Increases in regimen durability associated with the introduction of tenofovir at a large public-sector clinic in Johannesburg, South Africa

Cohort profile: the South African National Health Laboratory Service (NHLS) National HIV Cohort

PURPOSE

South Africa's National Health Laboratory Service (NHLS) National HIV Cohort was established in 2015 to facilitate monitoring, evaluation and research on South Africa's National HIV Treatment Programme. In South Africa, 84.8% of people living with HIV know their HIV status; 70.7% who know their status are on ART; and 87.4% on ART are virologically suppressed.

PARTICIPANTS

The NHLS National HIV Cohort includes the laboratory data of nearly all patients receiving HIV care in the public sector since April 2004. Patients are included in the cohort if they have received a CD4 count or HIV RNA viral load (VL) test. Using an anonymised unique patient identifier that we have developed and validated to linked test results, we observe patients prospectively through their laboratory results as they receive HIV care and treatment. Patients in HIV care are seen for laboratory monitoring every 6-12 months. Data collected include age, sex, facility location and test results for CD4 counts, VLs and laboratory tests used to screen for potential treatment complications.

FINDINGS TO DATE

From April 2004 to April 2018, 63 million CD4 count and VL tests were conducted at 5483 facilities. 12.6 million unique patients had at least one CD4 count or VL, indicating they had accessed HIV care, and 7.1 million patients had a VL test indicating they had started antiretroviral therapy. The creation of NHLS National HIV Cohort has enabled longitudinal research on all lab-monitored patients in South Africa's national HIV programme, including analyses of (1) patient health at presentation; (2) care outcomes such as 'CD4 recovery', 'retention in care' and 'viral resuppression'; (3) patterns of transfer and re-entry into care; (4) facility-level variation in care outcomes; and (5) impacts of policies and guideline changes.

FUTURE PLANS

Continuous updating of the cohort, integration with available clinical data, and expansion to include tuberculosis and other lab-monitored comorbidities.

Loss to follow-up from antiretroviral therapy clinics: A systematic review and meta-analysis of published studies in South Africa from 2011 to 2015

Background

South Africa has the largest antiretroviral therapy (ART) programme in the world. To optimise programme outcomes, it is critical that patients are retained in care and that retention is accurately measured.

Objectives

To identify all studies published in South Africa from 2011 to 2015 that used loss to follow-up (LTFU) as an indicator or outcome to describe the variation in definitions and to estimate the proportion of patients lost to care across studies.

Method

All studies published between 01 January 2011 and October 2015 that included loss to follow-up or default from ART care in a South African cohort were included by use of a broad search strategy across multiple databases. To be included, the cohort had to include any patient ART data, including follow-up time, from 01 January 2010. Two authors, working independently, extracted data and assessed risk of bias from all manuscripts. Meta-analysis was performed for studies stratified by the same loss to follow-up definition.

Results

Forty-eight adult, 15 paediatric and 4 pregnant cohorts were included. Median cohort size was 3737; follow-up time ranged from 9 weeks to 5 years. Meta-analysis did not reveal an important difference in LTFU estimates in adult cohorts at 1 year between loss to follow-up defined as 3 months (11.0%, n = 4; 95% CI 10.7% – 11.2%) compared with 6 months (12.0%, n = 4; 95% CI 11.8% – 12.2%). Only two cohorts reported reliable LTFU estimates at 5 years: this was 25.1% (95% CI 24.8% – 25.4%).

Conclusion

South Africa should standardise a LTFU definition. This would aid in monitoring and evaluation of ART programmes, with the broader goal of improving patient outcomes.

Long Term Exposure to Tenofovir Disoproxil Fumarate-Containing Antiretroviral Therapy Is Associated with Renal Impairment in an African Cohort of HIV-Infected Adults

OBJECTIVES AND METHOD

There are growing concerns of tenofovir disoproxil fumarate (TDF)-associated renal toxicity. We evaluated the effect of long-term TDF exposure on renal function in a cohort of HIV-1-infected Nigerians between 2006 and 2015. Multivariate logistic regression was used to identify predictors of renal impairment at different time over 144 weeks of antiretroviral therapy (ART).

