41 research outputs found
Outcomes among HIV-1 Infected Individuals First Starting Antiretroviral Therapy with Concurrent Active TB or Other AIDS-Defining Disease
Background: Tuberculosis (TB) is common among HIV-infected individuals in many resource-limited countries and has been associated with poor survival. We evaluated morbidity and mortality among individuals first starting antiretroviral therapy (ART) with concurrent active TB or other AIDS-defining disease using data from the âProspective Evaluation of Antiretrovirals in Resource-Limited Settingsâ (PEARLS) study. Methods: Participants were categorized retrospectively into three groups according to presence of active confirmed or presumptive disease at ART initiation: those with pulmonary and/or extrapulmonary TB (âTBâ group), those with other non-TB AIDS-defining disease (âother diseaseâ), or those without concurrent TB or other AIDS-defining disease (âno diseaseâ). Primary outcome was time to the first of virologic failure, HIV disease progression or death. Since the groups differed in characteristics, proportional hazard models were used to compare the hazard of the primary outcome among study groups, adjusting for age, sex, country, screening CD4 count, baseline viral load and ART regimen. Results: 31 of 102 participants (30%) in the âTBâ group, 11 of 56 (20%) in the âother diseaseâ group, and 287 of 1413 (20%) in the âno diseaseâ group experienced a primary outcome event (p = 0.042). This difference reflected higher mortality in the TB group: 15 (15%), 0 (0%) and 41 (3%) participants died, respectively (p<0.001). The adjusted hazard ratio comparing the âTBâ and âno diseaseâ groups was 1.39 (95% confidence interval: 0.93â2.10; p = 0.11) for the primary outcome and 3.41 (1.72â6.75; p<0.001) for death. Conclusions: Active TB at ART initiation was associated with increased risk of mortality in HIV-1 infected patients
Efficacy and Safety of Three Antiretroviral Regimens for Initial Treatment of HIV-1: A Randomized Clinical Trial in Diverse Multinational Settings
Background: Antiretroviral regimens with simplified dosing and better safety are needed to maximize the efficiency of antiretroviral delivery in resource-limited settings. We investigated the efficacy and safety of antiretroviral regimens with once-daily compared to twice-daily dosing in diverse areas of the world. Methods and Findings: 1,571 HIV-1-infected persons (47% women) from nine countries in four continents were assigned with equal probability to open-label antiretroviral therapy with efavirenz plus lamivudine-zidovudine (EFV+3TC-ZDV), atazanavir plus didanosine-EC plus emtricitabine (ATV+DDI+FTC), or efavirenz plus emtricitabine-tenofovir-disoproxil fumarate (DF) (EFV+FTC-TDF). ATV+DDI+FTC and EFV+FTC-TDF were hypothesized to be non-inferior to EFV+3TC-ZDV if the upper one-sided 95% confidence bound for the hazard ratio (HR) was â€1.35 when 30% of participants had treatment failure. An independent monitoring board recommended stopping study follow-up prior to accumulation of 472 treatment failures. Comparing EFV+FTC-TDF to EFV+3TC-ZDV, during a median 184 wk of follow-up there were 95 treatment failures (18%) among 526 participants versus 98 failures among 519 participants (19%; HR 0.95, 95% CI 0.72â1.27; p = 0.74). Safety endpoints occurred in 243 (46%) participants assigned to EFV+FTC-TDF versus 313 (60%) assigned to EFV+3TC-ZDV (HR 0.64, CI 0.54â0.76; p<0.001) and there was a significant interaction between sex and regimen safety (HR 0.50, CI 0.39â0.64 for women; HR 0.79, CI 0.62â1.00 for men; p = 0.01). Comparing ATV+DDI+FTC to EFV+3TC-ZDV, during a median follow-up of 81 wk there were 108 failures (21%) among 526 participants assigned to ATV+DDI+FTC and 76 (15%) among 519 participants assigned to EFV+3TC-ZDV (HR 1.51, CI 1.12â2.04; p = 0.007). Conclusion: EFV+FTC-TDF had similar high efficacy compared to EFV+3TC-ZDV in this trial population, recruited in diverse multinational settings. Superior safety, especially in HIV-1-infected women, and once-daily dosing of EFV+FTC-TDF are advantageous for use of this regimen for initial treatment of HIV-1 infection in resource-limited countries. ATV+DDI+FTC had inferior efficacy and is not recommended as an initial antiretroviral regimen
The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations.
Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http://umd.be/TREAT_DMD/). We analyzed genetic data for 7,149 DMD mutations held within the database. A total of 5,682 large mutations were observed (80% of total mutations), of which 4,894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1,445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0.3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations)
Suitability of external controls for drug evaluation in Duchenne muscular dystrophy
OBJECTIVE: To evaluate the suitability of real-world data (RWD) and natural history data (NHD) for use as external controls in drug evaluations for ambulatory Duchenne muscular dystrophy (DMD). METHODS: The consistency of changes in the 6-minute walk distance (Î6MWD) was assessed across multiple clinical trial placebo arms and sources of NHD/RWD. Six placebo arms reporting 48-week Î6MWD were identified via literature review and represented 4 sets of inclusion/exclusion criteria (n = 383 patients in total). Five sources of RWD/NHD were contributed by Universitaire Ziekenhuizen Leuven, DMD Italian Group, The Cooperative International Neuromuscular Research Group, ImagingDMD, and the PRO-DMD-01 study (n = 430 patients, in total). Mean Î6MWD was compared between each placebo arm and RWD/NHD source after subjecting the latter to the inclusion/exclusion criteria of the trial for baseline age, ambulatory function, and steroid use. Baseline covariate adjustment was investigated in a subset of patients with available data. RESULTS: Analyses included âŒ1,200 patient-years of follow-up. Differences in mean Î6MWD between trial placebo arms and RWD/NHD cohorts ranged from -19.4 m (i.e., better outcomes in RWD/NHD) to 19.5 m (i.e., worse outcomes in RWD/NHD) and were not statistically significant before or after covariate adjustment. CONCLUSIONS: We found that Î6MWD was consistent between placebo arms and RWD/NHD subjected to equivalent inclusion/exclusion criteria. No evidence for systematic bias was detected. These findings are encouraging for the use of RWD/NHD to augment, or possibly replace, placebo controls in DMD trials. Multi-institution collaboration through the Collaborative Trajectory Analysis Project rendered this study feasible
A flexible, interactive, graphical approach to modeling stochastic input processes
One of the main problems in the design and construction of large-scale simulation experiments is the selection of valid input models--that is, probability distributions that accurately represent the behavior of the stochastic input processes driving the system. The problem with using standard distribution families for simulation input modeling is that (a) they frequently do not reflect the true nature of the target input process with sufficient accuracy, (b) they are limited in the number of parameters that are available to control the shape of the distribution, and (c) their parameters are often difficult to estimate. In addition, instances where little data are available force use of intuition, judgment, and subjective information (which are not easily incorporated into the description of standard distributions) to complete the formulation of an input model. In this dissertation, we have developed a flexible, interactive, graphical methodology for modeling the broad diversity of input processes that arise in large-scale simulation studies. We implemented this methodology in a self-contained, Microsoft-Windows-based software system called P scRIME--PRobabilistic Input Modeling Environment. P scRIME integrates graphical and statistical concepts to form a tool that helps an analyst select and visualize an appropriate representation of a random input process using interactive-subjective, data-driven, and visually-based techniques. We have exploited the properties of Bezier curves to develop a flexible univariate and bivariate distribution family that has an open-ended parameterization capable of accurately representing an unlimited number of distributional shapes. Several numerical examples are presented to illustrate the application of this methodology
ABSTRACT RECENT DEVELOPMENTS IN INPUT MODELING WITH BĂZIER DISTRIBUTIONS
New methods are presented for estimating univariate and bivariate BĂ©zier distributions. A likelihood ratio test is used to estimate the number of control points for a univariate BĂ©zier distribution fitted to sample data. To estimate the control points of a bivariate BĂ©zier distribution with fixed marginals based on either sample data or subjective information about the joint dependency structure, a linear-programming approach is formulated. These methods are implemented in the Windows-based software system called PrimeâPRobabilistic Input Modeling Environment. Several examples illustrate the application of these estimation procedures.
Inclusivity of on-farm demonstration: gender, age, and geographic location
Purpose: To assess the inclusivity of on-farm demonstration across Europe, in relation to age, gender, and geographical location of participants. Methodology: The paper is based on a survey of 1162 on-farm demonstrators (farmers and organisations) and three supra-regional workshops. Findings: Overall, on farm-demonstrations were found to be engaging young(er) farmers who are at a career stage of being able to implement long-term innovations. However, across Europe demonstrations were primarily attended by men. On-farm demonstrations were most common in Northern Europe, where advisory services brought together multiple AKIS actors. There were fewer on-farm demonstrations in Southern Europe, where demonstrations were more likely to be led by research institutes or individual farmers. Eastern Europe is notable for greater diversity in terms of gender and age of demonstration participants. Within countries, on-farm demonstrations occurred more frequently in regions of high agricultural profitability; more remotely located farmers had fewer opportunities to participate. Practical implications: Demonstrations led by public and privately funded advisory services appear to attract primarily male farmers, thus reinforcing gendered patterns of participation in European agriculture. The location of advisory services and research institutes in high profitability locales disproportionately privileges farmers located there. More targeted efforts are required to ensure the participation of farmers who are female, older and located in less productive regions. Theoretical implications: The paper draws attention to the lack of inclusivity of on-farm demonstration, developing a conceptual framework based on Lukesâ three faces of power. Originality: The paper utilises the first European-wide inventory of on-farm demonstration to assess inclusivity.</p