Scoring and psychometric validation of the Perception of Anticoagulant Treatment Questionnaire (PACT-Q©)

<p>Abstract</p> <p>Background</p> <p>The 'Perception of Anti-Coagulant Treatment Questionnaire' (PACT-Q) was developed to assess patients' expectations of, and satisfaction with their anticoagulant treatment. This questionnaire needs to be finalised and psychometrically validated.</p> <p>Methods</p> <p>The PACT-Q was included in the United States, the Netherlands and France into three phase III multinational clinical trials conducted to evaluate efficacy and safety of a new long-acting anticoagulant drug (idraparinux) compared to vitamin K antagonist (VKA). PACT-Q was administered to patients with deep venous thrombosis (DVT), atrial fibrillation (AF) or pulmonary embolism (PE) at Day 1, to assess patients' expectations, and at 3 and 6 months to assess patients' satisfaction and treatment convenience and burden. The final structure of the PACT-Q (Principal Component Analysis – PCA – with Varimax Rotation) was first determined and its psychometric properties were then measured with validity of the structure (Multitrait analysis), internal consistency reliability (Cronbach's alpha coefficients) and known-group validity.</p> <p>Results</p> <p>PCA and multitrait analyses showed the multidimensionality of the "Treatment Expectations" dimension, comprising 7 items that had to be scored independently. The "Convenience" and "Burden of Disease and Treatment" dimensions of the hypothesised original structure of the questionnaire were combined, thus resulting in 13 items grouped into the single dimension "Convenience". The "Anticoagulant Treatment Satisfaction" dimension remained unchanged and included 7 items. All items of the "Convenience" and "Anticoagulant Treatment Satisfaction" dimensions displayed good convergent and discriminant validity. The internal consistency reliability was good, with a Cronbach's alpha of 0.84 for the "Convenience" dimension, and 0.76 for the "Anticoagulant Treatment Satisfaction" dimension. Known-group validity was good, especially with regard to occurrence of thromboembolic events within 3 months from randomisation.</p> <p>Conclusion</p> <p>The PACT-Q is a valid and reliable instrument that allows the assessment of patients' expectations and satisfaction regarding anticoagulant treatment, as well as their opinion about treatment convenience of use. Its two-part structure – assessment of expectations at baseline in the first part, and of convenience, burden and treatment satisfaction in the second – was validated and displays good and stable psychometric properties. These results are not sufficient to recommend the use of satisfaction as primary endpoint in clinical trials; further validation work is needed to support the interpretation of PACT-Q dimension scores. However, this first validation makes the PACT-Q an appropriate measure for use in clinical and pharmacoepidemiological research, as well as in real-life studies.</p> <p>Trial Registration</p> <p>(ClinicalTrials.gov numbers, NCT00067093, NCT00062803 and NCT00070655).</p

wav2letter++: The Fastest Open-source Speech Recognition System

This paper introduces wav2letter++, the fastest open-source deep learning speech recognition framework. wav2letter++ is written entirely in C++, and uses the ArrayFire tensor library for maximum efficiency. Here we explain the architecture and design of the wav2letter++ system and compare it to other major open-source speech recognition systems. In some cases wav2letter++ is more than 2x faster than other optimized frameworks for training end-to-end neural networks for speech recognition. We also show that wav2letter++'s training times scale linearly to 64 GPUs, the highest we tested, for models with 100 million parameters. High-performance frameworks enable fast iteration, which is often a crucial factor in successful research and model tuning on new datasets and tasks

Visualizing electrostatic gating effects in two-dimensional heterostructures

The ability to directly observe electronic band structure in modern nanoscale field-effect devices could transform understanding of their physics and function. One could, for example, visualize local changes in the electrical and chemical potentials as a gate voltage is applied. One could also study intriguing physical phenomena such as electrically induced topological transitions and many-body spectral reconstructions. Here we show that submicron angle-resolved photoemission (micro-ARPES) applied to two-dimensional (2D) van der Waals heterostructures affords this ability. In graphene devices, we observe a shift of the chemical potential by 0.6 eV across the Dirac point as a gate voltage is applied. In several 2D semiconductors we see the conduction band edge appear as electrons accumulate, establishing its energy and momentum, and observe significant band-gap renormalization at low densities. We also show that micro-ARPES and optical spectroscopy can be applied to a single device, allowing rigorous study of the relationship between gate-controlled electronic and excitonic properties.Comment: Original manuscript with 9 pages with 4 figures in main text, 5 pages with 4 figures in supplement. Substantially edited manuscript accepted at Natur