RESULTS

Data of 4897 patients, median age 42 years (interquartile range: 36-49), and 61% females were analyzed. The prevalence of renal impairment increased from 10% at week 24 to 45% at 144 weeks in TDF-exposed participants compared to an increase from 8% at 24 weeks to 14% at 144 weeks in TDF-unexposed participants. Tenofovir disoproxil fumarate exposure predicted the risk of renal impairment at 144 weeks of ART (odds ratio: 2.36; 95% confidence interval: 1.28-4.34).

CONCLUSION

Long-term exposure to TDF-based ART significantly increases the likelihood of renal impairment. The continued use of TDF-based regimen in our setting should be reviewed. We recommend the urgent introduction of tenofovir alafenamide-based regimen in the HIV treatment guidelines of Nigeria and other resource-limited countries.

Medication Side Effects and Retention in HIV Treatment: A Regression Discontinuity Study of Tenofovir Implementation in South Africa and Zambia

Tenofovir is less toxic than other nucleoside reverse-transcriptase inhibitors used in antiretroviral therapy (ART) and may improve retention of human immunodeficiency virus (HIV)-infected patients on ART. We assessed the impact of national guideline changes in South Africa (2010) and Zambia (2007) recommending tenofovir for first-line ART. We applied regression discontinuity in a prospective cohort study of 52,294 HIV-infected adults initiating first-line ART within 12 months (±12 months) of each guideline change. We compared outcomes in patients presenting just before and after the guideline changes using local linear regression and estimated intention-to-treat effects on initiation of tenofovir, retention in care, and other treatment outcomes at 24 months. We assessed complier causal effects among patients starting tenofovir. The new guidelines increased the percentages of patients initiating tenofovir in South Africa (risk difference (RD) = 81 percentage points, 95% confidence interval (CI): 73, 89) and Zambia (RD = 42 percentage points, 95% CI: 38, 45). With the guideline change, the percentage of single-drug substitutions decreased substantially in South Africa (RD = -15 percentage points, 95% CI: -18, -12). Starting tenofovir also reduced attrition in Zambia (intent-to-treat RD = -1.8% (95% CI: -3.5, -0.1); complier relative risk = 0.74) but not in South Africa (RD = -0.9% (95% CI: -5.9, 4.1); complier relative risk = 0.94). These results highlight the importance of reducing side effects for increasing retention in care, as well as the differences in population impact of policies with heterogeneous treatment effects implemented in different contexts.

Regimen durability in HIV-infected children and adolescents initiating first-line antiretroviral therapy in a large public sector HIV cohort in South Africa

INTRODUCTION

In April 2010, tenofovir and abacavir replaced stavudine in public sector first-line antiretroviral therapy (ART) for children under 20 years old in South Africa. The association of both abacavir and tenofovir with fewer side effects and toxicities compared to stavudine could translate to increased durability of tenofovir or abacavir-based regimens. We evaluated changes over time in regimen durability for paediatric patients 3-19 years of age at eight public sector clinics in Johannesburg, South Africa.

METHODS

Cohort analysis of treatment-naïve, non-pregnant paediatric patients from 3 to 19 years old initiated on ART between April 2004 and December 2013. First-line ART regimens before April 2010 consisted of stavudine or zidovudine with lamivudine and either efavirenz or nevirapine. Tenofovir and/or abacavir was substituted for stavudine after April 2010 in first-line ART. We evaluated the frequency and type of single-drug substitutions, treatment interruptions and switches to second-line therapy. Fine and Gray competing risk regression models were used to evaluate the association of antiretroviral drug type with single-drug substitutions, treatment interruptions and second-line switches in the first 24 months on treatment.

RESULTS

Three hundred and ninety-eight (15.3%) single-drug substitutions, 187 (7.2%) treatment interruptions and 86 (3.3%) switches to second-line therapy occurred among 2602 paediatric patients over 24-months on ART. Overall, the rate of single-drug substitutions started to increase in 2009, peaked in 2011 at 25% and then declined to 10% in 2013, well after the integration of tenofovir into paediatric regimens; no patients over the age of 3 were initiated on abacavir for first-line therapy. Competing risk regression models showed patients on zidovudine or stavudine had upwards of a fivefold increase in single-drug substitution vs. patients initiated on tenofovir in the first 24 months on ART. Older adolescents also had a two- to threefold increase in treatment interruptions and switches to second-line therapy compared to younger patients in the first 24 months on ART.

CONCLUSIONS

The decline in single-drug substitutions is associated with the introduction of tenofovir. Tenofovir use could improve regimen durability and treatment outcomes in resource-limited settings.

