Search

A decision can be defined as fair if equal individuals are treated equally and unequals unequally. Adopting this definition, the task of designing machine learning models that mitigate unfairness in automated decision-making systems must include causal thinking when introducing protected attributes. Following a recent proposal, we define individuals as being normatively equal if they are equal in a fictitious, normatively desired (FiND) world, where the protected attribute has no (direct or indirect) causal effect on the target. We propose rank-preserving interventional distributions to define an estimand of this FiND world and a warping method for estimation. Evaluation criteria for both the method and resulting model are presented and validated through simulations and empirical data. With this, we show that our warping approach effectively identifies the most discriminated individuals and mitigates unfairness.

There are limited options to estimate the treatment effects of variables which are continuous and measured at multiple time points, particularly if the true dose-response curve should be estimated as closely as possible. However, these situations may be of relevance: in pharmacology, one may be interested in how outcomes of people living with -- and treated for -- HIV, such as viral failure, would vary for time-varying interventions such as different drug concentration trajectories. A challenge for doing causal inference with continuous interventions is that the positivity assumption is typically violated. To address positivity violations, we develop projection functions, which reweigh and redefine the estimand of interest based on functions of the conditional support for the respective interventions. With these functions, we obtain the desired dose-response curve in areas of enough support, and otherwise a meaningful estimand that does not require the positivity assumption. We develop $g$-computation type plug-in estimators for this case. Those are contrasted with g-computation estimators which are applied to continuous interventions without specifically addressing positivity violations, which we propose to be presented with diagnostics. The ideas are illustrated with longitudinal data from HIV positive children treated with an efavirenz-based regimen as part of the CHAPAS-3 trial, which enrolled children $

BACKGROUND Antiretroviral therapy (ART) program mortality maybe underestimated if deceased patients are misclassified as lost. METHODS We used two-stage inverse probability weighting to account for probability of being: sampled for tracing and found by the tracer. RESULTS Among 680 children and youth aged

Objectives: The aim of the study was to determine the time to, and risk factors for, triple-class virological failure (TCVF) across age groups for children and adolescents with perinatally acquired HIV infection and older adolescents and adults with heterosexually acquired HIV infection. Methods: We analysed individual patient data from cohorts in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). A total of 5972 participants starting antiretroviral therapy (ART) from 1998, aged < 20 years at the start of ART for those with perinatal infection and 15–29 years for those with heterosexual infection, with ART containing at least two nucleoside reverse transcriptase inhibitors (NRTIs) and a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (bPI), were followed from ART initiation until the most recent viral load (VL) measurement. Virological failure of a drug was defined as VL > 500 HIV-1 RNA copies/mL despite ≥ 4 months of use. TCVF was defined as cumulative failure of two NRTIs, an NNRTI and a bPI. Results: The median number of weeks between diagnosis and the start of ART was higher in participants with perinatal HIV infection compared with participants with heterosexually acquired HIV infection overall [17 (interquartile range (IQR) 4–111) vs. 8 (IQR 2–38) weeks, respectively], and highest in perinatally infected participants aged 10–14 years [49 (IQR 9–267) weeks]. The cumulative proportion with TCVF 5 years after starting ART was 9.6% [95% confidence interval (CI) 7.0−12.3%] in participants with perinatally acquired infection and 4.7% (95% CI 3.9−5.5%) in participants with heterosexually acquired infection, and highest in perinatally infected participants aged 10–14 years when starting ART (27.7%; 95% CI 13.2−42.1%). Across all participants, significant predictors of TCVF were those with perinatal HIV aged 10–14 years, African origin, pre-ART AIDS, NNRTI-based initial regimens, higher pre-ART viral load and lower pre-ART CD4. Conclusions: The results suggest a beneficial effect of starting ART before adolescence, and starting young people on boosted PIs, to maximize treatment response during this transitional stage of development., 0, SCOPUS: ar.j, FLWOA, info:eu-repo/semantics/published