The X-ray spectra of the flaring and quiescent states of AT Microscopii observed by XMM-Newton

The X-ray spectrum of the late-type M-dwarf binary AT Mic (dM4.5e+dM4.5e) is observed in the wavelength range 1 - 40 Angstrom by means of rgs and epic-mos on board XMM-Newton. During the exposure a flare occured. We have performed a 3-temperature fit and a DEM-modeling to the flaring and quiescent part of the spectrum. We report the coronal temperature distribution, emission measures, and abundances of the flaring and quiescent state of this bright X-ray source. The temperature range stretches from about 1 to 60 MK. The total volume emission measure in this temperature interval is ~12.2*10^51 cm^-3 for the quiescent state and ~19.5*10^51 cm^-3 for the flare state. This difference is due to the contribution of the hot temperature component. The high-resolution spectrum of AT Mic, obtained by rgs, is dominated by the H- and He-like transitions of C, N, O, and Ne and by Fe XVII lines, produced by the plasma with temperatures from 1 to 10 MK. The epic-mos spectrum below 10 Angstrom shows H- and He-like Ne, Si and the iron K-shell transitions. They are produced by the hot component (30 MK). The iron K-shell is more prominent in the flare state. The abundance pattern in the quiescent state of AT Mic shows the depletion of low-FIP elements relative to high-FIP elements, indicating the presence of an I(nverse)FIP effect in this active star. In the flare state, however, some flattening of this IFIP effect is present.Comment: 7 pages, 11 figures ordered as: 1, 2ab, 3, 4abc, 5ab, 6a

Hypertension testing and treatment in Uganda and Kenya through the SEARCH study: An implementation fidelity and outcome evaluation.

BackgroundHypertension (HTN) is the single leading risk factor for human mortality worldwide, and more prevalent in sub-Saharan Africa than any other region [1]-although resources for HTN screening, treatment, and control are few. Most regional pilot studies to leverage HIV programs for HTN control have achieved blood pressure control in half of participants or fewer [2,3,4]. But this control gap may be due to inconsistent delivery of services, rather than ineffective underlying interventions.MethodsWe sought to evaluate the consistency of HTN program delivery within the SEARCH study (NCT01864603) among 95,000 adults in 32 rural communities in Uganda and Kenya from 2013-2016. To achieve this objective, we designed and performed a fidelity evaluation of the step-by-step process (cascade) of HTN care within SEARCH, calculating rates of HTN screening, linkage to care, and follow-up care. We evaluated SEARCH's assessment of each participant's HTN status against measured blood pressure and HTN history.FindingsSEARCH completed blood pressure screens on 91% of participants. SEARCH HTN screening was 91% sensitive and over 99% specific for HTN relative to measured blood pressure and patient history. 92% of participants screened HTN+ received clinic appointments, and 42% of persons with HTN linked to subsequent care. At follow-up, 82% of SEARCH clinic participants received blood pressure checks; 75% received medication appropriate for their blood pressure; 66% remained in care; and 46% had normal blood pressure at their most recent visit.ConclusionThe SEARCH study's consistency in delivering screening and treatment services for HTN was generally high, but SEARCH could improve effectiveness in linking patients to care and achieving HTN control. Its model for implementing population-scale HTN testing and care through an existing HIV test-and-treat program-and protocol for evaluating the intervention's stepwise fidelity and care outcomes-may be adapted, strengthened, and scaled up for use across multiple resource-limited settings

Two Types of X-ray Spectra in Cataclysmic Variables

We present Chandra HETG spectra of seven cataclysmic variables. We find that they divide unambiguously into two distinct types. Spectra of the first type are remarkably well fit by a simple cooling flow model, which assumes only steady-state isobaric radiative cooling. The maximum temperature and the normalization, which provides a highly precise measurement of the accretion rate, are the only free parameters of this model. Spectra of the second type are grossly inconsistent with a cooling flow model. They instead exhibit a hard continuum, and show strong H-like and He-like ion emission but little Fe L-shell emission, which is consistent with expectations for line emission from a photoionized plasma. Using a simple photoionization model, we argue that the observed line emission for these sources can be driven entirely by the hard continuum. The physical significance of these two distinct types of X-ray spectra is also explored.Comment: 12 pages including 2 color figures, accepted for publication in Astrophysical Journal Letter