Implication of First-Line Antiretroviral Therapy Choice on Second-Line Options

BACKGROUND

Although there are a number of studies comparing the currently recommended preferred and alternative first-line (1L) antiretroviral therapy (ART) regimens on clinical outcomes, there are limited data examining the impact of 1L regimen choice and duration of virologic failure (VF) on accumulation of drug resistance mutations (DRM). The patterns of DRM from patients failing zidovudine (AZT)-containing versus tenofovir (TDF)-containing ART were assessed to evaluate the predicted susceptibility to second-line (2L) nucleoside reverse-transcriptase inhibitor (NRTI) backbone options in the context of an ongoing programmatic setting that uses viral load (VL) monitoring.

METHODS

Paired samples from Nigerian ART patients who experienced VF and switched to 2L ART were retrospectively identified. For each sample, the human immunodeficiency virus (HIV)-1 polymerase gene was sequenced at 2 time points, and DRM was analyzed using Stanford University's HIVdb program.

RESULTS

Sequences were generated for 191 patients. At time of 2L switch, 28.2% of patients on AZT-containing regimens developed resistance to TDF, whereas only 6.8% of patients on TDF-containing 1L had mutations compromising susceptibility to AZT. In a stratified evaluation, patients with 0-6 months between tested VL samples had no difference in proportion compromised to 2L, whereas those with >6 months between samples had a statistically significant difference in proportion with compromised 2L NRTI. In multivariate analyses, patients on 1L AZT had 9.90 times higher odds of having a compromised 2L NRTI option than patients on 1L TDF.

CONCLUSIONS

In the context of constrained resources, where VL monitoring is limited, we present further evidence to support use of TDF as the preferred 1L NRTI because it allows for preservation of the recommended 2L NRTI option.

The incidence of first-line antiretroviral treatment changes and related factors among HIV-infected sex workers in Nairobi, Kenya

INTRODUCTION

In many settings, several factors including adverse drug reactions and clinical failure can limit treatment choices for combined antiretroviral therapy (cART). The aim of the study was to describe the incidence of first-line cART changes and associated factors in a cohort of Kenyan sex workers.

METHODS

This was a retrospective review of medical records collected from 2009 to 2013. The review included records of HIV-infected patients aged ≥ 18 years, who received either stavudine or zidovudine or tenofovir disoproxil fumarate-based regimens. Using systematic random sampling, the study selected 1 500 records and censoring targeted the first incident of a drug change from the first-line cART.

RESULTS

The overall incidence rate of cART changes was 11.1 per 100 person-years within a total follow-up period of 3 427.9 person-years. Out of 380 patients who changed cART, 370 (97%) had a drug substitution and 10 (3%) switched regimens. The most commonly cited reasons for changing cART were adverse drug reactions (76%). Tenofovir disoproxil fumarate had a lower drug change rate (1.9 per 100 person years) compared to stavudine (27 per 100 person years). Using zidovudine as the reference group, stavudine-based regimens were significantly associated with an increased hazard of drug changes (adjusted hazards ratio 10.2; 95% CI: 6.02-17.2).

CONCLUSION

These findings suggest a moderate incidence of cART changes among sex workers in Nairobi, Kenya. Individuals using stavudine were at a higher risk of experiencing a change in their cART, mostly presenting within 20 months, and primarily due to adverse drug reactions.

Changes in second-line regimen durability and continuity of care in relation to national ART guideline changes in South Africa

Introduction: Little is known about the impact of antiretroviral therapy (ART) guideline changes on the durability of second-line ART and continuity of care. This study examines predictors of early drug substitutions and treatment interruptions using a cohort analysis of HIV positive adults switched to second-line ART between January 2004 and September 2013 in Johannesburg, South Africa.

Methods: The main outcomes were having a drug substitution or treatment interruption in the first 24 months on second-line ART. Kaplan Meiers analyses and Cox proportional hazards regression were used to identify predictors of drug substitutions and treatment interruptions.