When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In contrast propensity score methods require the correct specification of an exposure model. Double-robust methods only require correct specification of either the outcome or the exposure model. Targeted maximum likelihood estimation is a semiparametric double-robust method that improves the chances of correct model specification by allowing for flexible estimation using (nonparametric) machine-learning methods. It therefore requires weaker assumptions than its competitors. We provide a step-by-step guided implementation of TMLE and illustrate it in a realistic scenario based on cancer epidemiology where assumptions about correct model specification and positivity (ie, when a study participant had 0 probability of receiving the treatment) are nearly violated. This article provides a concise and reproducible educational introduction to TMLE for a binary outcome and exposure. The reader should gain sufficient understanding of TMLE from this introductory tutorial to be able to apply the method in practice. Extensive R-code is provided in easy-to-read boxes throughout the article for replicability. Stata users will find a testing implementation of TMLE and additional material in the Appendix S1 and at the following GitHub repository: https://github.com/migariane/SIM-TMLE-tutorial.

Objectives: The aim of the study was to evaluate differences in immunovirological response to combination antiretroviral therapy (cART) in migrant and native men and women within a European collaboration of HIV cohorts Collaboration of Observational HIV Epidemiological Research in Europ (COHERE) in EuroCoord, 2004-2013. Methods: Migrants were defined as those with geographical origin (GO) different from the reporting country and were grouped as originating from Western Europe and Western Countries (WEWC), Eastern Europe (EE), North Africa and the Middle East (NAME), sub-Saharan Africa (SSA), Latin America (LA), Caribbean (CRB) and Asia/Oceania (ASIA/OCE). Native (NAT) individuals were defined as those originating from the reporting country. CD4 cell counts were modelled using piecewise linear mixed-effects models with two slopes, whereas models to estimate subdistribution hazard ratios (sHRs) were used for time to virological response (VR) (i.e. time from cART initiation to the first of two successive HIV RNA measurements < 400 HIV-1 RNA copies/ml). Results: Of 32 817 individuals, 25 799 (78.6%) were men. The percentage of migrants was higher in women (48.9%) than in men (21.2%) and migrants from SSA accounted for the largest migrant group (29.9% in men and 63.3% in women). Migrant men and women from SSA started at lower CD4 cell counts than NAT individuals, which remained lower over time. VR was ≥ 85% at 12 months for all groups except CRB women (77.7%). Compared with NAT men and women, lower VR was experienced by NAME [sHR 0.91; 95% confidence interval (CI) 0.86-0.97] and SSA (sHR 0.88; 95% CI 0.82-0.95) men and CRB (sHR 0.77; 85% CI 0.67-0.89) women, respectively. Conclusions: Immunovirological response to cART in Western Europe varies by GO and sex of patients. ART benefits are not equal for all, underlining the point that efforts need to prioritize those most in need.

Background: Non-Hodgkin lymphoma (NHL) is the most common AIDS-defining condition in the era of antiretroviral therapy (ART). Whether chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection promote NHL in HIV-infected patients is unclear. Objective: To investigate whether chronic HBV and HCV infection are associated with increased incidence of NHL in HIV-infected patients. Design: Cohort study. Setting: 18 of 33 cohorts from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). Patients: HIV-infected patients with information on HBV surface antigen measurements and detectable HCV RNA, or a positive HCV antibody test result if HCV RNA measurements were not available. Measurements: Time-dependent Cox models to assess risk for NHL in treatment-naive patients and those initiating ART, with inverse probability weighting to control for informative censoring. Results: A total of 52 479 treatment-naive patients (1339 [2.6%] with chronic HBV infection and 7506 [14.3%] with HCV infection) were included, of whom 40 219 (77%) later started ART. The median follow-up was 13 months for treatment-naive patients and 50 months for those receiving ART. A total of 252 treatment-naive patients and 310 treated patients developed NHL, with incidence rates of 219 and 168 cases per 100 000 person-years, respectively. The hazard ratios for NHL with HBV and HCV infection were 1.33 (95% CI, 0.69 to 2.56) and 0.67 (CI, 0.40 to 1.12), respectively, in treatment-naive patients and 1.74 (CI, 1.08 to 2.82) and 1.73 (CI, 1.21 to 2.46), respectively, in treated patients. Limitation: Many treatment-naive patients later initiated ART, which limited the study of the associations of chronic HBV and HCV infection with NHL in this patient group. Conclusion: In HIV-infected patients receiving ART, chronic co-infection with HBV and HCV is associated with an increased risk for NHL. Primary Funding Source: European Union Seventh Framework Programme.

