAID), including bilateral support through USAID South Africa’s Accelerating Program Achievements to Control the Epidemic; the NIH National Institute of Allergies and Infectious Diseases Award and Eunice Kennedy Shriver National Institute of Child Health & Human Development.https://www.nature.com/srepdm2022Human Nutritio

Incident pregnancy and time to death or AIDS among HIV-positive women receiving antiretroviral therapy.

BACKGROUND: Little is known about the impact of pregnancy on response to highly active antiretroviral therapy (HAART) in sub-Saharan Africa. We examined the effect of incident pregnancy after HAART initiation on clinical response to HAART. METHODS: We evaluated a prospective clinical cohort of adult women initiating HAART in Johannesburg, South Africa between 1 April 2004 and 31 March 2011, and followed up until an event, transfer, drop-out, or administrative end of follow-up on 30 September 2011. Women over age 45 and women who were pregnant at HAART initiation were excluded from the study. Main exposure was having experienced pregnancy after HAART initiation; main outcome was death and (separately) death or new AIDS event. We calculated adjusted hazard ratios (HRs) and 95% confidence limits (CL) using marginal structural Cox proportional hazards models. RESULTS: The study included 7,534 women, and 20,813 person-years of follow-up; 918 women had at least one recognized pregnancy during follow-up. For death alone, the weighted (adjusted) HR was 0.84 (95% CL 0.44, 1.60). Sensitivity analyses confirmed main results, and results were similar for analysis of death or new AIDS event. Incident pregnancy was associated with a substantially reduced hazard of drop-out (HR = 0.62, 95% CL 0.51, 0.75). CONCLUSIONS: Recognized incident pregnancy after HAART initiation was not associated with increases in hazard of clinical events, but was associated with a decreased hazard of drop-out. High rates of pregnancy after initiation of HAART may point to a need to better integrate family planning services into clinical care for HIV-infected women

Incidence of Pregnancy after Initiation of Antiretroviral Therapy in South Africa: A Retrospective Clinical Cohort Analysis

Background. Little is known about rates of incident pregnancy among HIV-positive women initiating highly active antiretroviral therapy (HAART). Methods. We conducted a retrospective clinical cohort study among therapy-naïve women ages 18–45 initiating HAART between 1 April 2004 and 30 September 2009 at an adult HAART clinic in Johannesburg, South Africa. We used Poisson regression to characterize rates and rate ratios of pregnancy. Results. We evaluated 5,996 women who experienced 727 pregnancies during 14,095 person-years at risk. The overall rate of pregnancy was 5.2 per 100 person-years (95% confidence limits [CL] 4.8, 5.5). By six years, cumulative incidence of first pregnancy was 22.9% (95% CL 20.6%, 25.4%); among women ages 18–25 at HAART initiation, cumulative incidence was 52.2% (95% CL 35.0%, 71.8%). The strongest predictor of incidence of pregnancy was age, with women 18–25 having 13.2 times the rate of pregnancy of women ages 40–45 in adjusted analysis. CD4 counts below 100 and worse adherence to HAART were associated with lower rates of incident pregnancy. Conclusions. Women experience high rates of incident pregnancy after HAART initiation. Understanding which women are most likely to experience pregnancy will help planning and future efforts to understand the implications of pregnancy for response to HAART

Estimated effect of pregnancy on time to death and alternate outcomes among 7,534 women initiating HAART in South Africa, 2004–2011.

<p>HR, hazard ratio; CL, confidence limit.</p>†<p>Weighted models accounted for age, employment status, active tuberculosis at study entry, calendar date at entry, WHO stage, and baseline and time-updated measures of weight, body mass index, hemoglobin, CD4 count and percent, adherence, and current drug regimen.</p>‡<p>Difference from unadjusted model due to missing data in any variable; only complete observations get weights.</p

Effect of pregnancy on time to (A) death, (B) death or new stage 4 AIDS, or (C) death or new stage 3 or 4 AIDS.

<p>Curves are inverse, weighted, extended Kaplan-Meier curves.</p