Results: Of 3028 patients on second-line ART, 353 (11.7%) had a drug substitution (8.6 per 100PY, 95% CI: 7.8–9.6) and 260 (8.6%) had a treatment interruption (6.3 per 100PY, 95% CI: 5.6–7.1). While treatment interruptions decreased from 32.5 per 100PY for the 2004 cohort to 2.3 per 100PY for the 2013 cohort, the rates of drug substitutions steadily increased, peaking at an incidence of 26.7 per 100PY for the 2009 cohort and then decreased to 4.2 per 100PY in the 2011 cohort. Compared to the 2004 to 2008 cohorts, the hazard of early drug substitutions was highest among patients switched to AZT + ddI + LPVr in 2009 to 2010 (aHR 5.1, 95% CI: 3.4–7.1) but remained low over time among patients switched to TDF + 3TC/FTC + LPVr or AZT/ABC + 3TC + LPVr. The main common predictor of both treatment interruption and drug substitution was drug toxicity.

Conclusions: Our results show a rapid transition between 2004 and 2010 ART guidelines and concurrent improvements in continuity of care among second-line ART patients. Drug toxicity reporting and monitoring systems need improvements to inform timely regimen changes and ensure that patients remain in care. However, reasons for drug substitutions should be closely monitored to ensure that patients do not run out of treatment options in the future.

Multi-state models for the analysis of time-to-treatment modification among HIV patients under highly active antiretroviral therapy in Southwest Ethiopia

BACKGROUND

Highly active antiretroviral therapy (HAART) has shown a dramatic change in controlling the burden of HIV/AIDS. However, the new challenge of HAART is to allow long-term sustainability. Toxicities, comorbidity, pregnancy, and treatment failure, among others, would result in frequent initial HAART regimen change. The aim of this study was to evaluate the durability of first line antiretroviral therapy and to assess the causes of initial highly active antiretroviral therapeutic regimen changes among patients on HAART.

METHODS

A Hospital based retrospective study was conducted from January 2007 to August 2013 at Jimma University Hospital, Southwest Ethiopia. Data on the prescribed ARV along with start date, switching date, and reason for change was collected. The primary outcome was defined as the time-to-treatment change. We adopted a multi-state survival modeling approach assuming each treatment regimen as state. We estimate the transition probability of patients to move from one regimen to another.

RESULT

A total of 1284 ART naive patients were included in the study. Almost half of the patients (41.2%) changed their treatment during follow up for various reasons; 442 (34.4%) changed once and 86 (6.69%) changed more than once. Toxicity was the most common reason for treatment changes accounting for 48.94% of the changes, followed by comorbidity (New TB) 14.31%. The HAART combinations that were robust to treatment changes were tenofovir (TDF) + lamivudine (3TC)+ efavirenz (EFV), tenofovir + lamivudine (3TC) + nevirapine (NVP) and zidovudine (AZT) + lamivudine (3TC) + nevirapine (NVP) with 3.6%, 4.5% and 11% treatment changes, respectively.

CONCLUSION

Moving away from drugs with poor safety profiles, such as stavudine(d4T), could reduce modification rates and this would improve regimen tolerability, while preserving future treatment options.

Cohort profile: the Right to Care Clinical HIV Cohort, South Africa

PURPOSE

The research objectives of the Right to Care Clinical HIV Cohort analyses are to: (1) monitor treatment outcomes (including death, loss to follow-up, viral suppression and CD4 count gain among others) for patients on antiretroviral therapy (ART); (2) evaluate the impact of changes in the national treatment guidelines around when to initiate ART on HIV treatment outcomes; (3) evaluate the impact of changes in the national treatment guidelines around what ART regimens to initiate on drug switches; (4) evaluate the cost and cost-effectiveness of HIV treatment delivery models; (5) evaluate the need for and outcomes on second-line and third-line ART; (6) evaluate the impact of comorbidity with non-communicable diseases on HIV treatment outcomes and (7) evaluate the impact of the switch to initiating all patients onto ART regardless of CD4 count.

PARTICIPANTS

The Right to Care Clinical HIV Cohort is an open cohort of data from 10 clinics in two provinces within South Africa. All clinics include data from 2004 onwards. The cohort currently has data on over 115 000 patients initiated on HIV treatment and patients are followed up every 3-6 months for clinical and laboratory monitoring.

FINDINGS TO DATE

Cohort data includes information on demographics, clinical visit, laboratory data, medication history and clinical diagnoses. The data have been used to identify rates and predictors of first-line failure, to identify predictors of mortality for patients on second-line (eg, low CD4 counts) and to show that adolescents and young adults are at increased risk of unsuppressed viral loads compared with adults.