BACKGROUND: There is limited knowledge about the optimal timing of antiretroviral treatment initiation in older children and adolescents. METHODS: A total of 20 576 antiretroviral treatment (ART)-naïve patients, aged 1-16 years at enrolment, from 19 cohorts in Europe, Southern Africa and West Africa, were included. We compared mortality and growth outcomes for different ART initiation criteria, aligned with previous and recent World Health Organization criteria, for 5 years of follow-up, adjusting for all measured baseline and time-dependent confounders using the g-formula. RESULTS: Median (1st;3rd percentile) CD4 count at baseline was 676 cells/mm 3 (394; 1037) (children aged = 1 and < 5 years), 373 (172; 630) (= 5 and < 10 years) and 238 (88; 425) (= 10 and < 16 years). There was a general trend towards lower mortality and better growth with earlier treatment initiation. In children < 10 years old at enrolment, by 5 years of follow-up there was lower mortality and a higher mean height-for-age z-score with immediate ART initiation versus delaying until CD4 count < 350 cells/mm 3 (or CD4% < 15% or weight-for-age z-score < -2) with absolute differences in mortality and height-for-age z-score of 0.3% (95% confidence interval: 0.1%; 0.6%) and -0.08 (-0.09; -0.06) (= 1 and < 5 years), and 0.3% (0.04%; 0.5%) and -0.07 (-0.08; -0.05) (= 5 and < 10 years). In those aged > 10 years at enrolment we did not find any difference in mortality or growth with immediate ART initiation, with estimated differences of -0.1% (-0.2%; 0.6%) and -0.03 (-0.05; 0.00), respectively. Growth differences in children aged < 10 years persisted for treatment thresholds using higher CD4 values. Regular follow-up led to better height and mortality outcomes. CONCLUSIONS: Immediate ART is associated with lower mortality and better growth for up to 5 years in children < 10 years old. Our results on adolescents were inconclusive.

Background: CD4 cell recovery following first-line combination ART (cART) is poorer in HIV-2+ than in HIV-1+ patients. Only large comparisons may allow adjustments for demographic and pretreatment plasma viral load (pVL). Methods: ART-naive HIV+ adults from two European multicohort collaborations, COHERE (HIV-1 alone) and ACHIeV2e (HIV-2 alone), were included, if they started first-line cART (without NNRTIs or fusion inhibitors) between 1997 and 2011. Patients without at least one CD4 cell count before start of cART, without a pretreatment pVL and with missing a priori-defined covariables were excluded. Evolution of CD4 cell count was studied using adjusted linear mixed models. Results: We included 185 HIV-2+ and 30321 HIV-1+ patients with median age of 46 years (IQR 36-52) and 37 years (IQR 31-44), respectively. Median observed pretreatment CD4 cell counts/mm(3) were 203 (95% CI 100-290) in HIV-2+ patients and 223 (95% CI 100-353) in HIV-1+ patients. Mean observed CD4 cell count changes from start of cART to 12months were + 105 (95% CI 77-134) in HIV-2+ patients and + 202 (95% CI 199-205) in HIV-1+ patients, an observed difference of 97 cells/mm(3) in 1 year. In adjusted analysis, the mean CD4 cell increase was overall 25 CD4 cells/mm(3)/year lower (95% CI 5-44; P=0.0127) in HIV-2+ patients compared with HIV-1+ patients. Conclusions: A poorer CD4 cell increase during first-line cART was observed in HIV-2+ patients, even after adjusting for pretreatment pVL and other potential confounders. Our results underline the need to identify more potent therapeutic regimens or strategies against HIV-2

[Objective] HIV controllers (HICs) spontaneously maintain HIV viral replication at low level without antiretroviral therapy (ART), a small number of whom will eventually lose this ability to control HIV viremia. The objective was to identify factors associated with loss of virological control., [Methods] HICs were identified in COHERE on the basis of ≥5 consecutive viral loads (VL) ≤500 copies/mL over ≥1 year whilst ART-naive, with the last VL ≤500 copies/mL measured ≥5 years after HIV diagnosis. Loss of virological control was defined as 2 consecutive VL >2000 copies/mL. Duration of HIV control was described using cumulative incidence method, considering loss of virological control, ART initiation and death during virological control as competing outcomes. Factors associated with loss of virological control were identified using Cox models. CD4 and CD8 dynamics were described using mixed-effect linear models., [Results] We identified 1067 HICs; 86 lost virological control, 293 initiated ART, and 13 died during virological control. Six years after confirmation of HIC status, the probability of losing virological control, initiating ART and dying were 13%, 37%, and 2%. Current lower CD4/CD8 ratio and a history of transient viral rebounds were associated with an increased risk of losing virological control. CD4 declined and CD8 increased before loss of virological control, and before viral rebounds., [Discussion] Expansion of CD8 and decline of CD4 during HIV control may result from repeated low-level viremia. Our findings suggest that in addition to superinfection, other mechanisms, such as low grade viral replication, can lead to loss of virological control in HICs., The COHERE study group has received unrestricted funding from: Agence Nationale de Recherches sur le SIDA et les Hépatites Virales (ANRS), France; HIV Monitoring Foundation, The Netherlands; and the Augustinus Foundation, Denmark. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under EuroCoord grant agreement n° 260694.

BACKGROUND Antiretroviral therapy (ART) initiation is now recommended irrespective of CD4 count. However data on the relationship between CD4 count at ART initiation and loss to follow-up (LTFU) are limited and conflicting. METHODS We conducted a cohort analysis including all adults initiating ART (2008-2012) at three public sector sites in South Africa. LTFU was defined as no visit in the 6 months before database closure. The Kaplan-Meier estimator and Cox's proportional hazards models examined the relationship between CD4 count at ART initiation and 24-month LTFU. Final models were adjusted for demographics, year of ART initiation, programme expansion and corrected for unascertained mortality. RESULTS Among 17 038 patients, the median CD4 at initiation increased from 119 (IQR 54-180) in 2008 to 257 (IQR 175-318) in 2012. In unadjusted models, observed LTFU was associated with both CD4 counts

INTRODUCTION: Routine viral load (VL) monitoring is utilized to assess antiretroviral therapy (ART) adherence and virologic failure, and it is currently scaled-up in many resource-constrained settings. The first routine VL is recommended as late as six months after ART initiation for early detection of sub-optimal adherence. We aimed to assess the optimal timing of first VL measurement after initiation of ART. METHODS: This was a retrospective, cohort analysis of routine monitoring data of adults enrolled at three primary care clinics in Khayelitsha, Cape Town, between January 2002 and March 2009. Primary outcomes were virologic failure and switch to second-line ART comparing patients in whom first VL done was at three months (VL3M) and six months (VL6M) after ART initiation. Adjusted hazard ratios (aHR) were estimated using Cox proportional hazard models. RESULTS: In total, 6264 patients were included for the time to virologic failure and 6269 for the time to switch to second-line ART analysis. Patients in the VL3M group had a 22% risk reduction of virologic failure (aHR 0.78, 95% CI 0.64-0.95; p=0.016) and a 27% risk reduction of switch to second-line ART (aHR 0.73, 95% CI 0.58-0.92; p=0.008) when compared to patients in the VL6M group. For each additional month of delay of the first VL measurement (up to nine months), the risk of virologic failure increased by 9% (aHR 1.09, 95% CI 1.02-1.15; p=0.008) and switch to second-line ART by 13% (aHR 1.13, 95% CI 1.05-1.21; p

To investigate the incidence of selected opportunistic infections (OIs) and cancers and the role of a history of tuberculosis (TB) as a risk factor for developing these conditions in HIV-infected patients starting antiretroviral treatment (ART) in Southern Africa.