FUTURE PLANS

Future analyses will inform national models of HIV care and treatment to improve HIV care policy in South Africa.

First-line antiretroviral drug discontinuations in children

Introduction

There are a limited number of paediatric antiretroviral drug options. Characterising the long term safety and durability of different antiretrovirals in children is important to optimise management of HIV infected children and to determine the estimated need for alternative drugs in paediatric regimens. We describe first-line antiretroviral therapy (ART) durability and reasons for discontinuations in children at two South African ART programmes, where lopinavir/ritonavir has been recommended for children <3 years old since 2004, and abacavir replaced stavudine as the preferred nucleoside reverse transcriptase inhibitor in 2010.

Methods

We included children (<16 years at ART initiation) who initiated ≥3 antiretrovirals between 2004–2014 with ≥1 follow-up visit on ART. We estimated the incidence of first antiretroviral discontinuation using Kaplan-Meier analysis. We determined the reasons for antiretroviral discontinuations using competing risks analysis. We used Cox regression to identify factors associated with treatment-limiting toxicity.

Results

We included 3579 children with median follow-up duration of 41 months (IQR 14–72). At ART initiation, median age was 44 months (IQR 13–89) and median CD4 percent was 15% (IQR 9–21%). At three and five years on ART, 72% and 26% of children respectively remained on their initial regimen. By five years on ART, the most common reasons for discontinuations were toxicity (32%), treatment failure (18%), treatment simplification (5%), drug interactions (3%), and other or unspecified reasons (18%). The incidences of treatment limiting toxicity were 50.6 (95% CI 46.2–55.4), 1.6 (0.5–4.8), 2.0 (1.2–3.3), and 1.3 (0.6–2.8) per 1000 patient years for stavudine, abacavir, efavirenz and lopinavir/ritonavir respectively.

Conclusions

While stavudine was associated with a high risk of treatment-limiting toxicity, abacavir, lopinavir/ritonavir and efavirenz were well-tolerated. This supports the World Health Organization recommendation to replace stavudine with abacavir or zidovudine in paediatric first-line ART regimens in order to improve paediatric first-line ART durability.

Has the phasing out of stavudine in accordance with changes in WHO guidelines led to a decrease in single-drug substitutions in first-line antiretroviral therapy for HIV in sub-Saharan Africa?

OBJECTIVE

We assessed the relationship between phasing out stavudine in first-line antiretroviral therapy (ART) in accordance with WHO 2010 policy and single-drug substitutions (SDS) (substituting the nucleoside reverse transcriptase inhibitor in first-line ART) in sub-Saharan Africa.

DESIGN

Prospective cohort analysis (International epidemiological Databases to Evaluate AIDS-Multiregional) including ART-naive, HIV-infected patients aged at least 16 years, initiating ART between January 2005 and December 2012. Before April 2010 (July 2007 in Zambia) national guidelines called for patients to initiate stavudine-based or zidovudine-based regimen, whereas thereafter tenofovir or zidovudine replaced stavudine in first-line ART.

METHODS

We evaluated the frequency of stavudine use and SDS by calendar year 2004-2014. Competing risk regression was used to assess the association between nucleoside reverse transcriptase inhibitor use and SDS in the first 24 months on ART.

RESULTS

In all, 33 441 (8.9%; 95% confience interval 8.7-8.9%) SDS occurred among 377 656 patients in the first 24 months on ART, close to 40% of which were amongst patients on stavudine. The decrease in SDS corresponded with the phasing out of stavudine. Competing risks regression models showed that patients on tenofovir were 20-95% less likely to require a SDS than patients on stavudine, whereas patients on zidovudine had a 75-85% decrease in the hazards of SDS when compared to stavudine.

CONCLUSION

The decline in SDS in the first 24 months on treatment appears to be associated with phasing out stavudine for zidovudine or tenofovir in first-line ART in our study. Further efforts to decrease the cost of tenofovir and zidovudine for use in this setting is warranted to substitute all patients still receiving stavudine.

Tenofovir stock shortages have limited impact on clinic- and patient-level HIV treatment outcomes in public sector clinics in South Africa

OBJECTIVE

Using data from four public sector clinics in South Africa, we sought to investigate provider- and patient-level outcomes, to understand how the 2012 tenofovir stock shortage affected the HIV care and monitoring of ART patients.