BACKGROUND There is limited evidence on the optimal timing of antiretroviral therapy (ART) initiation in children 2-5 y of age. We conducted a causal modelling analysis using the International Epidemiologic Databases to Evaluate AIDS-Southern Africa (IeDEA-SA) collaborative dataset to determine the difference in mortality when starting ART in children aged 2-5 y immediately (irrespective of CD4 criteria), as recommended in the World Health Organization (WHO) 2013 guidelines, compared to deferring to lower CD4 thresholds, for example, the WHO 2010 recommended threshold of CD4 count

INTRODUCTION South Africa has the largest number of individuals living with HIV and the largest antiretroviral therapy (ART) programme worldwide. In September 2016, ART eligibility was extended to all 7.1 million HIV-positive South Africans. To ensure that further expansion of services does not compromise quality of care, long-term outcomes must be monitored. Few studies have reported long-term mortality in resource-constrained settings, where mortality ascertainment is challenging. Combining site records with data linked to the national vital registration system, sites in the International Epidemiology Databases to Evaluate AIDS Southern Africa collaboration can identify >95% of deaths in patients with civil identification numbers (IDs). This study used linked data to explore long-term mortality and viral suppression among adults starting ART in South Africa. METHODS The study was a cohort analysis of routine data on adults with IDs starting ART 2004-2015 in five large ART cohorts. Mortality was estimated overall and by gender using the Kaplan-Meier estimator and Cox's proportional hazards regression. Standardized mortality ratios (SMRs) were calculated by dividing observed numbers of deaths by numbers expected if patients had been HIV-negative. Viral suppression in patients with viral loads (VLs) in their last year of follow-up was the secondary outcome. RESULTS Among 72,812 adults followed for 350,376 person years (pyrs), the crude mortality rate was 3.08 (95% CI 3.02-3.14)/100 pyrs. Patients were predominantly female (67%) and the percentage of men initiating ART did not increase. Cumulative mortality 12 years after ART initiation was 23.9% (33.4% male and 19.4% female). Mortality peaked in patients enrolling in 2007-2009 and was higher in men than women at all durations. Observed mortality rates were higher than HIV-negative mortality, decreasing with duration. By 48 months, observed mortality was close to that in the HIV-negative population, and SMRs were similar for all baseline CD4 strata. Three-quarters of patients had VLs in their last year, and 86% of these were virally suppressed. CONCLUSIONS The South African ART programme has shown a remarkable ability to initiate and manage patients successfully over 12 years, despite rapid expansion. With further scale-up, testing and initiating men on ART must be a national priority.

Background Globally, the population of adolescents living with perinatally acquired HIV (APHs) continues to expand. In this study, we pooled data from observational pediatric HIV cohorts and cohort networks, allowing comparisons of adolescents with perinatally acquired HIV in “real-life” settings across multiple regions. We describe the geographic and temporal characteristics and mortality outcomes of APHs across multiple regions, including South America and the Caribbean, North America, Europe, sub-Saharan Africa, and South and Southeast Asia. Methods and findings Through the Collaborative Initiative for Paediatric HIV Education and Research (CIPHER), individual retrospective longitudinal data from 12 cohort networks were pooled. All children infected with HIV who entered care before age 10 years, were not known to have horizontally acquired HIV, and were followed up beyond age 10 years were included in this analysis conducted from May 2016 to January 2017. Our primary analysis describes patient and treatment characteristics of APHs at key time points, including first HIV-associated clinic visit, antiretroviral therapy (ART) start, age 10 years, and last visit, and compares these characteristics by geographic region, country income group (CIG), and birth period. Our secondary analysis describes mortality, transfer out, and lost to follow-up (LTFU) as outcomes at age 15 years, using competing risk analysis. Among the 38,187 APHs included, 51% were female, 79% were from sub-Saharan Africa and 65% lived in low-income countries. APHs from 51 countries were included (Europe: 14 countries and 3,054 APHs; North America: 1 country and 1,032 APHs; South America and the Caribbean: 4 countries and 903 APHs; South and Southeast Asia: 7 countries and 2,902 APHs; sub-Saharan Africa, 25 countries and 30,296 APHs). Observation started as early as 1982 in Europe and 1996 in sub-Saharan Africa, and continued until at least 2014 in all regions. The median (interquartile range [IQR]) duration of adolescent follow-up was 3.1 (1.5–5.2) years for the total cohort and 6.4 (3.6–8.0) years in Europe, 3.7 (2.0–5.4) years in North America, 2.5 (1.2–4.4) years in South and Southeast Asia, 5.0 (2.7–7.5) years in South America and the Caribbean, and 2.1 (0.9–3.8) years in sub-Saharan Africa. Median (IQR) age at first visit differed substantially by region, ranging from 0.7 (0.3–2.1) years in North America to 7.1 (5.3–8.6) years in sub-Saharan Africa. The median age at ART start varied from 0.9 (0.4–2.6) years in North America to 7.9 (6.0–9.3) years in sub-Saharan Africa. The cumulative incidence estimates (95% confidence interval [CI]) at age 15 years for mortality, transfers out, and LTFU for all APHs were 2.6% (2.4%–2.8%), 15.6% (15.1%–16.0%), and 11.3% (10.9%–11.8%), respectively. Mortality was lowest in Europe (0.8% [0.5%–1.1%]) and highest in South America and the Caribbean (4.4% [3.1%–6.1%]). However, LTFU was lowest in South America and the Caribbean (4.8% [3.4%–6.7%]) and highest in sub-Saharan Africa (13.2% [12.6%–13.7%]). Study limitations include the high LTFU rate in sub-Saharan Africa, which could have affected the comparison of mortality across regions; inclusion of data only for APHs receiving ART from some countries; and unavailability of data from high-burden countries such as Nigeria. Conclusion To our knowledge, our study represents the largest multiregional epidemiological analysis of APHs. Despite probable under-ascertained mortality, mortality in APHs remains substantially higher in sub-Saharan Africa, South and Southeast Asia, and South America and the Caribbean than in Europe. Collaborations such as CIPHER enable us to monitor current global temporal trends in outcomes over time to inform appropriate policy responses.

There is limited evidence on the optimal timing of antiretroviral therapy (ART) initiation in children 2–5 y of age. We conducted a causal modelling analysis using the International Epidemiologic Databases to Evaluate AIDS–Southern Africa (IeDEA-SA) collaborative dataset to determine the difference in mortality when starting ART in children aged 2–5 y immediately (irrespective of CD4 criteria), as recommended in the World Health Organization (WHO) 2013 guidelines, compared to deferring to lower CD4 thresholds, for example, the WHO 2010 recommended threshold of CD4 count

BACKGROUND High early mortality in patients with HIV-1 starting antiretroviral therapy (ART) in sub-Saharan Africa, compared to Europe and North America, is well documented. Longer-term comparisons between settings have been limited by poor ascertainment of mortality in high burden African settings. This study aimed to compare mortality up to four years on ART between South Africa, Europe, and North America. METHODS AND FINDINGS Data from four South African cohorts in which patients lost to follow-up (LTF) could be linked to the national population register to determine vital status were combined with data from Europe and North America. Cumulative mortality, crude and adjusted (for characteristics at ART initiation) mortality rate ratios (relative to South Africa), and predicted mortality rates were described by region at 0-3, 3-6, 6-12, 12-24, and 24-48 months on ART for the period 2001-2010. Of the adults included (30,467 [South Africa], 29,727 [Europe], and 7,160 [North America]), 20,306 (67%), 9,961 (34%), and 824 (12%) were women. Patients began treatment with markedly more advanced disease in South Africa (median CD4 count 102, 213, and 172 cells/µl in South Africa, Europe, and North America, respectively). High early mortality after starting ART in South Africa occurred mainly in patients starting ART with CD4 count