METHODS

Prospective cohort analysis of ART-naïve, non-pregnant, HIV-infected patients >18 years initiating first-line ART between 1 July 2011-31 March 2013. Linear regression was used for all outcomes (number of ART initiates, days between pharmacy visits, transfers, single-drug substitutions, treatment interruptions, missed pharmacy visits, loss to follow-up and elevated viral load). We fit splines to smooth curves with knots at the beginning (1 February 2012) and end (31 August 2012) of the stock shortage and displayed results graphically by clinic. Difference-in-difference models were used to evaluate the effect of the stock shortage on outcomes.

RESULTS

Results suggest a potential shift in the management of patients during the shortage, mainly fewer average days between visits during the shortage vs. before or after at all four clinics, and a significant difference in the proportion of patients missing visits during vs. before (RD: 1.2%; 95% CI: 0.5%, 2.0%). No significant difference was seen in other outcomes.

CONCLUSION

While South Africa has made great strides to extend access to ART and increase the quality of the health services provided, patient care can be affected when stock shortages/outs occur. While our results show little effect on treatment outcomes, this most likely reflects the clinics' ability to mitigate the crisis by continuing to keep patient care and treatment as consistent as possible.

Modeling Outcomes of First-Line Antiretroviral Therapy and Rate of CD4 Counts Change among a Cohort of HIV/AIDS Patients in Ethiopia: A Retrospective Cohort Study

Background

Antiretroviral therapy has shown to be effective in reducing morbidity and mortality in patients infected with HIV for the past couples of decades. However, there remains a need to better understand the characteristics of long-term treatment outcomes in resource poor settings. The main aim of this study was to determine and compare the long-term response of patients on nevirapine and efavirenz based first line antiretroviral therapy regimen in Ethiopia.

Methods

Hospital based retrospective cohort study was conducted from January 2009 to December 2013 at University hospital located in Northwest Ethiopia. Human subject research approval for this study was received from University of Gondar Research Ethics Committee and the medical director of the hospital. Cox-proportional hazards model was used to assess the effect of baseline covariates on composite outcome and a semi-parametric mixed effect model was used to investigate CD4 counts response to treatments.

Results

A total of 2386 HIV/AIDS naive patients were included in this study. Nearly one-in-four patients experienced the events, of which death, lost to follow up, treatment substitution and discontinuation of Non-Nucleoside Reverse Transcriptase Inhibitors(NNRTI) accounted: 99 (26.8%), 122 (33.0%), 137 (37.0%) and 12 (3.2%), respectively. The hazard of composite outcome on nevirapine compared with efavirenz was 1.02(95%CI: 0.52-1.99) with p-value = 0.96. Similarly, the hazard of composite outcome on tenofovir and stavudine compared with zidovudine were 1.87 (95%CI: 1.52-2.32), p-value < 0.0001 and 1.72(95% CI: 1.22-2.32), p-value = 0.002, respectively. The rate of CD4 increase in response to treatment was high during the first 10 months and stabilized later.

Conclusions

This study revealed that treatment responses were comparable whether nevirapine or efavirenz was chosen to initiate antiretroviral therapy for HIV/AIDS patients in Ethiopia. There was significant difference on risk of composite outcome between patients who were initiated with Tenofovir containing ART regimen compared with zidovudine after controlling for NNRTI drug combinations.

Reasons and Risk Factors for the Initial Regimen Modification in Chinese Treatment-Naïve Patients with HIV Infection: A Retrospective Cohort Analysis

Background

To investigate the reasons and risk factors for modification of the first combined antiretroviral therapy (cART) currently used for HIV infected patients who were treatment naïve in Shanghai China.

Methods

Making a retrospective observational research on treatment naïve patients with HIV infection who initiated cART during the period of September 1st 2005---December 1st 2013. The demographic and clinical data were collected from the first visit to the time of the first regimen modification or the last visit in December 1st, 2014. The reasons of treatment modification were recorded. Survival analysis of modification was made by Kaplan-Meier curves analysis and log rank test, and a Cox multiple regression model was constructed to identify related factors of modification.