The World Health Organization (WHO) recommends antiretroviral therapy (ART) initiation at the time of HIV diagnosis irrespective of immunological criteria – known as Treat-All – aiming at improving individual level health outcomes and reducing HIV transmission. However, concerns were raised about the feasibility of further treatment expansion in already fragile health systems in resource-limited settings (RLS). This thesis evaluates the feasibility of ART expansion under the Treat-All approach in a public sector setting in Eswatini. A wide range of HIV care expansion outcomes were explored at patient, programme, and population level. The studies were conducted in outpatient departments of primary and secondary care facilities of the predominantly rural Shiselweni region of Eswatini, from 2007 to 2016. The study population consisted of people living with HIV (PLHIV) who were offered ART under Treat-All and standard of care (SOC) as well as HIV co-infected tuberculosis (TB) patients. The result section of this thesis presents the findings through submitted and published manuscripts. The first paper describes the feasibility of rapid public sector ART expansion before the Treat-All approach became policy. The active ART cohort and treatment coverage among PLHIV expanded approximately 8-fold. Attrition decreased over time, which was most pronounced in the most recent treatment cohort. Attrition remained high for previously described higher risk socio-demographic (e.g. young age, men), clinical (e.g. higher WHO clinical stage, lower CD4 cell count), and programme factors (e.g. toxic drug regimens). The second paper investigates the feasibility of ART initiation under Treat-All compared with SOC. ART initiation was higher and quicker under Treat-All, mainly because more patients with high baseline CD4 cell count initiated treatment under the policy of universal ART. ART initiation was delayed for patients co-infected with TB disease under Treat-All, but was higher overall after 1 month compared with patients without TB. Patients presenting with advanced HIV disease (CD4 < 200 cells/mm3 and/or WHO III/IV clinical stage) had similar cumulative ART initiation rates with both interventions, although initiation was faster under Treat-All during the first month after care enrolment. The third paper assesses treatment outcomes of patients initiated on ART under Treat-All compared with SOC. Patients under Treat-All initiated ART with a higher median CD4 cell count and were more likely to achieve viral suppression. The risk of an unfavourable treatment outcome and viral failure was similar between both interventions. Under Treat-All, previously described higher risk socio-demographic (e.g. younger age, pregnancy) and clinical factors (e.g. low CD4 cell count, higher WHO clinical staging) increased the risk of the unfavourable outcome. The fourth paper evaluated the effectiveness and efficacy of ART initiation on the day of facility-based HIV care enrolment under Treat-All compared with patients initiated 1 to 14 days after care enrolment. Among patients initiated on treatment, same-day ART initiation increased the risk of an unfavourable outcome. This effect was mainly seen during the first months of ART after HIV care enrolment. The fifth paper describes temporal trends in HIV-associated TB during rapid ART expansion including the time-period of Treat-All. Notifications of TB disease decreased by 5-fold over a period of 8 years, and the decline was most pronounced in HIV-associated TB disease compared with HIV-negative TB. The main population-level predictor of TB disease was HIV disease, and the decline in TB coincided with increased access to ART in PLHIV. The thesis concludes that ART expansion and Treat-All are feasible in this RLS, by achieving favourable HIV care outcomes in terms of ART initiation and treatment, for patients with high CD4 cell counts as well for patients presenting late to HIV care. It also highlights the potential population level impact of rapid ART expansion on reducing the burden of HIV-associated TB disease over time. It cautions however against the assumption that outcomes will be improved through ART initiation on the same day as facility-based HIV care enrolment under the Treat-All approach.