Results

A total number of the eligible participants were 3372 and 871(25.8%) patients changed their first cART regimen. The median follow up was 22 months [interquartile range (IQR) 14–39]. Among patients who modified the original regimen, drug toxicity occurred in 805(92.4%) participants and 44(5.1%) experienced treatment failure. In multiple regression analysis regimen modification was associated with patients’ age more than 40 years old (aHR 1.224, 95%CI 1.051–1.426, P = 0.010), CD4 less than 200(aHR 1.218, 95%CI 1.044–1.421, P = 0.012) and the initial regimen they received. Compared with the regimen of TDF+3TC+EFV, patients with regimen of d4T+3TC+NVP, d4T+3TC+EFV, AZT+3TC+NVP or AZT+3TC+EFV were 10.4, 8.2, 6.4, 2.5 times more likely to modify their initial regimen, respectively.

Conclusions

The main reason for the regimen switch was drug toxicity and main risk factors for regimen modification were age older than 40 years, CD4 cell counts less than 200 at baseline and regimen they received. Among the 2NRTI plus 1NNRTI regimens, the co-formulation of d4T+3TC+NVP had the highest risk for modification while the regimen of TDF+3TC+EFV was the most tolerable treatment regimen in first years’ follow up.

Changing utilization of Stavudine (d4T) in HIV-positive people in 2006-2013 in the EuroSIDA study

OBJECTIVES

The long-term side effects of stavudine (d4T) led to recommendations in 2009 to phase out use of this drug. We aimed to describe temporal patterns of d4T use across Europe.

METHODS

Patients taking combination antiretroviral therapy (cART) in EuroSIDA with follow-up after 1 January 2006 were included in the study. cART was defined as d4T-containing [d4T plus at least two other antiretrovirals (ARVs) from any class] or non-d4T-containing (at least three ARVs from any class, excluding d4T). Poisson regression was used to describe temporal changes in the prevalence of d4T use and factors associated with initiating d4T.

RESULTS

A total of 5850 patients receiving cART on 1 January 2006 were included in the current analysis, rising to 7768 patients on January 1 2013. During this time, the prevalence of d4T use fell from 11.2% to 0.7%, with an overall decline of 19% per 6 months [95% confidence interval (CI) 19-20%]. d4T use declined fastest in Northern Europe [26% (95% CI 23-29%) per 6 months], and slowest in Eastern Europe [17% (95% CI 16-19%) per 6 months]. In multivariable Poisson regression models, new d4T initiations decreased by 14% per 6 months [adjusted incidence rate ratio (aIRR) 0.86; 95% CI 0.80-0.91]. Factors associated with initiating d4T were residence in Eastern Europe (aIRR 4.31; 95% CI 2.17-9.98) versus other European regions and HIV RNA > 400 copies/mL (aIRR 3.11; 95% CI 1.60-6.02) versus HIV RNA < 400 copies/mL.

CONCLUSIONS

d4T use has declined sharply since 2006 to low levels in most regions; however, a low but persistent level of d4T use remains in Eastern Europe, where new d4T initiations post 2006 are also more common. The reasons for the regional differences may be multifactorial, but it is important to ensure that all clinicians treating HIV-positive patients are aware of the potential harmful effects associated with d4T.

Impact of choice of NRTI in first-line antiretroviral therapy: a cohort analysis of stavudine vs. tenofovir

OBJECTIVE

In April 2010, South Africa replaced stavudine with tenofovir in first-line antiretroviral therapy (ART) despite tenofovir's higher cost. We examined treatment outcomes over 24 months amongst patients initiated on tenofovir-based vs. stavudine-based first-line regimens.

METHODS

Prospective cohort analysis of 3940 patients newly initiating either stavudine-based (April 2009 to March 2010) or tenofovir-based (April 2010 to March 2011) ART in Johannesburg, South Africa. Cox proportional hazards models and Fine and Gray's competing risk regression accounting for death were used to model mortality and loss to follow-up, respectively. Linear and log-binomial regression were used to evaluate associations with immunologic response and unsuppressed virus (≥ 400 copies/ml), respectively.

RESULTS

About 1878 patients prescribed tenofovir and 2062 patients prescribed stavudine were included. One hundred and sixty-six (8.8%) tenofovir and 244 (11.8%) stavudine patients died. Three hundred and fifty (18.6%) tenofovir and 379 (18.4%) stavudine patients were lost to follow-up over 24 months on ART. Adjusted regression models showed tenofovir and stavudine were comparable regarding death, loss to follow-up, immunologic response and virologic status.

CONCLUSIONS

We found no difference in mortality, loss to follow-up, immunological and virologic outcomes over the first 24-months on ART associated with tenofovir compared with stavudine.