Analyzing survival in HIV treatment cohorts, Andrew Boulle and colleagues find mortality rates in South Africa comparable to or better than those in North America by 4 years after starting antiretroviral therapy. Please see later in the article for the Editors' Summary, Background High early mortality in patients with HIV-1 starting antiretroviral therapy (ART) in sub-Saharan Africa, compared to Europe and North America, is well documented. Longer-term comparisons between settings have been limited by poor ascertainment of mortality in high burden African settings. This study aimed to compare mortality up to four years on ART between South Africa, Europe, and North America. Methods and Findings Data from four South African cohorts in which patients lost to follow-up (LTF) could be linked to the national population register to determine vital status were combined with data from Europe and North America. Cumulative mortality, crude and adjusted (for characteristics at ART initiation) mortality rate ratios (relative to South Africa), and predicted mortality rates were described by region at 0–3, 3–6, 6–12, 12–24, and 24–48 months on ART for the period 2001–2010. Of the adults included (30,467 [South Africa], 29,727 [Europe], and 7,160 [North America]), 20,306 (67%), 9,961 (34%), and 824 (12%) were women. Patients began treatment with markedly more advanced disease in South Africa (median CD4 count 102, 213, and 172 cells/µl in South Africa, Europe, and North America, respectively). High early mortality after starting ART in South Africa occurred mainly in patients starting ART with CD4 count, Editors' Summary Background AIDS has killed about 36 million people since the first recorded case of the disease in 1981, and a similar number of people (including 25 million living in sub-Saharan Africa) are currently infected with HIV, the virus that causes AIDS. HIV destroys immune system cells (including CD4 cells, a type of lymphocyte), leaving infected individuals susceptible to other serious infections. Early in the AIDS epidemic, HIV-positive people usually died within 10 years of becoming infected. In 1996, effective antiretroviral therapy (ART) became available and, for people living in high-income countries, HIV infection became a chronic condition. But ART was expensive, so HIV/AIDS remained largely untreated and fatal in resource-limited countries. Then, in 2003, the international community began to work towards achieving universal access to ART. By the end of 2012, nearly two-thirds of HIV-positive people (nearly 10 million individuals) living in low- and middle-income countries who were eligible for treatment because their CD4 cell count had fallen below 350/mm3 blood or because they had developed an AIDS-defining condition were receiving treatment. Why Was This Study Done? It is known that a larger proportion of HIV-positive patients starting ART die during the first year of treatment in sub-Saharan Africa than in Europe and North America. This difference arises in part because patients in resource-limited settings tend to have lower CD4 counts when they start treatment than patients in wealthy countries. However, the lack of reliable data on mortality (death) in resource-limited settings has made it hard to compare longer-term outcomes in different settings. Information on the long-term outcomes of HIV-positive patients receiving ART in resource-limited countries is needed to guide the development of appropriate health systems and treatment regimens in these settings. In this collaborative analysis of prospective cohort studies, the researchers compare mortality up to 4 years on ART in South Africa, Europe, and North America. A prospective cohort study follows a group of individuals over time to see whether differences in specific characteristics at the start of the study affect subsequent outcomes. A collaborative analysis combines individual patient data from several studies. What Did the Researchers Do and Find? The researchers combined data from four South Africa cohorts of HIV-positive patients starting ART included in the International Epidemiologic Databases to Evaluate AIDS South African (IeDEA-SA) collaboration with data from six North American cohorts and nine European cohorts included in the ART Cohort Collaboration (ART-CC). The South African cohorts were chosen because unusually for studies undertaken in countries in sub-Saharan Africa the vital status of patients (whether they had died) who had been lost to follow-up in these cohorts could be obtained from the national population register. Patients in South Africa began treatment with more advanced disease (indicated by a lower average CD4 count) than patients in Europe or North America. Notably, high early mortality after starting ART in South Africa occurred mainly in patients starting ART with a CD4 count below 50 cells/mm3. The cumulative mortality after 4 years of ART was 16.6%, 4.7%, and 15.3% in South Africa, Europe, and North America, respectively. After adjusting for patient characteristics at ART initiation, the mortality rate among patients beginning ART was initially lower in Europe and North American than in South Africa. However, although the adjusted mortality rate in Europe remained lower than the rate in South Africa, the rate in North America was higher than that in South Africa between 24 and 48 months on ART. What Do These Findings Mean? Although the linkage to national vital registration systems (databases of births and deaths) undertaken in this collaborative analysis is likely to have greatly reduced bias due to under-ascertainment of mortality, the accuracy of these findings may still be limited by differences in how this linkage was undertaken in different settings. Nevertheless, these findings suggest that mortality among HIV-infected patients receiving ART in South Africa, although initially higher than in Europe and North America, rapidly declines with increasing duration on ART and, after 4 years of treatment, approaches the rate seen in high-income settings. Intriguingly, these findings also highlight the relatively higher late mortality in North America compared to either Europe or South Africa, a result that needs to be investigated to explore the extent to which differences in mortality ascertainment, patient characteristics and comorbidities, or health systems and treatment regimens contribute to variations in outcomes among HIV-positive patients in various settings. Additional Information Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001718. This study is further discussed in a PLOS Medicine Perspective by Agnes Binagwaho and colleagues Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS NAM/aidsmap provides basic information about HIV/AIDS, and summaries of recent research findings on HIV care and treatment Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on universal access to ART, on HIV and AIDS in sub-Saharan Africa, and on HIV and AIDS in South Africa (in English and Spanish) The World Health Organization provides information on all aspects of HIV/AIDS (in several languages); its 2013 Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infections: recommendations for a public health approach are available The 2013 UNAIDS World AIDS Day Report provides up-to-date information about the AIDS epidemic and efforts to halt it Information about the International Epidemiologic Databases to Evaluate AIDS South African (IeDEA-SA) collaboration and about the ART Cohort Collaboration is available Personal stories about living with HIV/AIDS are available through Avert, Nam/aidsmap, and Healthtalkonline